Clinical utility of a simple quantitative determination of hepatitis B e antigen

The titre of serum hepatitis B e antigen (HBeAg) was determined by using a simple quantitative system which is a slight modification of a commercially available enzyme immunoassay, and the relationship of serum HBeAg titre, hepatitis B virus (HBV)-associated DNA polymerase activity and HBV DNA level was evaluated. The HBeAg titre was found to have a significant correlation with DNA polymerase activity (r= 0.8153) and HBV DNA level (r= 0.8001). In 12 acute exacerbations of hepatitis in 10 patients with chronic type B hepatitis, these three parameters were found to be elevated either prior to or concurrent with the elevation of serum alanine aminotransferase, and the HBeAg titre peaked either simultaneously with or 1–4 weeks after the peaks of DNA polymerase activity and HBV DNA level, with average time lags of 1.00 weeks (s.d. = 1.29) and 1.08 weeks (s.d. = 1.25), respectively. Quantified HBeAg can be considered as a serum marker indicative of HBV replication, as is the case with DNA polymerase and HBV DNA. Furthermore, the HBeAg assay has the advantages of simplicity and low cost and it does not require special equipment. Therefore, quantification of HBeAg should be employed widely in clinical practice.