Are trans‐complementation systems suitable for hepatitis C virus life cycle studies?

Complementation is a naturally occurring genetic mechanism that has been studied for a number of plus‐strand RNA viruses. Although trans‐complementation is well documented for Flaviviridae family viruses, the first such system for hepatitis C virus (HCV) was only described in 2005. Since then, the development of a number of HCV trans‐complementation models has improved our knowledge of HCV protein functions and interactions, genome replication and viral particle assembly. These models have also been used to produce defective viruses and so improvements are necessary for vaccine assays. This review provides an update on HCV trans‐complementation systems, the viral mechanisms studied therewith and the production and characterization of trans‐encapsidated particles.     

Mechanism of intrauterine infection of hepatitis B virus

AIM:To explore the possible mechanism of intrauterineinfection of hepatitis B virus (HBV).METHODS:HBV DNA was detected in vaginal secretionand amniotic fluid from 59 HBsAg-positive mothers and invenous blood of their newborns by PCR.HBsAg and HBcAgin placenta were determined by ABC immunohistochemistry.RESULTS:The rate of HBV intrauterine infection was 40.1%(24/59).HBV DNA was detected in 47.5% of amniotic fluidsamples and 52.5% of vaginal secretion samples respectively.HBsAg and HBcAg were detected in placentas from HBsAg-positive mothers.The concentration of the two antigensdecreased from the mother's side to the fetus's side,in thefollowing order:maternal decidual cells > trophoblastic cells>villous mesenchymal cells > villous capillary endothelialcells.However,in 4 placentas the distribution was in thereverse order.HBsAg and HBcAg were detected in amnioticepithelial cells from 32 mothers.CONCLUSION:The main route of HBV transmission frommother to fetus is transplacental,from the mother side ofplacenta to the fetus side.However,HBV intrauterineinfection may take place through other routes.     

Molecular analysis of hepatitis B virus isolates in Mexico： Predominant circulation of hepatitis B virus genotype H

INTRODUCTIONHepatitis B virus(HBV)is an important cause of morbidity and mortality worldwide.It is estimated that2billion people are infected with HBV and350million individuals suffer from chronic HBV infection in the world[1,2].Chronic HBV infection may …     

Is hepatitis C virus a risk factor for thyroid autoimmunity?

The role of hepatitis C virus (HCV) in inducing thyroid autoimmunity is still under discussion and to assess the prevalence of thyroid autoantibodies and thyroid disease in the general population and to analyse the role of HCV in inducing thyroid autoimmunity. We studied 697 subjects residing in Arsita (a small town in central Italy). Thyroid autoantibodies and nonorgan-specific autoantibodies (NOSAs) were tested in each subject, who were also screened for anti-HCV antibodies; all subjects found positive to HCV-RNA were considered as being HCV-infected. Thyroid function tests were performed in all subjects positive for thyroid autoantibody. Seventy-one subjects were found HCV-positive; four of these (5.6%) were positive for at least one thyroid autoantibody, as opposed to 7 (4.9%) of the 142 sex- and age-matched controls of the same population (P = n.s.). Thyroid dysfunction was found in 2/4 HCV-positive, and in 1/7 HCV-negative subjects with thyroid autoantibodies (P = n.s.). NOSAs were significantly more common in HCV-positive than in HCV-negative subjects (P < 0.0001). Hence HCV per se is not responsible for thyroid autoimmune dysfunction, whereas HCV does seem to induce NOSAs. It should be taken into account, however, that the phenotypic expression of autoimmune diseases is obviously influenced by a number of risk factors, including genetic predisposition, female sex and infectious agents, that could trigger the onset of the disease.     

Is there a meaningful serum hepatitis B virus DNA cutoff level for therapeutic decisions in hepatitis B e antigen-negative chronic hepatitis B virus infection?

