Precore stop codon mutant in chronic hepatitis B virus infection in children: its relation to hepatitis B e seroconversion and maternal hepatitis B surface antigen.
OBJECTIVE
The aims of this study were to investigate the significance of the precore stop codon mutant in the natural course of hepatitis B virus infection in children, and the influence of maternal transmission.


METHODS
Sequential sera from 80 hepatitis B virus carrier children both before and after e seroconversion during long-term follow-up were studied using the polymerase chain reaction-amplification created restriction site method. Direct sequencing of the precore region was performed in 89 sera from 32 of the 80 children.


RESULTS
The precore stop codon mutant coexisting with wild strain was found in 10% of children initially, and later in 25% of children before e seroconversion. After e seroconversion, wild type was still present in 75% and mutant in 39% of children at the end of follow-up. The mutant alone was present in 15% of anti-HBe positive children without concomitant aminotransferase elevation. Children with earlier emergence of this mutant tended to have higher peak aminotransferase levels. This mutant emerged less frequently in children of hepatitis B virus carrier mothers (37.5%) than in those of non-carrier mothers (65%) (p<0.05).


CONCLUSIONS
These observations suggest that this mutant is selected by host immune pressure, but is not an initiator in the loss of immune tolerance during childhood chronic hepatitis B virus infection.
Department of Pediatrics, College of Medicine, National Taiwan University, Taipei. mhchang@ha.mc.ntu.edu.tw
M H
MH
Chang
H Y
HY
Hsu
Y H
YH
Ni
K S
KS
Tsai
P I
PI
Lee
P J
PJ
Chen
Y L
YL
Hsu
D S
DS
Chen
D000293:Adolescent; D002353:Carrier State / Q000821:virology; D002648:Child; D002675:Child, Preschool; D018388:Codon, Terminator / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006514:Hepatitis B Surface Antigens / Q000097:blood* / Q000235:genetics*; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology*; D015183:Restriction Mapping
D018388:Codon, Terminator; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens