Membranous glomerulonephritis overview

# Overview

# Historical Perspective
Membranous glomerulonephritis was first discovered by David Jones, renal pathologist from Syracuse University in New York, in 1957.

# Classification
There is no established system for the classification of MGN. however it can be divided in two groups based on etiology of MGN.

# Pathophysiology
Membranous glomerulonephritis is caused by immune complex formation in the glomerulus. The immune complexes are formed by binding of antibodies to antigens in the glomerular basement membrane. The antigens damage the basement membrane and activates the immune response. The immune complex serves as an activator that triggers a response from the complement system. PLA2R antigen detected within immune deposits by immunofluorescence of the biopsy specimen. Formation of the immune complex. Immune complex formation results in release of cytokines which release membrane attack complex C5-C9. Release of C5-C9 lead to injury of podocyte which causes loss of glomerular permeablity. The damage to podocyte reults in proteinuria.

# Causes
The main causes of Membranous Glomerulonephritis are Infectious causes like Hepatitis B, drugs like captopril and autoimmune diseases like systemic lupus erythematosus.

# Differentiating Hereditary pancreatitis from Other Diseases
MGN must be differentiated from other diseases that cause proteinuria, weight loss, and renal failure, such as MPGN, MCD, and FSGC.

# Epidemiology and Demographics
The incidence rate of membranous glomerulonephritis is 27 per 100.000. The prevalence rate of membranous glomerulonephritis is 690 per 100,000. The prevalence of membranous glomerulonephritis is approximately 690 per 100,000 individuals worldwide. In 2001, the mortality rate of membranous glomerulonephritis is approximately 380 per 100,000. The incidence of membranous glomerulonephritis increases with age; the median age at diagnosis is 40 years. Membranous glomerulopathy usually affects individuals of the caucasian race and chinese population. Membranous glomerulonephritis affects men and women equally. Membranous glomerulonephritis tends to affect Caucasian population and Chinese population.

# Risk Factors
The most common risk factors of membranous glomerulonephritis include SLE and drugs like captopril, penicilliamine.

# Screening
There is insufficient evidence to recommend routine screening for membranous glomerulonephritis.

# Natural History, Complications, and Prognosis
The symptoms of membranous glomerulonephritis usually develop in the fourth decade of life in males. Approximately 5-30% patients with MN have spontanous remission. Common complications of membranous glomerulonephritis include renal failure, hypertension, proteinuria, dyslipidemia, hypercoagulable state leading to thromboembolism, Increased risk of infection. Prognosis is generally good, and 1 year mortality rate of patients with membranous glomerulonephritis is approximately 0.38%. The presence of proteinuria and baseline renal insuffiency are associated with a particularly poor prognosis among patients with membranous glomerulonephritis. Membranous glomerulonephritis caused by NSAIDS is associated with the most favorable prognosis.

# Diagnosis

## Diagnostic Criteria
The most efficient and sensitive test is ANA, ds-DNA antibodies specific test that is utilized for diagnosis of membranous glomerulonephritis.
The gold standard test for the diagnosis of biopsy.

## History and Symptoms
The hallmark of membranous glomerulonephritis is nephrotic syndrome. A positive history of forthy urine and headache are suggestive of membranous glomerulonephritis.

## Physical Examination
Common physical examination findings of membranous glomerulonephritis include edematous feets and headache.

## Laboratory Findings
The major laboratory workup includes blood workup, auto-immune workup and urine workup.

## Electrocardiogram
There are no ECG findings associated with membranous glomerulonephritis.

## X-ray
There are no x-ray findings associated with membranous glomerulonephritis.

## Ultrasound
There are no echocardiography and ultrasound findings associated with membranous glomerulonephritis.

## CT scan
There are no CT scan findings associated with membranous glomerulonephritis.

## MRI
There are no MRI findings associated with membranous glomerulonephritis.

## Other Imaging Findings
There are no other imaging findings associated with membranous glomerulonephritis

## Other Diagnostic Studies
The patients with compromised renal functions are indicated for biopsy

# Treatment

## Medical Therapy
Pharmacologic medical therapy is recommended among patients who has infectious, autoimmune causes of membranous glomerulonephritis. The drugs like prednisone and cyclophospamide are recomended for the treatment of autoimmune cause of membranous glomerulonephritis. Drug like Angiotensin receptor inhibitior (ACEi) is recomended for managment of hypertension.

## Surgery
Surgery is not the first-line treatment option for patients with MGN. Surgery is usually reserved for patients requiring renal transplant.

## Primary Prevention
Vaccine against heptatis B and treatment of hepatitis C can be preventive for membranous glomerulopathy.

## Secondary Prevention
Early detection and treatment of hepatitis C can be preventive for developing membranous glomerulopathy. Safe sexual practice can prevent the risk of HIV which can eventually decreases the risk of MN. Safe sexual practice can prevent the risk of syphilis which can be preventive the risk of MN.