IgA Nephropathy

 National Kidney and Urologic Diseases Information Clearinghouse 

NATIONAL 

INSTITUTES 

OF HEALTH 

U.S. Department 

of Health and 

Human Services 

What is IgA nephropathy? 

IgA nephropathy is a kidney disorder that 

occurs when IgA—a protein that helps the 

body fight infections—settles in the kidneys. After many years, the IgA deposits 

may cause the kidneys to leak blood and 

sometimes protein in the urine. 

Many people with IgA nephropathy leak 

blood in the urine, but this leakage does 

not mean they will have long-term problems. Others leak both blood and protein 

in the urine. If too much protein leaks into 

the urine, the hands and feet can swell. 

After 10 to 20 years with IgA nephropathy, the kidneys may show signs of damage. About 25 percent of adults with IgA 

nephropathy develop total kidney failure. 

Only 5 to 10 percent of children develop 

total kidney failure. Symptoms of kidney 

failure include swelling in the hands and 

feet, nausea, fatigue, headaches, and sleep 

problems. By the time these symptoms 

occur, total kidney failure is near. Total 

kidney failure means the kidney damage 

is permanent. People with kidney failure 

need dialysis or a kidney transplant. 

How do people know that 

they have IgA nephropathy? 

In the early stages, IgA nephropathy has no 

symptoms. This disease can be silent for 

years, even decades. The first sign of IgA 

nephropathy may be blood in the urine. 

The blood may appear during a cold, sore 

throat, or other infection. At times, blood 

in the urine can only be detected by a 

doctor or nurse using special tests. If the 

amount of blood increases, urine may turn 

pink or the color of tea or cola. People 

who have blood in their urine should see 

a doctor or nurse, but the condition is not 

always a sign of a serious disease. For 

example, heavy exercise can cause blood in 

the urine. 

Who is at risk for IgA 

nephropathy? 

IgA nephropathy can occur at any age, 

even in childhood. More men are affected 

than women. Although found all over the 

world, IgA nephropathy is more common 

among Caucasians and Asians. It is one of 

the most common diseases of the kidney, 

other than those caused by diabetes or high 

blood pressure. 

What causes IgA 

nephropathy? 

Scientists do not know what causes IgA 

deposits to form in the kidneys. IgA 

nephropathy may run in families or be 

related to respiratory infections. No consistent trigger for the disease has been 

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How is IgA nephropathy 

diagnosed? 

A urine test called urinalysis usually provides the first clues. In a urinalysis, the 

doctor or nurse dips a special strip with 

chemicals into the urine sample. The strip 

changes color when blood or protein is 

present in the urine. If the test strip is 

positive, the urine will then be examined 

with a microscope to look for red blood 

cells. The red blood cells may be clumped 

together to form little tubes. These tubes 

are called casts because they are formed 

or molded inside the kidneys’ tiny draining structures. If casts are found, it usually 

means the kidney filters are damaged. 

Blood tests measure the waste products in 

the blood that the kidneys usually get rid 

of. Two examples are creatinine and blood 

urea nitrogen (BUN). If the BUN and creatinine levels are high, it means the kidneys 

are not working well. If the creatinine level 

is high at the time of diagnosis, the patient 

is more likely to develop kidney failure. 

If there is kidney damage, the doctor will 

probably recommend a kidney biopsy. In 

this procedure, a needle is used to retrieve 

a small piece of kidney tissue for examination with different microscopes. Only a 

biopsy can show the IgA deposits in the 

kidney filters. The biopsy can also tell 

how much kidney damage has already 

occurred. The biopsy results can help the 

doctor determine the best treatment. Once 

a diagnosis of IgA nephropathy is established, a person should have regular blood 

tests to monitor kidney function. 

How is IgA nephropathy 

treated? 

Kidney disease usually cannot be cured. 

When the kidneys are damaged, they 

cannot be repaired. Treatment focuses on 

slowing the disease and preventing 

complications. 

One complication is high blood pressure, 

also called hypertension. Hypertension 

damages the kidneys. Two types of blood 

pressure medicines called angiotensinconverting enzyme (ACE) inhibitors and 

angiotensin receptor blockers (ARBs) protect kidney function. These medicines not 

only lower blood pressure but also decrease 

the loss of protein into the urine. Because 

of this effect, they are often used in IgA 

nephropathy to protect the kidneys. They 

are good medicines but have certain side 

effects. Pregnant women should not take 

ACE inhibitors or ARBs because they can 

damage the unborn baby. 

People with IgA nephropathy may develop 

high cholesterol. By watching their diet 

and taking medicine, they can help lower 

their cholesterol level. Lowering cholesterol may help slow kidney damage. 

