Differential viral kinetics in treated genotype 4 chronic hepatitis C patients according to ethnicity

Sustained virological response and its treatment predictors in hepatitis C virus genotype 4 compared to genotypes 1, 2, and 3: a meta-analysis

BACKGROUND

Pegylated interferon and ribavirin (PEG-IFN+RBV) may be more cost-effective than direct-acting antivirals in resource-limited settings. Current literature suggests sustained virological response (SVR) in hepatitis C virus genotype 4 (HCV-4) is similar to genotype 1 (HCV-1), but worse than 2 and 3 (HCV-2/3). However, few studies have compared treatment response between these groups and these have been limited by small sample sizes with heterogeneous designs. We performed a meta-analysis of SVR predictors in HCV-4 versus HCV-1, 2, and 3 patients treated with PEG-IFN+RBV.

METHODS

In November 2013, we searched for 'genotype 4' in MEDLINE/EMBASE databases and scientific conferences. We included original articles with ≥25 treatment-naïve HCV-4 and comparisons to HCV-1, 2, and/or 3 patients treated with PEG-IFN+RBV. Random effects modelling was used with heterogeneity defined by Cochrane Q-test (p value<0.10) and I(2) statistic (>50%).

RESULTS

Five studies with 20 014 patients (899 HCV-4; 12 033 HCV-1; and 7082 HCV-2/3 patients) were included. SVR was 53% (CI 43% to 62%) for HCV-4, 44% (CI 40% to 47%) for HCV-1; and 73% (CI 58% to 84%) for HCV-2/3. SVR with EVR (early virological response) was 75% (CI 61% to 86%) in HCV-4; 64% (CI 46% to 79%) in HCV-1; and 85% (CI 71% to 93%) in HCV-2/3. SVR without EVR was 10% (CI 6% to 17%) for HCV-4; 13% (CI 12% to 15%) for HCV-1; and 23% (CI 16% to 33%) for HCV-2/3.

CONCLUSIONS

SVR rates are similar in HCV-4 (∼50%) and HCV-1 (∼40%). Lack of EVR is a good stopping rule for HCV-4 and HCV-1 since only 10% subsequently achieve SVR. In HCV-4 patients with EVR, three-quarters can expect to achieve SVR with PEG-IFN+RBV.

Current status and emerging challenges in the treatment of hepatitis C virus genotypes 4 to 6

Hepatitis C virus (HCV) genotypes 4, 5 and 6 are mainly present in Africa, the Middle East and Asia and they have been less extensively studied with respect to epidemiology, natural disease history and therapeutic endpoints. Response rates to a 48-wk combined peginterferon/ribavirin treatment range to 40%-69% for HCV 4, 55%-60% for HCV 5 and 60%-90% for HCV 6. Response-guided schedules are recommended to optimize the outcomes of peginterferon/ribavirin treatment in HCV 4 and, in form of preliminary data, for HCV 6, but no data are yet available to support such an individualization of therapy for HCV 5. Recently, the direct-acting antivirals (DAAs) with pan-genotypic activities simeprevir, sofosbuvir and daclatasvir have been recommended in triple regimens with peginterferon/ribavirin for the treatment of HCV genotypes 4 to 6 infections. In the future, DAA-based interferon-free therapies are awaited to drastically improve treatment outcomes in HCV. However, efforts to improve treatment outcomes with peginterferon/ribavirin should continue, as the HCV 4-6 infected population is mainly based in resource-limited settings with restricted access to the costly DAAs.

Meta-analysis: influence of host and viral factors in patients with chronic hepatitis C genotype 4 treated with pegylated interferon and ribavirin

The burden of hepatitis C virus genotype 4 (HCV-4) is high in Africa and East Mediterranean countries. Previous reports estimate sustained virologic response (SVR) rates in HCV-4 to be ∼20-70%. However, many of these studies are limited by different study designs and small sample sizes. Our aim was to evaluate treatment outcome and host/viral factors on SVR in HCV-4 patients treated with pegylated interferon and ribavirin (PEG IFN+RBV) in a systematic and quantitative manner. A comprehensive literature search in MEDLINE and EMBASE for 'genotype 4' was conducted in November 2013. Abstracts from American Association for the Study of Liver Diseases, Asian Pacific Study of the Liver, Digestive Disease Week, and European Association for the Study of the Liver in 2012/2013 were reviewed. Inclusion criteria were original studies with at least 25 treatment-naive HCV-4 patients treated with PEG IFN+RBV. Exclusion criteria were coinfection with HIV, hepatitis B virus, or other genotypes. Effect sizes were calculated using random-effects models. Heterogeneity was determined by Cochrane Q-test (P<0.05) and I statistic (>50%). We included 51 studies (11 102 HCV-4 patients) in the primary analysis. Pooled SVR was 53% [95% confidence interval (CI): 50-55%] (Q-statistic=269.20, P<0.05; I=81.43). On subgroup analyses, SVR was significantly associated with lower viral load, odds ratio (OR) 3.05 (CI: 1.80-5.17, P<0.001); mild fibrosis, OR 3.17 (CI: 2.19-4.59, P<0.001); and favorable IL28B polymorphisms, rs12979860 CC versus CT/TT, OR 4.70 (CI: 2.87-7.69, P<0.001), and rs8099917 TT versus GT/GG, OR 5.21 (CI: 2.31-11.73, P<0.001). HCV-4 patients treated with PEG IFN+RBV may expect SVR rates of ∼50%. Lower viral load, mild fibrosis, and favorable IL28B (rs12979860 CC and rs8099917 TT) are positively associated with SVR.

Predictors of sustained virological response in Greek and Egyptian patients with hepatitis C genotype 4: does ethnicity matter?

Hepatitis C virus genotype 4 (HCV-4) is spreading beyond Africa and the Middle East but data regarding treatment with pegylated interferon alpha and ribavirin of European populations infected with HCV-4 remains limited. Interestingly, European (vs. Egyptian) origin has been associated with lower sustained virological response rates. Hence the aim of this study was to investigate the treatment outcomes of Greek (vs. Egyptian), treatment-naïve patients infected with HCV-4 (subtype a) and to identify factors influencing response rates. One hundred seventy-seven consecutive patients (mean age: 44.6 ± 10.2, males: 143/177; 80.8%, Egyptians: 76/177; 42.9%) treated over a 7-year period at the Hepatology clinics of three tertiary care hospitals in Greece were retrospectively evaluated. Overall, sustained virological response was achieved in 75/177 (42.4%) of the cohort without a significant difference between the two ethnic groups [Greek: 44/101 (43.6%); Egyptian 31/76 (40.8%), P = 0.7598]. In multivariate analysis, it was found that ethnicity was not associated with an impaired response but age ≥45 years [odds ratio (OR): 0.4225, 95% confidence interval (CI): 0.2135-0.8133; P = 0.0134], diabetes (OR: 0.2346, 95% CI: 0.0816-0.0674; P = 0.0071), advanced liver fibrosis (OR: 0.3964, 95% CI: 0.1933-0.8133; P = 0.0116), and treatment suspension (OR: 0.1738, 95% CI: 0.0482-0.6262; P = 0.0075) showed an independent negative association with response to antiviral treatment. In contrast to previous European data suggesting Egyptian ethnicity to be a positive predictor for a sustained virological response, there was no influence of Greek versus Egyptian ethnicity on treatment outcomes. Higher age, advanced liver fibrosis, and diabetes have been shown to reduce significantly response rates in patients infected with HCV-4.