Anti-glomerular Basement Membrane Disease with Atypical Associations

Anti-glomerular basement membrane (anti-GBM) disease is a systemic autoimmune disorder characterized by circulating immunoglobulin (Ig) G antibodies to carboxy-terminal, noncollagenous 1 domain of type IV collagen of GBM. Patients typically present with rapidly progressive glomerulonephritis and pulmonary hemorrhage. Anti-GBM disease has been reported to coexist with pauci-immune antineutrophil cytoplasmic autoantibody-positive glomerulonephritis and membranous glomerulopathy. The presentation of anti-GBM disease with thrombotic microangiopathy (TMA) and IgA nephropathy has been rarely described. We herein report two cases of anti-GBM antibody disease, both with crescentic glomerulonephritis and peripheral linear deposits of IgG, one case with clinical and histological findings of associated TMA and other with findings of extensive mesangial IgA deposits. Both the patients were treated with corticosteroid, intravenous cyclophosphamide, and plasma exchange but had poor renal recovery. Association of anti-GBM disease with TMA or IgA nephropathy could open up new pathogenetic mechanism and may help us to prognosticate anti-GBM disease.