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Occult HBV (occult + hbv)

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Medical Sciences	77%

Terms modified by Occult HBV

occult hbv infection

Selected Abstracts

Occult hepatitis B viral DNA in liver carcinomas from a region with a low prevalence of chronic hepatitis B infection

JOURNAL OF VIRAL HEPATITIS, Issue 4 2004
R. Kannangai
Summary., Occult hepatitis B is defined by the presence of hepatitis B viral (HBV) DNA in the serum or liver in persons lacking hepatitis B surface antigen (HBsAg) in the serum. A high prevalence of occult HBV has been reported in hepatocellular carcinoma (HCC) from Asia, but little information is available on the prevalence of occult HBV in HCC from regions with a low prevalence of typical chronic hepatitis B infection. In a retrospective study, 19 cases of primary liver cancer were investigated for the presence of occult HBV DNA by amplification of the surface, core, and X gene. In addition, HBV copy numbers were quantitated by real time polymerase chain reaction, genotyped, and samples tested for covalently closed circular HBV DNA, which is a marker of active viral replication. Occult HBV was found in three of 19 cases (16%). Genotyping was successful in two cases, both of which were genotype A. HBV DNA copy numbers were low, all less than 10 copies/,g liver DNA. No closed circular HBV DNA was detected. Thus, in this study occult HBV was of genotype A and was found in a low percentage of cases of HCC and was associated with low tissue HBV DNA copy numbers and no detectable evidence for viral replication. [source]

Occult hepatitis B virus infection in patients with autoimmune liver diseases

LIVER INTERNATIONAL, Issue 3 2009
Sarah P. Georgiadou
Abstract Background: Occult hepatitis B virus (HBV) infection is characterized by undetectable serum HBV surface antigen (HBsAg) but detectable HBV-DNA in serum or liver. Aims: To determine the prevalence and clinical impact of occult HBV in autoimmune liver diseases as similar data are missing. Methods: One hundred and ninety-six sera samples from HBsAg-negative patients, including 66 autoimmune hepatitis (AIH), 93 primary biliary cirrhosis (PBC) and 37 primary sclerosing cholangitis (PSC), were investigated for HBV-DNA using the polymerase chain reaction (PCR) before treatment initiation. One hundred and three serial samples from 38 AIH patients under immunosuppression and 282 selected blood donors (HBsAg negative; antibodies to HBV-core antigen positive) were also investigated. Fourteen available paraffin-embedded AIH liver samples were also investigated for HBV-DNA by nested-PCR. Results: Hepatitis B virus DNA was detected in the serum of 24/196 patients (12.2%) and 0/282 donors (P=0.0000). Nine patients had AIH (13.6%), eight had PBC (8.6%) and seven had PSC (18.9%) (P=0.0000 vs healthy). HBV-DNA detection in AIH livers was higher than in serum. HBV-DNA was associated neither with HBV markers nor with epidemiological, laboratory and clinical data. Serial testing of AIH patients revealed two HBV-DNA-negative patients before treatment becoming positive during treatment, while all HBV-DNA-positive patients before immunosuppression became negative. Conclusion: Based mainly on serum HBV-DNA, we found a significant proportion of autoimmune liver disease patients with occult HBV compared with donors. However, taking into account our results in a small number of liver tissues, it should be emphasized that occult HBV could be even higher when both serum and liver specimens are investigated. Occult HBV does not seem to affect the clinical and laboratory features of the diseases, while AIH patients with occult HBV under immunosuppression do not deteriorate during follow-up. [source]

Occult hepatitis B virus infection in a North American adult hemodialysis patient population

HEPATOLOGY, Issue 5 2004
Gerald Y. Minuk
Hepatitis B virus (HBV) infections continue to occur in adult hemodialysis units. A possible contributing factor is the presence of occult HBV (serum hepatitis B surface antigen [HBsAg] negative but HBV DNA positive). Two hundred forty-one adult hemodialysis patients were screened for occult HBV. HBV DNA testing was performed by real-time polymerase chain reaction (PCR) with 2 independent primer sets (core promoter and surface). Two (0.8%) of the 241 patients were HBsAg positive. Of the remaining 239 HBsAg-negative patients, 9 (3.8%) were HBV DNA positive. Viral loads in these individuals were low (102 -104 viral copies/mL). Seven of the 9 (78%) were nt 587 mutation (sG145R mutant) positive. Demographic, biochemical, and HBV serological testing did not help to identify those with occult HBV. In conclusion, the prevalence of occult HBV in adult hemodialysis patients in this North American urban center is approximately 4 to 5 times higher than standard HBsAg testing would suggest. The majority of these infections are associated with low viral loads and a high prevalence of the sG145R mutant. Finally, the demographic, biochemical, and/or serological features of HBV DNA,positive subjects do not distinguish these individuals from the remainder of the dialysis patient population. (HEPATOLOGY 2004; 40:1072,1077.) [source]

A study on sequence variations in pre-S/surface, X and enhancer II/core promoter/precore regions of occult hepatitis B virus in non-B, non-C hepatocellular carcinoma patients in Taiwan

