Interleukin-28B rs12979860 C allele: Protective against advanced fibrosis in chronic hepatitis C genotype 1 infection

Extracellular Matrix Proteins Substantiate IL-28B T allele Effect on Histological Outcome of Chronic Hepatitis C

INTRODUCTION AND AIM

The correlation between interleukin-28B (IL-28B) polymorphisms and chronic hepatitis C (CHC) progression is debatable. Here, we aimed to evaluate the relation between IL-28B C/T genotypes and the development of cirrhotic liver. Extracellular matrix (ECM) proteins, FibroScan and model for end-stage liver disease (MELD) were used to substantiate the severity of liver disease.

MATERIAL AND METHODS

IL-28B rs12979860, liver stiffness and ECM proteins were assessed in 272 CHC patients.

RESULTS

Cirrhosis percentage increased to 10%, 52% and 96% with the increasing number of T alleles (CC, CT and TT, respectively). Also, elevated ECM proteins levels were correlated with the increasing number of T alleles. Interestingly, among cirrhotic patients, liver stiffness, MELD and ECM proteins were significantly (P < 0.0001) higher in patients with TT more than CT genotype. FibroScan, hyaluronic acid, Laminin, Collagen IV and the N-terminal pro-peptide of collagen type III have high accuracy to differentiate liver status in CC from TT genotype. Area under receiver-operating characteristic curve (95% CI) were 1.0 (1.0-1.0), 0.97 (0.96- 1.0), 0.93 (0.85-1.0), 0.98 (0.97-1.0) and 0.93 (0.91-0.97), respectively.

CONCLUSION

This study suggests that IL-28B T allele affects the natural course of CHC type 4 and also suggests that carriage of the IL-28B C allele protects from unfavorable clinical outcomes in CHC as coexistence of C allele with T allele reduced cirrhosis severity.

Hepatic IFNL4 expression is associated with non-response to interferon-based therapy through the regulation of basal interferon-stimulated gene expression in chronic hepatitis C patients

Single nucleotide polymorphisms (SNPs) within or near interferon lambda 4 (IFNL4) gene located upstream of IFNL3 are associated with response to anti-HCV therapy both in interferon (IFN)-based and IFN-free regimens. IFNL4 encodes IFNλ4, a newly discovered type III IFN, and its expression is controlled by rs368234815-TT/ΔG, which is in strong linkage disequilibrium (LD) with other tag SNPs within or near IFNL4 such as rs12979860 and rs8099917. Intrahepatic expression levels of IFN-stimulated genes (ISGs) affect the responsiveness to IFNα and are also associated with IFNL4 genotype. However, IFNL4 expressions and its role in intrinsic antiviral innate immunity remain unclear. This study evaluated the effect of IFNL4 on intrahepatic ISG expression and investigated its relationship with treatment outcomes in liver samples obtained from 49 chronic hepatitis C patients treated with pegylated (PEG)-IFN/ribavirin therapy. IFNL4 mRNA was detected in 11 of 22 patients with IFNL4-unfavorable SNPs but not in patients with favorable genotypes. IFNL4 expression was associated with non-response to PEG-IFN/ribavirin therapy. Intrahepatic expression of antiviral ISGs (ISG15 and MX1) was significantly higher in IFNL4-unfavorable patients with detectable IFNL4 mRNA than in patients with undetectable IFNL4 mRNA, whereas the expression of suppressive ISGs (RNF125, SOCS1, SOCS3, and RNF11) was lower in patients with detectable IFNL4 mRNA. In summary, intrahepatic expression of IFNL4 was associated with increased antiviral ISG expression and decreased suppressive ISG expression at baseline, resulting in poor responsiveness to IFNα-based therapy in HCV infection.

Chronic hepatitis C infection and liver disease in HIV-coinfected patients in Asia

Data on markers of hepatitis C virus (HCV) disease in HIV-HCV-coinfected patients in resource-limited settings are scarce. We assessed HCV RNA, HCV genotype (GT), IL28B GT and liver fibrosis (FibroScan® ) in 480 HIV-infected patients with positive HCV antibody in four HIV treatment centres in South-East Asia. We enrolled 165 (34.4%) patients in Jakarta, 158 (32.9%) in Bangkok, 110 (22.9%) in Hanoi and 47 (9.8%) in Kuala Lumpur. Overall, 426 (88.8%) were male, the median (IQR) age was 38.1 (34.7-42.5) years, 365 (76.0%) reported HCV exposure through injecting drug use, and 453 (94.4%) were on combination antiretroviral therapy. The median (IQR) CD4 count was 446 (325-614) cells/mm3 and 208 (94.1%) of 221 patients tested had HIV-1 RNA <400 copies/mL. A total of 412 (85.8%) had detectable HCV RNA, at a median (IQR) of 6.2 (5.4-6.6) log10 IU/mL. Among 380 patients with HCV GT, 223 (58.7%) had GT1, 97 (25.5%) had GT3, 43 (11.3%) had GT6, eight (2.1%) had GT4, two (0.5%) had GT2, and seven (1.8%) had indeterminate GT. Of 222 patients with IL28B testing, 189 (85.1%) had rs12979860 CC genotype, and 199 (89.6%) had rs8099917 TT genotype. Of 380 patients with FibroScan® , 143 (37.6%) had no/mild liver fibrosis (F0-F1), 83 (21.8%) had moderate fibrosis (F2), 74 (19.5%) had severe fibrosis (F3), and 79 (20.8%) had cirrhosis (F4). One patient (0.3%) had FibroScan® failure. In conclusion, a high proportion of HIV-HCV-coinfected patients had chronic HCV infection. HCV GT1 was predominant, and 62% of patients had liver disease warranting prompt treatment (≥F2).

Association with Spontaneous Hepatitis C Viral Clearance and Genetic Differentiation of IL28B/IFNL4 Haplotypes in Populations from Mexico

AIM

To analyze the genetic heterogeneity of the Amerindian and admixed population (Mestizos) based on the IL28B (rs12979860, rs8099917) and IFNL4 (rs368234815) haplotypes, and their association with spontaneous clearance (SC) and liver damage in patients with hepatitis C infection from West Mexico.

METHODS

A total of 711 subjects from West Mexico (181 Amerindians and 530 Mestizos) were studied for the prevalence of IL28B (rs12979860C/T, rs8099917G/T) and IFNL4 (rs368234815∆G/TT) genotypes. A case-control study was performed in 234 treatment-naïve HCV Mestizos (149 chronic hepatitis C and 85 with SC) for the association of haplotypes with SC and liver damage. A real-time PCR assay was used for genotyping, and transitional elastography staged liver damage.

RESULTS

Significant Fst-values indicated differentiation between the studied populations. The frequencies of the protective C, T, TT alleles were significantly lower in the Amerindians than in Mestizos (p<0.05). The r2 measure of linkage disequilibrium was significant for all variants and the T/G/ΔG risk haplotype predominated in Amerindians and secondly in Mestizos. The protective C/T/TT haplotype was associated with SC (OR = 0.46, 95% IC 0.22-0.95, p = 0.03) and less liver damage (OR = 0.32, 95% IC 0.10-0.97, p = 0.04) in chronic patients. The Structure software analysis demonstrated no significant differences in ancestry among SC and chronic patients.

CONCLUSIONS

West Mexico's population is genetically heterogeneous at the IL28B/IFNL4 polymorphisms. The T/G/ΔG high-risk haplotype predominated in Amerindians and the beneficial alternative haplotype in Mestizos. The C/T/TT haplotype was associated with SC and less liver damage in chronically infected Mestizo patients.