The correlation between hepatitis C core antigen and hepatitis C virus RNA levels with respect to human immunodeficiency virus status, hepatitis C virus genotype and interferon-lambda-4 polymorphism.

OBJECTIVES: Serum hepatitis C virus (HCV) core antigen (HCVcAg) concentrations correlate with HCV RNA levels in HCV monoinfected patients. Data in HCV/HIV coinfected patients are still limited. We aim to compare the use of HCVcAg measurement with respect to HIV status, HCV genotypes, interferon-lambda-4 (IFNL4) polymorphism and clinical parameters. METHODS: We analyzed an untreated cohort of 104 patients with HCV monoinfection and 85 patients with HCV/HIV coinfection. Serum HCVcAg was measured by a commercial chemiluminescent microparticle immunoassay. The presence of IFNL4 polymorphism ss469415590 was identified by real-time PCR. RESULTS: log10 HCVcAg levels were significantly correlated with corresponding log10 HCV RNA levels (r = 0.889, p < 0.001), but not with ALT levels and liver stiffness. The correlation between HCV RNA and HCVcAg was particularly high in coinfected patients and those with high viremia. Mean log10 HCVcAg concentration was significantly higher in coinfected patients than in monoinfected patients. Patients harboring the TT/TT genotype of ss469415590 had significantly higher levels of log10 HCVcAg than those with the non-TT/TT genotype. HCVcAg levels were similar across HCV genotypes. CONCLUSIONS: HCVcAg concentrations had an excellent correlation with HCV RNA levels, particularly in HCV/HIV-coinfected individuals and might be associated with IFNL4 polymorphism. HCVcAg testing could be used as an alternative to HCV RNA assays in resource-limited settings.

IFNL3 (IL28B) and IFNL4 polymorphisms are associated with treatment response in Thai patients infected with HCV genotype 1, but not with genotypes 3 and 6.

Recent studies have shown an association between single nucleotide polymorphisms (SNPs) in the interferon lambda-3 (IFNL3 or IL-28B) and IFNL4 genes and treatment response to hepatitis C virus genotype 1 (HCV-1) infection. The importance of these SNPs for HCV genotype 3 (HCV-3), and particularly HCV genotype 6 (HCV-6), remains to be elucidated. We analyzed a cohort of 225 Thai individuals with chronic HCV infection treated with pegylated-interferon and ribavirin, of whom 69 (30.7%), 114 (50.7%) and 42 (18.6%) patients were infected with HCV-1, HCV-3, and HCV-6, respectively. DNA extracted from blood samples was analyzed for the SNPs rs12979860 and ss469415590. The distribution of CC, CT, and TT genotypes of rs12979860 was 189 (84%), 28 (12.4%) and 8 (3.6%), respectively, while the distribution of TT/TT, ΔG/TT, and ΔG/ΔG genotypes of ss469415590 was 192(85.3%), 28(12.5%), and 5(2.2%), respectively. Significantly lower frequencies of the favorable genotypes CC (for rs12979860) and TT/TT (for ss469415590) were found in the HCV-1 group in comparison with the other groups. The favorable genotypes were associated significantly with rapid and sustained virological response in the HCV-1 group. However, they were only associated with rapid virological response in the HCV-3 and HCV-6 groups. Furthermore, both SNPs were associated equally with the treatment outcome in the HCV-1 group. In contrast, the role of these SNPs in predicting treatment response was attenuated in the HCV-3 and HCV-6 groups. Thus, identification of these SNPs may be useful only in patients with refractory HCV-1 infection.

Advanced liver fibrosis by transient elastography, fibrosis 4, and alanine aminotransferase/platelet ratio index among Asian hepatitis C with and without human immunodeficiency virus infection: role of vitamin D levels.

