Detection of hepatitis B virus X-region DNA in liver tissue from patients with hepatitis C virus-associated cirrhosis who subsequently developed hepatocellular carcinoma

Cyclin-dependent kinases and CDK inhibitors in virus-associated cancers

The role of several risk factors, such as pollution, consumption of alcohol, age, sex and obesity in cancer progression is undeniable. Human malignancies are mainly characterized by deregulation of cyclin-dependent kinases (CDK) and cyclin inhibitor kinases (CIK) activities. Viruses express some onco-proteins which could interfere with CDK and CIKs function, and induce some signals to replicate their genome into host's cells. By reviewing some studies about the function of CDK and CIKs in cells infected with oncoviruses, such as HPV, HTLV, HERV, EBV, KSHV, HBV and HCV, we reviewed the mechanisms of different onco-proteins which could deregulate the cell cycle proteins.

Incidence of transaminitis among HIV-infected patients with occult hepatitis B

BACKGROUND

The clinical significance of occult hepatitis B virus (HBV) infection, defined as the presence of HBV DNA in individuals with HBV core antibodies (anti-HBc) in the absence of HBV surface antigen (HBsAg), is unclear in HIV-infected patients. This information is needed to determine the importance of detecting and treating occult HBV in this population.

OBJECTIVE

To determine if HIV-infected patients with occult HBV infection have an increased incidence of transaminitis.

STUDY DESIGN

We performed a cohort study among randomly selected HBsAg-/anti-HBc+ HIV-infected patients in the Penn CFAR Database and Specimen Repository. HBV DNA was qualitatively detected using a transcription-mediated amplification assay. Hepatic transaminase levels, the main study outcome, were collected at 6-month intervals from the time of occult HBV determination.

RESULTS

Among 97 randomly selected subjects without baseline transaminitis, 13 (13%) had occult HBV. These subjects more frequently had detectable HIV RNA. The 2-year incidence of transaminitis among HIV-infected subjects with occult HBV (50 events/100 person-years) was not significantly different from those without occult HBV (38 events/100 person-years; adjusted incidence rate ratio=1.36 [95% CI, 0.72-2.59]).

CONCLUSIONS

Occult HBV did not increase the incidence of hepatic transaminitis over 2 years. Future studies should determine whether occult HBV is associated with other clinically important outcomes, particularly hepatocellular carcinoma.

Covalently closed circular DNA is the predominant form of duck hepatitis B virus DNA that persists following transient infection

Residual hepatitis B virus (HBV) DNA can be detected in serum and liver after apparent recovery from transient infection. However, it is not known if this residual HBV DNA represents ongoing viral replication and antigen expression. In the current study, ducks inoculated with duck hepatitis B virus (DHBV) were monitored for residual DHBV DNA following recovery from transient infection until 9 months postinoculation (p.i.). Resolution of DHBV infection occurred in 13 out of 15 ducks by 1-month p.i., defined as clearance of DHBV surface antigen-positive hepatocytes from the liver and development of anti-DHBV surface antibodies. At 9 months p.i., residual DHBV DNA was detected using nested PCR in 10/11 liver, 7/11 spleen, 2/11 kidney, 1/11 heart, and 1/11 adrenal samples. Residual DHBV DNA was not detected in serum or peripheral blood mononuclear cells. Within the liver, levels of residual DHBV DNA were 0.0024 to 0.016 copies per cell, 40 to 80% of which were identified as covalently closed circular viral DNA by quantitative PCR assay. This result, which was confirmed by Southern blot hybridization, is consistent with suppressed viral replication or inactive infection. Samples of liver and spleen cells from recovered animals did not transmit DHBV infection when inoculated into 1- to 2-day-old ducklings, and immunosuppressive treatment of ducks with cyclosporine and dexamethasone for 4 weeks did not alter levels of residual DHBV DNA in the liver. These findings further characterize a second form of hepadnavirus persistence in a suppressed or inactive state, quite distinct from the classical chronic carrier state.

Detection of different viral transcripts in sera of patients with chronic hepatitis B virus infection

AIM: To establish an assay for detecting serum hepatitis B virus (HBV) transcripts including the full-length (fRNA) and truncated RNA molecules (trRNA) in chronic HBV carriers, and to investigate its clinical significance.

METHODS: The serum viral nucleic acids were analyzed using PCR and RT-PCR targeted to the HBV x protein-encoding region. Reaction specificity was confirmed by Southern blotting. Representative amplification products were cloned and sequenced.

RESULTS: Different viral transcripts including fRNA and trRNA were identified in sera of HBV carriers. Presence of fRNA was closely correlated with seropositivity of hepatitis B e antigen and viral DNA. However, trRNA did not depend on serum e antigen, its association with circulating viral DNA was weak. Similarly, no remarkable correlation was observed between the levels of trRNA and the degrees of liver damage. Different age-dependent representations for fRNA and trRNA were recognized, fRNA was progressively decreased to undetectable levels and trRNA increased to high levels in the second decade of life and then remained in high level in the rest of life. The trRNA and RNA without polyadenylation at either of the two addition sites were detected even in the absence of any other conventional HBV markers such as viral DNA. They were also observed in sera from patients with cryptogenic cirrhosis or chronic hepatitis C.

CONCLUSION: The viral transcripts are potential serum markers for identifying replicative and non-replicative infection stages and diagnosis of occult HBV infection.