Inhibitory effect of maternal antibody on mother-to-child transmission of human T-lymphotropic virus type I. The Mother-to-Child Transmission Study Group.
In order to evaluate the protective role of the maternal antibody against mother-to-child transmission of HTLV-I, we followed a total of 780 children born to HTLV-I carrier mothers by investigating the level of anti-HTLV-I antibody transferred in utero, decline of the maternal antibody and seroconversion in post-natal life. The anti-HTLV-I antibody was positively detected within the first 3-6 months of life and declined at 6-12 months after birth in all children. After the maternal antibody declined, seroconversion occurred in some of the children following either breast feeding or bottle feeding. The seroconversion rates of short-term (less than or equal to 6 months) and long-term (greater than or equal to 7 months) breast feeders were 4.4% (4/90 cases) and 14.4% (20/139 cases), and the rate of bottle feeders was 5.7% (9/158 cases). Long-term breast feeding yielded more seroconverters than short-term breast feeding; 14.4% (20/139 cases) vs. 4.4% (4/90 cases), RR = 3.68, p = 0.018. The seroconversion rate of short-term breast feeders was nearly equal to that of bottle feeders; 4.4% (4/90 cases) vs. 5.7% (9/158 cases), RR = 0.770, p = 0.471. When neonatal lymphocytes were cultured with breast milk cells of HTLV-I carrier mothers, the in vitro infection of HTLV-I was inhibited by the addition of HTLV-I-seropositive cord-blood plasma. Our results suggest that the maternal antibody may inhibit HTLV-I infection by short-term breast feeding but not by long-term breast feeding after decline of the maternal antibody.
Department of Virology, Faculty of Medicine, Kagoshima University, Japan.
K
K
Takahashi
T
T
Takezaki
T
T
Oki
K
K
Kawakami
S
S
Yashiki
T
T
Fujiyoshi
K
K
Usuku
N
N
Mueller
M
M
Osame
K
K
Miyata
D000293:Adolescent; D000328:Adult; D002353:Carrier State / Q000276:immunology*; D002648:Child; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D015481:HTLV-I Antibodies / Q000097:blood / Q000276:immunology*; D015490:HTLV-I Infections / Q000276:immunology / Q000635:transmission*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D011446:Prospective Studies; D012189:Retrospective Studies
D015481:HTLV-I Antibodies