Giant cerebellar cavernous malformation in children: A case report and literature review.

Giant cerebellar cavernomas in children are rare and must be differentiated from hemorrhagic cerebellar tumors. The diagnosis and treatment of giant cerebellar cavernomas is challenging, but complete surgical resection can lead to favorable outcomes and complete neurological recovery in most cases. We present a case of eight months old baby who was diagnosed with a giant cavernoma resulting in secondary obstructive hydrocephalus with neuropsychiatric presentations. The patient underwent a paramedian craniotomy surgery with a suboccipital approach and complete surgical resection of the cavernoma was done. Over nine months of observation, the child showed improvement in their ability to walk and fully recovered from a neurological perspective. We also conducted a literature review to identify eleven cases of giant cerebellar cavernomas in children, including our case. The data were analyzed to determine the clinical features, treatment, and outcomes of giant cerebellar cavernomas in children.

IFNL3 genotype is associated with differential induction of IFNL3 in primary human hepatocytes.

BACKGROUND: Lambda interferons (IFNLs) have potent antiviral activity against HCV, and polymorphisms within the IFNL gene cluster near the IFNL3 gene strongly predict spontaneous- and treatment-related HCV infection outcomes. The mechanism(s) linking IFNL polymorphisms and HCV control is currently elusive. METHODS: IFNL induction was studied in primary human hepatocytes (PHH) from 18 human donors, peripheral blood mononuclear cells (PBMCs) from 18 human donors, multiple cell lines and induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-hepatocytes) from 7 human donors. After stimulation with intracellular RNA and infectious HCV, quantitative PCR (qPCR) primers and probes were designed to distinguish and quantify closely related IFNL messenger (m)RNAs from IFNL1, IFNL2 and IFNL3. RESULTS: PHH demonstrated the most potent induction of IFNLs, although had lower pre-stimulation levels compared to PBMCs, monocytes and cell lines. PHH stimulation with cytoplasmic poly I:C induced >1,000-fold expression of IFNL1, IFNL2 and IFNL3. PHH from donors who were homozygous for the favourable IFNL3 allele (IFNL3-CC) had higher IFNL3 induction compared to PHH from IFNL3-TT donors (P=0.03). Baseline IFNL mRNA expression and induction was also tested in iPSC-hepatocytes: iPSC-hepatocytes had significantly higher baseline expression of IFNLs compared to PHH (P<0.0001), and IFNL3 induction was marginally different in iPSC-hepatocytes by IFNL genotype (P=0.07). CONCLUSIONS: Hepatocytes express IFNLs when stimulated by a synthetic viral RNA that signals the cell through the cytoplasm. IFNL induction may be greater in persons with the favourable IFNL3 allele. These data provide insight into the strong linkage between IFNL3 genetics and control of HCV infection.

Molecular identification of hepatitis B virus genotypes/subgenotypes: revised classification hurdles and updated resolutions.

The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term "recombino-subgenotype". Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term "immigro-subgenotype" to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.

In vitro replication competence of a hepatitis B genotype D/A recombinant virus: dissimilar biological behaviour regarding its parental genotypes.

Hepatitis B virus (HBV) DNA recombinants contribute to ~30% of the overall full-length sequences already deposited in GenBank. However, their biological behaviour has not been analysed so far. In this study, the in vitro replication kinetics of the first D/A recombinant from the American continent differed from its parental genotypes, exhibiting higher extracellular levels of HBV DNA and hepatitis B e antigen. Southern blots of intracellular core-associated HBV DNA were in agreement with such results. Because this recombinant was obtained from an Argentinian injecting drug user belonging to a vulnerable community, these results are of singular relevance for regional public health. Further in vivo studies are urgently needed to determine the pathogenicity of these replicative competent clones.

Tracing the spread of hepatitis C virus in Turkey: a phylogenetic analysis.

