UTR Of Hepatitis C Virus Genome Research Articles

Post-transfusion hepatitis C virus infection among β-thalassaemic individuals with associated clinical parameters.

Background & objectives:Multiple transfusions in β-thalassaemia patients undergoing regular transfusion regimen are at a risk of developing transfusion transmitted infections, including hepatitis C virus (HCV). The present study was conducted to investigate the association of HCV viraemia and genotype with clinical parameters in HCV seroreactive β-thalassaemic individuals.Methods:A total of 172 HCV seroreactive β-thalassaemic individuals aged between 2-35 yr with at least 25 units of blood transfusion were catagorized into four groups (2-12 yr, group 1; 13-19 yr, group 2; 20-29 yr, group 3; 30-35 yr, group 4). Aged matched control samples (n=87; β-thalassaemics without HCV infection) were also included. HCV RNA was detected by nested reverse transcriptase polymerase chain reaction (RT-PCR) based on 5’ UTR of HCV genome, viral load was determined by real-time RT-PCR. Nested RT-PCR amplified partial core region was used for DNA sequencing. Liver function parameters [serum total bilirubin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST)] were also determined.Results:Of the 172 HCV seroreactive individuals, 59.30 per cent (n=102) were HCV RNA positive. HCV viral load ranged from 173 to 32.04×10[5] IU/ml; 87.65 per cent were infected with HCV genotype 3. Liver enzymes, such as ALT, AST and serum total bilirubin were significantly elevated in all age groups compared to control groups. Serum ferritin levels were found to be high in all individuals, but 16.27 per cent of HCV-infected individuals with >10,000 IU/ml viral load also showed high ferritin levels (>1500 μg/l) where the majority of them were infected with HCV genotype 3.Interpretation & conclusions:HCV genotype 3 was the major circulating genotype among β-thalassaemia patients in this region. Our findings indicated an association between HCV replication and hepatic iron load and also highlighted the need for sensitive quantitative RT-PCR-based detection of HCV RNA in the high risk population.

Transmission dynamics of hepatitis C virus among intra venous drug users in the border state of Manipur, India

Intra venous drug users (IVDUs) are at high risk for hepatitis C virus (HCV) infection owing to their high rate of drug abuses. The north-eastern part of India has a high prevalence of IVDUs with Manipur being the worst hit state. The aim of the study was to document the molecular epidemiology, the patterns of HCV transmission, genomic variation and recombination events within HCV genome among IVDUs of Manipur, India. 91 anti-HCV sero-reactive blood samples were collected from IVDUs in Manipur. The samples were processed for RNA extraction, nested RT-PCR, sequencing and quantitative viral RNA estimation. Phylogeographic analysis of the sequenced core and NS5B regions of HCV genome was performed to determine the probable transmission route and recombinant HCV strains. 83 out of 91 anti-HCV seropositive samples were RNA positive (91.20%) based on 5′UTR of HCV genome by nested RT-PCR. Of the RNA positive samples, 73 paired partial core and NS5B gene were sequenced. Three major genotype and eight subtypes were detected while no recombinant strains were found. Individuals with genotype 1 had the mean viral load (5.94±0.705log10IU/ml) followed by genotype 3 (4.91±0.49log10IU/ml) and 6 (3.96±0.32log10IU/ml). The viral load was statistically significant among the male individuals at 4.822±1.36log10IU/ml compared to 4.767±0.49log10IU/ml for females (t=3.249, p<0.005). The phylogeographic results indicated 3b, 6h originated from Vietnam, 1a had Indian origin, 3a, 6k originated from southern China while 1b originated from Myanmar, respectively. The incidence of eight different subtypes in Manipur reflects the transmission of these strains from the “Golden Triangle” drug trafficking regions. Sequence analysis confirmed the transmission routes of HCV, which is linked to China and Vietnam for the newly emergent genotype 6 in north-eastern India.

Let-7b is a novel regulator of hepatitis C virus replication.

The non-coding microRNA (miRNA) is involved in the regulation of hepatitis C virus (HCV) infection and offers an alternative target for developing anti-HCV agent. In this study, we aim to identify novel cellular miRNAs that directly target the HCV genome with anti-HCV therapeutic potential. Bioinformatic analyses were performed to unveil liver-abundant miRNAs with predicted target sequences on HCV genome. Various cell-based systems confirmed that let-7b plays a negative role in HCV expression. In particular, let-7b suppressed HCV replicon activity and down-regulated HCV accumulation leading to reduced infectivity of HCVcc. Mutational analysis identified let-7b binding sites at the coding sequences of NS5B and 5'-UTR of HCV genome that were conserved among various HCV genotypes. We further demonstrated that the underlying mechanism for let-7b-mediated suppression of HCV RNA accumulation was not dependent on inhibition of HCV translation. Let-7b and IFNα-2a also elicited a synergistic inhibitory effect on HCV infection. Together, let-7b represents a novel cellular miRNA that targets the HCV genome and elicits anti-HCV activity. This study thereby sheds new insight into understanding the role of host miRNAs in HCV pathogenesis and to developing a potential anti-HCV therapeutic strategy.

Comparison of genotyping and serotyping methods for the identification of hepatitis C virus types

The usefulness of identification of hepatitis C virus (HCV) genotype has recently been investigated for the clinical management of patients infected by HCV. In the present study, the HCV genotype infecting 127 patients was determined by two different methods: HCV genotyping using a dot-blot assay with type-specific probes derived from the 5'-UTR of HCV genome and HCV serotyping using an ELISA system in which type-specific antibodies against the NS4 region were detected. Overall, a good correlation of the two methods was observed, the main discrepancy being 4 patients with sequence-confirmed HCV-2 (2 cases) and HCV-3 (2 cases) genotypes recognized as HCV-1 by serotyping. Mixed infections were not detected by either method. In 19 PCR negative sera, in which the HCV genotype could not be evaluated, no particular serotype profile was observed. In conclusion, the molecular and serological techniques are almost equivalent in determining the viral type, although in individual cases, especially in PCR negative patients, the clinical meaning of the serotyping result remains to be determined.