Serum interleukin-6 in seropositive rheumatoid arthritis and response to tocilizumab: An observational study.
OBJECTIVE: There is no clinically useful biomarker as a predictor of response to any class of biological disease-modifying antirheumatic drugs (bDMARD). Serum interleukin-6 (IL-6) has a major role in the pathogenesis of rheumatoid arthritis (RA) and its s.....