The diagnosis of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B indicating therapeutic intervention currently requires serum hepatitis B virus (HBV) DNA >or=2,000 IU/mL. We evaluated the severity of liver histology and the presence of histological indication for treatment in patients with HBeAg-negative chronic HBV infection focusing on those with low viremia and/or normal alanine aminotransferase (ALT). In total, 399 patients with increased ALT and detectable serum HBV DNA (chronic hepatitis B patients) and 35 cases with persistently normal ALT and HBV DNA >2,000 IU/mL (inactive carriers) were included. Histological indication for treatment (grading score >or=7 and/or stage >or=2 in Ishak's classification) was found in 91% (185/203), 82% (75/91), 75% (47/63), and 62% (26/42) of chronic hepatitis B patients with HBV DNA >or=200,000, 20,000-199,999, 2,000-19,999, and <2,000 IU/mL, respectively (P < 0.001). Histological indication for treatment was more frequent in chronic hepatitis B patients with persistently elevated ALT (86% or 275/321), but it was also found in 74% (58/78) of those with transiently normal ALT (P = 0.025). All inactive carriers had HBV DNA <20,000 IU/mL. Histological indication for treatment was present in 17% (6/35) of inactive carriers always due to moderate (stage 2) fibrosis without active necroinflammation. CONCLUSION: HBeAg-negative chronic HBV patients with persistently or transiently increased ALT and HBV DNA >or=20,000 IU/mL almost always require therapeutic intervention, but histological indications for treatment are also present in the majority of such cases with HBV DNA <20,000 and even <2,000 IU/mL. In contrast, minimal histological lesions are observed in the majority of HBeAg-negative patients with persistently normal ALT and HBV DNA >2,000 IU/mL, who may not require immediate liver biopsy and treatment but only close follow-up.     

Transplantation of hepatitis D virus patients: Lifelong hepatitis B immunoglobulins?

The introduction of Hepatitis B Immunoglobulins (HBIg) prophylaxis at and after liver transplantation (LT) facilitated excellent long-term survival of transplant patients with chronic hepatitis B virus (HBV) infection. Several studies suggested that only short-term (i.e. 4–8 weeks) HBIg prophylaxis after LT followed by the long-term administration of HBV polymerase inhibitors prevents HBV recurrence. In hepatitis D virus (HDV)/HBV co-infected patients, the need for long-term HBIg prophylaxis on top of HBV polymerase inhibitors is unknown. HDV requires HBV surface antigen (HBsAg) for uptake into hepatocytes to subsequently establish HDV replication. Data on HDV recurrence and its impact on outcomes after LT are limited. In this review, we evaluated the available data on post-LT recurrence of HBV and/or HDV. Overall, HBIg prophylaxis was effective, but 10–13% of patients became HBsAg positive after LT. Only a single study from Turkey reported HDV recurrence, which was not observed in other LT centres. Since all studies administered continuous HBIg prophylaxis, the post-LT recurrence rates without HBIg prophylaxis remain unknown. In a German study, the clinical course and histopathological aspects of liver injury (inflammation, fibrosis and steatosis) were similar in post-LT patients on continuous HBIg and those who stopped HBIg after a median of 72 months. Discontinuation of HBIg in stable patients after LT for HBV/HDV co-infection did not lead to impaired overall survival or a higher recurrence rate in this long-term follow-up. In summary, discontinuation of HBIg after liver transplantation for HBV/HDV liver disease seems safe, but randomized controlled studies are needed before it can be generally recommended.     

Antiviral therapy for treatment-naïve hepatitis B virus patients

Hepatitis B virus infection is a major public health problem worldwide,responsible for considerable morbidity and mortality from chronic liver disease. It is estimated that there are 350 million hepatitis B virus carriers globally. The prevalence of chronic hepatitis B infection varies greatly in different regions of the world. In the United States, approximately 1.5 million people are infected and 50,000 to 100,000 new cases are reported annually despite the availability of effective vaccines. This article reviews various antiviral therapies for treatment na?ve hepatitis B virus patients.     

Adefovir dipivoxil for the treatment of lamivudine-resistant hepatitis B mutants

BACKGROUND: The recurrence of chronic hepatitis B after liver transplantation results in increased risk for graft failure and death of patients. Lamivudine has been shown to be effective in the treatment of chronic hepatitis B, but resistance to this agent is common after prolonged administration. METHODS: One patient with chronic hepatitis B virus (HBV) infection developed resistance to lamivudine after 15 months of treatment. The resistance was confirmed by mutation in the HBV DNA polymerase gene. The patient was treated subsequently with adefovir dipivoxil for 7 months. RESULT: HBV DNA and HBsAg were tested negative, but HBeAb and HBsAb were positive. CONCLUSION: This study provides an evidence that adefovir dipivoxil can be effective in the treatment of lamivudine-resistant HBV mutants.     

