Immune complexes in ankylosing spondylitis and controls.

Slight elevations in circulating immune complexes (CIC) were found in 10 ankylosing spondylitis patients when compared to healthy subjects, whilst higher levels of CIC and other complement products were found in patients with Reiter's syndrome and reactive arthritis. It is suggested that complement studies should be carried out at different stages of the disease; firstly during episodes of infection and secondly during the stage of chronic inflammatory disease.