Humoral immune responses and cytomegalovirus excretion in children with asymptomatic infection.
Forty-two seropositive children aged 3 to 5 years attending a kindergarten were followed up for 1 year in order to examine the relationship between humoral immunity and cytomegalovirus (CMV) excretion status. Anti-CMV antibodies were measured at the beginning and end of the study by enzyme-linked immunosorbent assay, neutralizing antibody test, and immunoblot techniques. Among these children, 32 persistently shed virus in urine, 2 intermittently shed CMV, and 4 experienced reactivation during the study. Virus was never isolated from 4 seropositive children. The level of anti-CMV IgG antibody in seropositive children who remained nonshedders was significantly higher than in children who shed virus during follow-up. On immunoblots, all seropositive nonshedders reacted to a CMV-specific 65 kD antigen, whereas most shedders (80%) did not. These findings suggest that humoral immunity plays a role in controlling persistent CMV infection in children with asymptomatic infection. However, the humoral immunity measured by the neutralizing test and the presence of antibodies against CMV-specific envelope antigens (116 kD/55 kD) apparently play a limited role in modifying persistent excretion and regulating reactivation of latent CMV. Immune evasion by CMV to block these antigens may explain these results.
Shen
C Y
CY
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China.
Chang
S F
SF
Yang
S L
SL
Yeh
T S
TS
Huang
E S
ES
Wu
C W
CW
D000914:Antibodies, Viral / Q000097:blood*; D002353:Carrier State / Q000276:immunology / Q000652:urine / Q000821:virology*; D002675:Child, Preschool; D003587:Cytomegalovirus / Q000302:isolation & purification*; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000652:urine / Q000821:virology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D014556:Urine / Q000382:microbiology
D000914:Antibodies, Viral; D007074:Immunoglobulin G