Lack of correlation between clinical disease activity and erythrocyte sedimentation rate, acute phase proteins or protease inhibitors in ankylosing spondylitis.

Disease activity was assessed clinically and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), orosomucoid, alpha 1-antitrypsin (alpha 1AT) and alpha 2-macroglobulin (alpha 2M) were measured in 65 patients with ankylosing spondylitis (AS). Positive correlations were found between ESR and the acute phase proteins (APP), CRP, orosomucoid and alpha 1AT, but none of these variables correlated with the clinical assessment of activity. No relationship was demonstrated between the protease inhibitor, alpha 2M and clinical activity, ESR or any of the APP. While the treatment of AS remains predominantly symptomatic, routine management of patients should continue to be founded on the clinical assessment of disease activity rather than on laboratory indices of inflammation.