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.

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.

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.

Hypertriglyceridemia induced acute pancreatitis (HTGP) was associated with increased risk of local complications, recurrent acute pancreatitis (AP), the frequency of other complications, and its high mortality as compared to other causes. Determining the factors associated with the severity of HTGP was necessary and important in the management of patients with AP.This study aims to examine the clinical and biochemical characteristics of HTGP patients, and to determine the factors associated with the severity of HTGP according to the revised Atlanta classification.This retrospective and prospective study enrolled 157 HTGP patients from January 2016 to May 2019 at Cho Ray Hospital who had serum TG levels measured within the first 48 hours of admittance with a TG concentration ≥ 1000 mg/dL and excluded other causes. The clinical features and outcomes of patients with HTGP were determined in terms of demographics, clinical symptoms, laboratory data, system complications, local complications, disease severity, and length of hospital stay. The primary outcome was the severity of HTGP as based according to the revised Atlanta classification. We evaluated the relationship between general information, clinical factors and laboratory data in the study population.There were 157 HTGP patients participated in this study. Patients with HTGP had evidence of obese or overweight range (61.2%), history of diabetes mellitus (32.5%) or undiagnosed diabetes (28.0%), history of AP (35.7%), alcohol use (23.6%), hypertension (15.9%), dyslipidemia (13.4%). The patients had typical symptoms of AP, including pancreatic abdominal pain (upper abdominal pain) (93%), nausea/vomiting (80.9%), fever (59.2%), distension abdomen (84.7%), and resistance of abdominal wall (24.8%). The severity of HTGP was significantly associated with fever, altered mental status, rapid pulse, and hypotension (P < .05). Patients with severe HTGP had significantly more pancreatic necrosis, higher values of Blood urea nitrogen and creatinine, longer prothrombin time and activated partial thromboplastin time on admission and higher CRP48 than not severe HTGP (P < .05).The severity of HTGP was significantly related to clinical factors including fever, altered mental status, rapid pulse, hypotension, and pancreatic necrosis. The value of Blood urea nitrogen, creatinine, prothrombin time, and activated partial thromboplastin time at admission is higher and longer in the severe AP group with P < .05.