Hepatitis B surface antigen quantification: Why and how to use it in 2011 – A core group report

Abstract

Quantitative HBsAg had been suggested to be helpful in management of HBV, but assays were cumbersome. The recent availability of commercial quantitative assays has restarted the interest in quantitative serum hepatitis B surface antigen (HBsAg) as a biomarker for prognosis and treatment response in chronic hepatitis B. HBsAg level reflects the transcriptional activity of cccDNA rather than the absolute amount of cccDNA copies. Serum HBsAg level tends to be higher in hepatitis B e antigen (HBeAg)-positive than HBeAg-negative patients. Among patients with a low HBV DNA (<2000IU/ml), HBsAg <1000IU/ml in genotype D HBV infection and HBsAg <100IU/ml in genotype B/C HBV infection is associated with inactive carrier state in HBeAg-negative patients. The HBsAg reduction by nucleos(t)ide analogues (NA) is not as pronounced as by interferon treatment. On peginterferon treatment, sustained responders tend to show greater HBsAg decline than the non-responders. The optimal on-treatment HBsAg cutoff to predict response needs further evaluation in HBeAg-positive patients, but an absence of HBsAg decline together with a <2 log reduction in HBV DNA at week 12 can serve as stopping rule in HBeAg-negative patients with genotype D HBV infection. A rapid serum HBsAg decline during NA therapy may identify patients who will clear HBsAg in the long-term. There are early reports among Asian patients that an HBsAg level of <100IU/ml might predict lower risk of relapse after stopping NA treatment. In clinical practice, serum HBsAg level should be used together with, but not as a substitute for, HBV DNA.

Inosine Pranobex (Isoprinosine) – a Potential Adjuvant in the Management of Chronic HBV Infection

“…Both spherical and filamentous forms of HBsAg are secreted at levels far in excess of mature virions. HBsAg may also be produced from HBV DNA integrated into the host genome (38). Current assays target epitopes in the S protein, and are therefore not capable of distinguishing between the different HBsAg proteins, nor can they distinguish between virion-associated HBsAg, subviral particles and HBsAg produced from integrated sequence (38).…”

The importance of the serum quantitative levels of hepatitis B surface antigen and hepatitis B e antigen in children with chronic hepatitis B

“…Pearson correlation analysis of decrease ratios (%) of HBsAg, HBeAg, HBV DNA (log 10 ), and ALT after treatment fact that histopathologic damage, serum HBsAg, HBeAg, HBV DNA, and ALT levels are complex and dynamic processes likely to reflect an interaction between virologic and host immunologic factors, genotypic features, and/or age. Analysis of HBeAg levels have not been included in previous studies (2,8). Thompson et al (7) reported a positive correlation between HBsAg and HBV DNA levels and between HBeAg and HBV DNA levels, but not between ALT and HBsAg levels.…”

“…The importance of HBsAg quantification was recognized earlier, but initial methods were not appropriate as routine tests. Standard assays for quantification of serum HBsAg have been developed for years; however, the clinical relevance of measuring HBsAg levels have recently been questioned (1,2).…”

Management of Chronic Hepatitis B: An Overview of Practice Guidelines for Primary Care Providers

“…With IFN-based antiviral therapy, a rapid reduction in qHBsAg is predictive of a sustained response; thus, an "early stopping rule" has been proposed, suggesting that IFN therapy can be stopped or switched by week 12 in patients without qHBsAg decline because they are unlikely to achieve a response with further IFN treatment. 79 In NUC-based therapy, the clinical relevance of qHBsAg is less well defined. qHBsAg reductions are generally less pronounced with NUCs compared with IFNs, and the data regarding a potential association of qHBsAg with serologic or virologic responses are inconsistent.…”

“…qHBsAg reductions are generally less pronounced with NUCs compared with IFNs, and the data regarding a potential association of qHBsAg with serologic or virologic responses are inconsistent. 79 Thus, more research is needed to understand qHBsAg kinetics during NUC therapy and allow potential tailoring of treatment duration to individual patients.…”