Immune-complex glomerulonephritis in Crohn's disease

A 13-year-old girl presented with a history of fever, arthritis, conjunctivitis, abdominal pain, and diarrhea. Colonoscopy and barium enema were consistent with Crohn's disease. A renal biopsy, performed because of persistent proteinuria and hematuria in the absence of obstruction to the urinary tract, revealed diffuse proliferative necrotizing glomerulonephritis: IgG, IgM, and C3 were deposited on the involved glomeruli. Circulating immune complexes were present in her serum. This immune-complex glomerulonephritis represents a previously unreported extraintestinal manifestation of inflammatory bowel disease.