De novo glomerulonephritis in patients during remission from Wegener's granulomatosis.

In a cohort of 20 consecutive patients with Wegener's granulomatosis and biopsy-proven pauci-immune crescentic glomerulonephritis three patients were in remission, but developed again a nephritic sediment without signs of systemic disease or positive ANCA titers. The second renal biopsy showed de novo mesangial IgA deposits 6, 17 and 28 months following admission for systemic disease and institution of immunosuppressive treatment. All patients were male, HLA-DR-2 positive and exhibited repeated upper respiratory tract infections. A fourth patient was admitted in end-stage renal failure with high titers of C-ANCA of the IgG isotype and proteinase 3 ab without clinical evidence of systemic manifestations of WG. Renal biopsy showed chronic sclerosing GN with marked IgA deposits. De novo development of IgA-GN is observed in a remarkable proportion of patients with WG and must be distinguished from exacerbation of the systemic disease.