Role of rapid virological response in prediction of sustained virological response to Peg-IFN plus ribavirin in HCV / HIV co-infected individuals

Effect of season and sunlight on viral kinetics during hepatitis C virus therapy

Background and aims

Rapid viral response (RVR) during antiviral treatment for hepatitis C virus (HCV) predicts sustained viral response (SVR). Recently, vitamin D levels have been associated with SVR. As sunlight is the most important source of vitamin D and shows seasonal variation, we evaluated the effect of season on viral kinetics during peginterferon/ribavirin-based therapy for HCV.

Methods

Consecutive HCV patients treated with peginterferon/ribavirin and boceprevir/ telaprevir (June 2011–July 2014) were included. Patients were grouped according to season when therapy was initiated (Season A: May–October and Season B: November–April) depending on hours of daily sunlight. Multiple logistic regression analysis included factors known to influence SVR to treatment. The dependent variables were undetectable viral load (VL) or VL ≤15 UI/mL (VL ≤15) at weeks 4, 8 and 12, end of treatment and SVR.

Results

The study included 930 patients (66.8% men; median 54 years) treated with telaprevir (n=537) or boceprevir, without (n=481) or with lead-in therapy of peginterferon/ribavirin. Baseline characteristics of patients in Season A (45.3%, n=421) and Season B groups were similar. Overall, a higher rate of RVR (23.5% vs 16.1%, p=0.005) and VL ≤15 (51.0% vs 38.6%, p≤0.001) was observed in patients starting treatment during Season A versus Season B. By logistic regression analysis, initiating treatment in Season A proved to be an independent predictor of RVR and VL ≤15.

Conclusions

In our setting, seasonality affects viral kinetics in HCV genotype 1 patients treated with peginterferon/ribavirin-based therapy. Our findings support the hypothesis that vitamin D influences viral response to peginterferon/ribavirin-based therapy.

Variation in both IL28B and KIR2DS3 genes influence pegylated interferon and ribavirin hepatitis C treatment outcome in HIV-1 co-infection

Pegylated-IFN and ribavirin remains the current treatment for chronic HCV infection in patients co-infected with HIV-1, but this regimen has low efficacy rates, particularly for HCV genotype 1/4 infection, has severe side effects and is extremely costly. Therefore, accurate prediction of treatment response is urgently required. We have recently shown that the NK cell gene, KIR2DS3 and a SNP associated with the IL28B gene synergise to increase the risk of chronic infection in primary HCV mono-infected patients. Identification of SNPs associated with the IL28B gene has also proven very powerful for predicting patient response to treatment. Patients co-infected with HIV-1 are of particular concern given they respond less well to HCV treatment, have more side effects and suffer a more rapid liver disease progression. In this study, we examined both IL28B and KIR2DS3 for their ability to predict treatment response in a cohort of HIV-1/HCV co-infected patients attending two treatment centres in Europe. We found that variation in both host genetic risk factors, IL28B and KIR2DS3, was strongly associated with sustained virological response (SVR) to treatment in our co-infected cohort (n = 149). The majority of patients who achieved a rapid virological response (RVR) achieved a SVR. However, it is currently impossible to predict treatment outcome in patients who fail to achieve an RVR. In our cohort, the presence of host genetic risk factors, IL28B-T and KIR2DS3 alleles, resulted in increased odds of treatment failure in these RVR negative patients (n = 88). Our data suggests that testing for host genetic factors will improve predicting treatment responsiveness in the clinical management of co-infected patients, and provides further evidence of the importance of the innate immune system in the immune response to HCV.

High uptake of hepatitis C virus treatment in HIV/hepatitis C virus co-infected patients attending an integrated HIV/hepatitis C virus clinic

Hepatitis C virus (HCV) is a major cause of liver disease in HIV-infected patients. The HCV treatment outcomes and barriers to HCV referral were examined in a centre with a HIV/HCV co-infection clinic. Patients who were antibody positive for both HIV and HCV between 1987 and January 2009 were identified. A retrospective chart review was undertaken. Multivariate analysis was performed to assess predictors of HCV clinic referral. Data were collected on 386 HIV/HCV patients; 202/386 had been referred to the co-infection clinic and 107/202 had HCV treatment. In addition, 29/202 were undergoing pretreatment work-up. Overall sustained virologic response (SVR) was 44%; SVR was equivalent in those who acquired HIV/HCV infection from intravenous drug use (IDU) and others. On multivariate analysis, patients who missed appointments, were younger, with active IDU and advanced HIV and who were not offered HCV treatment were less likely to be referred to the clinic. Patients attending the clinic were more likely to have been screened for hepatocellular carcinoma than those attending the general HIV service. Two-thirds of patients referred to the clinic had engaged with the HCV treatment programme. Dedicated co-infection clinics lower the threshold for treatment and improve management of liver disease in co-infected patients.

Current treatment for chronic hepatitis C virus/HIV-infected individuals: the role of pegylated interferon-alpha and ribavirin

PURPOSE OF REVIEW

Liver disease is an important cause of morbidity and mortality in the era of combination antiretroviral therapy in HIV/hepatitis C virus (HCV) co-infected patients. This review highlights the role of pegylated interferon-alpha (peg-IFN) and ribavirin (RBV) therapy and examines factors associated with response and strategies to maximize responses.

RECENT FINDINGS

HCV viral clearance is lower in HIV co-infected patients than in HCV mono-infected patients. However, in patients who attain sustained response there is clinical benefit in terms of liver disease associated morbidity and mortality and treatment is costeffective. Predictors of response appear similar, although there are a number of modifiable patient-associated and HIV-associated factors that could be addressed. Moreover, the use of weight-based RBV and treatment length guided by early viral responses improve response rate. Avoidance of drug-drug interactions and use of haematopoietic growth factors reduce adverse events and dose reductions and ultimately increase response rates. Very early prediction of treatment futility is promising. Induction dosing strategies have not yielded positive results, though twice weekly peg-IFN-alpha-2a induction therapy merits further investigation.

SUMMARY

Peg-IFN/RBV therapy plays an important role in the management of HCV in HIV-infected patients. Efforts to maximize response to current therapy need to continue while we await new therapies.