INTRAFAMILIAL TRANSMISSION OF HTLV-I AND ITS ASSOCIATION WITH ANTI-TAX ANTIBODY IN AN ENDEMIC POPULATION IN JAPAN

To assess the relationship of anti-Tax antibody to human T-cell lympho tropic virus type-1 (HTLV-1) transmission, the sero-prevalence of HTLV -1 was analyzed among married couples and among mother/child (both adu lts) pairs. HTLV-1 seroprevalence was significantly higher among wives with anti-Tax(+) than those with anti-Tax(-)HTLV-1 carrier husbands ( 82.4% vs. 59.5%). However, in the group of wives aged 60 years or olde r, there was no statistical difference in HTLV-1 seropositivity based on the husbands' anti-Tax sere-status. In the group whose wives were l ess than 60 years old, more anti-Tax sero-positive than sero-negative husbands had high DNA levels (57.1% and 20.0%), whereas in the group o f husbands whose wives were aged 60 years or older, the number of anti -Tax aero positive and sere-negative individuals with high DNA levels was similar. HTLV-1 sere-prevalence was significantly higher among the adult men with anti-Tax+ carrier mothers than those with anti-Tax-car rier mothers (52.0% vs. 14.3%). For women, HTLV-1 sero-prevalence did not differ significantly according to their mothers' anti-Tax sero-sta tus. Our results suggest that the presence of anti-Tax antibody in HTL V-1 carriers is an age-dependent risk factor for male-to-female HTLV-1 transmission. Furthermore, the effect of the mother's anti-Tax antibo dy as a risk factor for vertical HTLV-1 transmission could be observed in men even after becoming adults. (C) 1998 Wiley-Liss, Inc.