BACKGROUND/AIMS: Molecular epidemiology of hepatitis C virus (HCV) shows that HCV genotypes are unique with respect to their nucleotide sequence, geographical distribution and clinical relationship. METHODS: In this study we enrolled 67 HCV-infected individuals with various stages of liver disease from four geographical regions of Turkey. A partial NS5B region of the HCV genome was sequenced and subjected to phylogenetic analysis to determine the circulating HCV genotypes and subtypes. RESULTS: The results showed that HCV genotype 1 (subtype1b) is the main genetic variant of HCV in Turkey but did not reveal any Turkish indigenous phylogenetic cluster. Phylogenetic analysis showed that Turkish strains have their closest matches from both Asia (Japan) and Europe/USA. CONCLUSIONS: In view of Turkey's geographic position, HCV-1b transmission from Europe is not exceptional. This study could not establish a clear role of other HCV genotypes prevalent in neighboring Asian countries in Turkey's HCV transmission, which would need to be confirmed by further regional epidemiological studies.

Specific mutations of basal core promoter are associated with chronic liver disease in hepatitis B virus subgenotype D1 prevalent in Turkey.

The role of hepatitis B virus (HBV) genetics in the clinical manifestations of infection is being increasingly recognized. Genotype D is one of eight currently recognized major HBV genotypes. The virus is ubiquitous worldwide, but shows different features in different regions. One hundred and ninety-eight patients with chronic HBV infection were enrolled in this study, 38 of whom had been diagnosed with cirrhosis of the liver and/or hepatocellular carcinoma. HBV DNA was isolated from the patients' blood samples and the entire genome and/or the basal core promoter/core promoter region sequenced. Phylogenetic analysis of the complete genomes revealed that subgenotype D1 is the most prevalent subgenotype in Turkey, but there was no definite phylogenetic grouping according to geography for isolates from different regions within Turkey, or for isolates in Turkey relative to other parts of the world. Turkish isolates tended to be genetically similar to European and central Asian isolates. Overall, HBV-infection in Turkey appears to be characterized by early HBeAg seroconversion, a high incidence of the A1896 core promoter mutation and a small viral load. Genotype D characteristic mutations A1757 and T1764/G1766 were found in the BCP region. T1773 was associated with T1764/G1766 and a larger viral load. In conclusion, infection with HBV genotype D in Turkey has a similar clinical outcome to that of Europe and central Asia. Genotypic mutations in genotype D may be linked with disease prognosis in Turkey, but further studies with higher sample numbers and balanced clinical groups are needed to confirm this.

Genetic polymorphism in IL28B is associated with spontaneous clearance of hepatitis C virus genotype 4 infection in an Egyptian cohort.

Single-nucleotide polymorphisms (SNPs) around IL28B are associated with spontaneous hepatitis C virus (HCV) clearance of genotypes 1 and 3 in white and African-American populations. This study investigated whether the IL28B SNP (rs12979860) is associated with spontaneous clearance of HCV, principally genotype 4, in 162 Egyptians (80 with clearance). The protective C allele was more common in those with spontaneous clearance (76.3% vs 57.9%; P = .0006). Individuals with clearance were 3.4 (95% confidence interval, 1.8-6.5) times more likely to have C/C genotype. Thus, IL28B plays a role in spontaneous clearance of HCV genotype 4 in North Africa.

Investigating an outbreak of acute viral hepatitis caused by hepatitis E virus variants in Karachi, South Pakistan.