BACKGROUND AND AIM: Vitamin D insufficiency plays an important role in liver fibrosis in hepatitis C virus (HCV)-infected patients. We assessed liver fibrosis by transient elastography and 25 hydroxy vitamin D [25(OH)D] status in HCV-infected patients, with (HIV/HCV) or without HIV co-infection (HCV) from Thailand. METHODS: Fibrosis stage was defined as mild (< 7.1 kPa); moderate (7.2-9.4 kPa); severe (9.5-14 kPa), and cirrhosis (> 14 kPa). Hypovitaminosis D was defined as 25(OH)D < 30 ng/mL. Logistic regression analyses were used to assess predictors for significant fibrosis. Serum 25(OH) D levels, HCV genotypes (GT), interleukin-28B (IL28B) and HCV-RNA were assessed. RESULTS: A total of 331 HCV and 130 HIV/HCV patients were enrolled (70% male, 35% people who inject drugs [PWIDs]). HCV GT distribution was as follows: GT3 47%, GT1 34%, GT6 17%. IL-28B CC genotype (rs12979860) were found in 88% of HIV/HCV and 85% of HCV. In HCV, liver fibrosis was mild in 56.5%; moderate in 18.4%; severe in 12.4%; and cirrhosis in 12.7%. In HIV/HCV, these figures were 30.6%, 27.8%, 17.6%, and 24.1%, respectively. Patients with significant fibrosis were more often male, older, with HIV infection, hypovitaminosis D, and less likely to be infected with GT6. Factors associated with significant fibrosis by multivariate analysis were HIV infection (adjusted odd ratio [95% confidential interval]: 2.67, 1.20-5.93), P = 0.016, Fib-4 score > 1.45 (6.30, 2.70-14.74), P < 0.001, and hypovitaminosis D (2.48, 1.09-5.67), P = 0.031. GT 6 was less likely to have advanced liver fibrosis (0.17, 0.05-0.65), P = 0.01. CONCLUSIONS: HIV infection, Fib-4 score > 1.45, and hypovitaminosis D are strong and independent predictors for the presence of advanced fibrosis in our HCV-infected patients. These data highlight the urgent need of HCV treatment and vitamin D supplement in resource-limited settings.

Seroprevalence and genotype of hepatitis C virus among immigrant workers from Cambodia and Myanmar in Thailand.

OBJECTIVE: There is a large number of immigrant workers from Cambodia and Myanmar in Thailand. The aim of our study was to determine seroprevalence and genotypes of hepatitis C virus (HCV) in this group. METHODS: Immigrants aged between 15 and 60 years (1,431 Cambodians and 1,594 Myanmarese) were recruited into this study. Each sample was screened for anti-HCV by ELISA. RNA was extracted from seropositive samples and RT-PCR was performed in order to amplify the HCV core region. Each sample was subsequently sequenced, and the genotype was determined by phylogenetic analysis. RESULTS: The prevalence of HCV infection in immigrant workers from Cambodia and Myanmar was 33 (2.3%) and 27 (1.69%) samples, respectively. Of the anti-HCV-positive individuals, 25 (75.8%) from Cambodia and 15 (55.6%) from Myanmar harbored viral RNA. Phylogenetic analysis showed that the predominant HCV genotypes in this group were 1a, 1b, 3a, 3b and 6 (6e, 6f, 6m, 6p and 6r). Most HCV isolates can be found in Thailand, though some subtypes of HCV-6 are uncommon. CONCLUSIONS: This study shows the HCV seroprevalence and genotypes among immigrant Cambodians and Myanmarese which may reflect the prevalence in each country and closely relate to the prevalence in the guest country.

Geographic distribution of hepatitis C virus genotype 6 subtypes in Thailand.

The nucleotide sequence of hepatitis C virus (HCV) genotype 6 found mostly in south China and south-east Asia, displays profound genetic diversity. The aim of this study to determine the genetic variability of HCV genotype 6 (HCV-6) in Thailand and locate the subtype distribution of genotype 6 in various geographic areas. Four hundred nineteen anti-HCV positive serum samples were collected from patients residing in - the central part of the country. HCV RNA positive samples based on reverse transcriptase- polymerase chain reaction (RT-PCR) of the 5'UTR were amplified with primers specific for the core and NS5B regions. Nucleotide sequences of both regions were analyzed for the genotype by phylogenetic analysis. To determine geographic distribution of HCV-6 subtypes, a search of the international database on subtype distribution in the respective countries was conducted. Among 375 HCV RNA positive samples, 71 had HCV-6 based on phylogenetic analysis of partial core and NS5B regions. The subtype distribution in order of predominance was 6f (56%), 6n (22%), 6i (11%), 6j (10%), and 6e (1%). Among the 13 countries with different subtypes of HCV-6, most sequences have been reported from Vietnam. Subtype 6f was found exclusively in Thailand where five distinct HCV-6 subtypes are circulating. HCV-6, which is endemic in south China and south-east Asia, displays profound genetic diversity and may have evolved over a considerable period of time.

High prevalence of Hepatitis C virus genotype 6 in Vietnam.

