Circulation of multiple hepatitis B virus genotypes in individual pregnant women seeking antenatal care in northern Ghana.

BACKGROUND: Identification and monitoring of HBV genotype variations is important, since that can help forecast the likelihood of developing serious liver disease and how well patients respond to antiviral medication. Given that HBV genotyping tests are not widely available in our healthcare system, this study characterized HBV genotypes in pregnant women seeking prenatal treatment in northern Ghana. METHOD: By a cross-sectional approach, 2071 pregnant women seeking antenatal care in health facilities in northern Ghana were screened for HBV infection using hepatitis B surface antigen (HBsAg) rapid diagnostic test kit. The women were aged between 17 and 41 years, were of varying gravidae (primigravidae and multigravidae) and gestational age (first, second and third trimesters). A confirmatory PCR assay was used to detect HBsAg, and the distribution of HBV genotypes was determined using a nested PCR assay. RESULTS: Three HBV genotypes (A, D and E) were detected among the pregnant women, of which 175 (91.6%) had genotype E, 9 (4.7%) had mixed genotypes A and E, 5 (2.6%) had mixed genotypes D and E, and 2 (1.1) had mixed genotypes A, D and E. The proportions of women with the different HBV genotypes were independent of age (p = 0.925), gravidity (p = 0.193, χ2 = 4.729) and gestational age (p = 0.227, χ2 = 8.152). CONCLUSION: This study for the first-time characterized circulating HBV genotypes in pregnant women in northern Ghana, which reveals genotypes A and D are found in mixed infections with genotype E. The findings have clinical implications on the management of chronic HBV infection among pregnant women in northern Ghana.

Hepatitis B Virus Genotypes and Antiviral Resistance Mutations in Romanian HIV-HBV Co-Infected Patients.

Background and Objectives: Romania has one of the highest prevalence of hepatitis B virus (HBV) infection in human immunodeficiency virus (HIV) patients, mostly in those parenterally infected during childhood; nevertheless, there are scarce data on the virological profile of co-infection. The objective of this study was to assess the prevalence of HBV genotypes and antiviral resistance-associated mutations (RAMs) in these co-infected patients, in order to monitor the viral factors associated with the evolution of liver disease. Materials and Methods: HBV genotypes and RAMs were detected using nested PCR and line probe assays (INNO-LiPA HBV genotyping assay, and INNO-LiPA HBV DR v2, Innogenetics). Results: Out of 117 co-infected patients, 73.5% had detectable HBV-DNA, but only 38.5% presented an HBV viral load >1000 IU/mL. HBV genotype A was present in 66.7% of the cases and was dominant in patients parenterally infected during early childhood, who experienced multiple treatment regimens, with a mean therapy length of 15.25 years, and present numerous mutations associated with lamivudine (LAM) resistance, but very rarely active liver disease. HBV genotype D was detected in 33.3% of the cases, mostly in recently diagnosed injecting drug users who are treatment naïve, but, nevertheless, present RAMs in 63.5% of the cases, suggesting transmitted drug resistance, and display more frequently advanced liver fibrosis (36.1% vs. 12.3%; p = 0.033). The most frequently encountered RAMs are M204V/I: 48.8%, L180M: 33.3%, L80V: 28.8%, and V173L: 42.2%. There are no significant differences in the distribution of RAMs in patients infected with different HBV genotypes, except for the L80V and N236T mutations, which were more frequently found in HBV genotype A infections (p = 0.032 and p = 0.004, respectively). Conclusions: HBV genotypes A and D are the only genotypes present in HIV−HBV co-infected patients from Romania, with different distributions according to the infection route, and are frequently associated with multiple RAMs, conferring extensive resistance to LAM.

Production of the HBc Protein from Different HBV Genotypes in E. coli. Use of Reassociated HBc VLPs for Packaging of ss- and dsRNA.

