The relationship between disease activity, immunoglobulins and lymphocyte sub-populations in ankylosing spondylitis.

Fifteen patients with active ankylosing spondylitis (ESR greater than 30 mm/h and persistent well-defined symptomatology) and 15 patients with inactive ankylosing spondylitis were studied to investigate the effect of disease activity on T and B cell numbers, plasma viscosity (PV), C reactive protein (CRP) and immunoglobulins. The ability of patients' sera to inhibit normal T cell rosette formation was also assessed. We were able to confirm the close correlation of CRP and PV with clinical disease activity, but were unable to confirm the previously reported T lymphopoenia in ankylosing spondylitis in either of our disease groups. There was no evidence of a serum factor capable of inhibiting T cell rosette formation. B cell numbers, IgG and IgA levels were significantly higher in the active disease group, reflecting increased activity in the humoral immune system during active phases of ankylosing spondylitis.