Background: OCCULT HEPATITIS B is defined as presence of HBV DNA in tissue or serum without HEPATITIS B surface antigen. The aim of this study is to determine frequency of OCCULT HEPATITIS B among HEPATITIS C patients in Tehran and compare the route of transmission and liver enzymes between positive and negative HBV DNA patients.Methods: In a cross sectional study, serum of 103 HEPATITIS C cases (79.6% men and 20.4% women) were analyzed for s, x and core genes via a nested polymerase chain reaction technique.Results: HBV DNA was detectable in serum of 20 patients (19.4%). No significant difference in age, sex and route of transmission were seen in HBV DNA positive and negative patients. In HBV DNA positive and negative groups, mean of AST was 73, 47 (p<0.05) and mean of ALT was 76 and 36 respectively (p<0.05).Conclusion: OCCULT HEPATITIS B was observed in a considerable number of HEPATITIS C patients in Tehran. It was associated with elevation in liver enzyme but was not related to route of transmission.

Introduction: The HEPATITIS B virus (HBV) is one health problem in Iran. OCCULT HEPATITIS B (OBI) is diagnosed by the detection of HBV DNA in the serum or liver tissue of patients for whom other serology, especially HBsAg and HBcAg, are negative. The current study aimed to determine the prevalence of OBI in patients who refer for chemotherapy. Methods: All patients referring for chemotherapy to the oncology clinic of Baqiyatallah Hospital in Tehran, Iran from 2012 to 2013 were selected as the population of this cross-sectional study. Samples of 5 mL of blood were taken from each subject and assayed for HBsAg and HBcAb. If HBV markers were negative, a qualitative HBV DNA PCR was done to detect OBI. The data was analyzed using SPSS 17 software, and the frequency test was used to determine prevalence. Results: In this study, 251 candidates for chemotherapy were recruited. Of this number, 114 (45%) patients were women. Mean patient age was 52. 6 years. A total of 149 (59%) study subjects were employed, and the others were housekeepers or self-employed. About 67 (26. 6%) patients had a history of one dose and 40 (15. 9%) patients had a history of complete HBV vaccination. HBsAg was positive in 6 (2. 4%) and HBcAb was positive in 33 (13. 1%) patients; qualatative HBV DNA PCR was positive in 2 (0. 8%) patients. Conclusion: This study revealed that OBI infection has a low prevalence, but patients referring for chemotherapy are at risk for its reactivation. On the other hand, isolated HBcAb is also a risk factor; therefore, in addition to HBsAg, it is recommended that HBcAb be evaluated before chemotherapy.

Context: OCCULT HEPATITIS B (OHB), or persistent HBV DNA in patients who are HEPATITIS B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to sum- marize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings. Evidence Acquisition: OHB could be found in different population and clinical back-grounds including: viral co-infections (with either human immunodeficiency or HEPATITIS C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters.Results: The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and he- patocellular carcinoma development remains unknown. Conclusions: monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.

OCCULT HEPATITIS B (OHB), or persistent HEPATITIS B virus (HBV) viremia in surface-antigen-HBsAg-negative patients, has been recognized as a medical concern during the last decade. The exact magnitude, pathogenesis and clinical relevance of OHB are unclear. This review organizes the published data on OHB and presents an overview of the current hypotheses on OHB’s pathogenesis and clinical relevance. Many explanations have been offered for the pathogenesis of OHB, ranging from the inability of standard immunoassays to diagnose OHB to the involvement of the versatile virus-host factors Also, special care should be taken regarding the diagnosis of OBH. It seems that both shared viral-host factors are involved in the pathogenesis of OBH. Further molecular studies on cohort patients group need to explore such association.

I read with great interest the paper by Taheri et al. published in HEPATITIS Monthly (Number 31, February 2011). The results of this follow-up study are hopeful of HEPATITIS-B vaccine efficacy in patients who lost HBsAg and did not seroconvert to anti-HBs with no detectable HBV DNA. However, the editorial in the same issue, as well as Taheri et al. themselves, noted some important limitations to this study.