Genomic variation-guided management in chronic hepatitis C

An ITPA Enzyme with Improved Substrate Selectivity

Recent clinical data have identified infant patients with lethal ITPA deficiencies. ITPA is known to modulate ITP concentrations in cells and has a critical function in neural development which is not understood. Polymorphism of the ITPA gene affects outcomes for both ribavirin and thiopurine based therapies and nearly one third of the human population is thought to harbor ITPA polymorphism. In a previous site-directed mutagenesis alanine screen of the ITPA substrate selectivity pocket, we identified the ITPA mutant, E22A, as a gain-of function mutant with enhanced ITP hydrolysis activity. Here we report a rational enzyme engineering experiment to investigate the biochemical properties of position 22 ITPA mutants and find that the E22D ITPA has two- and four-fold improved substrate selectivity for ITP over the canonical purine triphosphates ATP and GTP, respectively, while maintaining biological activity. The novel E22D ITPA should be considered as a platform for further development of ITPA therapies.

Management of non-alcoholic fatty liver disease in patients with sarcopenia

INTRODUCTION

Sarcopenia usually occurs with aging, sedentary lifestyle, unhealthy dietary habits, and chronic disorders pathophysiologically and bi-directionally linked to obesity and nonalcoholic fatty liver disease (NAFLD). Because of the global increase in aging and obesity populations, patients with concomitant sarcopenia and NAFLD are common, accompanied by various disorders relevant to obesity and sarcopenia, with across-the-board impact on socio-economic and public health life worldwide. Therefore, developing effective and practical management of these patients has become a pressing clinical issue.

AREAS COVERED

The authors searched literature from PubMed and Ovid MEDLINE up until Feb 2020. Emerging data on the management of sarcopenia and nonalcoholic fatty liver disease were examined and discussed.

EXPERT OPINION

Although NAFLD in patients with sarcopenia has become a critical problem worldwide, we still don't know much about the management of such patients. Based on theoretical speculations, we can recommend lifestyle intervention, including diet control with adequate protein intake, exercise intervention, and weight reduction as the mainstay of management at the first stage. More studies are needed in the future to identify the most suitable treatment and solve this important problem.

Sarcopenia and chronic liver diseases

INTRODUCTION

Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, which is commonly associated with various chronic diseases, including chronic liver diseases. Growing lines of evidence indicate that sarcopenia not only correlates with the clinical outcomes and survival of patients undergoing liver transplant, but also serves as a prognostic factor for candidates of liver transplantation and patients with hepatocellular carcinoma. Areas covered: In this review, we conducted a narrative review and search of literature from PubMed, Ovid MEDLINE, and the Cochrane Library database up to August 2018. Studies relevant to the emerging data of sarcopenia and chronic liver diseases were examined and discussed. Expert commentary: Although sarcopenia has been shown to play a vital role in the outcomes of cirrhotic patients with or without liver transplant, its impact on non-cirrhotic patients remains unclear and deserves future research efforts. To develop an effective and practical measurement of sarcopenia has become an urgent issue in the management of patients with chronic liver diseases.

ABBREVIATIONS

HCC: hepatocellular carcinoma; L3SMI: third lumbar vertebra skeletal muscle index; NAFLD: nonalcoholic fatty liver disease; VAT: visceral adipose tissue; PMA: psoas muscle area; LT: liver transplantation; AUC: area under the curve; LC: liver cirrhosis; SPPB: short physical performance battery; HU: Hounsfield units; ASM: appendicular skeletal muscle; SMI: skeletal muscle index; FLI: fatty liver index; PCLD: polycystic liver disease; DEXA: dual energy X-ray absorptiometry; BCAAs: branched-chain amino acids; BIA: bioelectrical impedance analysis; CT: computed tomography; OS: overall survival; CSA: cross-sectional area; NASH: nonalcoholic steatohepatitis; TPMT: transversal psoas muscle thickness; IMAC: intramuscular adipose tissue content; LDLT: living donor liver transplantation; PMI: psoas muscle mass index; PMTH: psoas muscle thickness by height; TPA: total psoas area; OLT: orthotopic liver transplantation; 6MWD: Six-minute walk distance; HRQOL: health-related quality of life; SMA: skeletal muscle area.

