Fig. 1.

Expression of CD69 following activation with phorbol myristate acetate (PMA) and ionomycin in CD4 cells and CD8 cells and their CD28⁻ and CD28⁺ subsets. ‘Pre’ indicates samples taken prior to intravenous immunoglobulin (IVIG) infusion, and ‘post’ indicates samples following IVIG infusion, in common variable immunodeficiency (CVID) patients (○) and X-linked agammaglobulinaemia (XLA) patients (□). Normal donors (•) are shown for comparison, with ‘pre’ samples taken 3 h before ‘post’ samples and left at room temperature prior to simultaneous analysis with ‘post’ samples.