Sequential study of bacterial antibody levels and faecal flora in rheumatoid arthritis patients taking sulphasalazine

Faecal and serum samples were collected from 31 patients with active RA during treatment with DMARD sulphasalazine (SASP). These were examined for changes in faecal flora and antibodies to bacterial antigens respectively. Faecal counts of Clostridium perfrigens but not Escherichia coli or total aerobic or anaerobic counts fell significantly after 2 weeks of treatment, this decrease being maintained throughout the treatment period. There was, however, no relationship between changes in the faecal carriage of this micro-organism and response to drug treatment, as assessed using clinical and biochemical indicators of disease activity. Changes in antibody levels to antigen preparations of this organism were also unrelated to response to drug treatment. These results suggest that the anti-rheumatic properties of SASP are independent of its antibacterial effect on bacteria in the bowel and also that neither faecal carriage of, nor antibody responses to this bacterium are involved in disease pathogenesis. Antibody levels to an antigen preparation of Cl. perfringens were found to be significantly lower in those patients who respond well to SASP than those patients who show poor response; this may prove useful as a clinical marker for predicting those patients likely to respond to SASP therapy.