The core proteins (HBc) of the hepatitis B virus (HBV) genotypes A, B, C, D, E, F, and G were cloned and expressed in Escherichia coli (E. coli), and HBc-formed virus-like particles (VLPs) were purified with ammonium sulfate precipitation, gel filtration, and ion exchange chromatography (IEX). The best VLP yield was found for the HBc of the HBV genotypes D and G. For the HBc of the HBV genotypes D, F, and G, the possibility of dissociation and reassociation maintaining the native HBc structure was demonstrated. Single-stranded (ss) and double-stranded (ds) ribonucleic acid (RNA) was successfully packed into HBc VLPs for the HBV genotypes D and G.

Association of hepatitis B genotypes with clinical profile of patients with chronic hepatitis B.

Hepatitis B virus (HBV) infection is a common cause of chronic liver disease and is responsible for HBV-related deaths due to cirrhosis and HCC. It is well recognized that viral genotypes play an important role on the outcome of HBV infection. Ten HBV genotypes have been identified and the prevalence varies geographically. A hospital-based cross-sectional study was conducted to determine the association of HBV genotypes with the clinical profile of CHB patients. PCR-RFLP was performed to identify HBV genotypes. In this study, majority (70%) of patients were males; with ages between 22 to 67 years with a mean of 42.5 years. The ALT ranged from 23 to 111 U/L (mean 72.5 U/L). HBV DNA levels varied from less than 6 to more than 110,000,000 IU/ml. Forty-seven percent of the patients had chronic active hepatitis at the time of diagnosis. Of these, 36% were HBeAg positive while 64% were HBeAg negative. Inactive HBsAg carrier was found in 53% of cases. No significant association was established between HBV genotypes and fibrosis. PCR-RFLP analysis showed that 57%, 10%, and 13% of the samples belonged to HBV/A, HBV/B, and HBV/C, respectively and the remaining 20% had non-detectable HBV genotype. HBV/D to HBV/J were not observed in this study. Taken together, the patient's clinical profile such as sex, ALT levels, HBeAg status, HBV DNA levels and liver histology were not found to be significantly associated with HBV genotypes. A large-scale longitudinal study examining multiple HBV strains are needed to determine significant correlation of clinical profile.

The N-Terminus Makes the Difference: Impact of Genotype-Specific Disparities in the N-Terminal Part of The Hepatitis B Virus Large Surface Protein on Morphogenesis of Viral and Subviral Particles.

The N-terminus of the hepatitis B virus (HBV) large surface protein (LHB) differs with respect to genotypes. Compared to the amino terminus of genotype (Gt)D, in GtA, GtB and GtC, an additional identical 11 amino acids (aa) are found, while GtE and GtG share another similar 10 aa. Variants of GtB and GtC affecting this N-terminal part are associated with hepatoma formation. Deletion of these amino-terminal 11 aa in GtA reduces the amount of LHBs and changes subcellular accumulation (GtA-like pattern) to a dispersed distribution (GtD-like pattern). Vice versa, the fusion of the GtA-derived N-terminal 11 aa to GtD causes a GtA-like phenotype. However, insertion of the corresponding GtE-derived 10 aa to GtD has no effect. Deletion of these 11aa decreases filament size while neither the number of released viral genomes nor virion size and infectivity are affected. A negative regulatory element (aa 2-8) and a dominant positive regulatory element (aa 9-11) affecting the amount of LHBs were identified. The fusion of this motif to eGFP revealed that the effect on protein amount and subcellular distribution is not restricted to LHBs. These data identify a novel region in the N-terminus of LHBs affecting the amount and subcellular distribution of LHBs and identify release-promoting and -inhibiting aa residues within this motive.

Key mutations in the C-terminus of the HBV surface glycoprotein correlate with lower HBsAg levels in vivo, hinder HBsAg secretion in vitro and reduce HBsAg structural stability in the setting of HBeAg-negative chronic HBV genotype-D infection.

