Evidence-Based Clinical Practice Guidelines for IgA Nephropathy
2014

July 27th, 2015

Authors
Clinical Guidelines for IgA Nephropathy 2014 Advisory Committee
Committee chairman
Yukio Yuzawa
Committee member
Maki Urushihara
Shoji Kagami
Ritsuko Katafuchi

Fujita Health University
Tokushima University
Tokushima University
Fukuoka Higashi Medical Center

Hiroshi Kitamura
Hiroyuki Komatsu
Masashi Goto

Chiba East Hospital
Miyazaki University
Kyoto Medical Center

Shuji Kondo
Mitsuhiro Sato
Kazuo Takahashi
Miki Takahara
Makoto Tomita
Yasuaki Harabuchi
Yoshihide Fujigaki

Tokushima University
JCHO Sendai Hospital
Fujita Health University
Asahikawa Medical University
Fujita Health University
Asahikawa Medical University
Teikyo University

Takashi Yasuda
Yoshinari Yasuda
Ryohei Yamamoto

St. Marianna University
Nagoya University
Osaka University

Chief Chairman of the Clinical Practice Guidelines for Progressive Kidney
Diseases
Kenjiro Kimura
St. Marianna University
Leader of the Research for Progressive Kidney Diseases of the Ministry of
Health, Labour and Welfare
Seiichi Matsuo
Nagoya University

Cooperative Medical Society
The Japanese Society for Pediatric Nephrology
The Oto-Rhino-Laryngological Society of Japan

Preface
1. Background of this guideline
Immunoglobulin A (IgA) nephropathy (IgAN) is the most common primary
glomerulonephritis, and patients typically require dialysis when the diseaseprogresses to end-stage renal failure. As the incidence of IgAN is high in
Asian populations, including Japanese, establishing a treatment strategy inJapan is strongly warranted. In 1995, the joint committee of the Special Study
Group of the Progressive Renal Dysfunction Research Group of the Ministryof Health Labour and Welfare (MHLW) and the Japanese Society ofNephrology (JSN) developed the Clinical Practice Guides for IgAN for the
first time. Its second version was published with a partial amendment in 2002.
The third version, published in 2011, analyzed data from a multicenter study
conducted mainly by the Research Group for IgAN in the Progressive Renal
Dysfunction Research Group of MHLW to propose a novel prognostic
classification (risk stratification for dialysis), adding clinical severity tohistological severity. These clinical practice guides present clear prognostic
criteria and treatment guidelines according to the criteria. Therefore, theseguides have been widely used in clinical practice or pathological diagnosis,
and they have contributed to the diagnosis and treatment of IgAN in Japan.
Meanwhile, Kidney Disease: Improving Global Outcomes (KDIGO)
internationally published the Clinical Practice Guidelines for
Glomerulonephritis in 2011. Recommendation grades based on the systematic
review of clinical studies and the quality of evidence as a basis fordetermination of the strength of the recommendations are shown in the
KDIGO Clinical Guidelines for Glomerulonephritis. IgAN is described in
Chapter 10. However, careful evaluation was required to verify whether the
KDIGO Clinical Guidelines for Glomerulonephritis was applicable to theactual clinical situation of IgAN in Japan, because in Japan, IgAN has been
detected in routine checkups in the early stage, prognosis of IgAN has beenclassified in many cases according to the third version of the Clinical Guides
for IgAN, and tonsillectomy has been performed in many cases. Therefore,
establishing practice guidelines for IgAN that are adjusted to the situation in
Japan is warranted. Responding to this need, the Progressive Renal
Dysfunction Research Group of MHLW and JSN decided to develop theevidence-based Clinical Guidelines for IgA Nephropathy 2014. Thus, they

established the Clinical Guidelines for IgA Nephropathy 2014 Advisory
Committee. Against this background, the Clinical Guidelines for IgA
Nephropathy 2014 was published. It is the first-ever-publishedcomprehensive guideline only focusing on IgAN.
2. The Intended Purpose, Anticipated Users, and Predicted Social
Significance of the Guidelines
The purpose of the Clinical Guidelines for IgA Nephropathy 2014 was todefine evidence-based clinical guidelines that reflect the clinical situation of
IgAN in Japan. This guideline is developed to provide answers to clinicalquestions (CQ) that nephrologists may encounter in the clinical practice forthe treatment of IgAN. Each answer is shown as a statement, andrecommendation grades based on the evidence-based levels are noted for eachstatement in the Treatment section. It was not aimed at creating an
exhaustive textbook but at supporting clinical decisions by answering
questions raised by nephrologists in clinical practice and establishing astandard treatment. With the aim of comprehensively supporting
nephrologists in the treatment of IgAN in clinical settings, the Clinical
Guidelines for IgA Nephropathy 2014 Advisory Committee independently
evaluated the results of principal randomized parallel-group clinical trials
published to date and presented the scheme of indications for preventive
intervention of renal dysfunction progression in this guideline. Now, patientswith IgAN at any stage can be treated by using this guideline in combination
with the Evidence-based Practice Guideline for the Treatment of Chronic
Kidney Disease (CKD). The Clinical Guidelines for IgA Nephropathy 2014
also describe the characteristics and treatment of pediatric IgAN.
Evidence from the literature can provide information but is no substitute forthe specialized skills and experiences of individual physicians. Whether aparticular statement applies and how it applies to a particular patient
depends on the specialist abilities of each physician. The times demand that
medical care shift from a one-size-fits-all approach to a tailor-made approach.
Clinical guidelines are not supposed to impose a uniform style of care on
physicians. Each physician needs to determine what kind of care each patientneeds based on an understanding of the content of clinical guidelines. As such,these guidelines are not intended to limit physicians to certain forms of
medical behavior but were created to assist them in exercising their discretion

to decide the type of care to be provided. In addition, it should be stated clearly
that these guidelines are not criteria for deciding physician-patient conflicts
or medical malpractice lawsuits.
3. Patients within the scope of the guidelines
These guidelines apply to IgAN patients of all ages. In the KDIGO Clinical
Practice Guidelines, atypical IgAN is a minimal-change condition, in which
IgA deposits are observed in the mesangium, is an acute renal insufficiency
with gross hematuria, and presents as crescentic IgAN. Accordingly, thepresent guidelines recommend the aforementioned conditions should betreated as special types of IgAN. A summary of pediatric diagnostic andtreatment modalities was also included.
Cases requiring CKD management were addressed based on the “2013 CKDClinical Guideline Based on Evidence.” Finally, pregnancy-related items were,as a rule, not included.
4 ．Preparation procedure
Creating evidence-based guidelines first requires the enormous task ofgathering and evaluating evidence. We would like to sincerely thank themembers of the IgAN Clinical Guidelines Working Group for their dedicationand effort. (show list of contributors)
The first meeting of the clinical guidelines working group was held on
September 23, 2011. The group was led by Dr. Kenjiro Kimura of the St.
Marianna University School of Medicine, who explained the significance of
creating the guidelines and the procedures for the task. The IgAN clinicalguidelines committee first met on October 14, during which members of theIgAN Clinical Guidelines Working Group set about creating the guidelines
based on a shared understanding. In effect, this was the initial stage of thedrafting of the guidelines. The MINDS handbook for creating clinicalguidelines was followed, and the Delphi method was used in composing CQ,
which is the core of the guidelines. Recommendation grades were determinedby an informal consensus. As a rule, PubMed records up to July 2012 wereused to search the literature. If necessary, important studies from after thisdate were included, with reasons given.
The IgAN clinical guidelines committee met 12 times, although the group also
often communicated through e-mail. Through this process, the initial CQ andtext items were revised as needed, and a few deletions and additions were
made. From September 13 to October 13, 2013, each part was reviewed by
two designated referees and two designated academic societies.
Simultaneously, public comments were solicited from members of theJapanese Society of Nephrology (JSN). The manuscript was then revised
based on the referees’ opinions and public comments. The IgAN clinicalguidelines committee met on January 26, 2014, to examine the revisedmanuscript. Afterward, additional revisions were made as needed until a
final draft was obtained. The guidelines, as well as responses to the referees’
opinions and public comments, were posted on the JSN Web site.
5. Contents of the guideline
The guidelines are composed of three chapters as follows: I. Concepts, II.
Diagnosis, and III. Epidemiology and Prognosis. These guidelines werecreated in tandem with the “2013 CKD Clinical Guideline Based on Evidence,”and so were written by the same authors.
Items in the structured abstracts attached to the guidelines werestandardized to contain the reference number, reference title, Japanese title,
evidence level, author names, journal name, publication year/page, objectives,
study design, subject patients, intervention factors, primary outcomes,
results, and discussion.
6.
Evidence levels and recommendation grades
Evidence levels were evaluated in a manner similar to that described in the“2013 CKD Clinical Guideline Based on Evidence.”[Evidence Levels]
Level 1: Systematic review/meta-analysis.
Level 2: At least 1 randomized controlled trial (RCT).
Level 3: A non-RCT.
Level 4: An analytical epidemiologic study (cohort study or case-control study)
or a single-arm intervention study (no controls).
Level 5: A descriptive study (case report or case series).
Level 6: Opinion of an expert committee or an individual expert, which is notbased on patient data.
Evidence levels for meta-analyses and systematic reviews were determinedfrom the designs of the studies on which they were based. If the underlying

studies had mixed designs, consensus was reached to adhere to the lowest
level (e.g., a meta-analysis of cohort studies would be level 4, as would a metaanalysis that included both RCT and cohort studies).
Consensus was also reached to assign evidence level 4 to all RCT subanalyses
and post hoc analyses. Therefore, an RCT with a clear primary outcome would
be considered level 2, while a subanalysis or post hoc analysis of this RCT
would be considered level 4.
The following recommendation grades were assigned to statements about
treatments, which were based on the level of evidence for each statement.
[Recommendation Grades]
Grade A: Strongly recommended because the scientific basis is strong.
Grade B: Recommended because there is some scientific basis.
Grade C1: Recommended despite having only a weak scientific basis.
Grade C2: Not recommended because there is only a weak scientific basis.
Grade D: Not recommended because scientific evidence shows treatment to
be ineffective or harmful.
As a rule, standard treatments in Japan were recommended, but eligibility
for health insurance coverage was not necessarily required. Drugs ineligible
for insurance coverage were denoted as such. Recommendation grades wereassigned to statements about treatment-related CQ. In addition, questions
such as “To which subgroup would this be recommended?” and “To which
subgroup would this not be recommended?” were addressed wheneverpossible. Recommendation grades were decided through consultations among
the working group members by considering the tradeoffs between and balanceof benefits, damage, side effects, and risk. If differing views existed among
the referees or in the public comments, the group reexamined the area
through an exchange of opinions. The reasons for choosing a recommendation
grade and the decision-making process involved were described in thecommentary, as a rule.
7.