Hepatitis E is a classic water-borne disease in developing countries. Detection of anti-HEV IgM and IgG antibodies, in addition to HEV RNA are useful epidemiological markers in diagnosis of hepatitis E. This study was conducted to investigate an outbreak of acute viral hepatitis in South-Pakistan. Anti-HEV IgM and IgG were assessed comparatively with serological kits manufactured by Abbott, Cosmic, TGH, and Wantai, selecting HEV RNA as reference assay. Molecular evolutionary analysis was performed by phylogeny and HEV spread time analysis by Bayesian Coalescent Theory approach. Of the 89 patients, 24 (26.9%) did not have acute hepatitis viral marker. Of the remaining 65 cases, 4 (6.1%) were positive for anti-HAV IgM, one (1.5%) for anti-HBc IgM, 2 (3%) for HCV, 53 (81.5%) for anti-HEV IgM, and 5 (7.7%) were hepatitis-negative. The Wantai test was 100% sensitive and specific followed by Cosmic (98.1% and 100%), TGH (98.1% and 97.2%) and Abbott (79.2% and 83.3%). Two HEV variant strains were detected by phylogeny responsible for this acute hepatitis outbreak. Estimates on demographic history of HEV showed that HEV in Pakistan has remained at a steady nonexpanding phase from around 1970 to the year 2005, in which it expanded explosively with the emergence of new HEV variants. In conclusion, the limited sensitivity of available assay (Abbott anti-HEV EIA) may be a concern in HEV diagnosis in Pakistan. This study cautions that the dissemination of the variant strains to other areas of Pakistan may lead to explosive HEV outbreaks.

Virological and clinical characteristics on reactivation of occult hepatitis B in patients with hematological malignancy.

The virological characteristics of hepatitis B virus (HBV) implicated in the reactivation of occult hepatitis B in patients who have received hematopoietic stem-cell transplantation or chemotherapy for the hematological malignancy are not well defined. Twenty-eight HBsAg-negative patients who received hematopoietic stem-cell transplantation and 138 HBsAg-negative patients treated for malignant lymphoma with chemotherapy including rituximab were enrolled. Three of the 28 patients (10.7%) received hematopoietic stem-cell transplantation and one of the 138 (0.72%) patients treated for malignant lymphoma with chemotherapy developed de novo HBV hepatitis. Anti-HBc was detected in four and anti-HBs in two patients. Genotype Bj was detected in two and C in two of they all possessed wild-type sequences in the core promoter region. A precore stop mutation (A1896) was detected in a patient with genotype Bj who developed fulminant hepatic failure. HBV DNA was detected in pretreatment HBsAg-negative samples in two of four patients, and the HBV genome sequence identified from sera before chemotherapy and at the time of de novo HBV hepatitis showed 100% homology. In an in vitro replication model, genotype Bj with the A1896 clone obtained from a fulminant case had a replication level much higher than clones obtained from de novo hepatitis B patients with genotype Bj or C with G1896. In conclusion, this is the first report demonstrating de novo hepatitis B from the reactivation of occult HBV infection confirmed by molecular evolutional analysis. The fulminant outcome of HBV reactivation can be associated with genotype Bj exhibiting high replication due to the A1896 mutation.

Evolution of hepatitis B genotype C viral quasi-species during hepatitis B e antigen seroconversion.

BACKGROUND & AIMS: Although the evolution of viral quasi-species may be related to the pathological status of disease, little is known about this phenomenon in hepatitis B, particularly with respect to hepatitis B e antigen (HBeAg) seroconversion. METHODS: Nucleotide sequences of the hepatitis B virus (HBV) X/precore/core region was analyzed at five time-points in four groups of chronic hepatitis B patients, interferon-induced seroconverters (IS, N = 9), interferon non-responders (IN, N = 9), spontaneous seroconverters (SS, N = 9), and non-seroconverters (SN, N = 9) followed during 60 months on an average. Only patients with genotype C were studied. RESULTS: Analysis of 1800 nucleotide sequences showed that there was no statistical difference between the nucleotide genetic distances of seroconverters (IS and SS; 6.9 × 10⁻³ substitutions (st)/site and 6.7 × 10⁻³ st/site, respectively) and those of non-seroconverters (IN and SN; 5.3 × 10⁻³ st/site and 3.8 × 10⁻³ st/site, respectively) before seroconversion. Compared to non-seroconverters (IN and SN; 5.1 × 10⁻³ st/site and 5.9 × 10⁻³ st/site, respectively), the sequence diversity of seroconverters (IS and SS; 10.9 × 10⁻³ st/site and 9.9 × 10⁻³ st/site, respectively) was significantly higher after seroconversion (p < 0.05), and was higher in seroconverters after seroconversion than before seroconversion (p < 0.05), while this changed very little in non-seroconverters during the observation period. Phylogenetic trees showed greater complexity in secoconverters than non-seroconverters. Parsimony-based estimation of the direction of sequence change between descendants and ancestors before HBeAg seroconversion, revealed higher frequencies of transversional A to T substitution in seroconverters (0.06 vs. 0.02, p = 0.0036) that coincided with the dynamics of quasi-species possessing A1762T mutation. CONCLUSIONS: The distinctly greater viral diversity in HBeAg seroconverters after seroconversion could be related to escape mutants resulting from stronger selection pressure.

