An unusual case of IgA-mediated anti-glomerular basement membrane disease.

Anti-glomerular basement membrane (GBM) disease is mediated by circulating autoantibodies, principally IgG, targeted at the type IV collagen of GBM. The IgA variant of anti-GBM disease has rarely been described. We report a 65-year-old man with uremia, undergoing hemodialysis, who was referred because of hemoptysis. A chest X-ray showed diffuse infiltration in the right lung field. Laboratory data were remarkable for renal failure, anemia, and thrombocytopenia. Furthermore, laboratory evidence of microangiopathic hemolytic anemia was present. A kidney biopsy revealed diffuse crescentic glomerulonephritis. Circulating IgA anti-GBM antibody was found, as well as the presence of significant IgA deposition in a linear pattern along the GBM, suggesting an anti-GBM antibody-mediated disease. The patient was treated with plasmapheresis and pulse steroid therapy, which resulted in an immediate improvement in the pulmonary hemorrhage and hematological abnormalities. However, the patient did not regain renal function and remained on hemodialysis.