Increasing evidences suggest that HBsAg-production varies across HBV-genotypes. HBsAg C-terminus plays a crucial role for HBsAg-secretion. Here, we evaluate HBsAg-levels in different HBV-genotypes in HBeAg-negative chronic infection, the correlation of specific mutations in HBsAg C-terminus with HBsAg-levels in-vivo, their impact on HBsAg-secretion in-vitro and on structural stability in-silico.HBsAg-levels were investigated in 323 drug-naïve HBeAg-negative patients chronically infected with HBV genotype-D(N = 228), -A(N = 65) and -E(N = 30). Genotype-D was characterized by HBsAg-levels lower than genotype-A and -E (3.3[2.7-3.8]IU/ml; 3.8[3.5-4.2]IU/ml and 3.9[3.7-4.2]IU/ml, P < 0.001). Results confirmed by multivariable analysis correcting for patients'demographics, HBV-DNA, ALT and infection-status.In genotype-D, specific C-terminus mutations (V190A-S204N-Y206C-Y206F-S210N) significantly correlate with HBsAg<1000IU/ml(P-value from <0.001 to 0.04). These mutations lie in divergent pathways involving other HBsAg C-terminus mutations: V190A + F220L (Phi = 0.41, P = 0.003), S204N + L205P (Phi = 0.36, P = 0.005), Y206F + S210R (Phi = 0.47, P < 0.001) and S210N + F220L (Phi = 0.40, P = 0.006). Notably, patients with these mutational pairs present HBsAg-levels 1log lower than patients without them(P-value from 0.003 to 0.02). In-vitro, the above-mentioned mutational pairs determined a significant decrease in HBsAg secretion-efficiency compared to wt(P-value from <0.001 to 0.02). Structurally, these mutational pairs reduced HBsAg C-terminus stability and determined a rearrangement of this domain.In conclusion, HBsAg-levels in genotype-D are significantly lower than in genotype-A and -E in HBeAg-negative patients. In genotype-D, specific mutational clusters in HBsAg C-terminus correlate with lower HBsAg-levels in-vivo, hamper HBsAg-release in-vitro and affect its structural stability, supporting their detrimental role on HBsAg-secretion. In this light, genotypic-testing can be a valuable tool to optimize the clinical interpretation of HBsAg in genotype-D and to provide information on HBV-pathogenicity and disease-progression.

Hepatitis B virus genotype G and liver fibrosis progression in chronic hepatitis B and human immunodeficiency virus coinfection.

INTRODUCTION: Infection with hepatitis B virus (HBV) genotype G has been associated with increased liver fibrosis levels compared with other genotypes in cross-sectional studies, yet its role in fibrosis evolution remains to be established. METHODS: In this prospective cohort study, 158 human immunodeficiency virus (HIV)-HBV coinfected patients had available HBV genotyping at baseline. Liver fibrosis was assessed at baseline and every 6 to 12 months by the FibroTest (BioPredictive, Paris, France). Risk factors for fibrosis regression (F3-F4 to F0-F1-F2) and progression (F0-F1-F2 to F3-F4) between baseline and end of follow-up were evaluated. RESULTS: Most patients were male (88.6%) with a median age of 39 years. HBV genotype A was more prevalent compared with other HBV genotypes (62.7% vs D = 10.8%, E = 10.8%, and G = 15.8%). Patients were followed up for a median of 83 months (IQR = 37-97). In the 43 (27.2%) patients with F3-F4 baseline liver fibrosis, 7 (16.2%) regressed to F0-F1-F2 fibrosis at the last follow-up visit. In the 115 (72.8%) with F0-F1-F2 fibrosis at baseline, 19 (16.5%) progressed to F3-F4 fibrosis at last visit. In multivariable analysis, fibrosis progression was independently associated with older age (P <0.005), baseline CD4+ cell count less than 350/mm 3 ( P <0.01), longer antiretroviral therapy duration ( P <0.03), and HBV genotype G infection (vs non-G, P <0.01). When examining averages over time, the rate of FibroTest increase was faster in genotype G vs non-G-infected patients with baseline F0-F1-F2 fibrosis ( P for interaction = 0.002). CONCLUSION: In HIV-HBV coinfected patients, HBV genotype G is an independent risk factor for liver fibrosis progression as determined by noninvasive markers. HBV genotype G-infected patients with low initial liver fibrosis levels may require more careful monitoring.

HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil.

