Control of rheumatoid arthritis by oral tolerance

Objective. Previous randomized controlled trials for treatment of rheumatoi d arthritis (RA) with acid-soluble chicken and bovine type II collagen (CII ) have produced conflicting results. This randomized, double-blind, control led trial examined the therapeutic effect of bovine CH tablets in RA. Methods. CII tablets were prepared by adsorption onto a lactose base. Patie nts with a duration of RA of greater than or equal to2 years and who had fa iled treatment with at least 1 slow-acting drug were recruited, provided th at they had active arthritis. Patients were randomly assigned to receive ei ther 0.05 mg, 0.5 mg, or 5 mg of CH or placebo daily for 6 months. All slow -acting drugs were stopped at least 4 weeks before starting CII, although p rednisolone was permitted at dosages < 10 mg/day. Clinical assessments were performed at screening and at 0, 1, 4, 8, 12, 16, 20, and 24 weeks of trea tment. Results. Fifty-five patients were recruited. Initially, there were no signi ficant differences in mean Disease Activity Scores between groups. At 24 we eks, there was a significant difference (P = 0.041, by Kruskal-Wallis analy sis of variance); the major components of this difference were attributable to relatively large decreases in the 0.5 mg CH group (19% of initial value s) and to minimal decreases in patients receiving placebo (3% of initial va lues). Twenty patients had American College of Rheumatology 20% responses; 11 of these were in the 0.5 mg CII group and 3 were in each of the other gr oups, a significant difference (<chi>(2) = 14.6, P = 0.002). There was no s ignificant difference in any clinical measure between the placebo, 0.05 mg CII, and 5 mg CH groups. There were no side effects associated with CII tre atment. Conclusion. Treatment with 0.5 mg/day of bovine CH is well tolerated and pr oduces small, but significant, disease improvement in RA. However, the ther apeutic window is narrow. The difference between our results and those of o ther trials may relate to the dose, species, and formulation of the CH.