Silicone-induced arthritis in rats and possible role for T cells.

Intra-articular injection of silicone into the ankle joint of the rat induced persistent arthritis. Histologically, at 24 h after silicone injection, there was marked edema of the synovial tissue containing many inflammatory cells including polymorphs, monocytes and macrophages. This was followed by marked proliferation of synovium with dense infiltration of mononuclear cells and destruction of cartilage. Immunohistological studies showed that a large number of CD5+ and alpha beta+ T cells infiltrated in synovial tissues in the chronic phase of joint inflammation. Treatment of rats with a monoclonal antibody against TCR alpha beta significantly suppressed the development of chronic, but not acute arthritis. Thus, T cells may play a role in silicone-induced chronic arthritis.