Boleto G, et al. - The predictors of hypogammaglobulinemia in rheumatoid arthritis (RA) patients long-term treated with rituximab (RTX) were evaluated by the experts. Findings demonstrated that for developing subsequent hypogammaglobulinemia, gammaglobulin levels of less than 8 g/L at baseline was identified as a strong independent risk factor, whereas concomitant MTX therapy seemed to be a protective factor.