Is C-reactive protein an independent risk factor for essential hypertension?

CONTEXT: C-reactive protein (CRP), predicts coronary heart disease incidence in healthy subjects and has been associated with decreased endothelium-dependent relaxation, a potential risk factor for hypertension. However, the relationship between CRP and hypertension has not been studied. OBJECTIVE: To assess whether circulating levels of CRP are independently related to essential hypertension. DESIGN: Cross-sectional population survey. We measured circulating levels of CRP, blood pressure and cardiovascular risk factors among participants. Binomial regression was used to calculate the adjusted effect of CRP on the prevalence of hypertension. SETTING: General community of Bucaramanga, Colombia. PARTICIPANTS: A random sample of 300 subjects > or = 30 years old. MAIN OUTCOME MEASURE: Arterial blood pressure. RESULTS: Overall hypertension prevalence was 46.0%. The unadjusted prevalence of hypertension was 58.7% in the highest quartile of CRP, but only 34.7% in the lowest quartile. After adjustment for age, sex, body mass index, family history of hypertension, fasting glycemia, sedentary behaviour, and alcohol consumption, the prevalence of hypertension was 1.14 [95% confidence interval (CI), 0.82, 1.58; P= 0.442], 1.36 (95% CI, 0.99, 1.87; P= 0.057) and 1.56 (95% CI, 1.14, 2.13; P = 0.005) times higher in subjects in the second, third and fourth quartiles of CRP, as compared to subjects in the first quartile. CONCLUSIONS: Our results suggest, for the first time, that CRP level may be an independent risk factor for the development of hypertension. However, because of the cross-sectional nature of our study, this finding should be confirmed in prospective cohort studies, aimed at elucidating the role of CRP in the prediction, diagnosis and management of hypertension.     

Evaluating the risk of hepatitis B reactivation in patients with haematological malignancies: is the serum hepatitis B virus profile reliable?

Background/Aim: Patients with an occult hepatitis B virus (HBV) infection undergoing deep immunosuppression are potentially at risk of HBV reactivation. In order to assess whether a polymerase chain reaction (PCR) assay for HBV DNA in serum could be used to predict the reactivation of an occult HBV infection, we performed a retrospective study in a cohort of Sicilian patients with oncohaematological diseases. Methods: We studied by a highly sensitive ad hoc nested PCR for serum HBV DNA 75 HBsAg‐negative oncohaematological patients requiring chemotherapy. Results: Thirty‐three patients (44%) were HBV seronegative (anti‐HBc and anti‐HBs negative) and 42 patients (56%) were HBV seropositive (anti‐HBc and/or anti‐HBs positive). Baseline serum HBV DNA was positive in nine out of 33 HBV‐seronegative patients and in nine out of 42 HBV‐seropositive patients (27.3 vs. 21.4%; P=NS). HBsAg seroconversion was observed in five out of 33 seronegative vs. six out of 42 seropositive patients (15 vs. 14%, P=0.9), and in five out of 18 HBV DNA‐positive vs. six out of 57 HBV DNA‐negative patients (27.7 vs. 10.6%P=0.11). Hepatitis C virus infection was found in 18 patients (24.3%), although with no correlation to HBV serological status, presence of serum HBV DNA or frequency of HBsAg seroconversion. Conclusions: In oncohaematological patients undergoing chemotherapy, highly sensitive serum HBV DNA testing at baseline has a 28% predictive ability to forecast HBsAg seroconversion in HBV DNA‐positive patients, and a 90% ability to forecast persistent HBsAg negativity in HBV DNA‐negative patients, a better performance than serological tests.     

Recent advances in hepatitis C virus research and understanding the biology of the virus

Since the identification of hepatitis C virus (HCV) genome in 1989[1], a lot of progresses have been done about the understanding of HCV biology, natural history and therapeutic options. HCV is a member of the Flaviviridae viral family. Its genome is a positive simple strand RNA