Identification of immune-based biomarkers associated with response to abatacept (CTLA4-Ig) in rheumatoid arthritis patients.

RA patients (according to ACR/EULAR 2010 criteria) who started abatacept due to high disease activity (DAS28>5.1), were recruited to perform immunological studies at baseline, 3 and 6 months of therapy. Peripheral blood mononuclear cells (PBMCs) were isolated and immune cell populations were characterized using flow cytometry. Proteomic analysis was performed on baseline sera.