Recurrence of mesangial deposition of IgA after renal transplantation

Abstract

Mesangial deposition of IgA is found in about 20% of adult patients with idiopathic glomerular disease. The deposition involves the mesangium of every glomerulus and persists during the whole course of the nephropathy. The authors therefore believe it to be the hallmark of the disease in these patients. Mesangial IgA is usually accompanied by IgG. IgM has been found by some observers. C3 is present without Clq or C4, suggesting activation of the complement system by the alternative pathway. This is further supported by the demonstration of properdin. In the authors' experience, however, the deposition of properdin is much less conspicuous than in acute glomerulonephritis or membranoproliferative glomerulonephritis. Mesangial deposition is now generally considered to be a fairly distinct clinicopathological entity but some pathologists are still reluctant to recognize it as such. Recurrence after transplantation is one more argument in favor of the former opinion.