Objective: To investigate the intestinal immune system in patients with ankylosing spondylitis (AS) and the influence of sulfasalazine treatment.
Methods: Total IgA, secretory IgA and IgM and secretory component were determined in jejunal perfusion fluid in 19 patients with AS before and after 3 months' treatment with sulfasalazine and compared with 18 healthy control subjects. Serum immunoglobulins and inflammatory activity were measured with standard methods and compared with a clinical scoring of disease activity.
Results: Total IgA, secretory IgA, IgM and secretory component were significantly increased in the lavage fluid when compared with healthy controls. Treatment with sulfasalazine normalized these alterations.
Conclusion: Our findings demonstrate that the intestinal immune system is activated in AS and that such activation can be influenced by treatment. This observation supports the idea that antigenic stimulation in the gut is a possible causative event in AS.