A population-based cohort study for the risk factors of HCC among hepatitis B virus mono-infected subjects in Japan.

BACKGROUND: There have only been a few prospective studies investigating risk factors associated with the development of hepatocellular carcinoma (HCC) among chronic hepatitis B patients all over the world, and no study has been conducted in Japanese population. METHODS: A population-based cohort consisting of 19393 subjects (middle aged or older) with over 13 years' follow-up was investigated in Japan. RESULTS: Of 19393 subjects, 479 had hepatitis B virus (HBV) mono-infection (2.5%). During the 245923 person-years' follow-up (average follow-up period 12.7 years), 13 cases of newly diagnosed HCC were documented in the HBV mono-infected group. Several factors at baseline (male, smoking, alanine aminotransferase, the positivity of HBe antigen and HB core-related antigen, the proportion of HBV DNA ≥ 5 log copies/mL, T1753V mutation, and A1762T/G1764A double mutation) were significantly associated with HCC among HBV mono-infected subjects. Multivariate-adjusted Cox hazard model showed that A1762T/G1764A (hazard ratio 7.05 [95% confidence interval (CI) 1.03-48.12, P = 0.046]) was the only independent risk factor for the development of HCC. Kaplan-Meier method also showed that the probability of HCC occurrence-free was significantly lower in HBV mono-infected subjects with A1762T/G1764A double mutation than those without these mutations. CONCLUSION: HBV mono-infected subjects with A1762T/G1764A double mutation could be at high risk of HCC development during the natural course of HBV infection.

High sensitivity assay using serum sample for IL28B genotyping to predict treatment response in chronic hepatitis C patients.

AIM: Recent human genome-wide association studies (GWAS) revealed a strong association between IL28B gene variation and the pegylated interferon-α with ribavirin (PEG-IFN-α/RBV) treatment response in chronic hepatitis C patients. Two single nucleotide polymorphisms (SNP), rs8103142 and rs11881222 located in the IL28B gene, were found in significant association with the viral clearance. The present study employed these SNPs to develop a new accessible screening method allowing identification of potential non-responders before starting the therapy. METHODS: Primer sets were designed to amplify rs8103142 and rs11881222 fragments from genomic DNA extracted from serum samples. This method was validated using microarray typing (GWAS) and applied for genotyping of 68 hepatitis C virus-infected patients with PEG-IFN-α/RBV treatment at baseline. RESULTS: In comparison with GWAS, the screening method showed 100% and 95.6% accuracy in typing of rs8103142 and rs11881222, respectively, indicating incomplete specificity but 100% of sensitivity in both. Genotyping by both SNP showed that 53 (77.9%), 14 (20.6%) and one (1.5%) of the patients were of major homozygous, heterozygous and minor homozygous type, respectively. The majority (85%) of homozygous patients exhibited response to therapy in contrast to heterozygous patients (29%). Among all genotyped only one case was found with the minor homozygous genotype which had late virological response to therapy before relapsing. CONCLUSION: This study described a highly sensitive assay that can be useful in determining SNP genotypes as well as in predicting the response to IFN-based treatment.

