Long-term sequential changes of antibody to p40tax in HTLV-I carrier mothers and children

Antibody to p40tax (anti-p40tax) in serum specimens obtained sequentially from a human T cell lymphotropic virus type I carrier population of mothers and children were assayed. The prevalences of anti-p40tax at the initial sampling were 88% (7/8) in children and 55% (16/29) in mothers. Two of the seven positive children lost their anti-p40tax during the investigation period, resulting in a final prevalence of 63% (5/8) in children. However, anti-p40tax status was constant in all the 22 mothers with multiple serum samples (15 remained positive and seven remained negative). A decline in the absorbance value of EIA for anti-p40tax was observed in seven of the 15 anti-p40tax positive mothers. This decline may result in the disappearance of anti-p40tax in some of them.