BACKGROUND: Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil. OBJECTIVE: To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence. METHODS: A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients. RESULTS: The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each. CONCLUSIONS: These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil

ABSTRACT Background Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil. Objective To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence. Methods A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients. Results The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each. Conclusions These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

Occult Hepatitis B and Other Unexplored Risk Factors for Hepatocellular Carcinoma in Latin America.

Occult hepatitis B infection (OBI) is the presence of hepatitis B virus (HBV) DNA in the liver and/or serum (< 200 IU/mL) in HBsAgnegative patients with or without serologic markers of previous viral exposure. The clinical significance of OBI is of concern in posttransfusional hepatitis B infection, hepatitis B reactivation, chronic liver disease and hepatocellular carcinoma (HCC). The diagnosis of OBI relays on the use of highly sensitive and specific laboratory techniques. Herein, comments derived from a study analyzing the frequency and characteristics of OBI in HCC Japanese patients are stated. While OBI and other causes of HCC have been highly studied in Asia and Europe, research in Latin America in these topics is limited. Several findings such as population risk groups with high prevalence of overt and OBI infection, HBV genotype F in Argentinean HCC patients, and the clinical impact of the foreign A-D genotypes suggest the need of further investigation. Additionally, alcoholism, obesity, NASH and type 2 diabetes may override the presence of OBI. Therefore, OBI diagnosis is essential. It is known that anti-HBc alone is a predictive signal of potential OBI and given the fluctuations of the HBV infection markers, testing for HBsAg and anti-HBc at baseline and follow-up is recommended. In conclusion, OBI and other causes involved in the epidemiology of HCC in Latin America are unexplored risk factors. Genome-based research is required to decipher the role of gene-environmental interactions associated with chronic liver disease. Novel algorithms to detect OBI supported by basic/applied/clinical research are also needed.

An ultra-sensitive Abbott ARCHITECT® assay for the detection of hepatitis B virus surface antigen (HBsAg).

BACKGROUND: Critical to the identification of HBV infection and the prevention of transfusion transmitted disease is the sensitive and accurate detection of Hepatitis B virus surface antigen (HBsAg). Improvements in HBsAg assay sensitivity approaching the performance of nucleic acid testing (NAT) are essential to further reduce the detection window for acute HBV infection in regions where NAT is not widely available. OBJECTIVES AND STUDY DESIGN: An improved HBsAg assay on the fully-automated Abbott ARCHITECT® platform was developed to improve sensitivity, mutant and genotype detection. RESULTS: The analytical sensitivity of the improved prototype assay is 5.2 mIU/ml, which is 3.86- to 14.54-fold more sensitive than comparator assays based on the WHO International Reference Standard. The enhanced sensitivity was also demonstrated with 27 HBV seroconversion panels, detecting more panel members (191 of 364) vs. the ARCHITECT® Qual I (144), Qual II (160) and PRISM® (148) HBsAg assays. Further, the assay detected 7 of 12 HBV DNA positive/HBsAg negative samples, and detected all evaluated mutants and genotypes with higher sensitivity than the comparator assays. The improvement in sensitivity did not diminish assay specificity, attaining 100% (95% CI, 99.97-100%) on 10,633 blood donors. CONCLUSIONS: An Abbott ARCHITECT® HBsAg assay with clinical performance approaching that of mini-pool NAT (approximately 100 copies/ml was developed. The assay has superior HBsAg mutant and genotype detection and specificity, all of which are important for the diagnosis and management of HBV infection.

Hepatitis B Virus Genotype C is Predominant in Myanmar.

Myanmar is adjacent to India, Bangladesh, Thailand, Laos and China. In Myanmar, the prevalence of hepatitis B virus (HBV) infections is 6.5% and accounts for 60% of hepatocellular carcinoma. HBV has nine genotypes that have been identified by molecular genetic analysis. HBV genotypes are associated with several clinical features. We reviewed the prevalence of HBV genotypes in Myanmar and neighboring countries. We also reviewed HBV genotypes in refugees from Myanmar. HBV subgenotype C1 is predominant in Myanmar. As HBV genotype C is associated with hepatocellular carcinoma (HCC), it is important to screen for cirrhosis and HCC and to prevent their development in HBV-infected individuals of Myanmar.

