Immunoglobulin A nephropathy and ulcerative colitis - A focus on their pathogenesis

The immune response has largely been implicated in the pathogenesis of infl ammatory bowel disease (ulcerative colitis and Crohn's disease) and immunog lobulin A nephropathy. We present a 26-year-old woman with a long past hist ory of asymptomatic macroscopic hematuria who later developed several episo des of bloody stools and abdominal pain. A colonic biopsy disclosed ulcerat ive colitis and a renal biopsy was consistent with immunoglobulin A nephrop athy. Immunoglobulin A nephropathy is the most common glomerulonephritis, b eing end-stage renal disease a rare but the most serious complication. It c an be primary or secondary, but the association between both entities is un usually observed. We discuss the possible immunologic mechanisms involved a nd believe the initial immunologic derangement originates in the bone marro w. We suggest both conditions must be considered when either a patient with ulcerative colitis and micro- or macrohematuria or with renal involvement and a past history of diarrhea or abdominal pain presents. Copyright (C) 20 01 S. Karger AG, Basel.