The relationship between enthesitis indices and disease activity parameters in patients with ankylosing spondylitis

In this study, patients with ankylosing spondylitis (AS) were assessed both by patient and physician using two enthesitis indices and the relationship between these indices and disease activity parameters was investigated. The study involved 100 AS patients. The patients were evaluated with 10-cm visual analog scale (VAS) for spinal pain (VAS-S), peripheral joint pain (VAS-P), global assessment of patient, and global assessment of doctor. In the laboratory evaluations, the erythrocyte sedimentation rates (ESR) and serum C-reactive protein levels of the patients were determined. Bath AS disease activity index (BASDAI), Bath AS functional index (BASFI), Bath AS metrology index, and Bath AS radiology index were calculated. The severity of enthesitis was evaluated according to Mander enthesitis index (MEI) and Maastricht ankylosing spondylitis enthesitis score applied by both the patient (MASES-P) him/herself and the physician (MASES-D). There was a correlation between BASDAI and BASFI as well as MEI, MASES-D, and MASES-P indices (r = 0.447, r = 0.342, r = 0.663, r = 0.530, r = 0.464, and r = 0.435, respectively). No correlation between the laboratory parameters and enthesitis indices were detected. In multiple linear regression analysis, BASFI, VAS-S, and female gender (41.3%) were the best predictors of MEI-D, whereas BASFI, VAS-S, female gender, and ESR (32.5%) were the best predictors for MASES-D and BASFI (18.9%) was the best predictor of MASES-P. The assessment of simple and easily applicable MASES score by a patient may be expected to help the physician in clinical practice. When the disease activity of the patients with AS are evaluated, both BASDAI, the clinical importance of which has been confirmed in numerous studies and which is recommended by ASAS, and BASFI, which is valued by patients, should be considered.