Enumeration of CMV-specific CD4⁺ and CD8⁺ T cells in primary CMV infection.

Shown are the frequencies of CMV-specific CD4⁺ T cells, determined by intracellular staining for CD69 and IFN-γ on stimulation (○), CMV-specific CD8⁺ T cells, enumerated by tetramer binding (●), and first specific antibody appearance (dotted vertical line) in relation to viral load (CMV DNA, ▴) in one representative asymptomatic patient (patient 4, panel A) and one symptomatic patient (patient 8, panel B, closed vertical line, start of 14 days of ganciclovir therapy).