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.

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.

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.

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.

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.

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.

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.

Direct cytopathic effects of particular hepatitis B virus genotypes in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mouse with human hepatocytes.

BACKGROUND & AIMS: Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes. METHODS: Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera. RESULTS: Histologic analysis of mice infected with HBV/C2 for 22-25 weeks showed abundant ground-glass appearance of the hepatocytes and fibrosis in the humanized part of the murine liver owing to the activation of hepatic stellate cells mediated by oxidative stress through transforming growth factor-beta1 signaling, whereas neither was observed with HBV/A2 and B1. The HBV-DNA level in sera was the highest in mice infected with HBV/C2 compared with those with HBV/A2 and HBV/B1 (10(9), 10(7), and 10(4) log copies/mL, respectively, P < .05) during 6-8 weeks postinoculation. HB core-related antigen excretion had a similar trend among the genotypes, whereas secretion of HB surface antigen was more pronounced for HBV/A2 followed by HBV/C2 and much less for HBV/B1. Introduction of precore stop-codon mutation in the HBV/B1 caused a significant increase in viral replication, antigen expression, and a histopathologic picture similar to HBV/C2. CONCLUSIONS: By using a humanized in vivo model, we show that different HBV genotypes and even particular mutations resulted in different virologic and histopathologic outcomes of infection, indicating that particular genetic variants of HBV may be directly cytopathic in immunosuppressive conditions.

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.

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.

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.

Abbott RealTime hepatitis C virus (HCV) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assays for prediction of sustained virological response to pegylated interferon and ribavirin in chronic hepatitis C patients.

Two commercial real-time PCR assays are currently available for sensitive hepatitis C virus (HCV) RNA quantification: the Abbott RealTime HCV assay (ART) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM). We assessed whether the two real-time PCR assays were more effective than Roche Cobas Amplicor HCV Monitor test, v.2.0 (CAM) for prediction of the sustained virological response (SVR) to pegylated interferon (PEG-IFN) plus ribavirin (RBV) in chronic hepatitis C. Sixty patients chronically infected with HCV genotype 1b (37 males and 23 females, 53 +/- 12 years of age) were treated with PEG-IFNalpha2b plus RBV for 48 weeks. Stored specimens at nine time points for each patient (at baseline, on treatment, and 24 weeks after treatment) were tested by the two real-time PCR assays and CAM. Twenty-six (43.3%) patients reached SVR. The positive predictive values (PPVs) for SVR of undetectable HCV RNA at week 12 by CAM, ART, and CAP/CTM were 74.3%, 88.0%, and 95.2%, respectively. An undetectable HCV RNA level by CAM, ART, and CAP/CTM correctly predicted SVR at week 4 in 100%, 100%, and 100% of patients, at weeks 5 to 8 in 91.7%, 100%, and 100% of patients, at weeks 9 to 12 in 55.6%, 75%, and 87.5% of patients, and at weeks 13 to 24 in 0%, 26.7%, and 40% of patients, respectively. Of 16 patients who relapsed after treatment, HCV RNA was detectable in 2 patients at the end of treatment by CAP/CTM but undetectable by ART and CAM. HCV RNA tests using ART and CAP/CTM are considered to be more effective at predicting SVR than CAM, and the PPV for SVR was slightly higher in CAP/CTM than in ART.

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.

Genetic variability of hepatitis C virus in South Egypt and its possible clinical implication.

Egypt is one of the countries with very high rates of hepatitis C virus (HCV) related morbidity and mortality. However, little is known about geographical and clinical differences in genetic variability of HCV in Egypt. Using direct sequencing and phylogenetic analysis of partial core/E1 and NS5B regions of the HCV genome, HCV genotype/subtype was determined in 129 HCV-infected patients residing in three governates in south Egypt: Assuit, Sohag, and Qena. According to clinical stage of infection, patients were categorized into four groups: asymptomatic carriers, n = 16; chronic hepatitis C patients, n = 36; liver cirrhosis, n = 54; and hepatocellular carcinoma (HCC), n = 23. Genotype 4a was detected in 80.6%, whereas 1g, 4l, 4n, 4o, 4f, and 4m were identified in 7.7%, 4.7%, 3.9%, 1.6%, 0.8%, and 0.8% of cases, respectively. The prevalence of 4a differed regionally; from 88.5% (in Sohag) to 64% (in Assuit, P = 0.002). Genotypes 4l and 4n had a higher prevalence in Assuit (12.8%, 10.3%) than Sohag (0%, 0%; P < or = 0.011). Difference in clinical features of determined genotypes/subtypes was observed; more carriers of non-4a variants (4l and 4n, 4f, or 4m) had chronic hepatitis compared to carriers of 4a (53.3% vs. 23.1%, P = 0.025), while more patients with 4a had liver cirrhosis (45.2% vs. 13.3%, P = 0.023). Two HCV-4o strains were isolated in this study, both from patients with HCC. In conclusion, geographical diversity of HCV was revealed in this study in southern Egypt. A further case-control study is required to confirm the trends of differential pathogenicity of HCV subtypes, indicated by this study.

