In membranous glomerulonephritis (MGN) (synonyms: Glomerulonephritis, membranous; Glomerulopathy, membranous; Membranous nephropathy; ICD-10-GM N05.2: Unspecified nephritic syndrome: Diffuse membranous glomerulonephritis) is an autoimmune disease with chronic inflammation of the glomeruli. There are deposits of immune complexes on the outside of the glomerular basement membrane and a nephrotic syndrome. The thickening of the glomerular basement membrane led to the name “membranous glomerulonephritis.”
Nephrotic syndrome is characterized by proteinuria (increased excretion of protein in the urine), resulting hypoproteinemia (too little protein in the blood), hyperlipoproteinemia, and edema (water retention). In adults, membranous glomerulonephritis is the most common cause of nephrotic syndrome, accounting for approximately 30%.
The following main forms of glomerulonephritis are distinguished:
- Minimal-change glomerulonephritis (MCGN) (glomerular minimal lesion) – the most common cause of nephrotic syndrome in childhood.
- Focal segmental sclerosing glomerulonephritis (FSSGN) – associated with nephrotic syndrome in approximately 15% of cases.
- Membranous glomerulonephritis (MGN) – the most common cause of nephrotic syndrome in adults; accounts for 20-30% of all glomerulonephritides; may be primary or secondary (resulting from other diseases)
- Membranoproliferative glomerulonephritis (MPGN) – associated with nephrotic syndrome in 50%.
- Mesangial IgA glomerulonephritis – most common form with up to 35% of cases.
- Rapid progressive glomerulonephritis (RPGN) – occurs in 2-7% of patients; the disease is classified into several causative groups
An idiopathic (with no apparent cause) form (75% of cases) is distinguished from a secondary form (25% of cases; in the context of infectious diseases such as hepatitis B or C, HIV, syphilis, malaria, autoimmune diseases such as systemic lupus erythematosus, malignancies, the use of drugs / agents such as gold, penicillamine).
Sex ratio: males (Caucasians: fair-skinned people) are more commonly affected by the idiopathic form.
Frequency peak: idiopathic form of membranous glomerulonephritis occurs predominantly after the age of 40. Children are rarely affected overall.
Course and prognosis: In about 30% of cases, the disease heals spontaneously. In 35% of patients, partial remission (reduction of disease symptoms) occurs, with stable kidney function for years. Renal failure occurs in approximately 25% of cases, and approximately 10% die from extrarenal (nonrenal) causes.
