Diminished mixed lymphocyte response in ankylosing spondylitis.

A diminished mixed lymphocyte response was reported by Nikbin et al. (1976) among patients with ankylosing spondylitis, their asymptomatic relatives and also normal controls carrying the B27 antigen. In the present communication, the responses in 48 ankylosing spondylitis patients and 45 controls were examined in mixed lymphocyte cultures tested against a 'standard stimulator' made up of pooled lymphocytes. A significantly diminished response is confirmed among the ankylosing spondylitis patients, but not in the control group carrying the B27 antigen. The diminished mixed lymphocyte response therefore appears to be more directly associated with the disease than with the B27 antigen, and possibly represents a specific T-cell defect associated with the pathogenesis of the disease.