Issues on the preparation of this guideline

Although evidence concerning IgAN is gradually increasing in Japan, it isstill insufficient, which means that these guidelines were heavily influenced
by evidence from Europe and the United States. Whether the results ofclinical research from the West can be applied as is to Japan is a questionthat deserves careful consideration. Only a few large clinical studies have

been performed on IgAN even in the West, so the quality of evidence is limited.
In creating these guidelines, we strove to ensure that they would not deviate
greatly from the clinical practice in Japan.
8. Financial sources and conflict of interest
The funds used in creating the guidelines were provided by a research groupon progressive kidney disorders funded by the Ministry of Health, Labour,and Welfare’s research project for overcoming intractable diseases. These
funds were used to pay for transportation to and from meetings, to rent spacefor meetings, and for box lunches and snacks. The committee members
received no compensation . Everyone involved in creating the guidelines(including referees) submitted conflict-of-interest statements based onacademic society rules, which are managed by JSN. Opinions were soughtfrom multiple referees and related academic societies to prevent theguidelines from being influenced by any conflicts of interest. Drafts wereshown to the society members, and revisions were made based on theiropinions (public comments).
9. Publication and Future Revisions
The guidelines are to be published in Japanese-language journal of JNS andconcurrently released in book form by Tokyo Igakusha. They will also be
posted on the JSN Web site and on the MINDS Web site of the Japan Council
for Quality Health Care.

Content
I. Introduction
1. Definition and background
2. Pathogenesis and pathophysiology
II. Diagnosis
1. Diagnosis
2. Clinical manifestations and laboratory findings
3. Pathological findings
4. Classification
5. Atypical forms of IgA nephropathy
III. Epidemiology, prognosis, and follow-up
1. Incidence and prevalence
2. Natural course
3. Changes in prognosis with changes in treatment guidelines
4. Clinical predictors of progression at the time of initial examination or
renal biopsy
5. Clinical predictors of progression during follow-up
6. Remission of urinary findings and its significance
7. Follow-up
IV. Treatment
1. A summary of management of IgAN in adults, with a focus on preventionof renal dysfunction
2. Clinical questions (CQs) about immunosuppressive therapy (adults)
CQ 1. Are corticosteroids recommended in IgA nephropathy?
CQ 2. Is tonsillectomy combined with steroid pulse therapy recommended?
CQ 3. Is tonsillectomy (alone) recommended?
CQ 4. Are non-steroidal immunosuppressive agents recommended?
3. CQs about immunosuppressive therapy (children)
CQ 5. Is immunosuppressive therapy recommended in childhood IgA
nephropathy?
CQ 6. Is combination “cocktail” therapy recommended in childhood IgA
nephropathy?
4. CQs about supportive therapy (adults)
CQ 7. Are RAS blockers recommended in IgA nephropathy?
CQ 8. Are antiplatelet agents recommended in IgA nephropathy?

CQ 9. Are n-3 fatty acids (fish oil) recommended in IgA nephropathy?
5. CQs about lifestyle and dietary guidance in IgA nephropathy
CQ 10. Should limitation of salt intake be recommended?
CQ 11. Should restricted protein intake be recommended?
CQ 12. Should weight loss be recommended?
CQ 13. Should exercise restriction be recommended?
CQ 14. Should smoking cessation be recommended?
6. Adverse events associated with steroid therapy and immunosuppressive
agentsI. Introduction
1. Definition and background
IgA nephropathy (IgAN, also known as Berger’s disease) is a diseasecharacterized by urinary findings suggesting glomerulonephritis;
predominantly, IgA is deposited in the glomeruli, with no evidence of other
underlying disease. Glomerular hematuria and proteinuria are urinary
findings that suggest glomerulonephritis. Renal biopsy findings, which arerequired for confirming the diagnosis of glomerulonephritis, include IgA
deposits mainly in the glomerular mesangium and occasionally in thecapillary loops. In many cases, C3 is also co-deposited. The rate of progression
to end-stage renal disease (ESRD) is approximately 40% at 20 years after
diagnosis. Treatment may include therapy with renin-angiotensin system(RAS) blockers, antiplatelet agents, oral corticosteroids, fish oil, or nonsteroidal immunosuppressive agents; steroid pulse therapy; or tonsillectomy.
The therapeutic effects of each have been examined, but an effective
treatment regimen is yet to be established.
2. Pathogenesis and pathophysiology
1) Overview
In patients with IgAN, for some unknown reason, the level of nephritogenic
IgA1 increases in the circulation and is deposited in the mesangium, leading
to glomerular damage. The exact mechanism of IgAN is unknown.
Exacerbation in patients with upper respiratory infections has been wellknown, thereby suggesting changes in mucosal immunity are involved in thepathogenesis. Many other mechanisms are also involved in the pathogenesisof IgAN: production and increase of pathogenic IgA1, IgA1 deposition into theglomeruli, proliferation of mesangial cells and matrix expansion from thedeposits, and persistent and progressive glomerulonephritis. A genetic
predisposition may also play a role in the pathogenesis of IgAN.
2) Genetics
Most cases of IgAN are sporadic, but approximately 10% are familial cases.
Regional and ethnic differences are also seen in sporadic IgAN, and polygenic
inheritance is found to be involved. The responsible genes differ between
sporadic and familial IgAN, and genetic involvement in the disease may bemonogenic or polygenic, depending on the individual or family. Pedigrees with

autosomal dominant transmission have also been reported. Recent genomewide association studies (GWAS), in which whole-gene association analysis isapplied, have highlighted important findings.
3) Abnormal IgA molecules
Approximately half of all patients with IgAN have elevated levels of serum
IgA, associated with increased IgA1 production from the bone marrow and/or
mucosa. The IgA1 deposited in the glomeruli is from the circulating IgA1, andthe serum IgA1 in patients with IgAN has been analyzed in detail. Serum
IgA1 has clustered O-linked glycans on its hinge-region. Aberrantly
glycosylated IgA1, i.e., galactose (Gal)-deficiency in some O-glycans, isincreased in serum IgA1 and IgA1 extracted from the glomeruli.
4) Mucosal immunity
Some patients with IgAN have worsening clinical symptoms with macroscopic
hematuria after upper respiratory or gastrointestinal infections, thereby
suggesting a relationship between IgAN and mucosal immunity. Increased
polymeric IgA1 in the circulation of patients with IgAN after an upper
respiratory infection, and improvement in nephropathy after tonsillectomy,
have been reported. Abnormal mucosal reactions may increase circulating
polymeric IgA1, thus leading to glomerular deposition.
5) IgA1 glomerular deposition
IgA1 is selectively deposited in patients with IgAN; IgA1 has an affinity to
the mesangium, especially the dimeric and polymeric IgA1 with J chains, andacidic IgAN containing λ light chains. In addition, the deposited IgA1 hasabnormal hinge-region O-linked glycans. High-molecular-weight IgA1,
including serum polymeric IgA1, is deposited in the glomeruli.
6) Glomerular damage
Mesangial cell activation and complement activation through IgA deposition
lead to glomerulonephritis, followed by podocyte and renal tubular injury.
Humoral factors released from the mesangial cells play an important role inpodocyte injury and tubulointerstitial damage (glomerulus-podocyte-renal
tubule cross-talk).

II. Diagnosis
1. Diagnosis
Although various attempts have been made to diagnose IgAN according toclinical findings, IgAN is diagnosed on the basis of renal biopsy findings. On
immunohistochemical study, IgAN is defined as dominant staining with IgA
in a glomerulus. Histological findings such as in Henoch-Schönlein purpura
nephritis (IgA vasculitis), lupus nephritis, and nephritis associated with livercirrhosis and rheumatoid arthritis are similar to those in IgAN; therefore, adifferential diagnosis should be based on clinical characteristic andlaboratory data.
2. Clinical manifestations and laboratory findings
1) Clinical symptoms and physical examination findings
Most cases of IgAN are characterized by asymptomatic urinary abnormalities.
Acute nephritic syndrome or evaluation of edema due to nephrotic syndrome
may also lead to the diagnosis of IgAN. Macroscopic hematuria occurs inconjunction with an acute upper respiratory infection in some cases. However,macroscopically, no specific findings related to IgAN are observed in thepalatine tonsils. In IgAN patients with progressively deteriorating renal
function, moderate to severe proteinuria, followed by hypertension and a
decline in renal function usually occurs in order.
2) Urinalysis findings
Most patients with IgAN have asymptomatic hematuria or proteinuria; thisurinary abnormality leads renal biopsy. Therefore, urinalysis is essential forthe diagnosis of IgAN. Currently, routine urinalysis will not show findings
specific for IgAN. The Clinical Guidelines for IgA Nephropathy (ver. 3) statethat persistent microscopic hematuria is an essential finding, andintermittent or persistent proteinuria is a frequently associated finding.
Moreover, macroscopic hematuria may be an incidental finding. To confirm
reproducibility and persistence of the urinary abnormality, the results of atleast 3 urinalyses should be considered before confirming the diagnosis.
Furthermore, urinalysis on at least 2 of these occasions should, besides
qualitative dipstick testing, also include analysis of urinary sediment. No
urinary biomarker has yet been established to diagnose IgAN.

3) Blood biochemistry findings
No specific blood test results have been established for a diagnosis of IgAN. A
frequent finding in about half of patients is elevated serum IgA levels (≥315
mg/dL). In addition, a high serum IgA/C3 ratio is also reported as a usefulfinding for differential diagnosis. At the research level, serum levels ofaberrantly glycosylated IgA1, related immune complexes, and corresponding
antibodies are reported to be useful as blood biomarkers of IgAN.
4) Indications for renal biopsy
Clinically, persistent microscopic hematuria and proteinuria, elevated serum
IgA level, a high serum IgA/C3 ratio, and macroscopic hematuria with upper
respiratory infection are strong indicators of IgAN. However, a renal biopsy
is essential for a definitive diagnosis of IgAN. In addition, a renal biopsy forhistopathological examination is also important for patient management,
because clinical and laboratory findings alone are insufficient for assessing
prognosis and selecting the appropriate treatment modality. In patients who
only have asymptomatic microscopic hematuria or trace proteinuria, patientmanagement strategy will rarely be altered by histological findings, so a renal
biopsy may be optional. However, renal biopsy should be considered todifferentiate between thin basement membrane disease and Alport syndrome.
5) Features of childhood IgA nephropathy
Childhood IgA nephropathy in Japan is usually found on urinary screeningin schools, often leading to prompt diagnosis and initiation of treatment.
3. Pathological findings
IgAN is defined as glomerulonephritis with predominant IgA deposits in themesangium, and kidney biopsy is essential for its diagnosis. Histologicalchanges in IgAN mainly involve the mesangium, but various glomerularlesions other than those in the mesangium also occur; for instance, tubular,interstitial, and vascular lesions may also develop. Precise definitions haverecently been proposed for the various lesions that develop in IgAN, andexamination of the lesions based on these definitions is now recommended.
Pathologic diagnosis is important not only for diagnosing IgAN but also forassessing the prognosis of kidney function.