Performance of two Real-Time RT-PCR assays for quantitation of hepatitis C virus RNA: evaluation on HCV genotypes 1-4.

Accuracy for monitoring of the concentration of hepatitis C virus (HCV) RNA represents a major challenge throughout the management of patients with chronic hepatitis C. To investigate the genotype-independent efficiency and the accuracy of two real-time detection reverse transcription-polymerase chain reaction (RT-PCR) assays; the Cobas Ampliprep/Cobas TaqMan (CAP/CTM); and the Abbott RealTime HCV (ART), a total of 184 samples with different HCV subtypes were examined; 1b (n=58), 2a (n=39), 2b (n=26), 3a (n=20), and 4 (n=41). A robust linear correlation was observed between the two assays applied to genotypes 1b, 2a, 2b, and 3a [the correlation coefficient (R) ranged from 0.99 to 0.98], but not to genotype 4 specimens (R=0.78). A significant difference in measurements of HCV RNA using CAP/CTM and ART in serum samples with genotypes 1b and 4 was observed (0.72, -0.53 log IU/ml, P<0.0001, 0.01, respectively). A robust correlation was observed between the HCV core antigen and HCV RNA values by either of the HCV RNA quantitation assays applied to all genotypes with exception of genotype 4, for which R was higher with ART (R=0.95) than with CAP/CTM (R=0.80). The lower limit of detection of CAP/CTM and ART were 41.4 and 28.5 IU/ml using the WHO standards, respectively. In conclusion, two RT-PCR assays had a high efficiency and accuracy for quantitation of HCV RNA of genotypes 2a, 2b, and 3a, but the mean values of HCV RNA differed for genotype 1b and 4.

Occult hepatitis B in the genotype H-infected Nahuas and Huichol native Mexican population.

Mexico is considered to be a low endemic country for HBV infection. However, a high anti-HBc against a low hepatitis B surface antigen (HBsAg) seroprevalence is the reported characteristic of native Mexicans. HBV diagnosis and genotype distribution was examined in native populations (Nahuas and Huichol, n = 306), and compared to a non-native population (Mestizos, n = 17). Overall, 6% of the natives were positive for HBsAg and 33% had detectable anti-HBc. HBsAg prevalence was lower in Nahuas compared to Huichols (1.4% vs. 9.4%, P < 0.002). Occult hepatitis B was detected in 14.2% (41/289) of natives, who either tested positive (5.88%, 17/289 HBsAg-negative) or negative for anti-HBc marker (8%, 24/289 HBsAg-negative). Age-adjusted anti-HBc seroprevalence and HBsAg quantitation revealed a sub-optimal sensitivity of conventional immunoassays. Nahuas had HBV/H and Huichol had HBV/A as the predominant genotypes followed by genotypes D, C, B, A, and D, G and H, respectively. A less variable HBV/H was characteristic in Mestizos, compared to a much variable HBV/H identified among the Nahuas. In conclusion, these findings indicate a high HBV endemicity among native Mexican groups where occult B infection is common. The different distribution of HBV genotypes among natives suggests multiple reservoirs of HBV from which these genotypes spread into the local communities. High anti-HBc seroprevalence against a low HBsAg prevalence rate may be due to the limited sensitivity of the immunoassays for the detection of HBsAg that are available in Mexico and/or unknown immunogenetic characteristics of native Mexicans.

Positive selection of core 70Q variant genotype 1b hepatitis C virus strains induced by pegylated interferon and ribavirin.

