Reply to: “Obscure clinical implication of occult hepatitis B virus infection by perinatal transmission despite prophylaxis with hepatitis B vaccination and HBIG”
Authors: Seyed Mohammad Jazayeri, Seyed Moayed Alavian
Journal: Journal of Hepatology (2012)

Obscure clinical implication of occult hepatitis B virus infection by perinatal transmission despite prophylaxis with hepatitis B vaccination and HBIGJournal of HepatologyVol. 57Issue 6PreviewWe are much interested in the article by Shahmoradi et al. published in the Journal of Hepatology [1]. In the cross-sectional report, the authors investigated the serum samples of 75 children born to hepatitis B surface antigen (HBsAg)-positive mothers. Hepatitis B virus (HBV) DNA could be detected in 21 (28%) out of 75 children previously immunized by a dose of HBIG and three standard injections of hepatitis B vaccines. All were positive for antibody to hepatitis B surface antigen (anti-HBs), while only 5 (24%) were positive for antibody to hepatitis B core antigen (anti-HBc). Full-Text PDF Open AccessHigh prevalence of occult hepatitis B virus infection in children born to HBsAg-positive mothers despite prophylaxis with hepatitis B vaccination and HBIGJournal of HepatologyVol. 57Issue 3PreviewOccult hepatitis B virus (HBV) infection is a well-recognized clinical entity characterized by the detection of HBV DNA in serum and/or liver in the absence of detectable hepatitis B surface antigen (HBsAg). The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. We aimed at determining the prevalence of occult HBV infection in a high risk group of children who developed HBV infection despite immunoprophylaxis. Full-Text PDF We highly appreciate the valuable comments addressed by Chiang and Ni about our study [[1]Shahmoradi S. Yahyapour Y. Mahmoodi M. Alavian S.M. Fazeli Z. Jazayeri S.M. High prevalence of occult hepatitis B virus infection in children born to HBsAg-positive mothers despite prophylaxis with hepatitis B vaccination and HBIG.J Hepatol. 2012; 57: 515-521Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar]. The authors highlighted two major points: firstly, the correlation between maternal metabolic and HBV status with the infected children and secondly, the high prevalence of OBI in our study. Regarding the former, the files of all mothers and infected children showed that only 7 (9.3%) out of 75 mothers were HBeAg positive. There was no correlation between maternal HBeAg and anti-HBe positive in terms of demography, serology, and viral kinetics (as mentioned in the Results section). Only one out of 76 children was HBsAg positive and was excluded from the study. The metabolic factors were not considered in our survey. Regarding Ni’s comments on the high prevalence of OBI in our study, reports by Alavian et al., revealed the prevalence of HBV in Iran in the range of 1.7% and 2.5% in the general population [[2]Alavian S.M. Fallahian F. Lankarani K.B. The changing epidemiology of viral hepatitis B in Iran.J Gastrointest Liver Dis. 2007; 16: 403-406PubMed Google Scholar]. However, the prevalence of occult HBV infection in children born to HBV positive mothers was high (28%) in our study. Different studies have been carried out in South-East Asia after EPI (expanded program on immunization) on HBsAg positive children born to HBsAg positive mothers [3Oon C.J. Lim G.K. Ye Z. Goh K.T. Tan K.L. Yo S.L. et al.Molecular epidemiology of hepatitis B virus vaccine variants in Singapore.Vaccine. 1995; 13: 699-702Crossref PubMed Scopus (193) Google Scholar, 4Su H.X. Zhang Y.H. Zhang Z.G. Li D. Zhang J.X. Men K. et al.High conservation of hepatitis B virus surface genes during maternal vertical transmission despite active and passive vaccination.Intervirology. 2011; 54: 122-130Crossref PubMed Scopus (10) Google Scholar, 5Ho M. Mau Y. Lu C. Huang S. Hsu L. Lin S. et al.Patterns of circulating hepatitis B surface antigen variants among vaccinated children born to hepatitis B surface antigen carrier and non-carrier mothers. A population-based comparative study.J Biomed Sci. 1998; 5: 355-362Crossref PubMed Scopus (23) Google Scholar]. The surface protein mutants within or outside of “a” determinant were in association with a low frequency. In fact, in most of the studies on EPI, HBV DNA analysis has not been carried out on HBsAg negative cases to address the prevalence of OBI in this high-risk individuals. On the other hand, in the Mu’s study from Taiwan, authors found prevalence of OBI in vaccinated children (without such familial history) to be around 10.9%. In our opinion, these contradictory results might be related to the technical differences and the levels of sensitivity of the tests (methods for extraction and amplification, etc.), the geographical distribution of HBV infection, and the genotypic nature of the virus (genotype D in Iran, and genotypes B and C from South-East Asia). We believe that additional studies in large cohorts of patients with long-term clinical and laboratory follow-up are warranted to better understand the biological basis and significance of occult HBV infection and its consequences after HBV vaccination. The authors declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript.