RECURRENCE OF IMMUNOGLOBULIN-A NEPHROPATHY WITH IMMUNOGLOBULIN-A ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES FOLLOWING RENAL-TRANSPLANTATION

We previously reported the presence of immunoglobulin A (IgA) antineut rophil cytoplasmic antibodies (ANCAs) in patients presenting IgA nephr opathy (IgAN), particularly when associated with Henoch-Schonlein purp ura, Most of the patients exhibited IgA ANCAs directed at an unknown 5 0-kd neutrophil protein but no IgG ANCAs. A subgroup of patients prese nted IgG as well as IgA ANCAs, suggesting an overlap syndrome between Henoch-Schonlein purpura and microscopic polyangiitis. We aimed at con firming the correlation of IgA ANCA titer with disease activity in a p atient presenting IgAN relapse following kidney transplantation, The A NCAs were searched for by isotype- and antigen-specific enzyme-linked immunosorbent assay. Specificity was confirmed by antigen-specific enz yme-linked immunosorbent assay and Western blot analysis, At the onset of the disease in 1989, the patient presented with ANCAs of IgA and I gG class with specificity for myeloperoxidase and no rheumatoid factor . End-stage renal failure developed 1 year afterward, In 1991, he rece ived a cadaveric renal allograft, and 9 months later developed acute n ephrotic syndrome with rapidly progressive renal failure and recurrenc e of IgAN on the kidney transplant, An increase in IgA but not IgG ANC As was found on clinical relapse after kidney transplantation. We conc lude that rare patients may present an overlap syndrome between IgG AN CA-positive systemic vasculitis and IgAN, characterized by the presenc e of IgG and IgA anti-myeloperoxidase antibodies. (C) 1997 by the Nati onal Kidney Foundation, Inc.