Background Mechanisms regulating the chronic autoimmune response in rheumatoid arthritis (RA) are not well understood. However, activated T CD4+ play a pivotal role initiating and perpetuating the chronic inflammation characteristic for the disease.
Objectives Evaluate the number and distribution of circulating CD4+ T lymphocytes and their CD4+ naïve T cells (TN), central memory (TCM), non-terminated effector memory (TNTEM) and terminated effector memory (TTEM) T cells subsets in a population of recently diagnosed DMARD naive RA patients before and along the first 6 months of methotrexate (MTX) treatment.
Methods The number of circulating CD4+ T lymphocytes, and of their TN, TM, TCM and TEM subsets in fifty untreated patients with RA before MTX treatment and at 3 and 6 months of treatment were assayed using a multiparametric flow cytometry. We also studied twenty-four age- and sex-matched healthy subjects as controls.
Results RA naïve patients show a significant (p<0.05) expansion of the circulating CD4+ TNTEM subset. MTX non responder naïve RA patients show from basal conditions a significative expansion of CD4+ TNTEM lymphocytes and develop significant expansion of CD4+ TCM, and CD4+ TEM lymphocyte subsets along MTX treatment.
Conclusions Recently diagnosed DMARD naive RA patients show involvement of the circulating CD4+ T lymphocytes activation/differentiation stage subsets. MTX treatment show immunomodulatory effects on CD4+ T lymphocyte compartment with different behavior in responder and non-responder patients.
Disclosure of Interest None declared