Serum Calprotectin (S100A8/9) Correlates with Clinical and Ultrasound Outcomes in Patients with Early Rheumatoid Arthritis
Abstract
Objectives To test the hypothesis that calprotectin is associated with clinical and ultrasound disease activity in patients with RA in a cross-sectional study and to investigate the contribution of various parameters to predict ultrasound findings. Results We found that DAS28 (r=0.605, p<0.001; r=0.605, p<0.001, resp.) and CRP levels (r=0.451, p=0.006; r=0.463, p=0.004, resp.) correlate significantly with GS and PD synovitis.
In addition, calprotectin correlated significantly with PD synovitis (r=0.497, p<0.005). Furthermore, serum calprotectin significantly correlated with CRP (r=0.629, p<0.001) and DAS28 (r=0.385, p<0.019).
In addition to DAS28 (p=0.001), calprotectin (p<0.001) was a strong predictor of active PD synovitis (adjusted R2=0.811). Conclusions This study confirms tight association between clinical, laboratory and ultrasound assessment and support circulating calprotectin as an important biomarker for monitoring synovial inflammation in RA.