Exposure to cytomegalovirus (CMV) is associated with the CMV/Epstein-Barr virus (EBV) immune-response signature as well as generally altered T-cell immunity. (A) Box plots illustrate the distributions of the CMV/EBV PCA-1 score at baseline in 71 patients with RA, according to CMV and EBV serological status. The horizontal lines represent medians, the boxes represent the 25 to 75 percentiles, and the whiskers represent the 2.5 to 97.5 percentiles, and dots represent outliers. (B) Scatterplots depict the concentrations of selected cytokines (based on PCA weightings >0.5) for the immune-response profiles, according to CMV serological status and stimulus (CMV/EBV, PHA, CPG, and media alone) at baseline in 71 patients with RA. The horizontal bold lines represent the medians; *P <0.05, ***P <0.001. RA, rheumatoid arthritis; DAS28, Disease Activity Score in 28 joints; PCA, principal components analysis; PHA, phytohemagglutinin; CPG, CpG oligonucleotides; IgG, immunoglobulin-G.