Transmission of hepatitis B virus (HBV) genotypes among Japanese immigrants and natives in Bolivia.

Hepatitis B virus genotypes are associated with transmission pattern, virological and clinical features and outcome of the chronic infection course. HBV genotypes other than Genotype F (HBV/F) are considered a reflection of human migration into South America. A total of 487 individuals in Bolivia, including Japanese immigrants (n=287) and natives (n=200), were screened for HBV serological markers. Overall 22/487 (4.5%) of the subjects were positive for HBsAg, 217/487 (44.5%) for anti-HBc and 162/487 (33.3%) for anti-HBs. Genotypes were determinable in 22 cases by EIA, followed by sequencing and phylogenetic analysis in 17 cases. HBV genotype distribution in Japanese and Bolivians was HBV/F (4 and 8); HBV/C (5 and 3); and HBV/B (1 and 1), respectively. Phylogenetic analyses of nine complete and eight partial (HBsAg/pre-core/core region) genomes, revealed that HBV/F strains cluster with previously reported regional strains, whereas HBV/B and HBV/C strains belonged to Asian subgenotype B2 (Ba) and C2 (Ce), respectively. Japanese immigrants might have introduced HBV/B and HBV/C to natives in Bolivia, conversely, exposed to the indigenous HBV/F. This report provides evidence of an inter-communities transmission of HBV revealed by its genotypes. Further study is required to investigate peculiarities of the genotypes in different ethnic groups in Bolivia.

Detection of hepatitis C virus natural recombinant RF1_2k/1b strain among intravenous drug users in Uzbekistan.

AIM: A series of recent studies have indicated the presence of natural intergenotypic recombinant hepatitis C virus (HCV) strains in distinct parts of the world. The majority of the current genotyping methods are based on analysis of either 5'UTR, structural (Core/E1/E2) or non-structural (NS5B) genomic regions of the virus. METHODS: In the present study, based on both structural and non-structural regions, we determined the genotype of 55 anti-HCV-positive intravenous drug users (IDUs) in Uzbekistan. RESULTS: HCV-3a (67.3%) was the most prevalent genotype in this cohort, followed by HCV-1b (27.3%). A discrepancy in results was observed between structural and non-structural regions in one case (1.8%). Phylogenetically this strain was related to the previously reported RF1_2k/1b variant. Based on accumulated sequences, specific primers were designed for polymerase chain reaction (PCR) spanning the tentative intergenotypic crossover point of RF1_2k/1b. The sensitivity and specificity of the method were assessed using generated template clones of HCV-1b, 2a, 2 k and RF1_2k/1b. The method was applied to 55 cases in the present study and only one case showed a positive result, indicating that in these individuals, the variant is not present as a minor quasispecies clone. CONCLUSION: In conclusion, the finding of RF1_2k/1b in Central Asia indicates that the variant has wide geographic distribution. The PCR-based screening method developed in this study should be useful in further epidemiological and clinical studies on the recombination phenomenon in HCV.

Virological and clinical implication of core promoter C1752/V1753 and T1764/G1766 mutations in hepatitis B virus genotype D infection in Mongolia.

BACKGROUND AND AIM: The aim of the present study was to reveal virological and clinical features of hepatitis B virus (HBV) genotype D infection. METHODS: One hundred and twenty-two Mongolian chronic liver disease (CLD) patients infected with HBV were subjected for serological HBV-markers screening and HBV-enzyme immunoassay (EIA) genotyping. Nucleotide sequences were analyzed for 48 HBV/D strains (23 isolated from hepatocellular carcinoma (HCC) and 25 from CLD patients). RESULTS: Prevalence of hepatitis B e antigen (HBeAg) positivity was low (25.9%) in young patients (< or =30 years old) indicating early HBeAg seroclearance in HBV/D carriers. The T1764/G1766 double mutation was the most common basal core promoter (BCP) mutation (29.2%) and was frequent in HBeAg-negative patients (39.3%). Patients harboring T1764/G1766 mutants exhibited lower HBV-DNA and HBV core antigen (HBcAg) levels than those with wild-type BCP strains (P = 0.024, 0.049, respectively). C1752 and/or V (not T) 1753 mutation was significantly prevalent in HCC patients (HCC vs CLD; 52.2% vs 20%, P = 0.033). T1762/A1764 mutation was detected in 75.0% of HCC patients with high viral load (> or =5 log copies/mL). Precore stop codon mutation A1896 was detected in (70.8%) of HBV/D-infected patients. CONCLUSIONS: In Mongolians infected with HBV/D, C1752 and/or V1753 mutation was associated with HCC.