Performance evaluation of the ADVIA Centaur anti-HBe and HBeAg assays.
ABSTRACT Detection of HBeAg and anti-HBe is valuable for the evaluation and therapeutic management of hepatitis B infection.
To determine the clinical performance of the newly CE-approved(a) HBeAg and anti-HBe assays on the fully automated, random access ADVIA Centaur immunoassay system.
Patient samples collected at two sites were used to compare the ADVIA Centaur assays to Abbott AxSYM assays. Consensus of discordant results was reached using Roche Elecsys assays. Additionally, two well-characterized seroconversion panels were evaluated.
The ADVIA Centaur HBeAg assay sensitivity was 100% and specificity was 99.5%. The ADVIA Centaur anti-HBe assay sensitivity was 100% and the resolved specificity was 98.2%. Fewer samples required retesting with the ADVIA Centaur assays than with the AxSYM. In two well-characterized seroconversion panels, the ADVIA Centaur anti-HBe assay detected anti-HBe 20-25 days earlier than the AxSYM assay; the ADVIA Centaur and AxSYM HBeAg assays detected HBe reactivity on the same day.
The ADVIA Centaur HBeAg and anti-HBe assays demonstrated good sensitivity and specificity, and thus are suitable for clinical use. Their novel algorithms require reduced retesting, suggesting these assays may be more cost effective.
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ABSTRACT: Due to the lack of proof reading activity of hepatitis B virus (HBV) polymerase, mutation/variation of the viral sequence is frequently found during long term follow-ups. In the majority of children with chronic HBV infection, wild type HBV is the dominant viral strain during the natural course of chronic HBV infection. During long-term follow-up, HBV precore mutants developed spontaneously in approximately 10 to 24% of children before HBeAg seroconversion, and in around 50% of children after HBeAg seroconversion mutants. Occasionally, children may be infected primarily by mutant strains of HBV. Approximately 36% of children with fulminant hepatitis and 30% of children with acute hepatitis B were infected by precore mutants of HBV transmitted by their mothers or blood donors. In addition, after universal HBV vaccination, HBV surface gene variants emerge or are selected under the immune pressure generated by the host or by administration of hepatitis B immune globulin and hepatitis B vaccination. In HBV DNA positive children from four sequential surveys in Taiwan, the prevalence of hepatitis B surface gene a determinant mutants increased from 7.8% before the vaccination program, to 19.6%, 28.1%, and 23.1% at 5, 10, and 15 years after the program. Nucleoside analogue may also induce mutant strains, which reduces the antiviral effects. The most common example is the YMDD mutation of the HBV polymerase gene after antiviral therapy with lamivudine. It developed in 19% of the treated children. In conclusion, children may be infected primarily by mutant strains of HBV either naturally during acute HBV infection. Those infected with wild type HBV initially may develop mutant strains gradually during the course of chronic infection under the host immune pressure. Vaccine escape mutants may develop after immunoprophylaxis. In addition, antiviral therapy with nucleoside anlogues may also induce drug resistant mutant strains. Understanding the viral mutation status will help to design accurate strategies of immunoprophylaxis and antiviral therapy against HBV infection.The Indian Journal of Pediatrics 08/2006; 73(9):803-807. · 0.72 Impact Factor
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ABSTRACT: Chronic hepatitis B (CHB) is one of the leading causes of morbidity and mortality worldwide. Although various drugs are available for the treatment of CHB, emergence of the hepatitis B e antigen (HBeAg)-negative mutant variant, specifically in Asia, the Middle East and southern Europe, is creating a new challenge as this variant is less responsive to available treatments. HBeAg-negative CHB rapidly progresses to cirrhosis and its related complications. This review discusses the available literature on the approved and under-trial treatment options and their respective efficacies for HBeAg-negative CHB.Postgraduate medical journal 02/2007; 83(975):32-9. · 1.38 Impact Factor
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ABSTRACT: Human hepatitis B virus (HBV) can cause acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HBV e antigen (HBeAg), a secreted protein and not required for viral replication, is thought to play an immunoregulatory role during viral infection. However, the functional involvement of HBeAg in host immune response has not been fully elucidated. We report in this study that HBeAg can bind to interleukin-1 receptor accessory protein (IL-1RAcP). Interleukin-1 (IL-1) plays an important role in inflammation and regulation of immune response, and membrane form of IL-1RAcP (mIL-1RAcP) is an essential component of trimeric IL-1/IL-1 receptor/mIL-1RAcP complex. We show that glutathione S-transferase- or polyhistidine-tagged recombinant HBeAg can interact with endogenous mIL-1RAcP in vitro. Purified (His)6-HBeAg added in the culture medium can interact with overexpressed FLAG-tagged mIL-1RAcP in vivo. Indirect immunofluorescence and confocal microscopy show that HBeAg colocalizes with mIL-1RAcP on the cell surface. Furthermore, HBeAg is able to induce the interaction of IL-1 receptor I (IL-1RI) with mIL-1RAcP and trigger the recruitment of adaptor protein myeloid differentiation factor 88 (MyD88) to the IL-1RI/mIL-1RAcP complex. Assembly and activation of IL-1RI/mIL-1RAcP signaling complex by HBeAg can activate downstream NF-kappaB pathway through IkappaB degradation, induce NF-kappaB-dependent luciferase expression, and induce the expression of IL-1-responsive genes. Silencing of IL-1RAcP by small interfering RNA dramatically abolishes HBeAg-mediated NF-kappaB activation. These results demonstrate that HBeAg can trigger host IL-1 response by binding to mIL-1RAcP. The interaction of HBeAg with mIL-1RAcP may play an important role in modulating host immune response in acute and chronic HBV infection.Journal of Biological Chemistry 12/2006; 281(45):34525-36. · 4.65 Impact Factor