Immune response to herpesvirus antigens in adults with acute cytomegaloviral mononucleosis.

The immune response of eight patients with mononucleosis caused by cytomegalovirus (CMV) was measured early in their illness--when virus was present in their urine and/or blood--and subsequently during convalescence. Levels of CMV-specific antibody rose early in the illness, but the proliferative response of mononuclear cells to CMV antigen did not reach the level characteristic of CMV-immune donors until several months later. The production of interferon by mononuclear cells in response to CMV antigen was also low early in the illness. Although these patients had prior immunity to herpes simplex virus and varicella-zoster virus, their mononuclear cells responded poorly to antigens prepared from these viruses. The proliferative response to these antigens returned to normal in parallel with the development of a normal response to CMV. It is suggested that acute CMV mononucleosis suppresses the proliferative response of human mononuclear cells.