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2009
Chien-Hung Chen
Abstract This study was to investigate the clinical significance and virologic factors of occult hepatitis B virus (HBV) infection in hepatocellular carcinoma (HCC) patients without hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (non-B, non-C) in Taiwan. Serum HBV DNA (occult HBV) was detected in 90 of 222 non-B, non-C HCC patients and 24 of 300 non-B, non-C controls without HCC. Of 90 occult HBV-infected HCC patients, the sequences of HBV pre-S/surface, X and enhancer II/core promoter/precore genes were analyzed from 40 patients. Direct sequencing of such genes was also performed in 24 non-B, non-C controls without HCC and 40 HBsAg-positive HCC controls. Compared with non-B, non-C controls without HCC, non-B, non-C subjects with HCC had significantly higher prevalence of occult HBV (p < 0.0001). Moreover, M1I and Q2K in pre-S2 gene and G1721A were more common in occult HBV-infected patients with HCC than in those without HCC. Compared with the HBsAg-positive HCC controls, occult HBV-infected HCC patients had higher frequencies of M1I and Q2K in pre-S2 gene, G185R and S210N in surface gene, A36T and A44L in X gene, and G1721A in enhancer II gene, and had lower rates of pre-S deletions and A1762T/G1764A, A1846T, G1896A and G1899A in core promoter/precore genes. Multivariate analysis showed Q2K in pre-S2 gene, G1721A and A1846T were independent factors for occult HBV-infected HCC. Our study suggested that the virological factors of HBV related to HCC were different between occult HBV-infected and HBsAg-positive patients. The G1721A, M1I and Q2K in pre-S2 gene may be useful viral markers for HCC in occult HBV carriers. © 2009 UICC [source]

Molecular characterization of a variant virus that caused de novo hepatitis B without elevation of hepatitis B surface antigen after chemotherapy with rituximab

JOURNAL OF MEDICAL VIROLOGY, Issue 12 2008
Masami Miyagawa
Abstract Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative patients following treatment with rituximab has been reported increasingly. The aim of this study was to investigate the molecular mechanisms underlying HBV reactivation in an HBsAg-negative patient. HBV was reactivated in a 75-year-old man following chemotherapy with rituximab, without elevation of HBsAg. The patient's full-length HBV genome was cloned and the entire sequence was determined. Transfection studies were performed in vitro using recombinant wild-type HBV (wild-type), the patient's HBV (patient), and two chimeric HBV constructs, in which the preS/S region of the patient and wild-type virus had been exchanged with one another. Secreted HBsAg and intra- and extra-cellular HBV DNA were measured. The number of amino acid substitutions in HBV from this patient was much higher than in previous reports of HBV mutants, such as occult HBV and vaccine escape HBV mutants. Levels of HBsAg and HBV DNA production in vitro were significantly lower in the patient compared to wild-type transfections. From analyses of the chimeric constructs, the altered preS/S region was responsible mainly for this impairment. These results show that highly mutated HBV can reactivate after chemotherapy with rituximab, despite an unusually large number of mutations, resulting in impaired viral replication in vitro. Severe immune suppression, probably caused by rituximab, may permit reactivation of highly mutated HBV. These findings have important clinical implications for the prevention and management of HBV reactivation and may explain partially the mechanism of recent, unusual cases of HBV reactivation. J. Med. Virol. 80:2069,2078, 2008. © 2008 Wiley-Liss, Inc. [source]

Can the serological status of "anti-HBc alone" be considered a sentinel marker for detection of "occult" HBV infection?

JOURNAL OF MEDICAL VIROLOGY, Issue 4 2008
Francesco Vitale
Abstract Some individuals have "occult" infection with hepatitis B virus (HBV), defined as presence of HBV genome in the serum or liver tissue without HBV surface antigen (HBsAg) in the serum. The aim of this study was to investigate whether serum antibodies against HBV core antigen in isolation ("anti-HBc alone") are a useful marker of "occult" HBV in patients with or without hepatitis C virus (HCV) infection. "Anti-HBc alone" was detected in the sera of 119/6,544 (1.8%) asymptomatic outpatients referred to the diagnostic laboratory for routine testing for viral hepatitis, 62/607 (10.2%) drug users, and 42/195 (21.5%) patients with hepatocellular carcinoma. Using three in-house nested-PCR amplification assays to detect HBV preS-S (S), precore-core (C), and Pol viral regions, respectively, "occult" HBV sequences were found in 9 of the 223 sera (4.0%) with "anti-HBc alone." The highest prevalence of "occult" HBV sequences (5.9%) was detected in "anti-HBV alone" sera of individuals referred to the diagnostic laboratory without HCV antibodies. Direct sequencing of all PCR products confirmed the specificity of the PCR reactions and revealed the predominance of HBV genotype D. The data presented in this study suggest that detection of "anti-HBc alone" could reflect unrecognized "occult" HBV infection and that physicians should consider investigating such patients with HBV molecular tests. J. Med. Virol. 80:577,582, 2008. © 2008 Wiley-Liss, Inc. [source]