CD4 IFN-γ and IL-10 expression in responders (R) and nonresponders (NR). Peripheral blood samples were collected before each dose of abatacept and 1 month after the administration of 6 doses of abatacept. Peripheral blood mononuclear cells were isolated and CD4 T cells were assessed for intracellular expression of IFN-γ and IL-10 by flow cytometry. (A) Comparing responders with nonresponders, there was no difference in baseline CD4 IFN-γ expression (P = .33). One month after 6 abatacept doses, there was no significant change in CD4 IFN-γ expression in clinical responders (P = .09). (B) When comparing responders vs nonresponders, no difference in baseline CD4 Il-10 expression (P = .14) was observed. One month after 6 doses of abatacept, there was no significant difference in CD4 IL-10 expression (P = .08) in clinical responders.