Prevalence of IgM anti-HBc among HBsAg carriers in Okinawa, Japan.

To evaluate the presence of IgM antibody to hepatitis B core antigen (IgM anti-HBc) in hepatitis B surface antigen (HBsAg) carriers, serial serum specimens of 698 carriers in Okinawa, Japan, from infants to adults, were studied by radioimmunoassay. IgM anti-HBc was detected in 7.6% of these carriers, with no difference between the sexes. The prevalence of IgM anti-HBc was higher in the age groups 0-9, 50-59 and over 60 than in the age group 20-29 and 30-39 years. In hepatitis B e antigen (HBeAg) positive carriers, the prevalence of IgM anti-HBc was 15.4%, a value significantly higher than in the HBeAg-negative carriers at 6.6%. In carriers with liver damage, the prevalence of IgM anti-HBc was 33.3%, a level significantly higher than the 6.3% in carriers without liver damage. However, IgM anti-HBc was detected in 34 carriers with neither HBeAg nor liver damage. These carriers are being closely followed. We discussed the presence of IgM anti-HBc in association with HBeAg or liver damage. The presence of IgM anti-HBc among HBsAg carriers was closely associated with liver damage.