Efficacy of cyclophosphamide combined with prednisolone in patients with AA amyloidosis secondary to rheumatoid arthritis

Abstract

Secondary amyloid A (AA) amyloidosis is an uncommon yet important complication of rheumatoid arthritis (RA). It is one of the most relentless of the extra-articular features of RA, and suitable treatments have not yet been found. We studied the efficacy of cyclophosphamide (CYC) combined with prednisolone (PSL) in amyloidotic patients who had serum amyloid A (SAA) 1.3 genotype, which is a risk factor for secondary amyloidosis in Japanese RA patients. Fifteen RA patients who were SAA1.3 homo- and heterozygotes with biopsy-confirmed AA amyloidosis were treated with a combination of CYC and PSL. Laboratory variables of C-reactive protein (CRP), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), serum albumin (Alb), serum creatinine (Cre) and Lansbury's index were carried out by statistical analysis of changes between before and during the medication. According to the Mann-Whitney rank test, CRP, RF, ESR, Alb and Cre levels improved significantly with the combination treatment (p<0.05). Also, paired t-tests showed significance in Lansbury's index between before and during the medication (p=0.007). CYC combined with PSL ameliorated not only laboratory markers but also clinical rheumatoid activity in patients with amyloidosis secondary to RA, whose genotypes were SAA1.3 homo- and heterozygous. CRP, ESR, RF, Alb and Cre will be surrogate markers of therapeutic efficacy. The combination of CYC and PSL appears to be beneficial for Japanese RA patients who are SAA1.3 homo- and heterozygous carriers, associated with secondary AA amyloidosis.