Interleukin-28B genetic variants in untreated Italian HCV-infected patients: a multicentre study

Role of Functional IFNL4, IFNLR1, IFNA, IFNAR2 Polymorphisms in Hepatitis B virus-related liver disease in Han Chinese population

Recent studies show that variants in some interferon genes together with interferon receptor genes are associated with the outcome of infectious diseases. We examined the association between the risk of hepatitis B virus (HBV)-related liver disease and the functional polymorphisms within IFNL4, IFNLR1, IFNA1, IFNA2, IFNA5 and IFNAR2 genes (14 loci in all) in a Han Chinese population. A total of 3128 people participated and were divided into 5 groups: healthy controls, natural clearance, chronic hepatitis B(CHB), liver cirrhosis and hepatocellular carcinoma (HCC). Significant associations were observed for 4 variants in IFNAR2, IFNLR1 with HBV infection, and IFNLR1-rs4649203 was associated with HBV recovery. Moreover, we demonstrated the clear relevance of 5 polymorphisms in IFNA1, IFNA2, IFNL4 with HCC. Three SNPs in IFNL4 gene may be important susceptible factors for the progression of HBV-related liver disease by trend chi-square test. The IFNL4 haplotype conformed by rs12971396_G, rs8113007_T and rs7248668A was more frequent in HCC than CHB and LC group. Three polymorphisms in the 5' region of the IFNL4 gene are associated with the progression of HBV-related liver disease. IFNA1- rs1831583 and IFNA2- rs649053 are associated with the development of HCC. IFNLR1- rs4649203, rs7525481 are predictors for HBV infection, and rs4649203 is a predictor of spontaneous clearance. IFNAR2 -rs1051393, rs12233338 may be predictive markers of HBV infection in the Chinese population.

Fine-mapping of genetic loci driving spontaneous clearance of hepatitis C virus infection

Approximately three quarters of acute hepatitis C (HCV) infections evolve to a chronic state, while one quarter are spontaneously cleared. Genetic predispositions strongly contribute to the development of chronicity. We have conducted a genome-wide association study to identify genomic variants underlying HCV spontaneous clearance using ImmunoChip in European and African ancestries. We confirmed two previously reported significant associations, in the IL28B/IFNL4 and the major histocompatibility complex (MHC) regions, with spontaneous clearance in the European population. We further fine-mapped the association in the MHC to a region of about 50 kilo base pairs, down from 1 mega base pairs in the previous study. Additional analyses suggested that the association in MHC is stronger in samples from North America than those from Europe.

Distribution of IL28B Polymorphism in a Cohort of Italians and Immigrants with HCV Infection: Association with Viraemia, Stage of Fibrosis and Response to Treatment

Aims of the study are to investigate, in a cohort of patients affected by HCV chronic hepatitis with genotypes 1 and 4, the prevalence of interleukin 28B (IL28B) genotypes, the possible association between IL28B polymorphism and severity of liver damage, the role of IL28B CC as a predictor of outcome. 365 patients with HCV infection were observed between 2013 and 2014. Demographic, virological, biochemical, and genetic characteristics of each patient were investigated. Liver fibrosis was assessed by transient elastometry. Mean age of the patients (72.9 % males, 27.1 % females) is 50 years. 91.5 % % of patients are Caucasian, 8.5 % African. In the patients with HCV1 and HCV4 a higher frequency of IL28B CT is observed with a prevalence of 52.1 and 61.8 % respectively. As regards ethnic group, African people have a prevalence of 35.5 % for CC, while Caucasians have a prevalence of 23.8 % for CC. In our cohort, IL28B polymorphism does not show significant differences among ethnic groups and in HCV1 and HCV4 genotypes. As described in literature, IL28B CC genotype is confirmed as predictor of sustained virological response in both Caucasians and Africans. A significant correlation between liver fibrosis and IL28B polymorphism emerges.

IL28B genotype is associated with cirrhosis or transition to cirrhosis in treatment-naive patients with chronic HCV genotype 1 infection: the international observational Gen-C study

Background and purpose

Contradictory data exist on the association between host interleukin-28B (IL28B) rs12979860 genotype and liver fibrosis in patients with chronic hepatitis C (CHC). This large, international, observational study (NCT01675427/MV25600) investigated relationships between IL28B rs12979860 genotype and liver fibrosis stage in CHC patients.

Methods

A total of 3003 adult, treatment-naive CHC patients were enrolled into the study. Patients made one study visit to provide a blood sample for genotyping; other data were obtained from medical records.

Results

2916 patients comprised the analysis population; the majority were enrolled in Europe (n = 2119), were Caucasian (n = 2582) and had hepatitis C virus (HCV) genotype (G)1 infection (n = 1702) (G2 = 323, G3 = 574, G4 = 260). Distribution of IL28B genotypes varied according to region of enrolment, patient ethnicity and HCV genotype. A significant association was observed between increasing number of IL28B T alleles and the prevalence of cirrhosis/transition to cirrhosis (based on biopsy or non-invasive assessments) in G1-infected patients (CC = 22.2% [111/499], CT = 27.5% [255/928], TT = 32.3% [87/269]; p = 0.0018). The association was significant in the large subgroup of European Caucasian G1 patients (n = 1245) but not in the smaller Asian (n = 25), Latin American (n = 137) or Middle Eastern (n = 289) G1 subgroups. IL28B genotype was not associated with liver fibrosis stage in patients with HCV G2, G3 or G4 infection.

Conclusion

This large, international study found that IL28B rs12979860 genotype is significantly associated with liver fibrosis stage in CHC patients with HCV G1 infection. This association was evident in European Caucasians but not in G1-infected patients from Asia, Latin America or the Middle East.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3663-6) contains supplementary material, which is available to authorized users.