Mesangioproliferative Glomerulonephritis



This histopathological pattern may occur in dis­eases discussed elsewhere but is best exemplified by the idiopathic syndrome of IgA nephropathy. This is a distinctive glomerulopathy found in about half of patients with benign recurrent he­maturia, a syndrome predominantly of young adult males. The classic presentation is that of re­peated bouts of asymptomatic gross hematuria, which often occur in conjunction with an upper respiratory infection and which are separated by periods when only microscopic hematuria is ev­ident. Proteinuria is usually modest, < 1 gm/day, but up to 10 per cent of patients develop the ne­phrotic syndrome. Serum complement levels are normal.

The light microscopy is nondiagnostic, but the most typical finding is that of focal, segmental proliferation within glomeruli. The diagnosis is made by the invariable presence of IgA seen by immunofluorescence within the mesangium . IgG and/or IgM are found alongside IgA in about half the cases. Mesangial IgA can also be seen in lupus nephritis and in anaphylactoid pur­pura. Electron microscopy confirms the presence of deposits within the mesangium.

Originally thought to represent a benign dis­order, mesangioproliferative glomerulonephritis is now known to progress to terminal renal failure in 10 to 15 years in 10 to 20 per cent of patients, especially those with heavy proteinuria. The course of the disease is not known to be altered by corticosteroids or immunosuppressive agents. Mesangial deposits of IgA, sometimes associated with hematuria, occur regularly in transplanted kidneys.