THE PATHOGENESIS OF RHEUMATOID ARTHRITIS AND THE MODE OF ACTION OF VARIOUS DRUGS: AN

IT now appears that rheumatoid arthritis may be successfully treated by drugs said to be immunosuppressive and also by drugs said to be immunostimulant. This apparently bizarre finding would seem to merit some form of hypothesis about the pathogenesis of the disease and the mode of action of drugs. THE DISEASE A dominant feature of rheumatoid synovitis is the relentless persistence of the chronic inflammatory response. Allison and Davies (1974) postulated that the macro-phage plays a key role in chronic inflammation. Chronicity of inflammation may be maintained by persistent migration of monocytes, proliferation of cells at the site of inflammation or persistence of long-lived cells at the site (Ryan and Spector, 1970; Adolph et al., 1975; Wynn et al, 1975). The types of stimulus that could conceivably maintain this process include micro-organisms, particulate matter or antigenic material. The antigen could be foreign, or could result from alteration of normal tissue com-ponents, and could result in a T-cell response with liberation of lymphokines, or a B-cell response with antigen-antibody complex formation, which is known to be able to main