[Studies on factor affecting mother-to-child HTLV-I transmission].
Epidemiological data indicate that breast feeding is the primary route of mother-to-child transmission of HTLV-I. However, serological studies show that 60 to 90% of infants who are fed breast milk from HTLV-I carriers avoid HTLV-I infection. To understand the mechanism of the virus transmission, the titer of HTLV-I antibodies and p40tax antibody and the copy number of the HTLV-I proviral DNA in peripheral lymphocytes in the HTLV-I carrier-mothers were surveyed. The seroprevalence of HTLV-I in the children born to carrier mothers was 6.1% in a normal breast feeding group, 7.7% in a group fed with freeze-thawed breast milk and none in a bottle-fed group. The difference between the seroconversion rate for the normal breast feeding group and others was statistically insignificant. Our studies also indicated that neither the titer of HTLV-I antibodies in carriers nor the duration of breast feeding was relevant to seroconversion in the children. The seroconversion rate in children was higher in p40tax antibody-positive mothers than in a seronegative group, but the difference was statistically insignificant. In conclusion, the copy number of the HTLV-I provirus in the lymphocytes of the carrier mothers was the most relevant factor in the seroconversion of infants who received breast milk from HTLV-I carriers.
Maehama
T
T
Department of Obstetrics and Gynecology, Faculty of Medicine, University of the Ryukyus, Okinawa.
Nakayama
M
M
Nagamine
M
M
Nakashima
Y
Y
Takei
H
H
Nakachi
H
H
D001483:Base Sequence; D001942:Breast Feeding; D002353:Carrier State / Q000635:transmission*; D005260:Female; D016356:Gene Products, tax / Q000235:genetics; D015481:HTLV-I Antibodies / Q000032:analysis* / Q000235:genetics; D015490:HTLV-I Infections / Q000635:transmission*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious
D016356:Gene Products, tax; D015481:HTLV-I Antibodies