Methods The investigators will obtain blood samples from 60 RA patients treated with tocilizumab, according to the local clinical guidelines. Blood samples will be collected before treatment, as well as one and four months following tocilizumab treatment. The blood samples will initially undergo microarray analysis and then the results will be confirmed for specific miRNAs by quantitative real-time PCR (qPCR). The serum level of the tested cytokines, like adipokines, will be measured using ELISA methods. The changes in cytokines level and miRNAs expression, either up-regulation or down-regulation, during tocilizumab therapy will be correlated to the severity of the disease and to specific demographic and medical data. The results obtained will be compared to 60 healthy controls gender- and age-matched