Objective: To study the clinical presentation, immunogenetics, and serum immune response to lipopolysaccharide (LPS) in a cohort of patients with post-Salmonella reactive arthritis (ReA).
Methods: A validate ReA screening questionnaire (Quest 2) was mailed to 919 individuals reporting symptoms of gastroenteritis to the health department after eating at a single restaurant. Three hundred twenty-one persons returned questionnaires; 170 reported symptoms outside the gastrointestinal tract; 23 of those 170 reporting persistent joint symptoms were seen 4 to 16 weeks after the outbreak and 5 of the 23 were seen in followup 12 to 20 weeks later. Clinical features, HLA Class I typing, serum soluble CD8 levels, and serum antibodies to gram negative LPS by ELISA were determined.
Results: Joint complaints were reported more frequently by individuals with a longer duration of diarrhea. Upper extremity joints were frequently involved, and 66% reported one or more extraarticular symptoms of Reiter's syndrome. Three of 5 typed individuals were HLA-B27 positive, including 3 of the 4 most severely involved. Serum soluble CD8 levels correlated poorly with disease activity measured either clinically or by C-reactive protein. Antibodies to Klebsiella and Shigella LPS rose over time, while antibodies to Salmonella LPS fell.
Conclusion: The clinical picture of post-Salmonella ReA is less stereotyped than often assumed, although severity correlated with HLA-B27 status. The association of joint symptoms with duration of diarrhea and the kinetics of the anti-LPS antibody response support the hypothesis that abnormal gut permeability plays a role in the pathogenesis of post-Salmonella ReA.