Proliferative glomerulonephritis with monoclonal immunoglobulin in renal allografts

Glomerulopathy due to dysproteinemia can have a wide spectrum of pathologic and clinical features based on specific characteristics of the abnormal protein and the response induced within the parenchymal tissue. Monoclonal immunoglobulin G (IgG) deposition can manifest as a different glomerular disease. Proliferative glomerulonephritis (GN) with monoclonal IgG deposits (PGNMID) is a unique entity mimicking immune complex GN that does not conform to any of those subtypes. IgG monoclonal granular deposition in the glomeruli with a pattern similar to immune complex disease suggested by C3 and C1q deposition should prompt consideration of PGNMID. Literature is scarce in terms of recurrence of disease in renal allografts. In this article we present the clinical–pathologic features of three cases of PGNMID in the renal allograft showing the variable course and manifestation of the disease.