Colchicine treatment of AA amyloidosis of familial Mediterranean fever. An analysis of factors affecting outcome.

Objective: To elucidate factors possibly influencing the outcome of colchicine therapy in patients with amyloidosis of familial Mediterranean fever (FMF).
Methods: Retrospective analysis of data abstracted from the charts of all 68 FMF patients with amyloidosis who presented during the study period (1974-1992) with proteinuria (> or = 0.5 gm/24 hours) and creatinine values < or = 2.5 mg/dl, received colchicine, and were followed up for > or = 5 years.
Results: At the end of the study period, kidney disease had worsened in 31 patients and remained stable in 22. Proteinuria had regressed in 15 patients. Deterioration was related to initial serum creatinine values > or = 1.5 mg/dl (P < 0.01) and to mean colchicine dosage < or = 1.5 mg/day (P < 0.001). The 3 groups were comparable in terms of initial urinary protein levels, duration of proteinuria, presence of hypertension, occurrence of febrile attacks, sex distribution, and proportion of non-compliant patients.
Conclusion: The therapeutic dosage of colchicine for amyloidosis of FMF is > 1.5 mg/day. This dosage is effective only in patients with initial serum creatinine levels < 1.5 mg/dl.