SAT0188 Serum Calprotectin (S100A8/9) Correlates with Clinical and Ultrasound Outcomes in Patients with Early Rheumatoid Arthritis

Background Calprotectin, a heterodimeric complex of S100A8/9 (MRP8/14), has been demonstrated as an important biomarker of clinical and laboratory disease activity and structural joint damage in rheumatoid arthritis (RA).1,2 Ultrasound is a sensitive and reliable tool for assessing synovial inflammation in RA.3 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. Methods A total of 37 patients with RA (24 females, median disease duration 18 months) underwent clinical examination (DAS28) and 7-joint ultrasound score (US-7) of clinically dominant wrist, second and third metacarpophalangeal and proximal interphalangeal, and second and fifth metatarsophalangeal joints to assess synovitis and tenosynovitis by gray-scale (GS) and power Doppler (PD) ultrasound using semiquantitative grading 0-3. The levels of serum calprotectin and C-reactive protein were measured at the time of ultrasound assessment. Clinical and laboratory measures were correlated with ultrasound findings. Multiple regression analysis was used to determine the predictive value of calprotectin, CRP and DAS28 to determine PD synovitis. Results We found that DAS28 (r=0.605, p