Control of AA amyloidosis complicating Crohn's disease: a clinico-pathological study

Background Immunosuppressive drugs may prevent or partially reverse progression of renal AA-amyloidosis, a rare complication of Crohn's disease, often fatal due to renal failure. Materials and methods The clinical, biological and pathological data of 16 patients treated since 1976 were reviewed. Serum amyloid A was determined in surviving patients. Results The median age of the 16 patients (13 men) was 23 center dot 5years (range 1669). At Crohn's disease onset, Montreal phenotypes were similar to reported data. Out of 15 patients with renal insufficiency, 8 developed a nephrotic syndrome and 7 a low grade proteinuria. The single patient without renal insufficiency had nephrotic syndrome. A significant correlation (P<0 center dot 05) between the extension of renal amyloid A and sclerosis was found in 12 patients. One patient had a 10year remission of nephrotic syndrome with immunosuppressive drugs. In 6 patients treated with anti-TNF- (Tumor-Necrosis-Factor-) agents, anaphylactic reaction (1/6), death from septic shock (1/6), 5-year remission (1/6) or reduction of nephrotic syndrome (1/6) and stabilization of renal insufficiency (2/6) were observed. Surgery was performed in 10 patients. Kidney transplantation was performed in 5 of the 8 patients dialysed for end-stage renal failure. Among 6/16 patients (37%) still alive, 3 belong to the 5 transplanted patients (survival: 320years) and 3 to the anti-TNF- drugs treated patients; all but one exhibited a low serum amyloid A level. Conclusions Suppression of Crohn's disease inflammation potentially leads to the control of amyloid A production, assessed by a decrease of serum amyloid A. Kidney transplantation provides a long survival.