Lymphocyte proliferative responses to bacterial antigens in B27-associated arthropathies.

Lymphocyte transformation tests to Yersinia enterocolitica 0:3 and 0:6, Klebsiella pneumoniae and Streptococcus faecalis antigens have been carried out in ankylosing spondylitis, reactive arthritis/Reiter's disease and controls. Ankylosing spondylitis cases gave significantly lower responses than reactive arthritis/Reiter's to Yersinia enterocolitica 0:6 (p = 0.003) and Klebsiella pneumoniae (p = 0.008), and less than controls to S. faecalis (p = 0.008). It appears, therefore, that within the B27 arthritis population there is heterogeneity of cell-mediated response to certain enteric bacteria, with the hyporesponders manifesting ankylosing spondylitis and the hyper-responders reactive arthritis/Reiter's disease.