This study aimed to update the prevalence of the various Hepatitis C virus genotypes in Vietnamese blood donors. One hundred and three HCV antibody-positive plasma samples were collected from blood donors at the National Institute of Hematology and Blood Transfusion, Hanoi, Vietnam. All specimens were subjected to RT-PCR of the 5' untranslated region (UTR) to confirm the presence of HCV RNA. The core and NS5B regions of thh positive samples were subsequently amplified by RT-PCR followed by direct sequencing and phylogenetic analysis. Seventy out of 103 samples (68.0%) were RNA positive. Core and NS5B were successfully amplified and sequences were obtained for 70 and 65 samples, respectively. Phylogenetic analysis revealed that genotype 6a was the most predominant among Vietnamese blood donors with a prevalence of 37.1% (26/70), followed by genotype 1a at 30.0% (21/70) and genotype 1b at 17.1% (12/70). The prevalence of two other genotype 6 variants, 6e and 61 was 8.6% and 1.4%, respectively. Further analysis of recent studies showed that the geographic distribution of genotype 6 covered mainly southern China and the mainland of Southeast Asia including Vietnam, Laos, Thailand, and Myanmar. The GenBank accession numbers for the sequences reported in this study are FJ768772-FJ768906.

Hepatitis C virus genotype 6: virology, epidemiology, genetic variation and clinical implication.

Hepatitis C virus (HCV) is a serious public health problem affecting 170 million carriers worldwide. It is a leading cause of chronic hepatitis, cirrhosis, and liver cancer and is the primary cause for liver transplantation worldwide. HCV genotype 6 (HCV-6) is restricted to South China, South-East Asia, and it is also occasionally found in migrant patients from endemic countries. HCV-6 has considerable genetic diversity with 23 subtypes (a to w). Although direct sequencing followed by phylogenetic analysis is the gold standard for HCV-6 genotyping and subtyping, there are also now rapid genotyping tests available such as the reverse hybridization line probe assay (INNO-LiPA II; Innogenetics, Zwijnaarde, Belgium). HCV-6 patients present with similar clinical manifestations as patients infected with other genotypes. Based on current evidence, the optimal treatment duration of HCV-6 with pegylated interferon/ribavirin should be 48 wk, although a shortened treatment duration of 24 wk could be sufficient in patients with low pretreatment viral load who achieve rapid virological response. In addition, the development of direct-acting antiviral agents is ongoing, and they give high response rate when combined with standard therapy. Herein, we review the epidemiology, classification, diagnosis and treatment as it pertain to HCV-6.

Early viral kinetics during hepatitis C virus genotype 6 treatment according to IL28B polymorphisms.

AIM: To investigate the early viral kinetics and interleukin-28B (IL28B) polymorphisms of hepatitis C genotype 6 during pegylated interferon and ribavirin therapy. METHODS: Sixty-five patients with chronic hepatitis C virus (HCV) infection treated with pegylated interferon and ribavirin (PEG-IFN/RBV) were included, of whom 15 (23.1%), 16 (24.6%) and 34 (52.3%) patients were infected with hepatitis C genotype 1 (HCV-1), genotype 3 (HCV-3) and genotype 6 (HCV-6), respectively. Serum HCV-RNA levels were measured frequently during the first 4-wk of therapy. DNA extracted from samples was analyzed for the IL28B single nucleotide polymorphism (SNP) rs12979860 by polymerase chain reaction and direct sequencing. RESULTS: During the first 4-wk of therapy, the mean viral decline for patients with HCV-6 (5.55 ± 1.82 log10IU/mL) was comparable to that of patients with HCV-3 (5.55 ± 1.82 log10IU/mL vs 5.86 ± 1.02 log10IU/mL, P = 0.44) and was significantly higher than patients with HCV-1 (5.55 ± 1.82 log10IU/mL vs 4.23 ± 1.99 log10IU/mL, P = 0.04). In the HCV-6 group, the first phase (days 0-2) viral decline was significantly higher in patients with the favorable rs12979860 CC than non-CC genotypes (2.46 ± 1.01 log10IU/mL/wk vs 1.70 ± 0.67 log10IU/mL, respectively, P = 0.045). A statistically insignificant decrease in the second-phase (days 7-28) decline was also found in patients with the CC genotype than those with the non-CC genotype, though not significantly different (1.24 ± 0.64 log10IU/mL/wk vs 0.80 ± 0.65 log10IU/mL/wk, respectively, P = 0.172). At baseline, the SNP genotype was an independent predictor of rapid virological response but not of sustained virological response. CONCLUSION: The IL28B genotype was linked to an impact on early viral kinetics in response to PEG-IFN/RBV therapy in HCV-6 infected patients.

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.