Immunoprotein deposition in synovial tissue in Reiter's syndrome

SUMMARY The aetiology of Reiter's syndrome (RS) is unknown. In order to evaluate the role of immunological mechanisms in this disease we performed synovial biopsies on 12 patients with RS looking for deposition of immunoglobulins and complement components in synovial tissue. By immunofluorescent techniques 11 synovia were found to have immunoprotein deposition. IgM deposition was found around vessels in 8 synovia and in the interstitial tissue in 4. C3 was present perivascularly in 11 cases; in 4 of those there was also staining in the interstitial tissue. No immuno-proteins were found in infiltrating or synovial lining cells. The finding of immunoproteins in the synovium of the majority of patients with RS suggests that immunological mechanisms are involved in the pathogenesis of this disease. The aetiology of Reiter's syndrome (RS) is unknown. Its relationship to sexual contact and epidemic dysentery has led investigators to see an infectious aetiology, but efforts to find a causative agent have been largely unsuccessful. Reports by Brewerton et al.] and Morris et al.2 that 75-96 % of RS patients are HLA B27 positive have spurred interest in genetic mechanisms which might play a role in its pathogenesis. A predetermined susceptibility for developing RS is likely. Immunological factors have also received consideration in the pathogenesis of RS. Other reports3 4 support this possibility. In an effort better to understand immunological mechanisms in RS we have performed synovial biopsies on 12 patients with the disease looking for deposition of immunoglobulins and complement components in the involved synovium. Our findings show a consistent pattern of immunoprotein de-position implicating immune phenomena as taking part in the pathogenesis of RS. Materials and methods Twelve patients with RS were seen between Jul