CD28 and rheumatoid arthritis: For instance, after specific HCMVpp65 long-term stimulation, increased anti-HCMV IgG antibodies and intracellular IFN-γ-producing HCMVpp65-specific CD28-CD8+ T-cells were observed in RA and juvenile arthritis (JIA) patients vs. healthy controls (HCs), indicating a possible enhancement of the inflammatory response following endogenous HCMV reactivation [99].