We wish to comment on the case reported by Iizuka and colleagues (Gut 2006;55:744–5) of a patient who experienced a reduction in creatine levels from 4 to 2 mg/dl after three weeks of treatment with infliximab for amyloidosis associated with Crohn’s disease. Unfortunately, no details were provided of other concomitant factors, such as volume depletion or drugs, which may have affected baseline creatinine levels and their later course, irrespective of amyloidosis, or of the results of proteinuria observed in 1992.

In our experience,¹ anti-TNF-α therapy has a rapid effect on proteinuria but not on renal function. In our patients it took several months (the most rapid decrease was from 1.6 to 0.94 mg/dl in three months) for serum creatinine levels to decrease by (mean (SD) percentage since baseline) 8.5 (16.6)% (range −21.4 to 39.4) after 70 (44) weeks (range 2–120), and only 36% of patients experienced a 20% reduction or greater.

We should also like to comment on the choice of anti-TNF for the management of amyloidosis in patients with quiescent Crohn’s disease but active spondyloarthropathy.

One of our patients was diagnosed by clinical, endoscopic, and histological criteria with spondyloarthropathy associated with Crohn’s disease …