To evaluate the efficacy of oral chicken type II collagen (CII) in the treatment of rheumatoid arthritis (RA).
Sixty patients with clinically active RA of long duration (mean 7.2 +/- 5.5 years) were treated for 6 months with oral chicken CII at 0.25 mg/day (n = 31) or with placebo (n = 29) in a double-blind randomized study.
The response rate to treatment of the collagen-treated group, based on the ACR 20% criteria, was higher than that of the control group but this difference was not statistically significant at any time. Intention-to-treat (ITT) analysis did not show statistically significant improvement in any of the several secondary outcome measures over the 6 months of the study in the collagen-treated patients in comparison with the placebo-treated group. However, in 2 collagen-treated patients we observed a clinical remission according to the criteria of the American Rheumatism Association.
Our study seems to show that the oral treatment of RA patients with chicken CII is ineffective and results in only small and inconsistent benefits. Furthermore, our results raise the possibility that in a sub-group of patients oral collagen administration, usually considered devoid of harmful effects, may actually induce disease flares.