4. Classification
Classification should be useful for predicting prognosis and selecting anappropriate treatment regimen. Although various classifications have beenreported so far, not one has achieved worldwide consensus. Recently, theClinical Guidelines for IgA Nephropathy (ver. 3) published in Japan 31) andhistologic classification based on a multicenter case-control study on IgAN in
Japan have been put forth (Table 1A-C). At the international level, the Oxford
Classification has been published (Table 2). Thus, the management of IgAN
will be based on these guidelines and classification. Both classifications
should be modified on the basis of the findings of further validation studies
in the future.
5. Atypical forms of IgA nephropathy
1) Minimal change nephrotic disease (MCD) with mesangial IgA deposits
Rarely, in some patients with nephrotic syndrome, the kidney biopsy shows
minimal glomerular changes on light microscopy, and predominant
glomerular deposits of IgA on immunohistochemical study. Because prompt,
complete remission after corticosteroid therapy and the following clinicalcourse, with frequent nephrotic syndrome relapses, are very suggestive ofminimal change nephrotic disease (MCD), a coincidence of MCD and IgAN
has been proposed as the most likely explanation for such cases. Nephrotic
syndrome occurs in 5–25% of all patients with IgAN, and the coincidence of
MCD among these patients is 25–47% (1.8–6% of all patients with IgAN).
2) Acute kidney injury (AKI) associated with macroscopic hematuria
Episodic macroscopic hematuria coinciding with mucosal infection is ahallmark of IgAN. The macroscopic hematuria usually resolves
spontaneously in a few days, and kidney function usually recovers completely
after the disappearance of macroscopic hematuria. However, in rare cases,
the macroscopic hematuria is prolonged and acute kidney injury (AKI)develops. AKI occurs in less than 5% of the patients with IgAN. Histologically,
crescent formation and obstruction of tubules by red blood cell casts andtubular epithelial cell injury are frequently observed. AKI cannot be
explained by the percentage of crescent formation in the glomerulus alone,
and many studies have reported that AKI is mainly caused by red blood cell
casts and the resulting renal tubular epithelial injury. In a majority ofpatients, kidney function returns to baseline after the disappearance ofmacroscopic hematuria, but incomplete recovery of kidney function has beenreported in up to 25% of the affected patients in long-term follow-up studies.
Macroscopic hematuria lasting longer than 10 days is the most significant
risk factor of persistent kidney impairment.
3) Crescentic IgA nephropathy
Crescentic IgAN is defined by different studies according to the percentage ofthe glomeruli with crescent formation ranging between 10% and 80% of theglomeruli with crescent formation. Crescentic IgAN was found to account for
5% of all IgAN cases in a study that used a definition of crescentic IgAN as
more than 30% of the glomeruli with crescent formation and for 1.14% of all
IgAN cases in a study that used a definition of crescentic IgAN as more than
50% of the glomeruli with crescent formation. The histopathological analysis
yields not only active lesions such as widespread cellular crescents,
endocapillary hypercellularity, and tuft necrosis, but also a varying degree ofchronic lesions such as glomerular sclerosis and interstitial fibrosis. Clinicalmanifestations include rapidly progressive glomerulonephritis, hypertension,
severe proteinuria, and frequently macroscopic hematuria. Steroid andcyclophosphamide therapy may be effective in crescentic IgAN, but theireffectiveness remains controversial.
III. Epidemiology, prognosis, and follow-up
1. Incidence and prevalence
In Japan, about one-third of all patients who undergo renal biopsy are
diagnosed with IgAN. The incidence of IgAN is estimated to be 3.9 to 4.5 per
100,000 persons per year. An estimated 33,000 persons have IgAN (95% CI:
28,000–37,000).
2. Natural course
The 10-year renal survival rate in adult-onset IgAN is approximately 80–85%.
The 10-year renal survival rate in childhood-onset IgAN is over 90%.
3. Changes in prognosis with changes in treatment guidelines
Various studies show that the prognosis of IgAN is better in patientsdiagnosed in the 1990s and later than in patients diagnosed before then,suggesting that changes in treatment guidelines for IgAN have beensuccessful.
4. Clinical predictors of progression at the time of initial examination or
renal biopsy
Clinical predictors of progression in patients with IgAN at the time of theinitial examination or renal biopsy include amount of proteinuria, bloodpressure levels, degree of renal dysfunction, and histological severity.
Therefore, models to predict the renal prognosis from the time of the initial
examination or renal biopsy have been developed with combinations of thesefactors and are used in prognostic predictions for IgAN. 35-39) However, alongwith the prolonged disease duration and progression of disease, the amountof proteinuria, blood pressure level, renal function, and histological lesions
progressively deteriorate. Therefore, these factors may simply reflect thestage (grade) of disease. Factors indicating the progression rate of disease ateach stage (grade) of IgAN have not been identified.
5. Clinical predictors of progression during follow-up
Because multiple renal biopsies are not feasible, the clinical predictors ofprogression of IgAN during follow-up are proteinuria, blood pressure, andhematuria. Both the mean proteinuria level and the mean blood pressurelevels during follow-up have known to be stronger risk factors for ESRD thanfactors like amount of proteinuria, blood pressure level, degree of renal
dysfunction, and histological severity of IgAN at the time of initial
examination or renal biopsy. In particular, maintaining proteinuria at <1.0
g/day and blood pressure at <130/80 mmHg during follow-up are associatedwith improved renal prognosis.
6. Remission of urinary findings and its significanceIn patients with IgAN, normalization of urinary findings during the natural
course or after treatment, in other words, a remission of urinary findings
defined as an improvement or disappearance of hematuria and proteinuria isreported to be associated with improved renal prognosis. However, remissionof urinary findings has been variously defined to date. Therefore, thesignificance of remission of urinary findings during the natural course or after
treatment in the renal prognosis in patients with IgAN is unclear. Studies

have been initiated to standardize the definition of remission, evaluate thetherapeutic effectiveness of treatment regimens based on a standard
definition of remission, and clarify the significance of the remission of urinary
findings. Furthermore, patients who have achieved remission of urinary
findings may later again experience worsening of urinary findings, in otherwords, a recurrence. Recurrence after remission of urinary findings has also
not been defined, and its significance is also unclear.
7. Follow-up
At present, there is no robust evidence for the follow-up protocols of IgAN to
improve renal prognosis. Currently, both the degree of renal dysfunction andamount of proteinuria are used as markers in follow-up protocols. As renal
dysfunction worsens and proteinuria level increases, careful monitoring of theclinical course and treatment effectiveness at shorter follow-up intervals is
recommended. In addition, follow-up intervals should be adjusted according
to renal biopsy findings, urinary findings, achieved blood pressure levels, therate of progression of renal dysfunction, and the type of treatment regimen.
Moreover, urinary findings may improve over a period of years after various
treatments, while recurrence after improved urinary findings may occur after
long period of time. Therefore, long-term follow-up is strongly recommendedin patients with IgAN, even in patients with only mild urinary abnormalities.
IV. Treatment
1. A summary of management of IgAN in adults, with a focus on preventionof renal dysfunction
In Japan, the major potential treatment modalities for adult IgAN are the useof RAS blockers, corticosteroids, non-steroidal immunosuppressive agents,
antiplatelet agents, and n-3 fatty acids (fish oil) and tonsillectomy (withcorticosteroid pulse therapy). We evaluated the reduction of proteinuria andpreservation of kidney function caused by therapeutic interventions based on
the results of several randomized controlled trials (RCTs), as shown in figures
1 and 2 . Consequently, the following guidelines have been developed for thetreatment of patients with IgAN: To suppress IgAN progression, treatments
should be based on renal function, urinary protein, age, and renal
histopathological findings. Interventions to optimize blood pressure, salt
intake, lipid and glucose metabolism, body weight, and smoking habits should

be considered, if necessary. (Figure 3)
2. Clinical questions (CQs) about immunosuppressive therapy (adults)
CQ 1. Are corticosteroids recommended in IgA nephropathy?
Recommendation grade: B
To control the progression of renal dysfunction in patients with IgAN withurinary protein level ≥1 g/day and CKD stage G1-2, a short course of highdose oral steroid therapy (prednisolone at dose of 0.8–1.0 mg/kg for about 2
months, followed by gradual tapering over about 6 months) is recommended.
Recommendation grade: B
To control the progression of renal dysfunction in patients with IgAN withurinary protein level ≥1 g/day and CKD stage G1-2, steroid pulse therapy(methylprednisolone 1 g for 3 days by infusion (or IV) every other month, 3
times + prednisolone 0.5 mg/kg, every other day, for 6 months) is
recommended.
Recommendation grade: C1
Steroid therapy may reduce proteinuria in patients with IgAN with urinary
protein level of 0.5–1.0 g/day and CKD stage G1-2, and this may also be
considered a treatment option.
[Summary]
To evaluate the effectiveness of corticosteroid therapy for treating IgAN,
patients with IgAN with urinary protein level ≥1 g/day and CKD stage G1-2
were enrolled in a randomized controlled trial (RCT). A short course of highdose oral steroid therapy (prednisolone at a dose of 0.8–1.0 mg/kg for about 2
months, followed by gradual tapering over about 6 months), along withconcomitant administration of RAS blockers, improved the renal function, as
seen in 2 different studies, so this regimen is recommended. Steroid pulse
therapy (methylprednisolone 1 g for 3 days, every other month, 3 times +prednisolone 0.5 mg/kg, every other day, for 6 months) also improved the renal
function; however, this improvement was reported in 1 study only. The
validity of this result needs to be reconfirmed. Therefore, high-dose oral
steroid therapy may be effective in reducing urinary protein levels forpatients with IgAN with urinary protein level of 0.5–1.0 g/day and CKD stage
G1-2. Nevertheless, further investigation is necessary.

CQ 2. Is tonsillectomy combined with steroid pulse therapy recommended?
Recommendation grade: C1
Tonsillectomy combined with steroid pulse therapy may improve urinary
findings in patients with IgAN and lower the progression of renal dysfunction.
This may also be considered a treatment option.
[Summary]
In a retrospective cohort study, Hotta et al. reported that tonsillectomy
combined with steroid pulse therapy normalized urinary findings, which are
predictive factors for renal failure. Additionally, in a non-randomized
comparative study, Komatsu et al. reported that the normalization rate ofurinary findings was higher with tonsillectomy combined with steroid pulse
therapy than with steroid pulse therapy alone. However, the level of evidence
is regarded as insufficient because these studies were not designed as RCTs.
At a meeting of the Japanese Society of Nephrology in 2011, the Ministry of
Health, Labour and Welfare (MHLW) Progressive Renal Dysfunction
Research Group stated that tonsillectomy combined with steroid pulse
therapy was found to be more effective than steroid pulse therapy alone inreducing urinary protein in RCTs. This regimen was suggested as a possible
treatment option for IgAN. To establish more substantial evidence, thesuperiority of tonsillectomy combined with steroid pulse therapy should befurther investigated.
CQ 3. Is tonsillectomy (alone) recommended?
Recommendation grade: C1
Tonsillectomy may improve urinary findings in patients with IgAN and slow
the progression of renal dysfunction. This may also be considered as atreatment option.
[Summary]
The efficacy of tonsillectomy has been reported since the 1980s, but different
studies have yielded different results owing to differences in the levels of
renal dysfunction, urinary protein, and histopathological damage. In theearly 2000s, a retrospective cohort study with a follow-up period of 11 ± 4
years showed no association between tonsillectomy and the rate ofprogression to ESRD. On the other hand, another study with a longer followup of 16 ± 6 years reported a lower incidence of ESRD in the tonsillectomy
group than in the non-tonsillectomy group. Because of flaws in the design ofprevious studies, it is difficult to definitively conclude the efficacy of
tonsillectomy. Meanwhile, previous reports show that the tonsillectomy may
improve urinary findings in patients with IgAN and may lower the
progression of renal dysfunction for a long period of ≥15 years, especially at a
relatively early stage, with no serological renal dysfunction or sclerotic lesions
in the glomeruli. Previous studies may have shown the efficacy of
tonsillectomy in cases of IgAN for a long period, but none of these studies wasa RCT. Therefore, according to current clinical practices in Japan, theGuidelines Advisory Committee has decided on a recommendation grade of
C1.
CQ 4.

