Relation between systemic cytokine profiles and herpesvirus carriage at 5 years of age. Plasma from 5-year-old children (n = 128 for all cytokines except IL-12p70 and IL-18, where 80 and 71 samples were tested, respectively) with various EBV and CMV serostatuses was assessed by ELISA for a range of cytokines related to antiviral and NK cell activity. The levels of IFN-α (A), IFN-γ (B), IL-12p70 (C), IL-15 (D), and IL-18 (E) were compared between CMV− and CMV+ children or after subdivision of CMV− and CMV+ groups with regard to EBV serostatus (F to J, respectively). Values below detection limits are not shown in the figure.