Prevalence and clinical implications of IL28B genotypes in Taiwanese patients with chronic hepatitis C

BACKGROUND/PURPOSE

Clinical implications of IL28B gene in Taiwanese chronic hepatitis C (CHC) patients remain unknown. We thus investigated the prevalence and clinical implications of IL28B rs8099917 genotypes in CHC patients with different hepatitis C virus (HCV) genotypes and healthy controls.

METHODS

A total of 200 HCV genotype 1 patients and 200 HCV genotype 2 patients who received liver biopsy, as well as 197 healthy controls were enrolled to determine the frequencies of IL28B rs8099917 genotypes. In addition, the association of IL28B rs8099917 genotype with baseline data, including HCV RNA level, HCV genotype, histological activity grade, fibrosis stage, and body mass index, were evaluated and further stratified by covariant factors.

RESULTS

Compared with healthy controls, CHC patients had a lower prevalence rate of favorable IL28B rs8099917 TT genotype (81.0% vs. 89.3%, p = 0.025). In addition, the prevalence rates of favorable TT genotype in patients with HCV genotypes 1 and 2 were 76.0% and 86.0%, respectively (p = 0.007). Using ordered logistic regression analysis, higher fibrosis stages were found to be associated with a lower prevalence of TT genotype (p = 0.033), but not histological activity grades (p = 0.748). The association with fibrosis stages was more pronounced in female patients (p = 0.024).

CONCLUSION

In Taiwan, CHC patients have a lower frequency of favorable IL28B TT genotype than healthy controls. Among patients with CHC, the frequency of TT genotype is higher in HCV genotype 2 patients than in HCV genotype 1 patients. In addition, CHC patients with TT genotype, particularly females, have a lower likelihood of advanced fibrosis.

Association of SCARB1 Gene Polymorphisms with Virological Response in Chronic Hepatitis C Patients Receiving Pegylated Interferon plus Ribavirin Therapy

The scavenger receptor type B class I(SR-BI) is a receptor for high-density lipoproteins(HDL) and one of entry factors for hepatitis C virus(HCV). We examined the association of single nucleotide polymorphisms(SNPs) of the SCARB1 gene, which encodes SR-BI, with virologic responses to pegylated interferon-based treatment in Asian chronic hepatitis C(CHC) patients. Human genomic and clinical data were collected from 156 consecutive Taiwanese HCV genotype 1 or 2 patients who received pegylated interferon plus ribavirin therapy and 153 non-HCV healthy subjects. Three SNPs(rs10846744, rs5888, and rs3782287) of the SCARB1 gene that have been linked to humans diseases were investigated. rs10846744 rather than rs5888 or rs3782287 was associated with serum HCV RNA level and sustained virologic response(SVR) to pegylated interferon plus ribavirin therapy in CHC patients(GG vs. non-GG genotype, Adjusted Odds Ratio, 95% CI: 0.32, 0.11–0.95, P = 0.039). Among patients with IL28B rs8099917 non-TT genotypes, those with rs10846744 non-GG genotype had a higher SVR rate than those with GG genotypes. In addition, patients with GG genotype had a higher fasting blood glucose level than those with CC genotype. In conclusion, SCARB1 gene polymorphisms may serve as a potential predictor of treatment responses in CHC patients receiving interferon-based therapy. (ClinicalTrials.gov number, NCT02714712).

