[Quantification of hepatitis B virus HBsAg: clinical implications]

A Systematic Review of T Cell Epitopes Defined from the Proteome of Hepatitis B Virus

Hepatitis B virus (HBV) infection remains a worldwide health problem and no eradicative therapy is currently available. Host T cell immune responses have crucial influences on the outcome of HBV infection, however the development of therapeutic vaccines, T cell therapies and the clinical evaluation of HBV-specific T cell responses are hampered markedly by the lack of validated T cell epitopes. This review presented a map of T cell epitopes functionally validated from HBV antigens during the past 33 years; the human leukocyte antigen (HLA) supertypes to present these epitopes, and the methods to screen and identify T cell epitopes. To the best of our knowledge, a total of 205 CD8⁺ T cell epitopes and 79 CD4⁺ T cell epitopes have been defined from HBV antigens by cellular functional experiments thus far, but most are restricted to several common HLA supertypes, such as HLA-A0201, A2402, B0702, DR04, and DR12 molecules. Therefore, the currently defined T cell epitope repertoire cannot cover the major populations with HLA diversity in an indicated geographic region. More researches are needed to dissect a more comprehensive map of T cell epitopes, which covers overall HBV proteome and global patients.

Nationwide large survey on hepatitis B surface antigen quantification use in real-life clinical practice

BACKGROUND AND AIM

Hepatitis B surface antigen quantification (qHBsAg) is a relevant biomarker assay in the therapeutic management of hepatitis B virus-infected patients; however, little is known about its use in France. The aim of this study was to describe the knowledge of qHBsAg use and the indications for the prescription of qHBsAg in France.

METHODS

From March 2014 to May 2014, 135 questionnaires were sent to hepatologists and gastroenterologists from several health centers (private practice, public practice, and outlying health centers). There were 20 items in each questionnaire on the use of qHBsAg.

RESULTS

Seventy-six percent of the practitioners had previously used qHBsAg, among whom 88% had prescribed the use of qHBsAg before treatment, 73% had prescribed the use of qHBsAg in combination with hepatitis B virus viral load, 64% had prescribed the use of qHBsAg at week 12 or week 24 of treatment, 62% had prescribed the use of qHBsAg for stopping rules, and 49% had prescribed the use of qHBsAg to identify inactive carriers. The reason for nonprescription of qHBsAg was mainly because of difficulty accessing the test (50% of the practitioners), followed by nonreimbursement of the test (27%); 97% of the practitioners who did not prescribe qHBsAg indicated an interest in accessing the test.

CONCLUSION

This survey describes the characteristics of the prescription of qHBsAg in France. More than three out of four practitioners have previously used qHBsAg. The use of the qHBsAg just before treatment was the main reason for prescription. The main reason for nonprescription was because of difficulty in accessing the test.

[Is it possible to stop treatment with nucleos(t)ide analogs in patients with e-antigen negative chronic hepatitis B? Experience and new expectations]

BACKGROUND

Treatment of HBeAg-negative chronic hepatitis B (CHB) with nucleos(t)ide analogues (NA) is usually indefinite, since the loss of HBsAg, as a criterion for its discontinuation, is a rare event. Recent evidence suggests that discontinuing NA therapy may be feasible in selected patients.

OBJECTIVES

To analyze the rate of virological relapse in patients with HBeAg-negative CHB who discontinued treatment with NAs.

METHODS

We performed a single-center observational study that included 140 patients with HBsAg-negative CHB. Twenty-two patients, who received only NAs, discontinued treatment for different reasons and were subsequently monitored. All had normal ALT and AST, undetectable DNA and absence of cirrhosis or significant comorbidities before stopping treatment.

RESULTS

Twelve patients showed virologic relapse (54.54%). The mean interval between discontinuation and relapse was 6.38 months (± 1.9) (75% relapsed during the first 12 months after discontinuation). Five received adefovir, 1 lamivudine and adefovir, 1 tenofovir and 5 lamivudine alone. The mean treatment duration in this group was 38.5 months (± 4.5). The sustained response group had a higher mean age and longer treatment duration than patients with virologic relapse but these differences were not statistically significant.

CONCLUSIONS

The results suggest that NA treatment can be stopped in selected patients with CHB as long as they are not cirrhotic, have completed a minimum period of treatment, have normal ALT and sustained undetectable DNA. These patients should be closely monitored during the first year and then indefinitely.