Are non-steroidal immunosuppressive agents recommended?

Recommendation grade: C1
Cyclophosphamide, azathioprine, cyclosporine, mycophenolate mofetil, andmizoribine may improve the renal prognosis in patients with IgAN. They may
also be considered treatment options (off-label use).
[Summary]
RCTs for the effectiveness of cyclophosphamide, azathioprine, cyclosporine,
mycophenolate mofetil, and mizoribine for treatment of IgAN have mostly
been small-scale studies with a small number of patients. Therefore, it has
been difficult to reach a consensus about their effectiveness. Some studies
have reported effectiveness in reducing urinary protein level and improving
the prognosis of renal function. Further investigations are necessary.

3. CQs about immunosuppressive therapy (children)
CQ 5. Is immunosuppressive therapy recommended in childhood IgA
nephropathy?
Recommendation grade: B
Immunosuppressive therapy is effective and recommended for reducing
urinary protein level, preventing progression to glomerular sclerosis, andimproving the renal prognosis in children with severe IgAN.
[Summary]Children with IgAN can be categorized into 2 broad groups according toclinical or histological severity. For children with mild urinary protein
excretion (morning urinary protein/creatinine ratio <1.0), focal mesangial

proliferation, and <30% crescentic glomeruli (mild cases), nonimmunosuppressive therapy with RAS blockers and/or Sairei-to (herbal
medicine) is recommended. However, for children with severe urinary protein
excretion (morning urinary protein/creatinine ratio ≥1.0), moderate or greatermesangial proliferation, crescent formation, adhesions, or sclerotic lesions(any of the above) involving ≥80% of all the glomeruli or ≥30% of crescentic
glomeruli (severe cases), combination therapy with corticosteroids and nonsteroidal immunosuppressive agents, anticoagulants, and antiplatelet agentsis highly effective.
CQ 6. Is combination “cocktail” therapy recommended in childhood IgA
nephropathy?
Recommendation grade: B
Combination therapy with corticosteroids, non-steroidal immunosuppressive
agents, anticoagulants, and antiplatelet agents is recommended in severe
childhood IgAN with a poor prognosis in order to reduce proteinuria, prevent
progression of glomerular sclerosis, and improve the prognosis of renal
function.
[Summary]
In severe childhood IgAN with diffuse mesangial proliferation, combination“cocktail” therapy for 2 years with 4 drugs, consisting of corticosteroids, nonsteroidal immunosuppressive agents (azathioprine), anticoagulants, andantiplatelet agents, is more effective than therapy with corticosteroids alone
in reducing proteinuria and preventing the progression of glomerularsclerosis. In addition, combination therapy using azathioprine is associatedwith a significantly higher 10-year renal survival rate than combined
treatment with an anticoagulant and antiplatelet agents. Combination
therapy using mizoribine has similar therapeutic effectiveness as
combination therapy with azathioprine.

4. CQs about supportive therapy (adults)
CQ 7.

Are RAS blockers recommended in IgA nephropathy?

Recommendation grade: A
RAS blockers control the progression of renal dysfunction in patients with
IgAN with urinary protein level ≥1.0 g/day and CKD stage G1-3b; therefore,their use is recommended.
Recommendation grade: C1
RAS blockers may reduce proteinuria in patients with IgAN with urinary
protein level of 0.5–1.0 g/day. They may be considered treatment options.
[Summary]
To evaluate the effectiveness of RAS blockers for treating IgAN, patients with
IgAN with urinary protein level ≥1 g/day and CKD stage G1-3b have beenenrolled in RCTs. Many studies have reported anti-proteinuric effects of RAS
blockers, and 2 studies with a mean follow-up period of ≥5 years reported an
improvement in the prognosis of renal function. Therefore, RAS blockers arerecommended for patients with IgAN with urinary protein level ≥1 g/day and
CKD stage 1-3b. The effectiveness of RAS blockers in patients with IgAN withurinary protein level <1 g/day has not been fully evaluated. Combination
therapy with ACE inhibitors, angiotensin receptor blockers (ARBs),
aldosterone antagonists, and renin inhibitors is an issue requiring further
investigation. RAS blockers are contraindicated in women who are pregnant
or trying to conceive. RAS blockers for IgAN patients without hypertension
are off-label use in Japan.
CQ 8.

Are antiplatelet agents recommended in IgA nephropathy?

Recommendation grade: C1
Dipyridamole may be effective in reducing proteinuria and controlling the
progression of renal dysfunction. This may be considered a treatment option.
Recommendation grade: C1
Dilazep hydrochloride (dilazep) may be effective in reducing proteinuria, andit may be considered a treatment option.
[Summary]
Only few studies have evaluated the effectiveness of antiplatelet agents(dipyridamole, dilazep, ticlopidine, and aspirin) and anticoagulants(warfarin) in adult IgAN. Therefore, their effectiveness is currently unknown.
In a multicenter double-blind RCT conducted in Japan by Tojo et al. in the
1980s, a subgroup analysis showed that dipyridamole and dilazep was
effective in reducing proteinuria in patients with IgAN. The effectiveness of
dipyridamole and dilazep in patients with IgAN should be further
investigated in meticulously planned RCTs.

CQ 9.

Are n-3 fatty acids (fish oil) recommended in IgA nephropathy?

Recommendation grade: C1
The n-3 fatty acids (fish oil) may improve renal prognosis in patients with
IgAN. They may be considered a treatment option.
[Summary]
Only 6 RCTs have evaluated the effectiveness of n-3 fatty acids (fish oil) in
IgAN, so it has been difficult to reach a consensus about their effectiveness.
In the largest and longest study involving 106 patients with IgAN, fish oil
was reported to inhibit the progression to ESRD. However, other small-scale
short-term studies have not confirmed the effectiveness of fish oil. Further
investigation is necessary.

5．CQs about lifestyle and dietary guidance in IgA nephropathy
CQ 10.

Should limitation of salt intake be recommended?

Recommendation grade: B
Limiting excess salt intake should be recommended to patients with IgAN. In
patients with IgAN with hypertension and renal dysfunction, limiting salt
intake helps lower the progression to ESRD and reduces the risk ofcardiovascular disease and death. Therefore, limiting salt intake to 3 to 6
g/day is recommended.
Recommendation grade: C2
A relationship between low sodium intake and cardiovascular event has beenreported. Therefore, salt intake of less than 3 g/day is not recommended.
[Summary]
There is no direct evidence showing that salt intake restriction is effective inpatients with IgAN. However, in an intervention study of non-diabetic
patients with CKD, limited salt intake helped reduce blood pressure anddecrease urinary protein excretion. Because blood pressure and urinary
protein are related to prognosis in IgAN, limiting salt intake is probably
beneficial in these patients. Furthermore, in a cohort study involving nondiabetic patients with CKD, higher salt intake increased the risk of renal
dysfunction and accelerated progression to ESRD, suggesting that limited
salt intake is also a treatment option in patients with IgAN. Nevertheless,these studies were conducted outside Japan and included patients without

IgAN. Therefore, the effectiveness and indications for salt intake restrictionin Japanese patients with IgAN requires further investigation.
CQ 11.

Should restricted protein intake be recommended?

Recommendation grade: C1
Limitation of protein intake is not uniformly recommended for all patientswith IgAN. Instead, the condition of each individual patient, their risk ofprogressive renal dysfunction, and adherence to treatment should beconsidered when deciding whether to recommend protein intake restriction.
[Summary]
No direct evidence exists to show that protein restriction is effective inpatients with IgAN. However, in a meta-analysis involving patients with
CKD, limited protein intake did reduce the risk of ESRD and death. On theother hand, limited protein intake has not been shown to reduce the rate of
decline in the glomerular filtration rate (GFR). Moreover, severe protein
restriction may increase the risk of death, especially after dialysis is initiated.
Factors such as age and overall condition differ among individual patientswith IgAN, so uniform protein restrictions should not be recommended to all
patients. The indications for protein restrictions should be decided on thebasis of comprehensive assessments, the risk of progressive renal dysfunction,
and adherence to treatment. In addition, when recommending protein
restrictions, caution should be taken to avoid malnutrition.
CQ 12.

Should weight loss be recommended?

Recommendation grade: A
Patients with IgAN who are obese (body mass index [BMI] ≥ 25) should be
advised to lose weight.
[Summary]
Patients with IgAN who are obese have higher levels of proteinuria, exhibit
greater histological injury on renal biopsy associated with obesity, and havea higher future risk of hypertension and progressive renal dysfunction thannon-obese patients with IgAN. Moreover, obesity increases the risk of thedevelopment and exacerbation of lifestyle-related diseases such as
hypertension, diabetes, and lipid disorders. These lifestyle-related diseases
adversely affect the prognosis in patients with kidney disease. Therefore,
weight loss should be recommended to obese patients with IgAN. However,there is currently no evidence suggesting that weight reduction helps control
renal dysfunction or reduce the level of urinary protein. Further investigationis needed.
CQ 13.

Should exercise restriction be recommended?

Recommendation grade: C2
In patients with IgAN, exercise has been reported to transiently increase
proteinuria, but after completion of the exercise, the urinary protein levels
return to resting levels. Excessive rest (disuse) is also harmful in many
conditions, and no evidence has shown that exercise worsens the prognosis in
IgAN. Therefore, exercise restriction should not be recommended to patientswith IgAN.
[Summary]
Exercise is reported to transiently increase urinary protein excretion inpatients with IgAN, On the other hand, exercise therapy improves maximum
oxygen uptake in patients with CKD. Although there is insufficient evidence
regarding the effects and indications for exercise therapy in CKD, exercise
restriction should not be recommended to patients with IgAN. Meanwhile,with regard to strenuous exercise, almost no evidence exists regarding theassociation of exercise in CKD, with a relatively rapid decline in GFR or in
CKD with severe nephrotic-level proteinuria. Therefore, the indications forexercise therapy or exercise restrictions should be based on comprehensive
assessment of each individual patient’s condition. These patients will require
careful follow-up.
CQ 14.

