The relationship of serum calprotectin with disease activity, functional status, ultrasonographic findings and radiological damage in rheumatoid arthritis patients

Abstract

Aim of the workTo measure the levels of serum calprotectin (CLP) in rheumatoid arthritis (RA) patients and to assess its association with disease activity, functional status, ultrasonographic findings, and radiological damage. Patients and methodsThis study included 47 RA patients and 33 controls. The erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), C-reactive protein (CRP), disease activity score (DAS28), health assessment questionnaire (HAQ), modified Larsen radiological score, musculoskeletal ultrasound and serum CLP levels were assessed. ResultsThe mean age of the patients was 42.5 ± 12.8 years; 34 females and 13 males (F:M 2.6:1) with a mean disease duration of 2.6 ± 1.1 years. RF was positive in 72%. CLP level was significantly increased in patients compared to control (2.78 ± 0.89 μg/ml vs. 0.84 ± 0.5 μg/ml; p < 0.001) and in those with activity (3.27 ± 0.75 μg/ml) compared to those in remission (1.92 ± 0.15 μg/ml). A significant correlation was detected between CLP and DAS28, ESR, CRP, HAQ, and modified Larsen scores (p < 0.001). On regression, tender and swollen joint counts, ESR, CRP, HAQ, modified Larsen, ultrasound 7 score and CLP level were significant predictors of activity but were insignificant on multivariate analysis. At a cut-off value of 2.35 μg /ml CLP can significantly differentiate active RA patients from those in remission (AUC 0.95; p < 0.001) at a sensitivity of 90%, specificity of 100%, and accuracy of 95%. ConclusionThe serum CLP levels were significantly high in RA patients and these high levels were associated with disease activity, functional status, ultrasonographic findings, and radiological damage.