HBSAG SUBTYPES AMONG HBSAG-CARRIERS IN OKINAWA, JAPAN - EVIDENCE OF AN IMPORTANT RELATIONSHIP IN SEROCONVERSION FROM HBEAG TO ANTI-HBE

In Okinawa, Japan 1261 hepatitis B surface antigen (HBsAg) carriers were investigated for clinical differences among HBsAg subtypes. Among the 854 for whom they could be determined, subtype adw was found in 604 (70·7 %), adr in 232 (27·2 %) and others in 18 (2·1 %). The overall prevalence of hepatitis B e antigen (HBeAg) was significantly lower in subtype adw (11·9 %) than in adr (17·7 %) (P < 0·01). The mean age of HBeAg-positive carriers was significantly lower in adw (20·4 years) than in adr (26·9 years) (P < 0·05). Seroconversion from HBeAg to antibody to HBeAg (anti-HBe) occurred in 43 carriers. The seroconversion rate was higher in adw (43·1 %) than in adr (29·3 %) and the seroconversion age was younger in adw (22·7 years) than in adr (27·9 years). These results suggest that carriers with subtype adw tend to seroconvert from HBeAg to anti-HBe at a higher rate and a younger age than do those with adr. HBsAg subtypes may be closely associated with the HBeAg/anti-HBe status. © 1994 The British Society for the Study of Infection.