Should smoking cessation be recommended?

Recommendation grade: A
Smoking is associated with decreased renal function in patients with IgAN.
Smoking is also a major risk factor for lung cancer, chronic obstructive
pulmonary disease (COPD), and cardiovascular disease. Therefore, smoking
cessation should be recommended to patients with IgAN.
[Summary]
In a cohort study of patients with IgAN in Japan and overseas, smoking andthe number of cigarettes smoked per day at the time of renal biopsy wereassociated with a decrease in renal function. In a cohort study of the general
population in Japan and overseas, current smoking was related to decreased

renal function and renal failure, positive findings for proteinuria, andalbuminuria. Therefore, patients with IgAN should be advised to stopsmoking to prevent decreased renal function and increased proteinuria.
Previous smoking is also a risk factor for renal failure and albuminuria, but
the lower risks are associated with previous smoking than current smoking;therefore, smoking cessation in current smokers may potentially prevent any
further decline in renal function or increase in proteinuria.
In addition, the number of cigarettes per day and cumulative smoking(pack/years) are risk factors for decreased renal function. Therefore, evenwhen patients are unable to quit smoking, reducing the number of cigarettes
smoked per day may help reduce the risk of renal dysfunction. Although nodirect evidence exists to show that smoking cessation or reduction prevents
deterioration in renal function or exacerbation of proteinuria, smoking itself
is an important risk factor not only for renal prognosis but also for lung cancer,
COPD, and cardiovascular disease. Therefore, it is important for healthcare
providers to provide guidance for smoking cessation.

6. Adverse events associated with steroid therapy and immunosuppressive
agentsTo date, no study has shown a high rate of serious adverse events associatedwith steroid therapy in adult patients with IgAN. However, because it is notcertain whether these findings were based on sufficient disclosure of
information, an assessment of risk factors for adverse events and preventive
measures should be conducted before starting steroid therapy. Meanwhile,the indications for immunosuppressive therapy must be carefully decided
after weighing the potential benefits against the potential risks, because
immunosuppressive agents induce serious adverse events in some cases. A“cocktail” therapy involving a combination of corticosteroids andimmunosuppressive agents has been shown to be effective in children with
IgAN. However, the safety of this combination therapy must be further
confirmed, because for some patients, this therapy was discontinued owing to
the adverse events. Tonsillectomy in patients with IgAN has a very low rateof serious complications. Cooperation between otolaryngologists andnephrologists is essential for prevention of complications during surgery forpatients on immunosuppressive therapy after kidney transplantation and todetect any remnant tonsillar tissue in the patients.

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6. Diagnosis
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44. Nakayama K, et al. J Clin Lab Anal 2008；22：114—8.
45. Jones CL, et al. Kidney Int 1990；38：323—31.
46. Allen AC, et al. Clin Exp Immunol 1995；100：470—4.
47. Tomana M, et al. 1997；52：509—16.
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3. Zidar N, et al. Kidney Int 1992；42：1444—9.
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9. Classification
1. Lee SM, et al. Hum Pathol 1982；13：314—22.
2. Meadow SR, et al. Q J Med 1972；41：241—58.
3. Lee HS, et al. Clin Nephrol 1987；27：131—40.
4. Lee HS, et al. Nephrol Dial Transplant 2005；20：342—8.
5. Haas M. Am J Kidney Dis 1997；29：829—42.
6. Manno C, et al. Am J Kidney Dis 2007；49：763—75.
7. Alamartine E, et al. Clin Nephrol 1990；34：45—51.
8. Radford MG Jr, et al. J Am Soc Nephrol 1997；8：199—207.
9. Shigematsu H. Pathol Int 1997；47：194—202.
10. Katafuchi R, et al. Clin Nephrol 1998；49：1—8.
11. Magistroni R, et al. J Nephrol 2006；19：32—40.
12. Okonogi H, et al. Nephron Clin Pract 2011；118：c292—300.
13. Wakai K, et al. Nephrol Dial Transplant 2006；21：2800—8.
14. Goto M, et al. Nephrol Dial Transplant 2009；24：3068—74.
15. Goto M, et al. Nephrol Dial Transplant 2009；24：1242—7.
16. Working Group of the International IgA Nephropathy Network and theRenal Pathology Society. Kidney Int 2009；76：546—56.
17. Working Group of the International IgA Nephropathy Network and theRenal Pathology Society. Kidney Int 2009；76：534—45.
18. Working Group of the International IgA Nephropathy Network and theRenal Pathology Society. Kidney Int 2010；77：921—7.

19. Herzenberg AM, et al. Kidney Int 2011；80：310—7.
20. Yau T, et al. Am J Nephrol 2011；34：435—44.
21. Shi SF, et al. Clin J Am Soc Nephrol 2011；6：2175—84.
22. Alamartine E, et al. Clin J Am Soc Nephrol 2011；6：2384—8.
23. Katafuchi R, et al. Clin J Am Soc Nephrol 2011；6：2806—13.
24. Kang SH, et al. Nephrol Dial Transplant 2012；27：252—8.
25. Edström Halling S, et al. Nephrol Dial Transplant 2012；27：715—22.
26. Shima Y, et al. Pediatr Nephrol 2012；27：783—92.
27. Kawamura. T, et al. J Nephrol 2013；26：350—7.
10. Atypical forms of IgA nephropathy
1) Minimal change nephrotic disease (MCD) with mesangial IgA deposits
1. Mustonen J, et al. Clin Nephrol 1983；20：172.6.
2. Lai KN, et al. Am J Clin Pathol 1986；86：716.23.
3. Lai KN, et al. Clin Nephrol 1986；26：174.80.
4. Fukushi K, et al. Jpn J Nephrol 1988；30：253.8.
5. Kim SM, et al. J Korean Med Sci 2009；24 Suppl：S44.9.
2) Acute kidney injury (AKI) associated with macroscopic hematuria
1. Bennett WM, et al. Kidney Int 1983；23：393—400.
2. Praga M, et al. Kidney Int 1985；28：69—74.
3. Delclaux C, et al. 1993；8：195—9.
4. Kveder R, et al. Ther Apher Dial 2009；13：273—7.
5. Gutiérrez E, et al. Clin J Am Soc Nephrol 2007；2：51—7.
3) Crescentic IgA nephropathy
1. Abuelo JG, et al. Medicine（Baltimore）1984；63：396—406.
2. Roccatello D, et al. Nephrol Dial Transplant 1995；10：2054—9.
3. Chambers ME, et al. J Clin Apher 1999；14：185—7.
4. Tumlin JA, et al. Nephrol Dial Transplant 2003；18：1321—9.
5. Bazzi C, et al. Clin J Am Soc Nephrol 2009；4：929—35.
6. Lai KN, et al. Am J Kidney Dis 1987；10：66—70.
7. Welch TR, et al. Am J Dis Child 1988；142：789—93.
8. Harper L, et al. J Nephrol 2000；13：360—6.
9. Nicholls K, et al. Am J Kidney Dis 1985；5：42—6.
10. Coppo R, et al. Int J Artif Organs 1985；Suppl 2：55—8.
11. McIntyre CW, et al. Clin Nephrol 2001；56：193—8.
12. Tang Z, et al. Am J Nephrol 2002；22：480—6.

III. Epidemiology, prognosis, and follow-up
8. Incidence and prevalence
1. Donadio JV, et al. N Engl J Med 2002；347：738—48.
2. Utsunomiya Y, et al. Pediatr Nephrol 2003；18：511—5.
3. McGrogan A, et al. Nephrol Dial Transplant 2011；26：414—30.
9. Natural course
1. Shen P, et al. Nephron Clin Pract 2007；106：c157—61.
2. Chauveau D, et al. Contrib Nephrol 1993；104：1—5.
3. Koyama A, et al. Am J Kidney Dis 1997；29：526—32.
4. D’Amico G. Semin Nephrol 2004；24：179—96.
5. Kusumoto Y, et al. Clin Nephrol 1987；28：118—24.
10. Changes in prognosis with changes in treatment guidelines
1. Komatsu H, et al. Am J Nephrol 2009；30：19—25.
2. Yata N, et al. Pediatr Nephrol 2008；23：905—12.
3. Asaba K, et al. Intern Med 2009；48：883—90.
11. Clinical predictors of progression at the time of initial examination or
renal biopsy
1. Wakai K, et al. Nephrol Dial Transplant 2006；21：2800—8.
2. Manno C, et al. Am J Kidney Dis 2007；49：763—75.
3. Goto M, et al. Nephrol Dial Transplant 2009；24：3068—74.
4. Berthoux F, et al. J Am Soc Nephrol 2011；22：752—61.
5. D’Amico G. Semin Nephrol 2004；24：179—96.
6. Eiro M, et al. Nephron 2002；90：432—41.
7. Ieiri N, et al. Clin Exp Nephrol 2012；16：122—9.
12. Clinical predictors of progression during follow-up
1. Kobayashi Y, et al. Nephrology 1997；3：35—40.
2. Bartosik LP, et al. Am J Kidney Dis 2001；38：728—35.
3. Donadio JV, et al. Nephrol Dial Transplant 2002；17：1197—203.
4. Reich HN, et al. J Am Soc Nephrol 2007；18：3177—83.
5. Berthoux F, et al. J Am Soc Nephrol 2011；22：752—61.
6. Le WB, et al. Nephrol Dial Transplant 2012；27：1479—85.
7. Pozzi C, et al. J Am Soc Nephrol 2004；15：157—63.
8. Cheng J, et al. Int J Clin Pract 2009；63：880—8.
9. Lv J, et al. Am J Kidney Dis 2009；53：26—32.
10. Manno C, et al. Nephrol Dial Transplant 2009；24：3694—701.
11. Hwang HS, et al. Nephrology 2010；15：236—41.