A pilot study of add-on oral hypoglycemic agents in treatment-naïve genotype-1 chronic hepatitis C patients receiving peginterferon alfa-2b plus ribavirin

BACKGROUND/PURPOSE

Insulin resistance (IR) affects sustained virological response (SVR) to peginterferon alfa plus ribavirin (PR) in patients with chronic hepatitis C (CHC). Whether add-on oral hypoglycemic agents (OHAs) to PR improve SVR remains unclear; therefore, we conducted a prospective, randomized pilot trial on 23 consecutive patients with genotype 1 CHC and IR in Taiwan.

METHODS

Patients were randomized to receive acarbose (Arm A; n = 7) or metformin (Arm B; n = 6) or pioglitazone (Arm C; n = 5) in addition to peginterferon alfa-2b (1.5 μg/kg/week) plus ribavirin (1000-1200 mg/day) or just PR (Arm D; n = 5). The primary end point was SVR, and secondary end points were viral clearance at Weeks 17, 29, and 53. There were no differences among all arms at baseline.

RESULTS

Using intent-to-treat analysis, SVR was observed in 66.7% (4/6), 83.3% (5/6), 66.7% (4/6), and 60% (3/5) in Arms A, B, C, and D, respectively. SVR was higher in female patients receiving OHA [90% (9/10)] than in male patients [50% (4/8)]. Results of per protocol analysis showed that SVR was 80.0% (4/5) in Arm A, 100% (5/5) in Arm B, 66.7% (4/6) in Arm C, and 60% (3/5) in Arm D. Patients receiving OHA had a higher rapid virologic response: 11/18 (61%) versus 2/5 (40%). Complete early virologic response was comparable between patients receiving OHA and PR [15/18 (83%) vs. 4/5 (80%)].

CONCLUSION

Our preliminary data show add-on OHAs to PR might achieve better early viral kinetics and SVR. However, further larger studies are needed to confirm these findings.

HBeAg-positive chronic hepatitis B: why do I treat my patients with pegylated interferon?

Although chronic hepatitis B (CHB) is a global health threat, it is now a preventable and treatable disease. Seven agents have been approved for the treatment of CHB. Although many patients prefer potent long-term nucleos(t)ide analogues (NAs) as the first-line therapy because they are convenient to use and well-tolerated, a finite duration of pegylated interferon (PEG-IFN) is still an attractive strategy because it provides higher rates of off-therapy host immune control over hepatitis B virus (HBV) compared with NAs. In addition, the rates of HBeAg/HBsAg loss or seroconversion increase over time in patients who respond to PEG-IFN therapy. Nevertheless, these benefits are limited to 30% of all patients, and significant adverse effects are still a concern. Therefore, patients who can benefit most from PEG-IFN therapy should be more carefully selected according to baseline host and viral predictors, such as age, ALT level, viral load, HBV genotype and HBV mutants. In addition, on-treatment predictors including HBV DNA, HBeAg and HBsAg kinetics, can help decide who should continue or discontinue PEG-IFN and shift to NA. Understanding these factors can help determine personalized PEG-IFN therapy for CHB patients. In the near future, the treatment paradigm of CHB should be tailored on the basis of viral (HBV DNA level, HBV genotype and HBV mutants) and host (age, gender, ALT level and host genetic polymorphisms) factors, disease status (stage of fibrosis and comorbidities) and the selection of antiviral agents (immunomodulatory effect, antiviral potency, adverse effects and rate of drug resistance).

Best strategies for global HCV eradication

Worldwide eradication of hepatitis C virus (HCV) is possible through a combination of prevention education, universal clinical and targeted community screening, effective linkage to care and treatment with promising new direct-acting antiviral drug regimens. Universal screening should be offered in all healthcare visits, and parallel community screening efforts should prioritize high-prevalence, high-transmission populations including injection drug users, prison inmates and those with HIV/HCV co-infection. Increasing awareness of HCV infection through screening, improving treatment uptake and cure rates by providing linkage to care and more effective treatment, and ultimately combining education efforts with vaccination campaigns to prevent transmission and reinfection can slow and eventually stop the 'silent epidemic'.