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

Abstract

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/microg 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.

Hepatitis B Virus DNA in Liver Tissue and Risk for Hepatocarcinogenesis in Patients with Hepatitis C Virus-Related Chronic Liver Disease

“…We studied the HBV gene in liver tissue several years before the emergence of HCC, and in a retrospective study, we have already reported that the presence of HBV DNA in patients with HCV-related chronic liver disease appears to promote hepatocarcinogenesis [18] . In contrast, some published reports indicate a low prevalence of HBV DNA in patients with HCC without HBsAg [19][20][21] . Thus, the influence of occult HBV infection on hepatocarcinogenesis remains controversial.…”

A weak association between occult HBV infection and non-B non-C hepatocellular carcinoma in Japan

“…Occult HBV infection is defi ned by serologically undetectable HBsAg despite the presence of HBV DNA in serum or liver 8,10,11 Interestingly, a previous report indicated that HBV DNA was integrated into the human genome in NBNC-HCC tissues, suggesting that occult HBV infection might play a role in hepatocarcinogenesis in patients with so-called NBNC. 12 However, another report has demonstrated that levels of HBV-DNA in patients with occult HBV infection are very low, and covalently closed circular HBV-DNA cannot be detected, 13 which makes the role of occult HBV infection in the development of HCC unclear.…”

Infecção oculta pelo vírus da hepatite B em comunidade amazônica submetida a intenso fluxo migratório, estado do Pará, Brasil

“…A associação entre o VHB e o carcinoma hepatocelular (CHC) está bem estabelecida, entretanto, permanece controverso se a IOB também estaria implicada no surgimento do CHC -prevalência variável da IOB em pacientes com CHC tem sido relatada na Ásia, no Japão e nos EUA 19,20,21,22 .…”