12. Payton CD, et al. Nephrol Dial Transplant 1988；3：138—42.
13. Remission of urinary findings and its significance
1. Hotta O, et al. Am J Kidney Dis 2001；38：736—43.
2. Komatsu H, et al. Clin J Am Soc Nephrol 2008；3：1301—7.
3. Miura N, et al. Clin Exp Nephrol 2009；13：460—6.
4. Kawaguchi T, et al. Nephrology 2010；15：116—23.
5. Tatematsu M, et al. Clin Exp Nephrol 2012：1—9.
6. Hwang HS, et al. Nephrology 2010；15：236—41.
7. Pozzi C, et al. Lancet 1999；353：883—7.
8. Hotta O, et al. Am J Kidney Dis 2002；39：493—502.
9. Matsuzaki K, et al. Clin Exp Nephrol 2013；17：827—33.
14. Follow-up
1. Hotta O, et al. Am J Kidney Dis 2001；38：736—43.
2. Szeto C, et al. Am J Med 2001；110：434—37.
3. Shen P, et al. Nephron Clin Pract 2007；106：c157—61.
4. Goto M, et al. Nephrol Dial Transplant 2009；24：3068—74.
5. Goto M, et al. Nephrol Dial Transplant 2009；24：1242—7.
6. Shen P, et al. Neth J Med 2008；66：242—7.
IV. Treatment
7. A summary of management of IgAN in adults, with a focus on preventionof renal dysfunction
8. Clinical questions (CQs) about immunosuppressive therapy (adults)
CQ 1. Are corticosteroids recommended in IgA nephropathy?
1. Lv J, et al. J Am Soc Nephrol 2012；23：1108—16 (Level 1)
2. Zhou YH, et al. PLoS One 2011；6：e18788 (Level 4)
3. Cheng J. Am J Nephrol 2009；30：315—22 (Level 1)
4. Samuels JA, et al. Cochrane Database Syst Rev 2003；4：CD003965．
(Level 3)
5. Lv J, et al. Am J Kidney Dis 2009；53：26—32 (Level 2)
6. Manno C, et al. Nephrol Dial Transplant 2009；24：3694—701. (Level 2)
7. Pozzi C, et al. Lancet 1999；353：883—7 (Level 2)
8. Pozzi C, et al. J Am Soc Nephrol 2004；15：157—63 (Level 2)
9. Lai KN, et al. Clin Nephrol 1986；26：174—80 (Level 2)
10. Julian BA, et al. Contrib Nephrol 1993；104：198—206 (Level 2)
11. Katafuchi R, et al. Am J Kidney Dis 2003；41：972—83 (Level 2)
12. Hogg RJ. Clin J Am Soc Nephrol 2006；1：467—74 (Level 2)

13. Koike M, et al. Clin Exp Nephrol 2008；12：250—5 (Level 2)
14. Shoji T, et al. Am J Kidney Dis 2000；35：194—201 (Level 2)
CQ 2. Is tonsillectomy combined with steroid pulse therapy recommended?
1. Hotta O, et al. Am J Kidney Dis 2001；38：736—43 (Level 4)
2. Kawaguchi T, et al. Nephrology（Carlton）2010；15：116—23 (Level 4)
3. Sato M, et al. Nephron Clin Pract 2003；93：c137—45 (Level 4)
4. Komatsu H, et al. Clin J Am Soc Nephrol 2008；3：1301—7 (Level 3)
5. Miura N, et al. Clin Exp Nephrol 2009；13：460—6 (Level 4)
6. Hotta O, et al. Jpn J Nephrol 1993；35：967—73 (Level 4)
7. Hotta O, et al. Acta Otolaryngol Suppl 1996；523：165—8 (Level 4)
8. Kawamura T, et al. Nephrol Dial Transplant 2014；29：1546—53.
CQ 3. Is tonsillectomy (alone) recommended?
1. Iino Y, et al. Acta Otolaryngol Suppl 1993；508：29—35 (Level 4)
2. Kosaka M. Nihon Jibiinkoka Gakkai Kaiho 1998；101：916—23 (Level 4)
3. Rasche FM, et al. Clin Nephrol 1999；51：147—52 (Level 4)
4. Chen, Y, et al. Am J Nephrol 2007；27：170—5 (Level 4)
5. Xie, Y, et al. Kidney Int 2003；63：1861—7 (Level 4)
6. Akagi H, et al. Acta Otolaryngol Suppl 2004；555：38—42 (Level 4)
7. Wang, Y, et al. Nephrol Dial Transplant 2011；26：1923—31 (Level 4)
8. Komatsu H, et al. Ren Fail 2012；34：448—53 (Level 4)
9. Maeda I, et al. Nephrol Dial Transplant 2012；27：2806—13 (Level 4)
CQ 4. Are non-steroidal immunosuppressive agents recommended?
1. Walker RG, et al. Clin Nephrol 1990；34：103—7 (Level 2)
2. Ballardie FW, et al. J Am Soc Nephrol 2002；13：142—8 (Level 2)
3. Pozzi C, et al. J Am Soc Nephrol 2010；21：1783—90 (Level 2)
4. Harmankaya O, et al. Int Urol Nephrol 2002；33：167—71 (Level 2)
5. Lai KN, et al. BMJ 1987；295：1165—8 (Level 2)
6. Frisch G, et al. Nephrol Dial Transplant 2005；20：2139—45 (Level 2)
7. Tang S, et al. Kidney Int 2005；68：802—12 (Level 2)
8. Maes BD, et al. Kidney Int 2004；65：1842—9 (Level 2)
9. Xu G, et al. Am J Nephrol 2009；29：362—7 (Level 1)
10. Xie Y, et al. Am J Med Sci 2011；341：367—72 (Level 2)
9. CQs about immunosuppressive therapy (children)
CQ 5. Is immunosuppressive therapy recommended in childhood IgA
nephropathy?

1. Yoshikawa N, et al. Pediatr Nephrol 2001；16：446—57.
2. Yoshikawa N, et al. Nihon Jinzo Gakkai Shi. 1997 Jul；39(5)：503—6．
3. Yoshikawa N, et al. J Am Soc Nephrol 1999；10：101—9 (Level 2)
4. Yata N, et al. Pediatr Nephrol 2008；23：905—12 (Level 4)
5. Kamei K, et al. Clin J Am Soc Nephrol 2011；6：1301—7 (Level 2)
CQ 6. Is combination “cocktail” therapy recommended in childhood IgA
nephropathy?
1. Yoshikawa N, et al. J Am Soc Nephrol 1999；10：101—9 (Level 2)
2. Yoshikawa N, et al. Clin J Am Soc Nephrol 2006；1：511—7 (Level 2)
3. Kamei K, et al. Clin J Am Soc Nephrol 2011；6：1301—7 (Level 2)
4. Yoshikawa N, et al. Pediatr Nephrol 2008；23：757—63 (Level 4)
5. Pozzi C, et al. J Am Soc Nephrol 2010；21：1783—90.
10. CQs about supportive therapy (adults)
CQ 7. Are RAS blockers recommended in IgA nephropathy?
1. Cheng J, et al. Int J Clin Pract 2009；63：880—8 (Level 1)
2. Reid S, et al. Cochrane Database Syst Rev 2011；3：CD003962 (Level 1)
3. Praga M, et al. J Am Soc Nephrol 2003；14：1578—83 (Level 2)
4. Woo KT, et al. Cell Mol Immunol 2007；4：227—32 (Level 2)
5. Ruggenenti P, et al. Am J Kidney Dis 2000；35：1155—65 (Level 2)
6. Woo KT, et al. Kidney Int 2000；58：2485—91 (Level 2)
7. Park HC, et al. Nephrol Dial Transplant 2003；18：1115—21 (Level 2)
8. Li PK, et al. Am J Kidney Dis 2006；47：751—60 (Level 2)
9. Nakamura T, et al. Am J Nephrol 2000；20：373—9 (Level 2)
10. Coppo R, et al. J Am Soc Nephrol 2007；18：1880—8 (Level 2)
11. Horita Y, et al. Hypertens Res 2004；27：963—70 (Level 2)
12. Nakamura T, et al. Am J Hypertens 2007；20：1195—201 (Level 2)
CQ 8. Are antiplatelet agents recommended in IgA nephropathy?
1. Taji Y, et al. Clin Exp Nephrol 2006；10：268—73 (Level 4)
2. Liu XJ, et al. Intern Med 2011；50：2503—10 (Level 1)
3. Chan MK, et al. Am J Kidney Dis 1987；9：417—21 (Level 2)
4. Lee GSL, et al. Nephrology 1997；3：117—21 (Level 2)
5. Camara S, et al. Nephron 1991；58：13—6 (Level 2)
6. Cheng I, et al. Nephrology 1998；4：19—26 (Level 2)
CQ 9. Are n-3 fatty acids (fish oil) recommended in IgA nephropathy?
1. Miller ER Ⅲ, et al. Am J Clin Nutr 2009；89：1937—45 (Level 4)
2. Bennett WM, et al. Clin Nephrol 1989；31：128—31 (Level 2)

3. Pettersson EE, et al. Clin Nephrol 1994；41：183—90 (Level 2)
4. Donadio JV, Jr., et al. J Am Soc Nephrol 1999；10：1772—7 (Level 2)
5. Alexopoulos E, et al. Ren Fail 2004；26：453—9 (Level 2)
6. Ferraro PM, et al. Nephrol Dial Transplant 2009；24：156—60 (Level 2)
7. Liu LL, et al. Clin Nephrol 2012；77：119—25 (Level 1)
8. Hogg RJ, et al. Clin J Am Soc Nephrol 2006；1：467—74 (Level 2)
9. Reid S, et al. Cochrane Database Syst Rev 2011；3：CD003962 (Level 1)
10. Donadio JV, Jr., et al. N Engl J Med 1994；331：1194—9 (Level 2)
11. Donadio JV Jr., et al. J Am Soc Nephrol 2001；12：791—9 (Level 2)
11. CQs about lifestyle and dietary guidance in IgA nephropathy
CQ 10. Should limitation of salt intake be recommended?
1. Vogt L, et al. J Am Soc Nephrol 2008；19：999—1007 (Level 2)
2. Slagman MC, et al. BMJ 2011；343：d4366 (Level 2)
3. Lin J, et al. Clin J Am Soc Nephrol 2010；5：836—43 (Level 4)
4. Vegter S, et al. J Am Soc Nephrol 2012；23：165—73 (Level 4)
5. Stolarz—Skrzypek K, et al. JAMA 2011；305：1777—85 (Level 4)
6. O’Donnell MJ, et al. JAMA 2011；306：2229—38 (Level 4)
7. Cook NR, et al. BMJ 2007；334：885—8 (Level 4)
CQ 11. Should restricted protein intake be recommended?
1. Pedrini MT, et al. Ann Intern Med 1996；124：627—32 (Level 3)
2. Fouque D, et al. Cochrane Database Syst Rev 2009；3：CD001892 (Level
1)
3. Kasiske BL, et al. Am J Kidney Dis 1998；31：954—61 (Level 1)
4. Koya D, et al. Diabetologia 2009；52：2037—45 (Level 2)
5. Cianciaruso B, et al. Am J Kidney Dis 2009；54：1052—61 (Level 2)
6. Menon V, et al. Am J Kidney Dis 2009；53：208—17 (Level 2)
CQ 12. Should weight loss be recommended?
1. Tanaka M, et al. Nephron Clin Pract 2009；112：c71—8 (Level 4)
2. Bonnet F, et al. Am J Kidney Dis 2001；37：720—7 (Level 4)
CQ 13. Should exercise restriction be recommended?
1. Fuiano G, et al. Am J Kidney Dis 2004；44：257—63 (Level 4)
2. Eidemak I, et al. Nephron 1997；75：36—40 (Level 4)
3. Boyce ML, et al. Am J Kidney Dis 1997；30：180—92 (Level 4)
4. Painter PL, et al. Transplantation 2002；74：42—8 (Level 4)
5. Toyama K, et al. J Cardiol 2010；56：142—6 (Level 4)
6. Pechter U, et al. Int J Rehabil Res 2003；26：153—6 (Level 4)

