Rheumatoid arthritis - the role of T cells in this complex systemic autoimmune disease.

Rheumatoid arthritis (RA) is a chronic inflammatory disease of the joints that can affect individuals at any age of life. While involvement of the immune system in RA has long been clear, current treatments remain limited to interventions that broadly suppress immune responses with a lack of personalization. This review highlights recent advances in our understanding of immune dysregulation in RA in three settings: (1) before disease onset; (2) in synovial tissue the site of inflammation; and (3) during disease flares after drug withdrawal. These findings provide a detailed view of T cell subsets correlated with the presence or imminent onset of RA, which provides guidance for future investigations to validate new biomarkers that would allow clinicians to diagnose and intercede earlier. It suggests mechanisms that could be leveraged for novel targeted therapeutic approaches and individualized precision treatment wherein clinicians would be able to predict effective treatments for each patient.