MONITORING OF ANTIVIRAL THERAPY WITH QUANTITATIVE-EVALUATION OF HBEAG- A COMPARISON WITH HBV DNA TESTING

The serological endpoint of response in the treatment of chronic hepat itis B is the loss of hepatitis B virus DNA and HBeAg. Because the qua ntitative measurement of hepatitis B virus DNA in serum has been shown to be useful for monitoring and predicting response to interferon-alp ha therapy, we decided to evaluate whether changes in HBeAg concentrat ion could also be used in this manner. Twenty-nine patients who were i nitially positive for HBeAg and HBV DNA were serially evaluated for HB eAg concentration with a microparticle-capture enzyme immunoassay. HBe Ag levels in serum were calculated by means of comparison with a stand ard curve of fluorescence rate vs. HBeAg concentration. The results, e xpressed in milliunits per milliliter, were compared with hepatitis B virus DNA levels determined by means of solution hybridization. The ba seline HBeAg concentration proved to be the best independent predictor of response on stepwise Cox regression analysis (p = 0.026). Similar disappearance curves were observed for the two markers, although hepat itis B virus DNA became undetectable at an earlier interval in 13 of 1 6 cases (81%). In the 16 responders, a decline in HBeAg concentration of more than 90% was observed by wk 12 of therapy (mean +/- S.D., 95% +/- 13%). Nonresponders did not demonstrate such steep declines in HBe Ag values by wk 12 (mean +/- S.D., 45% +/- 27%), and levels tended to increase at subsequent time points. We conclude that serial monitoring of HBeAg concentration with a technique that should be readily adapta ble to clinical laboratories may be useful in the initial evaluation a nd monitoring of patients undergoing antiviral therapy.