Serological detection of HBeAg and anti-HBe using automated microparticle enzyme immunoassays

Controversies in Treating Chronic Hepatitis B Virus Infection: Discordant Serologic Results

Despite effective vaccines and approved therapeutic agents, hepatitis B virus (HBV) remains a prevalent global health problem. Current guidelines rely on a combination of serologic, virological, and biochemical markers to identify the phase in the natural history of chronic HBV infection. Discordant serologic results can occur, which may lead to misclassification. Commonly encountered results that differ from the typical profiles seen in chronic HBV infection are described. For each scenario, the frequency of occurrence, possible explanations, and recommendations for clinical management are discussed. Recognition of discordant serologic findings is crucial for optimal clinical decision.

Evaluation of newly developed microparticle enzyme immunoassays for the detection of HCV antibodies

The newly developed anti-HCV assays AxSYM HCV version 3.0 and IMx HCV version 3.0 were evaluated with regard to their precision, sensitivity and specificity in comparison to the HCV EIA 3.0 (Abbott GmbH, Wiesbaden, Germany). Precision testing was undertaken using five positive controls with different anti-HCV levels for each assay. Specificity was estimated by testing 4383 blood donor specimens. The supplemental assay Matrix HCV 2.0 (Abbott GmbH, Wiesbaden, Germany) was used to confirm repeatedly reactive results. Samples which had been found to be positive or indeterminate by Matrix HCV 2.0 were tested by qualitative polymerase chain reaction after reverse transcription (RT-PCR, Amplicor HCV test, Roche Diagnostic Systems, Basel, Switzerland). To determine sensitivity, 20 commercially available seroconversion panels were tested. Based on supplemental testing, the apparent specificities of AxSYM HCV version 3.0, IMx HCV version 3.0 and HCV EIA 3.0 were estimated to be 99.84, 99.98 and 99.80%, respectively. In seroconversion panel testing, AxSYM and IMx HCV version 3.0 detected seroconversion in up to 12/20 panels earlier and in up to 1/20 cases later than the comparison EIA. The highest sensitivity was shown in AxSYM HCV version 3.0, followed by IMx HCV version 3.0 and HCV EIA 3.0. Based on the improved seroconversion sensitivity and specificity, the AxSYM and IMx HCV version 3.0 assays appear to be suitable for detecting HCV antibodies in blood donor testing and other routine laboratory assessments.

Quantitative measurement of HBeAg in chronic hepatitis B: a comparison between a radioimmunoassay, a fluorescence ELISA and a chemiluminescence ELISA

The presence of the hepatitis B e antigen (HBeAg) in peripheral blood of chronic hepatitis B patients is a widely accepted marker of active replication of the hepatitis B virus. HBeAg determination during interferon therapy is a useful guide for the therapeutic regimen. The aim of the study was to compare the suitability of an HBeAg radioimmunoassay (RIA, Abbott Laboratories, North Chicago, IL, USA), the IMx-HBeAg assay (IMx, Abbott Laboratories) and the HBeAg/anti-HBe Amerlite assay (Amerlite, Johnson & Johnson Clinical Diagnostics, Cardiff, UK) for semiquantitative monitoring of HBeAg during therapy. HBeAg levels in serum samples obtained before and during interferon therapy were measured using an in-house standard calibrated against the Paul Ehrlich Institute HBeAg reference preparation (PEI standard). When serial dilutions of pretreatment serum samples were assayed by the three methods, radioimmunoassay was found to be highly sensitive although it had a very limited working range (0.5 to 12 PEI U/ml). A broader linear working range was observed for Amerlite (0.5 to 50 PEI U/ml) and the IMx assay (0.5 to 100 PEI U/ml). The intra-assay and interassay variations did not differ significantly. Since the IMx assay was less susceptible to sample variation and had a broad working range, semiquantitative measurement of HBeAg in one diluted and one undiluted sample by this assay may justifiably be introduced as routine procedure. Routine semiquantitative HBeAg measurement may improve individual dose adjustments and thus the success of interferon therapy.

Long-term outcome of hepatitis B virus-related glomerulonephritis after therapy with interferon alfa

BACKGROUND & AIMS

Glomerulonephritis is an uncommon complication of chronic hepatitis B virus (HBV) infection in adults. A high percentage of patients seem to have short-term response to interferon therapy with improvement of proteinuria. The aim of this study was to assess the long-term response of patients with HBV-related glomerulonephritis to interferon alfa therapy.

METHODS

All patients with chronic hepatitis B and glomerulonephritis who were treated with interferon alfa at the National Institutes of Health between 1985 and 1993 were assessed.

RESULTS

Of the 15 patients treated, 8 (53%) had a long-term serological response with sustained loss of serum hepatitis B e antigen and HBV DNA. After 1-7 years of follow-up, all 8 responders have normal serum aminotransferase levels and 5 are hepatitis B surface antigen negative. Seven of the responders also showed a gradual but marked improvement in proteinuria. In contrast, the 7 nonresponders continued to have evidence of active renal disease and 1 required long-term dialysis therapy. All 8 responders had membranous glomerulonephritis, whereas 4 of 7 nonresponders had membranoproliferative glomerulonephritis.

CONCLUSIONS

Interferon alfa therapy resulted in long-term remission in liver disease in 8 of 15 patients with chronic hepatitis B and glomerulonephritis. This response was accompanied by significant improvement in markers of renal disease in the majority of patients.