Membranous glomerulonephritis



Membranous glomerulonephritis (MGN; also membranous nephropathy, MN) mainly affects middle-aged or older adults. Most often (70-80% of cases) it is a primary idiopathic autoimmune disease, 20-30% of the disease is secondary to infectious, tumor, systemic autoimmune diseases or after the administration of certain drugs. MGN is the most common cause of nephrotic syndrome in adults (20-40%), more common in men.

Microscopically we find a diffuse thickening of the glomerular capillary wall caused by the deposition of immunocomplexes into the subepithelial space (between the podocytes and the basement membrane).

Etiology

 * Idiopathic (primary) form of MGN (most common)
 * Most diseases of this group are associated with the formation of autoantibodies against the M-type receptor for phospholipase A2 (PLA2R). Some polymorphisms of the PLA2R gene in combination with some HLA-DQA1 polymorphisms are associated with a high risk of this form of the disease.


 * Secondary form of MGN (20-30%):
 * infections (viral hepatitis B and C),
 * tumors (lung cancer, prostate cancer, hematological malignancies ),
 * systemic autoimmune diseases (SLE),
 * drugs (penicillamine, gold preparations, captopril, NSA).

Clinical picture
Clinical manifestations may be unremarkable.
 * sudden appearance of DKK swellings + their progression
 * non-selective proteinuria + erythrocyturia, often fully developed nephrotic syndrome
 * arterial hypertension (20-40%)
 * impairment of renal function (at the time of dg. in 5-10%)



Therapy

 * Idiopathic MGN: corticoids, cyclophosphamide, chlorambucil, cyclosporine,
 * secondary MGN: stop precipitating drugs / treat primary disease.

Prognosis

 * The fundamental importance of influencing the formation of immunocomplexes,
 * with successful therapy, nephrotic syndrome may disappear,
 * many years stationary or developing CKD.

Related Articles

 * Glomerulonephritis: Acute glomerulonephritis • Rapidly progressive glomerulonephritis • Chronic glomerulonephritis
 * Glomerulopathy: Glomerulopathy manifested by nephrotic syndrome