Slauenwhite D, McAlpine SM, Hanly JG, et al. - The intent of this study was to evaluate whether baseline immune phenotypes differ between subsequent MTX-responders and non-responders is unknown. The comprehensive T cell immune phenotyping was used to distinguish specific immunologic pathways correlated with methotrexate (MTX)-non-responsive joint inflammation. Thirty-two individuals with recent-onset rheumatoid arthritis (RA) were treated with MTX therapy. Fifteen individuals were classified as responders and 17 as non-responders after 6 months. Researchers conducted a comprehensive blood T cell immunophenotyping using multi-parameter immunofluorescent flow cytometry at baseline and following 6 months of treatment. The data indicated that MTX-non-responsive RA patients show a bias towards type 2-polarized T cell inflammatory responses. In MTX-resistant RA individuals, targeting the IL-13+CD4+ T cell pathway could be a new strategy.