Relationship between some acute phase reactants and the bath ankylosing spondylitis disease activity index in patients with ankylosing spondylitis

Objectives: The aims of this study were to investigate a possible relationship between the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and some acute phase reactant (APR) levels in patients with ankylosing spondylitis (AS). Methods: Twenty outpatients who fulfilled the modified New York criteria for AS were included in the study. Laboratory activity was assessed by examining erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), haptoglobin (Hp), and beta(2) microglobulin (beta(2)MG). Disease activity was assessed according to the BASDAI, which includes a 10-point visual analogue scale to measure pain, fatigue, morning stiffness, swelling, and areas of local tenderness. Results: When APR values were analyzed for the BASDAI, a positive correlation between CRP and BASDAI was observed (r = 0.556, P < 0.05). There was no clear, statistically significant correlation between BASDAI and the other APRs (ESR, r = 0.328, P > 0.05; Hp, r = 0.035, P > 0.05; and beta(2)MG, r = -0.190, P > 0.05). Conclusions: Our data suggest that CRP is a better marker of disease activity than ESR, Hp, and beta(2)MG.