Heterogeneous recombination among Hepatitis B virus genotypes.

The rapid evolution of Hepatitis B virus (HBV) through both evolutionary forces, mutation and recombination, allows this virus to generate a large variety of adapted variants at both intra and inter-host levels. It can, for instance, generate drug resistance or the diverse viral genotypes that currently exist in the HBV epidemics. Concerning the latter, it is known that recombination played a major role in the emergence and genetic diversification of novel genotypes. In this regard, the quantification of viral recombination in each genotype can provide relevant information to devise expectations about the evolutionary trends of the epidemic. Here we measured the amount of this evolutionary force by estimating global and local recombination rates in >4700 HBV complete genome sequences corresponding to nine (A to I) HBV genotypes. Counterintuitively, we found that genotype E presents extremely high levels of recombination, followed by genotypes B and C. On the other hand, genotype G presents the lowest level, where recombination is almost negligible. We discuss these findings in the light of known characteristics of these genotypes. Additionally, we present a phylogenetic network to depict the evolutionary history of the studied HBV genotypes. This network clearly classified all genotypes into specific groups and indicated that diverse pairs of genotypes are derived from a common ancestor (i.e., C-I, D-E and, F-H) although still the origin of this virus presented large uncertainty. Altogether we conclude that the amount of observed recombination is heterogeneous among HBV genotypes and that this heterogeneity can influence on the future expansion of the epidemic.

High prevalence of HBV infection, detection of subgenotypes F1b, A2, and D4, and differential risk factors among Mexican risk populations with low socioeconomic status.

Hepatitis B virus (HBV) infection may be underestimated among high-risk individuals in regions of low HBs antigenemia. This study aimed to assess HBV serological markers, genotypes, and risk factors in Mexican patients with risk of HBV infection and low socioeconomic status. Demographics, clinical, and risk factor data were collected in patients with HIV (n = 289), HCV (n = 243), deferred blood donors (D-BD) (n = 83), and two native populations, Mixtecos (n = 57) and Purepechas (n = 44). HBV infection was assessed by HBsAg, anti-HBc, and HBV-DNA testing. Overall, patients had low education and very-low income. Totally, HBsAg prevalence was 16.5% (113/684) ranging from 0.7% (HCV) to 37.3% (D-BD), while anti-HBc was 30.2% (207/684). Among 52 sequences, genotypes H (n = 34, 65.4%), G (n = 4, 7.7%), subgenotypes F1b (n = 7, 13.5%), A2 (n = 6, 11.5%), and D4 (n = 1, 1.9%) were detected. Surgeries, sexual promiscuity, and blood transfusions had a differential pattern of distribution. In HCV patients, single (OR = 5.84, 95%Cl 1.91-17.80, P = 0.002), MSM (OR = 4.80, 95%Cl 0.75-30.56, P = 0.097), and IDU (OR = 2.93, 95%CI 1.058-8.09, P = 0.039) were predictors for HBV infection. While IDU (OR = 2.68, 95%CI 1.08-6.61, P = 0.033) and MSM (OR = 2.64, 95%CI 1.39-5.04, P = 0.003) were predictors in HIV patients. In this group, MSM was associated with HBsAg positivity (OR = 3.45, 95%CI 1.48-8.07, P = 0.004) and IDU with anti-HBc positivity (OR = 5.12, 95%CI 2.05-12.77, P < 0.001). In conclusion, testing with a combined approach of three different HBV markers, a high prevalence of HBV infection, a differential distribution of HBV genotypes, including subgenotypes F1b, A2, and D4, as well as risk factors in low-income Mexican risk groups were detected.

Serologic and genotypic characterization of hepatitis B virus in HIV-1 infected patients from South West and Littoral Regions of Cameroon.