Medicines such as prednisone may help 

treat IgA nephropathy. Prednisone 

belongs to a class of medicines called corticosteroids, which can have harmful side 

effects. In research studies, fish oil supplements containing omega 3 fatty acids also 

slowed kidney damage in some patients. 

Vitamin E may help lower protein in the 

urine but not blood. One of the newer 

immunosuppressive agents called mycophenolate mofetil (MMF) is also being 

tested in treating IgA nephropathy. 

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Hope through Research 

In recent years, researchers have learned 

much about kidney disease. The National 

Institute of Diabetes and Digestive and 

Kidney Diseases (NIDDK) sponsors several 

programs aimed at understanding kidney 

failure and finding treatments to stop its 

progression. 

The NIDDK’s Division of Kidney, Urologic, 

and Hematologic Diseases (DKUHD) supports basic research into normal kidney 

function and the diseases that impair normal function at the cellular and molecular 

levels, including diabetes, high blood pressure, glomerulonephritis, and other diseases 

marked by protein in the urine. 

Researchers sponsored by the DKUHD are 

studying families in which IgA nephropathy is prevalent in order to understand 

genetic factors that may influence the disease. Other researchers are working to 

understand how the polyunsaturated fatty 

acids found in fish oils may work to reduce 

inflammation in diseases like IgA nephropathy and rheumatoid arthritis. Clinical trials 

are under way to test the effectiveness of 

MMF in reducing protein in the urine and 

slowing the progression of kidney disease in 

people with IgA nephropathy. 

For More Information 

American Kidney Fund 

6110 Executive Boulevard, Suite 1010 

Rockville, MD 20852 

Phone: 1–800–638–8299 

1–866–300–2900 (Spanish) 

Email: helpline@kidneyfund.org 

Internet: www.kidneyfund.org 

American Society of Pediatric Nephrology 

3400 Research Forest Drive, Suite B7 

The Woodlands, TX 77381 

Phone: 281–419–0052 

Fax: 281–419–0082 

Email: info@aspneph.com 

Internet: www.aspneph.com 

IgA Nephropathy Support Network 

89 Ashfield Road 

Shelburne Falls, MA 01370 

Phone: 413–625–9339 

Internet: www.igansupport.org 

National Heart, Lung, and Blood Institute 

Health Information Center 

P.O. Box 30105 

Bethesda, MD 20824–0105 

Phone: 301–592–8573 

Email: nhlbiinfo@nhlbi.nih.gov 

Internet: www.nhlbi.nih.gov 

National Kidney Foundation, Inc. 

30 East 33rd Street 

New York, NY 10016 

Phone: 1–800–622–9010 or 

212–889–2210 

Fax: 212–689–9261 

Internet: www.kidney.org 

3 IgA Nephropathy 
You may also find additional information about this 

topic by visiting MedlinePlus at www.medlineplus.gov.

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National Kidney and 

Urologic Diseases 

Information Clearinghouse

3 Information Way 

Bethesda, MD 20892–3580 

Phone: 1–800–891–5390 

Fax: 703–738–4929 

Email: nkudic@info.niddk.nih.gov 

Internet: www.kidney.niddk.nih.gov

The National Kidney and Urologic Diseases 

Information Clearinghouse (NKUDIC) is a 

service of the National Institute of Diabetes and 

Digestive and Kidney Diseases (NIDDK). The 

NIDDK is part of the National Institutes of 

Health of the U.S. Department of Health and 

Human Services. Established in 1987, the 

Clearinghouse provides information about 

diseases of the kidneys and urologic system to 

people with kidney and urologic disorders and 

to their families, health care professionals, and 

the public. The NKUDIC answers inquiries, 

develops and distributes publications, and works 

closely with professional and patient organizations and Government agencies to coordinate 

resources about kidney and urologic diseases.

Publications produced by the Clearinghouse are 

carefully reviewed by both NIDDK scientists and 

outside experts. The NKUDIC would like to 

thank the following members of the American 

Society of Pediatric Nephrology Clinical Affairs 

Committee for their review of this fact sheet: 

Maria Ferris, M.D.; Barbara Fivush, M.D.; 

Joseph Flynn, M.D.; Ann Guillot, M.D.; Tej 

Mattoo, M.D.; Cynthia Pan, M.D.; Jeff Saland, 

M.D.; and Steve Wassner, M.D.

This publication is not copyrighted. The Clearinghouse encourages users of this fact sheet to duplicate 

and distribute as many copies as desired.

This fact sheet is also available at 

www.kidney.niddk.nih.gov.

U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES

National Institutes of Health

NIH Publication No. 08–4571 

February 2008