THE INFLUENCE OF SILICONE IMPLANTATION ON TYPE-II COLLAGEN-INDUCED ARTHRITIS IN MICE

Objective. To determine whether silicone implantation exacerbates auto immune disease in a murine experimental model of arthritis. Methods. D BA/1 mice were implanted with silicone in the form of an elastomer, ge l, or oil, and immunized with type II collagen, The influence of silic one implantation on collagen-induced arthritis and the immune response to type II collagen were determined by comparison against control mic e receiving sham implantation, Adjuvant effects of silicone implantati on were examined by measuring cytokine levels in implanted animals and assessing autoantibodies against proteins extracted from recovered si licone implants. Results. No adverse influence of silicone implantatio n on the clinical aspects of collagen-induced arthritis was observed, Further, polydimethylsiloxane silicone oil failed to serve as an adjuv ant in the immune or arthritogenic response to type II collagen in mic e, Cytokine analysis indicated that tumor necrosis factor alpha levels were lower and interleukin-2 levels were higher in silicone-implanted mice, The development of arthritis increased protein binding to impla nted elastomers and gel, and autoantibodies against silicone-bound pro teins were present in sera from arthritic mice and absent in sera from nonarthritic mice. Conclusion. The data suggest that silicone implant ation may result in autoantibodies against silicone-bound proteins, an d the presence of arthritis may either provoke or increase the level o f such autoantibodies, However, silicone implantation did not increase the incidence or severity of disease compared with sham-operated cont rols, Thus, it appears that autoantibodies against silicone-bound prot eins may not have pathologic significance in this experimental model o f arthritis.