BACKGROUND: HBV and HIV share similar transmission routes. Concurrent infection with the two viruses usually results in more severe and progressive liver disease, and a higher incidence of cirrhosis, liver cancer and mortality. Further, this co-infection may lead to cross-resistance between HIV and HBV drugs and increased liver injury, either due to direct hepatotoxicity or drug-related immune-reconstitution hepatitis. These challenges necessitate continuous surveillance for HBV among HIV infected individuals to guide patient management. We conducted this study to understand the serologic and genotypic characteristics of HBV among HIV/HBV infected patients in South West and Littoral Regions of Cameroon. METHODS: Plasma samples were screened for HBsAg, HBeAg, Anti-HBs and anti-HBc using ELISA followed by DNA extraction from all HBsAg positive samples. A 366 bp region covering the overlapping surface/polymerase gene was amplified by a nested PCR and the product sequenced using Big Dye sequencing chemistry. The resulting sequences were then analyzed for genotypes and both escape and drug resistance mutations. RESULTS: Of the 455 samples in this study, 25.5 % (n = 116) were HBsAg positive and 46 of these had their DNA successfully amplified. Genotype E was found in 32 samples (69.6 %) and genotype A in the rest of the samples. Escape mutations associated with failure of diagnosis (Y100C, R122K and Q129H) and with vaccine escape (Q129R and T131N) were detected in varying frequencies in the population. Polymerase mutations implicated in resistance to lamivudine and other ʟ-nucleoside analogues were detected in seven patients (15.2 %), while all the samples lacked mutations associated with resistance to adefovir and tenofovir. CONCLUSIONS: These findings suggest the endemicity of HBV and the predominance of genotypes A and E in the study population. Also, drug resistance findings support the use of tenofovir based ART regimens among HIV/HBV co-infected persons. There is need for continuous HBV screening and monitoring in HIV infected individuals in these regions.

Distribution and clinical significance of hepatitis B virus genotypes in Pakistan.

BACKGROUND: Hepatitis B virus (HBV) genotype and its role in disease progression and patients' response to antiviral treatment, is not well studied in Pakistan. This comprehensive study was aimed to determine the distribution of HBV genotypes in Pakistan and their possible association with phases of HBV infection. METHODS: A total of 840 HBsAg positive samples was collected and tested for HBV DNA quantity. Samples below 100 IU/ml were excluded from the study. A total of 715 samples representing all the six parts of the country were genotyped by type specific primer PCR method. Clinical data of only 384 patients was compared as the remaining 332 were either receiving antiviral treatment or their infection phase was not confirmed. RESULTS: Genotype D was found in 509 samples (71.2 %), genotype A in 55 samples (7.7 %) and mixed infection with genotypes A and D in 124 samples (17.3 %). Genotypes B, C and E were identified in less than 1 % of the total samples. Genotype A, D and their mixture (A + D) were compared for severity of HBV infection. Significant differences were not found in distribution of HBV genotypes among different disease stages. CONCLUSION: HBV genotype D was the predominant infection in all study areas of Pakistan followed by mixed genotypes infection (A + D) whereas genotype A has 10 times lower prevalence than genotype D. Genotypes B, C, E and F altogether make only 1.5 % of the prevalence. Genotype do not appears to show the severity of liver disease.

Prevalence of mutations within major hydrophilic region of hepatitis B virus and their correlation with genotypes among chronically infected patients in Egypt.

BACKGROUND AND STUDY AIMS: Mutations within the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) have been reported in relation to viral persistence by evasion from vaccine and immunotherapy, severity of liver disease and lack of detection by commercial kits. The aim of this study was to elucidate the circulation of hepatitis B virus (HBV) genotypes, subgenotypes and serotypes in Egypt, with recognition of the pattern and prevalence of MHR mutations possibly occurring during the course of the disease. PATIENTS AND METHODS: Eighty-eight samples from patients with chronic HBV infection were included in the study. The surface protein-encoding gene (S gene) in the HBV genome was subjected to amplification and partial sequencing. RESULTS: Based on phylogenetic analysis, only genotype D was found circulating among patients. The majority of isolates belonged to subgenotype D3 (86.3%), followed by D7 (8%), then D5 (3.4%) and lastly D1 (2.3%). Two subtypes were identified: ayw2 (97%) and ayw3 (2%). The 'w' sub-determinant was not defined in one isolate (1%). A significant proportion of patients (13/88, 14.8%) exhibited mutations in the MHR, 10 of whom harboured mutations in the 'a' determinant region and three outside. The first loop comprised four patients with three mutations (P127S, P127T and Y134F). The second loop contained six patients, all with one mutation, S143L, which was most frequently encountered in this study (6.8%). CONCLUSIONS: We conclude that genotype D, subgenotype D3 and HBsAg subtype ayw2 are the most common types circulating in Egypt, which account for 100%, 86.3% and 97% of the population, respectively, with a moderate degree of MHR mutations.

