Influence of IL28B polymorphisms on response to a lower-than-standard dose peg-IFN-α 2a for genotype 3 chronic hepatitis C in HIV-coinfected patients

Hepatitis C virus genotype 3: a genotype that is not 'easy-to-treat'

The efficacy of antiviral treatment depends on which of the seven genotypes (G1-G7) of hepatitis C virus (HCV) has infected the patient. Conventionally, clinicians regarded G2 and G3 infections as 'easy-to-treat': dual therapy with pegylated interferon and ribavirin produces a sustained virologic response in approximately 40-50% of patients with G1 infection, compared with 80% when analyses report combined data for G2 and G3 patients, which is standard practice in many clinical studies. However, sustained virologic response rates appear to be lower in certain subgroups of people infected with G3 compared with those with G2 or the general HCV-infected population. This review examines the growing evidence that factors related to the virus (e.g., baseline viral load and a rapid virologic response) and host characteristics (e.g., steatosis and fibrosis, metabolic syndrome, host polymorphisms and ethnicity) contribute to variations in therapeutic success in G3 HCV.

The role of pharmacogenetics in the treatment of chronic hepatitis C infection

Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection.

Functional polymorphisms of interferon-gamma affect pneumonia-induced sepsis

OBJECTIVE

Sepsis is an inflammatory syndrome caused by infection, and both its incidence and mortality are high. Because interferon-gamma (IFN-γ) plays an important role in inflammation, this work assessed IFN-γ single nucleotide polymorphism (SNPs) that may be associated with sepsis.

METHODS

A total of 196 patients with pneumonia-induced sepsis and 213 age- and sex-matched healthy volunteers participated in our study from July 2012 to July 2013 in Guangzhou, China. Patient clinical information was collected. Clinical pathology was assessed in subgroups defined based on clinical criteria, APACHE II (acute physiology and chronic health evaluation) and SOFA (sepsis-related organ failure assessment) scores and discharge rate. Four functional SNPs, -1616T/C (rs2069705), -764G/C (rs2069707), +874A/T (rs2430561) and +3234C/T (rs2069718), were genotyped by Snapshot in both sepsis patients and healthy controls. Pearson's chi-square test or Fisher's exact test were used to analyze the distribution of the SNPs, and the probability values (P values), odds ratios (OR) and 95% confidence intervals (CIs) were calculated.

RESULTS

No mutations in the IFN-γ -764G/C SNP were detected among the participants in our study. The +874A/T and +3234C/T SNPs were in strong linkage disequilibrium (LD) (r(2) = 0.894). The -1616 TC+TT, +874 AT+AA genotype and the TAC haplotype were significantly associated with sepsis susceptibility, while the CTT haplotype was associated with protection against sepsis incidence. Genotype of -1616 TT wasn't only protective against severity of sepsis, but also against higher APACHE II and SOFA scores as +874 AA and +3234 CC. The TAC haplotype was was protective against progression to severe sepsis either.

CONCLUSION

Our results suggest that functional IFN-γ SNPs and their haplotypes are associated with pneumonia-induced sepsis.

Treatment outcomes of treatment-naïve Hepatitis C patients co-infected with HIV: a systematic review and meta-analysis of observational cohorts

Introduction

Co-infection with Hepatitis C (HCV) and HIV is common and HIV accelerates hepatic disease progression due to HCV. However, access to HCV treatment is limited and success rates are generally poor.

Methods

We conducted a systematic review and meta-analysis to assess HCV treatment outcomes in observational cohorts. Two databases (Medline and EMBASE) were searched using a compound search strategy for cohort studies reporting HCV treatment outcomes (as determined by a sustained virological response, SVR) in HIV-positive patients initiating HCV treatment for the first time.

Results

40 studies were included for review, providing outcomes on 5339 patients from 17 countries. The pooled proportion of patients achieving SVR was 38%. Significantly poorer outcomes were observed for patients infected with HCV genotypes 1 or 4 (pooled SVR 24.5%), compared to genotypes 2 or 3 (pooled SVR 59.8%). The pooled proportion of patients who discontinued treatment due to drug toxicities (reported by 33 studies) was low, at 4.3% (3.3–5.3%). Defaulting from treatment, reported by 33 studies, was also low (5.1%, 3.5–6.6%), as was on-treatment mortality (35 studies, 0.1% (0–0.2%)).

Conclusions

These results, reported under programmatic conditions, are comparable to those reported in randomised clinical trials, and show that although HCV treatment outcomes are generally poor in HIV co-infected patients, those infected with HCV genotypes 2 or 3 have outcomes comparable to HIV-negative patients.

Differences in HCV viral decline between low and standard-dose pegylated-interferon-alpha-2a with ribavirin in HIV/HCV genotype 3 patients

Background

The aim of the study was to analyze the different impact of standard and low-dose Peg-IFN-α2a/RBV therapies on HCV viral decline in HIV/HCV genotype 3 co-infected patients during the first weeks of treatment.

Methods

Plasma HCV viral decline was analyzed between baseline and weeks 1, 2 and 4 in two groups of treatment-naïve HCV genotype 3 patients with HIV co-infection. The Standard Dose Group (SDG) included patients who received Peg-IFN at 180 µg/per week with a weight-adjusted dose of ribavirin; Low-Dose Group (LDG) patients received Peg-IFN at 135 µg/per week with 800 mg/day ribavirin. The effect of IL28B genotype on HCV viral decline was evaluated in both groups. HCV viral decline was analyzed using a multivariate linear regression model.

Results

One hundred and six patients were included: 48 patients in the SDG and 58 in the LDG. HCV viral decline for patients in the LDG was less than for those in the SDG (week 1∶1.72±0.74 log₁₀ IU/mL versus 1.78±0.67 log₁₀ IU/mL, p = 0.827; week 2∶2.3±0.89 log₁₀ IU/mL versus 3.01±1.02 log₁₀ IU/mL, p = 0.013; week 4∶3.52±1.2 log₁₀ IU/mL versus 4.09±1.1 log₁₀ IU/mL, p = 0.005). The linear regression model identified the Peg-IFN/RBV dose as an independent factor for HCV viral decline at week 4.

Conclusions

Our results showed that HCV viral decline was less for patients in the low-dose group compared to those receiving the standard dose. Until a randomized clinical trial is conducted, clinicians should be cautious about using lower doses of Peg-IFN/RBV in HIV/HCV genotype 3 co-infected patients.