Abstract
To assess quantitative serology in chronic hepatitis B virus (HBV) infection, testing by novel immunoassays has been carried out on 202 specimens from untreated patients and in 83 samples from 10 patients with chronic hepatitis B treated with lamivudine. Serum samples were assayed for quantitative HBsAg, in comparison with quantitative HBV‐DNA, and for anti‐HBc IgM and the avidity index (AI) of total anti‐HBc antibodies. The AI was high (mean: 0.93 ± 0.19) in all groups, confirming the consistency of this procedure in chronic HBV infections. A low‐level positivity (2–28 Paul‐Ehrlich units/ml) for IgM anti‐HBc was detectable both in HBeAg‐positive and in HBeAg‐negative untreated chronic hepatitis cases (mean S/CO values by the Abbott Architect assay: 0.51 ± 0.12 and 0.48 ± 0.10, respectively; correlation between assays: r = 0.685), while treated patients (mean: 0.20 ± 0.15) and inactive carriers (mean: 0.17 ± 0.21), were generally negative for IgM. The levels of HBsAg (IU/ml) showed a weak correlation with HBV‐DNA (IU/ml). A difference in HBsAg levels was found between inactive carriers (1,935 ± 2,887 IU/ml) and chronic hepatitis B cases, either treated (5,199 ± 9,259 IU/ml) or untreated (14,596 ± 15,227 IU/ml). Pre‐treatment levels of HBsAg in patients undergoing lamivudine treatment were correlated with a sustained response to therapy over 13–33 months (mean: 27.3) of follow‐up: mean HBsAg values were 1,576 + 1,487 IU/ml in five responders and 6,063 + 5,142 in five nonresponders or breakthrough responders (P < 0.05). The availability of standardized quantitative immunoassays for HBsAg and anti‐HBc IgM may be considered in addition to quantitative HBV‐DNA in the staging and monitoring of chronic HBV infection. J. Med. Virol. 80:974–979, 2008. © 2008 Wiley‐Liss, Inc.