Hepatitis B virus genotyping in chronic hepatitis B patients in southwestern Saudi Arabia.

The distribution of hepatitis B virus genotypes in Saudi Arabia is largely unknown. To the best of our knowledge there are no data available about HBV genotypes in southwestern region of the country. This study aimed to determine the epidemiologic distribution of hepatitis B virus genotypes in chronic hepatitis B patients in southwestern region, and to verify possible correlations between these genotypes and the clinical symptoms. A total of 160 patients with chronic hepatitis B infection were enrolled in this study. Sera were tested for liver function tests, hepatitis B virus markers and DNA load by standard procedures. HBV genotyping was performed by 2-tube nested PCR for determination of six genotypes (A-F). Genotype D was the most common, found in 135 (84.4%) patients, followed by A (18; 11.3%) and E (7; 4.3%). The rate of HBeAg positivity in genotype D patients was significantly lower compared with that in genotype A and E patients (p=0.01). There was no significant association between HBV genotypes and age, gender, liver function tests, or HBV DNA load. Genotypes D and E were predominant in chronic hepatitis B patients in southwestern Saudi Arabia. Awareness of hepatitis B virus serologic and genotypic patterns might help in the formulation of management plans, predicting clinical outcomes and updating prevention strategies.

The impact of viral molecular diversity on the clinical presentation and outcome of acute hepatitis B in Italy.

The incidence of acute hepatitis B (AHB) in Italy, mostly sustained by hepatitis B virus (HBV) genotype D, has significantly decreased in the last two decades, but the new HBV strains introduced through immigrant populations from countries with a higher endemicity constitute a new emergency. HBV-genotype D still predominates in AHB, the subgenotype D3 being associated with parenteral transmission, and the recently emerging subgenotype A2 with unsafe sexual intercourse. Genetic, phylogenetic and evolutional analyses are powerful tools for countries with high immigration rates to monitor new viral strains with different aggressiveness and a different response to therapy.

Influence of the basal core promoter and precore mutation on replication of hepatitis B virus and antiviral susceptibility of different genotypes.

Mutations in the basal core promoter (BCP) and precore (PC) regions of the hepatitis B virus (HBV) are more common in genotypes B and C than in genotype A, suggesting that these mutations might affect replication competency depending on genotype. The purpose of the study was to investigate the influence of these mutations on the capacity of HBV for replication and antiviral drug susceptibility according to genotype. Genotypes A, B, and C of HBV strains with a BCP mutation, PC mutation, or BCP + PC mutation were made by site-directed mutagenesis. Replication competency of each construct and susceptibility to nucleos(t) ide analogues were tested in an Huh7 cell line. In genotype A, the BCP and BCP + PC mutations increased the viral replication around 6.5 times compared with the wild type, and the PC mutation alone similarly increased the viral replication around three times. In genotypes B and C, all three mutant types increased viral replication to a similar extent, regardless of mutation pattern. Interestingly, the BCP mutation appeared to have a greater effect on viral replication in genotype A than in genotypes B and C. This finding was unexpected because the BCP mutation is more common in HBV genotypes B and C. Moreover, the BCP, PC, and BCP + PC mutations decreased the sensitivity of HBV to antiviral agents to various degrees (2- to 10-fold) regardless of genotype. In conclusion, BCP and PC mutations increased viral replication regardless of HBV genotype and decreased in vitro antiviral susceptibility to the nucleos(t) ide analogues.