ANALYSIS OF THE HYPERVARIABLE REGION OF HEPATITIS-C VIRUS E2 NS1 GENEIN AN INFANT INFECTED BY BLOOD-TRANSFUSION/

We investigated the sequential change in the hypervariable region 1 (H VR1) of hepatitis C virus (HCV) E2/NS1 gene in an infant. He was trans fused with 160 mt of blood containing the HCV (0.7 Meq/mL) on the 6th d after birth and subsequently developed chronic viremia. At 16 mo, th e HVR1 amino acid sequences of HCV observed in the infant's sera were very similar to those from the donor (his maternal grandfather) on the day of transfusion. However, highly variable amino acid sequences of HVR1 were observed throughout infancy. These results demonstrate that an adaptive response of HCV to evade host immunity seems to occur, as in adult cases, even in early infancy when the ability to produce humo ral immunoglobulin is thought to be low.