There is growing evidence that vitamin D is related to chronic hepatitis C (CHC) pathogenicity. We analyzed the relationship of vitamin D status with advanced liver fibrosis (ALF) in CHC treatment‐naïve patients and sustained virologic response (SVR) in CHC patients on pegylated interferon alpha plus ribavirin (pegIFNα/ribavirin) therapy. We performed a meta‐analysis of all eligible studies published to date (April, 2014) in PubMed, SCOPUS, LILACS, and the Cochrane Library, assessing plasma/serum vitamin D levels related to ALF and/or SVR. Pooled odds ratios (ORs) were estimated by either fixed or random effects models. Fourteen studies were selected from the literature search, seven for ALF (1,083 patients) and 11 for SVR (2,672 patients). For liver fibrosis, low vitamin D status was related to a diagnosis of ALF, with the cutoffs of 10 ng/mL (OR = 2.37, 95% confidence interval [CI] = 1.20, 4.72) and 30 ng/mL (OR = 2.22, 95% CI = 1.24, 3.97) being significant, and a near‐significance for 20 ng/mL (OR = 1.44, 95% CI = 0.99, 2.12). Regarding SVR, a significant heterogeneity among studies was found (P < 0.001), and we only found a significant association with SVR for a vitamin D cutoff of 20 ng/mL (OR = 0.53, 95% CI = 0.31, 0.91). When meta‐analysis was performed excluding the outliers, significant pooled ORs were found for all patients (10 ng/mL [OR = 0.48, 95% CI = 0.34, 0.67] and 20 ng/mL [OR = 0.58, 95% CI = 0.45, 0.76]) and GT1/4 patients (10 ng/mL [OR = 0.53, 95% CI = 0.34, 0.81] and 20 ng/mL [OR = 0.54, 95% CI = 0.39, 0.74]). Conclusion: Low vitamin D status in CHC patients is associated with a higher likelihood of having ALF and lower odds of achieving SVR following pegIFNα/ribavirin therapy. (Hepatology 2014;60:1541–1550)

BackgroundSince 2009, several studies have identified single-nucleotide polymorphisms (SNPs) near the gene encoding for interleukin (IL)-28 (IL28B) that are strongly associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Because this large amount of data includes some inconsistencies, we consider assessment of the global estimate for each SNP to be essential.MethodsRelevant studies assessing IL28B polymorphisms associated with sustained virologic response (SVR) and spontaneous clearance (SC) were identified from a literature search of PubMed up to 9 July, 2012. Studies were eligible studies if they included patients infected with HCV or HCV/HIV, or assessed any SNP located within or near the IL28B gene, SVR data available under standard treatment, and/or SC data in patients with acute HCV infection. Pooled odds ratios were estimated by fixed or random effects models when appropriate. Variables such as HCV genotype, ethnicity, and type of co-infection were studied.ResultsOf 282 screened studies, 67 were selected for SVR and 10 for SC. In total, 20,163 patients were studied for SVR and 3,554 for SC. For SVR, we found that all SNPs showed strong associations in patients with HCV genotypes 1 and 4, whereas the pooled ORs were almost three times lower for genotypes 2 and 3 (rs12979860 and rs8099917). Regarding ethnicity, the SNP most associated with SVR was rs12979860 in white patients, whereas in East Asians it seemed to be rs8099917. The most studied SNP (rs12979860) showed similar results for patients co-infected with HCV/HIV, as for those infected with HCV only. Finally, rs12979860 and rs8099917 both appeared to be associated with SC.ConclusionsIL28B polymorphisms influence both the outcome of interferon treatment and the natural clearance of HCV. However we did not identify a universal predictor SNP, as the best genetic markers differed depending on patient ethnicity, genotype, and type of infection. Nevertheless, our results may be useful for more precise treatment decision-making.

Viral fitness quantifies the degree of virus adaptation to a given environment. How viral fitness can influence the mutant spectrum complexity of a viral quasispecies subjected to lethal mutagenesis has not been investigated. Here we document that two high fitness hepatitis C virus populations display higher resistance to the mutagenic nucleoside analogues favipiravir and ribavirin than their parental, low fitness HCV. All populations, however, exhibited a mutation transition bias indicative of active mutagenesis. Resistance to the analogues was associated with a limited expansion of mutant spectrum complexity, as evidenced by several diversity indices used to characterize mutant spectra. The results are consistent with a replicative site-drug competition mechanism that was previously proposed for HCV fitness-associated resistance to non-mutagenic inhibitors. Other alternative, non-mutually exclusive mechanisms are considered. The results introduce viral fitness as a relevant parameter to evaluate the response of viruses to lethal mutagenesis, with implications for antiviral designs.