Membranous glomerulonephritis | |
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Micrograph of membranous nephropathy showing prominent glomerular basement membrane spikes. Jones' stain. | |
Classification and external resources | |
Specialty | urology |
ICD-10 | N03.2 |
ICD-9-CM | 583.1 |
DiseasesDB | 7970 |
eMedicine | med/885 |
MeSH | D015433 |
Membranous glomerulonephritis (MGN) is a slowly progressive disease of the kidney affecting mostly people between ages of 30 and 50 years, usually Caucasian.
It is the second most common cause of nephrotic syndrome in adults, with focal segmental glomerulosclerosis (FSGS) recently becoming the most common.
The closely related terms membranous nephropathy and membranous glomerulopathy both refer to a similar constellation but without the assumption of inflammation.
Membranous nephritis (in which inflammation is implied, but the glomerulus not explicitly mentioned) is less common, but the phrase is occasionally encountered. These conditions are usually considered together.
By contrast, membranoproliferative glomerulonephritis has a similar name, but is considered a separate condition with a distinctly different causality. Membranoproliferative glomerulonephritis involves the basement membrane and mesangium, while membranous glomerulonephritis involves the basement membrane but not the mesangium. (Membranoproliferative glomerulonephritis has the alternate name "mesangiocapillary glomerulonephritis", to emphasize its mesangial character.)
Some people may present as nephrotic syndrome with proteinuria, edema with or without renal failure. Others may be asymptomatic and may be picked up on screening or urinalysis as having proteinuria. A definitive diagnosis of membranous nephropathy requires a kidney biopsy.
85% of MGN cases are classified as primary membranous glomerulonephritis—that is to say, the cause of the disease is idiopathic (of unknown origin or cause). This can also be referred to as idiopathic membranous nephropathy. One study has identified antibodies to an M-type phospholipase A2 receptor in 70% (26 of 37) cases evaluated. Other studies have implicated neutral endopeptidase and cationic bovine serum albumin as antigens.