CQ 14. Should smoking cessation be recommended?
1. Yamamoto R, et al. Am J Kidney Dis 2010；56：313—24 (Level 4)
2. Orth SR, et al. Kidney Int 1998；54：926—31 (Level 4)
3. Hallan SI, et al. Kidney Int 2011；80：516—23 (Level 4)
4. Yamagata K, et al. Kidney Int 2007；71：159—66 (Level 4)
5. Ishizaka N, et al. Hypertens Res 2008；31：485—92 (Level 4)
12. Adverse events associated with steroid therapy and immunosuppressive
agents1. Cheng J, et al. Am J Nephrol 2009；30：315—22 (Level 1)
2. Lv J, et al. J Am Soc Nephrol 2012；23：1108—16． (Level 1)
3. Zhou YH, et al. PLoS One 2011；6：e18788．(Level 1)
4. Weinstein RS. Endocrine 2012；41：183—90.
5. Drescher W, et al. Nephrol Dial Transplant 2011；26：2728—31.
6. Fujimoto S, et al. Am J Nephrol 1990；10：231—6． (Level 4)
7. Ballardie FW, et al. J Am Soc Nephrol 2002；13：142—8．(Level 2)
8. Pozzi C, et al. J Am Soc Nephrol 2010；21：1783—90． (Level 2)
9. Stangou M, et al. Clin Exp Nephrol 2011；15：373—80． (Level 2)
10. Maes BD, et al. Kidney Int 2004；65：1842—9． (Level 2)
11. Tang S, et al. Kidney Int 2005；68：802—12． (Level 2)
12. Frisch G, et al. Nephrol Dial Transplant 2005；20：2139—45．(Level 2)
13. Yoshikawa N, et al. Clin J Am Soc Nephrol 2006；1：511—7．(Level 2)
14. Yoshikawa N, et al. J Am Soc Nephrol 1999；10：101—9．(Level 2)
15. Yoshikawa N, et al. Pediatr Nephrol 2008；23：757—63．(Level 4)
17. Salonen A, et al. Laryngoscope 2002；112：94—8.
18. Heiser C, et al. Laryngoscope 2010；120：2119—24.
19. Heiser C, et al. Laryngoscope 2012；122：1265—6.
20. Windfuhr JP, et al. Eur Arch Otorhinolaryngol 2010；267：289—93.
21. Windfuhr JP, et al. Ann Otol Rhinol Laryngol 2003；112：63—70.
22. Lowe D, et al. Lancet 2004；364：697—702.
23. Walker P, et al. Otolaryngol Head Neck Surg 2007；136（4 Suppl）
：S27—
31.
24. Arnoldner C, et al. Wien Klin Wochenschr 2008；120：336—42.
25. Hessén Söderman AC, et al. Laryngoscope 2011；121：2322—6.
26. Tomkinson A, et al. Laryngoscope 2011；121：279—88.
27. Kennoki T, et al. Transplantation 2009；88：935—41.
28. Kurata N, et al. Nihon Jibiinkoka Gakkai Kaiho.2012 Jan；115(1)：29—

36．
31. Pratt LW. Trans Am Acad Ophthalmol Otolaryngol 1970；74：1146—54.

Table 1. Histologic classification presented by a multicenter case-control study on patients with IgAN in Japan
A. Histological grade
Histological grade% glomeruli with pathological

Acute lesion

Acute andChronic

variables* predicting progression to

onlychronic

lesion only

ESRD

lesionH-Grade I

0-24.9%A

A/CC

H-Grade II

25-49.9%

A

A/C

C

H-Grade III

50-74.9%

A

A/C

C

H-Grade IV

>75%

A

A/C

C

*Acute lesion (A): cellular crescent, tuft necrosis, fibrocellular crescent
Chronic lesion (C): global sclerosis, segmental sclerosis, fibrous crescent

B. Clinical grade
Clinical grade

Proteinuria

eGFR(g/day)(ml/min/1.73m2)

<0.5

―

C-Grade I
C-Grade II

60≦

0.5≦

C-Grade III<60

C. Grading system for predicting progression to ESRD
Histological grade

H-GradeH-Grade I

H-Grade II

C-Grade I

Low

ModerateHigh

C-Grade II

Moderate

ModerateHigh

C-Grade III

High

High

Super highClinical grade

III + IV

Low risk group: *1 of 72 (1.4%) of IgAN patients developed to ESRD in 18.6 yr after RBx.
Moderate risk group: *13 of 115 (11.3%) of IgAN patients developed to ESRD in 11.5 (3.7-19.3) yr. after RBx.
High risk group: *12 of 49 (24.5%) of IgAN patients developed to ESRD in 8.9 (2.8-19.6) yr. after RBx.
Super high risk group: *22 of 34 (64.7%) of IgAN patients developed to ESRD in 5.1 (0.7-13.1) yr. after RBx.
*The data from retrospective multicenter case-control study on IgAN (n=287)

Table 2. Definitions of pathological variables used in the Oxford classification
Variable

Definition

Score

Mesangial hypercellularity <4

Mesangial cells/mesangial area = 0

M0≦0.54-5

Mesangial cells/mesangial area = 1

M1＞0.5a

6-7

Mesangial cells/mesangial area = 2≧8Mesangial cells/mesangial area = 3
The mesangial hypercellularity score is the mean score
for all glomeruli

Segmental

Any amount of the tuft involved in sclerosis, but not

glomerulosclerosis

involving the whole tuft or the presence of an adhesion

S0 – absent
S1 – present

Endocapillary

Hypercellularity due to increased number of cells within

hypercellularity

glomerular capillary lumina causing narrowing of the lumina

E0 – absent
E1 – present

Tubular atrophy/interstitial Percentage of cortical area involved by the tubular atrophy or
fibrosisinterstitial fibrosis, whichever is greater

T0 – 0–25%
T1 – 26–50%
T2 – >50%aMesangial score should be assessed in periodic acid-Schiff-stained sections. If more than half the glomeruli havemore than three cells in a mesangial area, this is categorized as M1. Therefore, a formal mesangial cell count is notalways necessary to derive the mesangial score.

Author, year,
country, No. of
institutions●Intervention (Max. dose/day, duration:
Year; Y, Month; M, Week; W)○ControlRAS blocker Control Patient Primary Follow-up ITT(%)(No.) require outcomeb (yr)
PP
ment
(No.)

CyA

CPA/AZAmPSL

PSN/PSLLai 1986●PSN/PSL 40-60 mg, 4 M
China (Hong Kong), 1 ○No immunosuppressant

MMF

17
17

-

-

ITT

Julian 1993
United States, 6●PSN 26 mg, 2 Y○No steroid

35
44

17
18

-

2

ITT

Lv 2009
China, 1●PSN 0.8-1.0mg/kg, 6-8 M + ○○Cilazapril 5mg

100
100

33
30

sCr
67
67 ≥150%

5

ITT

Manno 2009
Italy, 14●PSN 1.0 mg/kg, 6M + ○○Ramipril

100
100

48
49

sCr
60
60 ≥200%

5

ITT

Katafuchi 2003
Japan, 1●PSL 20 mg 2 Y + ○○Antiplatelet agents

(0)§
(4)§

43
47

-

-

PP

Hogg 2006
United States 37●PSN 30 mg/m2 2 Y○Placebo

(50)§

33
31

41
41

5

ITT

Koike 2008
Japan, 1●PSL 0.4 mg/kg 2 Y + ○○Antiplatelet agents

38
25

24
24

-

2

ITT

Shoji 2000
Japan, 1●PSL 0.8 mg/kg 1 Y○Antiplatelet agents)

0
0

11
8

-

1

ITT

Pocci 1999
Italy, 7●mPSL 1 g 3 days  3 + oral PSL○No steroid

58
51

43
43

sCr
42
42 ≥150%

5

ITT

Walker 1990
Australia, 1●CPA (1-2 mg/kg)＋Dipyridamole (400mg)○No CPA＋ Dipyridamole

0
0

25
27

-

2

ITT

Balladie 2002
United Kingdom, 1●CPA (1.5mg/kg 3M)＋AZA (1.5mg/kg)＋PSL (40mg) 26○No immunosuppression therapy
26

19
19

-

5

ITT

Pozzi 2010
Italy, Swiss, 27●AZA (1.5mg/kg 6M)＋ ○○mPSL(1g 3days, every 2M)＋PSL (0.25mg/kg 6M)

89
92

101 173 sCr
106 173 ≥150%

5

ITT

Harmankaya 2002
Turkey, 1●AZA (100mg 4M)＋PSL (40mg 4M)○ No immunosuppression therapy

-

21
20

-

-

ITT

-

9
10

-

0.5 ITT

100
100

17
15

50
sCr
50 ≥150%

2

100
100

20
20

20
20

1.4 ITTLai 1987●CyA (5mg/kg 1W)
China (Hong Kong), 1 ○Placebo (CyA0.05mg/kg 12W)
Frisch 2005
United States, 1

MZR-●MMF (1g/day, 1 Y)
○Placebo (1 Y)

Tang 2005●MMF (1.5-2.0g/day, 6M)
China (Hong Kong), 2 ○No MMF

eGFR
<60%

UP
≤50%

ITT

Mae 2004
Belgium, 1●MMF(2g/day, 4M) ＋ Enalapril○Placebo (4M)＋ Enalapril

100
100

21
13

-

3

ITT

Xie 2011
China, 8●MZR (150-250 mg/kg)＋Losartan (100mg)○MZR (150-250 mg/kg)○Losartan (100mg)

100
0
100

34
35
30

30
Not
30
1
mentioned
30

PP

Figure 1 (Left)0

Before intervention
Proteinuria
1
2
3

4

*

*

sCr
Follow-up
sCr
sCr
ESRD
period≥200% ≥150% (mg/dL)(No.)(year)(No.) (No.)