BACKGROUND: Approximately 20% of patients with hepatitis C virus (HCV) genotype 1b infection have nonresponse to the most current treatment, pegylated interferon with ribavirin. Mutations in the HCV core region were recently proposed to be associated with nonresponse. Our aim was to evaluate the viral factors associated with treatment failure. METHODS: HCV variants were determined directly and after cloning in 66 HCV-1b-infected Japanese patients and in 5 urokinase-type plasminogen activator transgenic severe combined immunodeficiency mice with human hepatocytes (chimeric mice), at baseline, during treatment, and after treatment. RESULTS: At baseline, glutamine at position 70 of the HCV core protein (70Q) was detected by direct sequencing in 20% of patients with virologic response and in 43.8% of patients with nonresponse. Among patients with nonresponse, who were examined during and after treatment, the prevalence of the 70Q substitution increased to 56.3%, which indicates that treatment-induced selection occurred in all patients with nonresponse who had 70Q quasispecies detectable by cloning. This observation was reinforced by the results from experimentally infected chimeric mice. Logistic regression analysis indicated that detection of 70Q quasispecies was associated with a statistically significantly increased risk of nonresponse (odds ratio, 15.1; P = .004) in the studied cohort. CONCLUSION: Presence of the 70Q quasispecies at baseline was associated with an increased risk of treatment failure, as indicated by the positive selection of the 70Q clones induced by treatment with pegylated interferon with ribavirin. These results urge further investigation of the mechanisms of this association.

Molecular epidemiology of hepatitis C virus genotypes in west Mexico.

The identification of hepatitis C virus (HCV) genotypes and subtypes may be helpful to identify the source of an HCV outbreak among a specific group of individuals within a given country or the pattern of spread throughout nations worldwide. Mexico is a transit country for people who migrate north towards the United States from Central and South America, however, to date, no Mexican HCV sequences have been reported. The present study was conducted to identify the HCV genotypes and subtypes prevalent in Mexico by DNA sequencing and phylogenetic analysis in the NS5B region of the HCV genome. Serum samples from a total of 75 anti-HCV positive patients were included in this study. Out of the 75 samples, 48 cases (64%) were amplifiable in the 5' UTR and 46 (61%) in NS5B region. HCV genotype 1a determined in 54.3% (25/46) was predominant in this cohort, followed by 1b 21.8% (10/46), 2b 13% (6/46), 3a 6.5% (3/46), and 2a 4.4% (2/46). Phylogenetic analysis showed that HCV sequences of genotype 1 (1a and 1b) were clustering more closely to the United States isolates published previously. These results may suggest that both Mexico and the United States share an epidemiological network of HCV genotype 1 while other genotypes represent sporadic infections that are specific to Mexico.

Geographical and genetic diversity of the human hepatitis B virus.

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.

Mechanism of entecavir resistance of hepatitis B virus with viral breakthrough as determined by long-term clinical assessment and molecular docking simulation.

The mechanism by which entecavir resistance (ETVr) substitutions of hepatitis B virus (HBV) can induce breakthrough (BT) during ETV therapy is largely unknown. We conducted a cross-sectional study of 49 lamivudine (LVD)-refractory patients and 59 naïve patients with chronic hepatitis B. BT was observed in 26.8% of the LVD-refractory group during weeks 60 to 144 of ETV therapy. A line probe assay revealed ETVr substitutions only in the LVD-refractory group, i.e., in 4.9% of patients at baseline, increasing to 14.6%, 24.4%, and 44.8% at weeks 48, 96, and 144, respectively. Multivariate logistic regression analysis adjusted for age, gender, HBV DNA levels, and LVD resistance (LVDr) (L180M and M204V, but not M204I) indicated that T184 substitutions and S202G (not S202C) were a significant factor for BT (adjusted odds ratio [OR], 141.12, and 95% confidence interval [CI], 6.94 to 2,870.20; OR, 201.25, and 95% CI, 11.22 to 3608.65, respectively). Modeling of HBV reverse transcriptase (RT) by docking simulation indicated that a combination of LVDr and ETVr (T184L or S202G) was characterized by a change in the direction of the D205 residue and steric conflict in the binding pocket of ETV triphosphate (ETV-TP), by significantly longer minimal distances (2.2 A and 2.1 A), and by higher potential energy (-117 and -99.8 Kcal/mol) for ETV-TP compared with the wild type (1.3 A; -178 Kcal/mol) and LVDr substitutions (1.5 A; -141 Kcal/mol). Our data suggest that the low binding affinity of ETV-TP for the HBV RT, involving conformational change of the binding pocket of HBV RT by L180M, M204V plus T184L, and S202G, could induce BT.

