IgA antiglomerular basement membrane nephritis associated with Crohn's disease: a case report and review of glomerulonephritis in inflammatory bowel disease.

A case of glomerulonephritis in a 35-year-old man with Crohn's disease is described here. The patient presented with severe diarrhea, nephrotic range proteinuria, hematuria, microangiopathic hemolytic anemia, thrombocytopenia, hypocomplementemia, acute renal failure requiring hemodialysis, cryoglobulinemia, and extensive thrombotic gangrene of the distal upper and lower limbs. The patient did not respond to plasmapheresis and steroid therapy and died of upper gastrointestinal bleeding. Renal tissue obtained at autopsy showed IgA-mediated antiglomerular basement membrane crescentic glomerulonephritis. Linear staining of the glomerular basement membrane by non-IgG antibodies is quite unusual with only 11 cases previously reported in the worldwide literature, 8 caused by IgA. Glomerulonephritis is a rarely reported extraintestinal manifestation of inflammatory bowel disease, and there are only 24 previously described cases that are reviewed and summarized in this report. Glomerulonephritis occurred in the setting of active bowel inflammation in all cases, circulating immune complexes were found in nearly half the cases, and serum complements usually were normal. Renal insufficiency and nephrotic range proteinuria were typically present at the time of diagnosis of glomerulonephritis and most often improved in parallel with treatment of the gastrointestinal disorder. The histologic findings were varied and included membranoproliferative glomerulonephritis, mesangioproliferative glomerulonephritis, membranous nephropathy, IgA nephropathy, and IgM nephropathy. Thus, the authors present the first case of glomerulonephritis caused by antiglomerular basement membrane disease in association with inflammatory bowel disease.