Impaired cell-mediated immunity to cytomegalovirus (CMV) in leukemic children with prolonged CMV viruria

To determine the role of cell-mediated immunity (CMI) to cytomegalovirus (CMV) in leukemic children after CMV infection, CMI to CMV antigen was studied using CMV-specific lymphocyte blastogenic responses (LBR) and interferon (IFN) production. Four children, who continuously secreted CMV in urine more than 2 years after symptomatic CMV infection (CMV disease) (group 1), showed impaired LBR to CMV antigen, though they had normal LBR to phytohemagglutinin (PHA) and concanavalin A (Con A). Impairment of LBR either to AD-169 strains or autologous and heterologus wild strains was observed. IFN production was not detected in three of four children. Six leukemic children, who had no viruria after cessation of CMV disease (group 2), showed good responses to CMV antigens. IFN was detected in all six children in group 2. Eight leukemic children, who were seropositive to CMV and the onset of leukemia (group 3), showed good responses to CMV antigens and IFN production. These results suggest that impaired cell-mediated immunity to CMV antigen might contribute to prolonged excretion of CMV in urine in leukemic children.