A genetic variant of hepatitis B virus divergent from known human and ape genotypes isolated from a Japanese patient and provisionally assigned to new genotype J.

Hepatitis B virus (HBV) of a novel genotype (J) was recovered from an 88-year-old Japanese patient with hepatocellular carcinoma who had a history of residing in Borneo during the World War II. It was divergent from eight human (A to H) and four ape (chimpanzee, gorilla, gibbon, and orangutan) HBV genotypes, as well as from a recently proposed ninth human genotype I, by 9.9 to 16.5% of the entire genomic sequence and did not have evidence of recombination with any of the nine human genotypes and four nonhuman genotypes. Based on a comparison of the entire nucleotide sequence against 1,440 HBV isolates reported, HBV/J was nearest to the gibbon and orangutan genotypes (mean divergences of 10.9 and 10.7%, respectively). Based on a comparison of four open reading frames, HBV/J was closer to gibbon/orangutan genotypes than to human genotypes in the P and large S genes and closest to Australian aboriginal strains (HBV/C4) and orangutan-derived strains in the S gene, whereas it was closer to human than ape genotypes in the C gene. HBV/J shared a deletion of 33 nucleotides at the start of preS1 region with C4 and gibbon genotypes, had an S-gene sequence similar to that of C4, and expressed the ayw subtype. Efficient infection, replication, and antigen expression by HBV/J were experimentally established in two chimeric mice with the liver repopulated for human hepatocytes. The HBV DNA sequence recovered from infected mice was identical to that in the inoculum. Since HBV/J is positioned phylogenetically in between human and ape genotypes, it may help to trace the origin of HBV and merits further epidemiological surveys.

Epidemic spread of hepatitis C virus genotype 3a and relation to high incidence of hepatocellular carcinoma in Pakistan.

Studies conducted in different populations worldwide revealed an association between HCV genotype 1 and the development of hepatocellular carcinoma (HCC) than in infection with other HCV genotypes. There are reports which reveal the association of HCV genotype 3a (HCV-3a) with hepatic steatosis and fibrosis but its relation with the development of HCC has not been investigated. In Pakistan, where the incidence of HCC is increasing, 189 patients with chronic liver disease including 82 with HCC were enrolled. HCV genotypes were determined by phylogeny in the NS5B region and the epidemic history of HCV-3a was examined using coalescent theory based methods. HCV-3a was the predominant genotype (81.4%) in the cohort studied, followed by 3b (9.3%), 3k (2.3%), 1a (1.5%), 1c (1.5%), 1b (0.8%), and 2a (0.8%) where 76% of HCC and 86% of non-HCC were infected with HCV-3a. The significant factors associated with HCC were older age (mean +/- SD) 55.8 (+/-9.9) (P < 0.0001), and male gender (P < 0.001). HCV RNA was significantly higher in patients with HCC and chronic hepatitis than in liver cirrhosis (P < 0.0001). Molecular evolutionary analysis revealed a distinct phylogenetic cluster of HCV-3a in Pakistan and an estimation of the effective number of HCV infections indicated the appearance of HCV-3a in this region around 1920s and a rapid exponential growth in the 1950s. This indicates that the epidemic spread of HCV-3a occurred earlier in Pakistan than in other countries in which this genotype has been reported. HCV-3a which spread earlier in Pakistan may be associated with an increasing incidence of HCC.