Einarsson JT, et al. - This study was conducted to investigate the effect of 2 different initial doses and cumulative 2-year dose of rituximab (RTX) on drug adherence and predictors of adherence to treatment in rheumatoid arthritis (RA) patients in an observational clinical setting. Moreover, the authors examined the immunoglobulin levels (IgG/IgM/IgA) during repeated treatment and their relation to infections and development of anti-rituximab antibodies (ADA). In RA patient, long-term adherence to RTX was not influenced by starting- or cumulative 2-year doses. At baseline, MTX use and low DAS28 was positively correlated with drug adherence. During treatment, decreasing Ig levels were not associated with risk of infections. Development of ADA could influence treatment efficacy and tolerability.