Although colchicine is effective on prevention and regression of amyloidosis in many cases, rate of unresponsiveness to colchicine therapy is not too low. However, there is no sufficient data about which factors effect to response of colchicine therapy on regression of amyloidosis.
24 patients with renal amyloidosis were enrolled into the study. The patients were divided in two groups according to urinary protein excretions: non-nephrotic stage (14/24) and nephrotic stage (10/24). The patients were also categorized according to the etiology of amyloidosis; familial Mediterranean fever (FMF)-associated amyloidosis (15/24) versus rheumatoid disorders (RD)-associated amyloidosis (9/24). The changes of amount of proteinuria and estimated glomerular filtration rates were investigated after colchicine treatment started in these groups.
The mean follow-up period was 27.7 ± 19.2 months. After initiating colchicine therapy, the degree of proteinuria was decreased higher than 50% in 11/14 (78%) of non-nephrotic patients and elevated only in three (22%) patients. In nephrotic group, proteinuria was increased in 5/10 (50%) of patients. Glomerular filtration rates were stable in nephrotic and non-nephrotic groups. Presenting with nephrotic syndrome was higher in RD-associated amyloidosis (RD_A) group (5/9) than FMF-associated amyloidosis (FMF_A) group (5/15) without statistical significance (p > 0.05). After colchicine treatment, proteinuria was decreased in 12/15 patients in FMF_A group, however, the significant decreasing of proteinuria was not observed in RD_A group (p = 0.05 vs. p > 0.05).
Colchicine therapy was found more effective in low proteinuric stage of amyloidosis. The beneficial effect of colchicine therapy was not observed in patients with RD- associated amyloidosis.