Longitudinal Kinetics of Cytomegalovirus-Specific T-Cell Immunity and Viral Replication in Infants With Congenital Cytomegalovirus Infection

Background. Congenital cytomegalovirus (CMV) is reported to affect up to 1% of all live births in the United States. T-cell immunity may be important for controlling CMV replication in congenital CMV-infected infants. We describe the natural history of CMV-specific T-cell evolution and CMV replication in infants with congenital CMV infection. Methods. Cytomegalovirus viral load, CMV urine culture, and CMV-specific CD4 and CD8 T-cell responses were assessed in a prospective longitudinal cohort of 51 infants with congenital CMV infection who were observed from birth to 3 years of age. Results. We found a kinetic pattern of decreasing urinary CMV replication and increasing CMV-specific CD4 and CD8 T-cell responses during the first 3 years of life. We also found higher CMV-specific CD8 T-cell responses were associated with subsequent reduction of urine CMV viral load. Conclusion. For infants with congenital CMV infection, our data suggest an age-related maturation of both CMV-specific CD4 and CD8 T-cell immunity that is associated with an age-related decline in urinary CMV replication.