30

Mean±SD

Changing
ratio in UP
(%)

2
0

2
1

1.4±0.9
1.5±0.6

74±24
65±21

2.3±2.2
3.3±2.1

41±37 *
70±38

Cases of 1 year 1
64%
2

-

-

1.1
1.8

-

1.3
1.8

-

2.3±0.6
2.2±0.7

0
2

-

1 *
7

-

-

1.0±0.5
1.6±0.9-

5.3†(3.8, 7.0)
4.8†(2.6, 6.4)

1 *
7

2 *
13

-

-

-

0.7(0.4, 1.2)
1.0(0.4, 1.6)-

5.4±2.1
5.3±1.933--

1.0±0.7
1.0±0.4-

1.3±0.5
0.8±0.7-

Cases of  2 years
75%

-

-

1.0†
1.1†

-

-

-

2#

-

-

-

0.9
1.2

-

0.3±0.5
0.7±0.7-

1.1±0.2---

0.8±0.2
0.8±0.3

110±26108±220.3±0.2 *0.7±0.4-

4†[1-10]

0
3

1
9

9 *
14

-

-

0.8(0.6, 1.3) *1.7(1.1, 3.0)-

2.0†[0.5-2.0]
2.0†[1.5-2.0]

0
0

-

-

1.4±0.6
1.5±0.6-

1.2±1.6
1.9±2.3

-

-

4 *
15

-

-

-

-

0.7
4.1

-

4.9†(3.0, 6.4)

6
4

-

13
12

-

-

1.16†
0.98†

-

5.3†[1.0-10.0]
4.8†[1.0-9.5]

-

-

-

0.9†[0.8-1.3]
1.0†[0.9-1.5]

-

-

-

0.5#

-

-

-

0.7±0.2
0.6±0.1

146±43150±291.3±1.4
2.3±1.0-

4.9[0.4-10.8]
6.3[0.7-11.0]

5
2

-

5
2

4.0±2.9
3.0±1.8-

2.7±2.3
2.5

-

1.4#

-

-

1
3

-

-

1.1±1.0 * 62±8 *
2.4±1.8 120±14

3#

2
0

-

3
0

1.7
1.5

60
67

1.6
1.0

Cases of ≥1 year
85%

-

-

-

91±29
96±21
94±28

0.4±0.3
0.5±0.3
0.7±0.6*

With
conditions

UP(g/day,g/gCr)

00

3.1±2.3
3.2±1.6

Inclusion

OutcomeGFRMedian (25%,75%)

Median (Min-Max)

Figure 1 (Right)-*

Before Intervention
GFR
3 120
90
60

*

0

sCr (mg/dL)
12-

ACE-I/ ARB

Author, year,
country, No. of
institutions● Intervention (Max. dose mg/day) b○Controlb

Ruggenenti 2000
Italy, 14●Ramipril (5mg)○Placebo

100
0

39 Sub36 analysis

Woo 2000
Singapore, 1●Enalapril (10mg) / Losartan (100mg)○Non-RAS blocker

100
0

21
20

20
Not
20 mentioned

ITT

Woo 2007
Singapore, 1●Enalapril (10mg) / Losartan (100mg)○Non-RAS blocker

100
0

37
38

-

ITT

Park 2003
South Korea, 1●Losartan (50mg)○Amlodipine (5mg)

100
0

20
16

UP
19
0.25 ITT
19 TGF-β1

Li 2006●Valsartan (160mg)
China (Hong Kong), 5 ○Placebo

100
0

54
55

sCr
55
55 ≥200%

2

ITT●Enalapril (40mg)○Non-RAS blocker

100
0
100
100
0
0
100
0

23
21
8
8
8
8

sCr
21
21 ≥150%

-

ITT

-

0.25 ITT

32
34

Ccr
61
61 ≧70%

3

100
100
100
100
100
100

8
8
8
11
10
10
73 Sub74 analysis

Praga 2003
Spain, 1
Nakamura 2000
Japan, 3

Combination
ACE-I and ARB

Coppo 2007
5 countries in
Europe, 23Nakamura 2007
Japan, 4
Horita 2004
Japan, 1n-3 fatty acids (fish oil)

Antiplatelet agents

Tojo 1987
Japan, 84

RAS blocker Control Patient Primary Follow-up ITT(%)(No.) require outcomeb (yr)
PP
ment
(No.)

●Trandolapril (2mg)●Candesartan (8mg)○Verapamil (120mg)○Placebo●Benazepril (0.2mg/kg)○Placebo●Temocapril (2mg)＋ Olmesartan (10mg)○Temocapril (2mg)○Olmesartan (10mg)●Temocapril (1mg)＋ Losartan (12.5mg)○Temocapril (1mg)○Losartan (12.5mg)●Dipyridamole (300mg)○Placebo

Chan 1987●Dipyridamol (225mg)＋Aspirin (650mg)
China (Hong Kong), 1 ○Vitamin B

-

19
19

-

1

4

5.3 ITT

5

ITT0.25 ITT

0.5

PP

0.5

PP

-

PP

Camara 1991
Spain, 2●Dipyridamole (300mg)○Placebo-

12-0.25 PPLee 1997
Singapore, 1●Dipyridamol (225mg)＋Warfarin○No Dipyridamole ＋Warfarin

0
0

10
11

-

3

ITT

Tojo 1986
Japan, 67●Dilazep (300mg)○Placebo

51 Sub43 analysis

0.5

PP

Cheng 1998
Singapore, 1●Ticlopidine (500mg) + Captopril (150mg)○Captopril (13.5-150mg)

100
100

20
15

-

-

PP

Donadio 1994, 1999
United States, 21●EPA(1.9g)＋DHA(1.4g)○Placebo

58
57

55
51

-

≥2 ITT

Alexopoulos 2004
Greece, 1●EPA(0.9g)＋DHA(0.6g)○No EPA＋DHA

79
36

14
14

-

4

PP

Pettersson 1994
Sweden, 1●EPA(3.3g)＋DHA(1.8g)○Placebo

40
59

15
17

-

6

PP

Bennett 1989
United States, 1●EPA(1.8g)＋DHA(1.2g)○No EPA＋DHA

-

17
20

-

2

PP

Hogg 2006
United States, 3●EPA(1.9g)＋DHA(1.5g)○Placebo

(50)§

32
31

41
41

5

ITT

Ferraro 2009
Italy, 1●EPA + DHA(2.6g)＋RAS blocker○RAS blocker

100
100

15
15

-

0.5 ITT

Donadio 2001
Unites States, 14●High dose EPA(3.8g)＋DHA(2.9g)○Low dose EPA(1.9g)＋DHA(1.5g)

-

36
37

-

2

eGFR
<60%

0

Before intervention
Proteinuria
2
3

Figure 2 (Left)

ITT

*

With
conditions

Mean±SD30

Mean (25%,75%)sCr
Follow-up
sCr
sCr
ESRD
period≥200% ≥150% (mg/dL)(No.)(year)(No.) (No.)

Outcome
GFR

UP(g/day,g/gCr)

Changing
ratio in UP(%)-

2.5(1.3, 4.0)
ALL

7
9

-

-

-

-

-

1.0±0.6
0.9±0.3

0
0

0
2

2
6

2.0±1.3
2.3±1.1-

1.8±1.6 *2.9±1.8

5.2±0.4
5.0±0.6

7 *
21

7 *
26

8 * 2.4±2.0 *28 5.0±2.8-

1.1±0.9 *1.9±1.0

0.25#

-

-

-

1.5±0.6
1.5±0.7

62±22
64±25

1.2±1.5
2.2±1.6

2#

-

1
4

-

-

72±34
63±35

1.2±1.3 * 66±41 *
2.0±1.7 115±67

6.5±3.1
6.2±3.0--

3 * 1.2±0.5 * 95±30 * 0.9±1.0 *12 1.9±1.9 64±31
2.0±1.8

0.25#

-

-

-

0.8±0.3
0.8±0.2
0.8±0.2
0.8±0.3

110±14110±16106±14110±12

1.2±0.5
1.1±0.6
1.4±0.5
1.7±0.7

63±15
61±17
78±8

3.2[0.0-4.8]

0
0

-

-

-

-

-

-

0.25#

-

-

-

-

-

0.5#

-

-

-

0.9±0.2
0.9±0.2
0.9±0.2

86±29
88±18
86±21

44
0.8±0.2 ***1.3±0.3 * 6772
1.5±0.4
0.3±0.2
37±63 *
0.4±0.359±52 *
0.6±0.4
63±35

0.5#

-

-

-

-

63±44
60±29

1.7±1.92.2±1.969±45 *
112±66

0.25#

-

-

-

-

NS

-

40
93

2.8±0.833--

2.2±2.8
2.3±2.6

78±39
72±35

2.5±3.4
2.2±2.4

-

3#

1
4

-

-

2.5±1.2
3.3±1.1-

1.3±1.1
1.5±1.1

-

0.5#

-

-

-

-

79±31
75±26

1.6±1.4
2.2±2.3-

4.5[2.2-4.7]
4.5[1.0-4.6]

1
2

4
2

-

-

-

-

-

6.4, 6.8†

8 *
19

-

17 *
29

-

-

-

-

4#

1
6

-

1
6

2.3±2.2
5.9±3.9

41±13
34±30

0.8±0.4
0.9±0.6

-

0.5#

8
19

-

17
29

1.6±0.4
1.4±0.5

59±21
68±27

1.7±0.91.8±1.2

-

2#

2
2

-

-

-

57±70
55±63

-

-

Cases of ≧2
75%

-

-

-

1.1†
1.1†

-

-

-

0.5#

-

-

-

-

94±35
68±35

0.4±0.5 *1.4±1.3

-

2#

0
0

-

-

-

-

1.7†
1.1†

-

Mean (Min-Max)

Figure 2 (Right)

-

-

*

Inclusion

Beforeintervention
介入前所見
GFR
3 120
90
60

*

*

0

sCr (mg/dL)
1
2

0.5

90

4

GFR (mL/min/1.73 m2)

Follow-up observation

UP (g/day)

3
・RAS blocker (C1)・Corticosteroids (C1)・Others¶ (C1)・Follow-up
observation

1.0

1First choice・RAS blocker (A)・Corticosteroids (B)Second choice・Others¶ (C1)

60

2

5

First choiceConservative therapy(according to the CKD management guidelines ¶ ¶) ・RAS blockers (A)Second choice・Corticosteroids (C1)・Others¶ (C1)30

Figure 3

Figure 1. The summary of

randomized controlled trials ofcorticosteroids andimmunosuppressive agents in adult patients with IgAN

Figure 2. The summary of randomized controlled trials of RAS blockers, antiplatelet agents, andfish oils in adult patients with IgAN

Figure 3. An outline of treatment of IgAN in adults with a focus on prevention of renal
dysfunction (based on randomized controlled trials for IgAN)
This figure shows the indications for treatment intervention, based mainly on the results (Figs. 1, 2)of RCTs, often focusing on renal function and amount of urinary protein excreted as patient
inclusion/exclusion criteria. In actual clinical practice, besides renal function and urinary protein level,other factors such as renal histopathological findings and age should also be considered to carefully
decide the indications for these treatment interventions.
Others¶: Tonsillectomy (combined with high-dose pulse corticosteroid therapy) and therapy with nonsteroidal immunosuppressive agents, antiplatelet agents, and n-3 fatty acids (fish oil).
CKD management guidelines ¶ ¶: The Japanese Society of Nephrology Evidence based Clinical
Practice Guideline for CKD 2013: Hypertension (Chapter 4), salt intake (Chapters 3, 4), lipid disorders(Chapter 14), glucose intolerance (Chapter 9), obesity (Chapter 15), smoking (Chapter 2), anemia(Chapter 7), CKD mineral and bone disorders (CKD-MBD, Chapter 8), and metabolic acidosis(Chapter 3) should also be managed as necessary.