RESUMO
BACKGROUND: Hepatitis C virus (HCV) infection is a public health concern worldwide. Several factors, including genetic polymorphisms, may be evolved in the progression of HCV infection to liver diseases. Interferon lambdas (IFNLs) modulate the immune response during viral infections. IFNLs induce antiviral activity, interfering in the viral replication by promoting the expression of several genes that regulate immunological functions. The interferon lambda-4 (IFNL4) rs12979860 polymorphism, which is characterized by a C to T transition in intron 1, is associated with spontaneous and treatment-induced clearance of HCV infection and may play a role in the development of HCV-associated liver diseases, including hepatocellular carcinoma (HCC). AIM: To investigate the association of IFNL4 rs12979860 polymorphism with fibrosis, cirrhosis, and HCC in patients with chronic HCV infection. METHODS: This study was comprised of 305 chronic HCV-infected patients (53 fibrosis, 154 cirrhosis, and 98 HCC cases). The control group was comprised of 260 HCV-negative healthy individuals. The IFNL4 rs12979860 polymorphism was genotyped using the TaqMan assay. Fibrosis was diagnosed based on liver biopsy findings, while cirrhosis was diagnosed through clinical, laboratory, anatomopathological, and/or imaging data. HCC was diagnosed through imaging tests, tumor, and/or anatomopathological markers. RESULTS: The T allele was observed in the three groups of patients (fibrosis, cirrhosis, and HCC) at a significantly higher frequency when compared with the control group (P = 0.047, P < 0.001, and P = 0.01, respectively). Also, genotype frequencies presented significant differences between the control group and cirrhosis patients (P < 0.001) as well as HCC patients (P = 0.002). The risk analysis was performed using the codominant and dominant T allele models. In the codominant model, it was observed that the CT genotype showed an increased risk of developing cirrhosis in comparison with the CC genotype [odds ratio (OR) = 2.53; 95% confidence interval (CI): 1.55-4.15; P < 0.001] as well as with HCC (OR = 2.54; 95%CI: 1.44-4.56; P = 0.001). A similar result was observed in the comparison of the TT vs CC genotype between the control group and cirrhosis group (OR = 2.88; 95%CI: 1.44-5.77; P = 0.001) but not for HCC patients. In the dominant T allele model, the CT + TT genotypes were associated with an increased risk for progression to cirrhosis (OR = 2.60; 95%CI: 1.63-4.19; P < 0.001) and HCC (OR = 2.45; 95%CI: 1.42-4.31; P = 0.001). CONCLUSION: These findings suggest that the T allele of IFNL4 rs12979860 polymorphism is associated with the development of cirrhosis and HCC in chronic HCV-infected patients.
RESUMO
In this study we investigated the impact of rs2596542A/G single nucleotide polymorphism (SNP) in the major histocompatibility complex class I chain-related sequence A (MICA) gene on HCV-induced hepatocellular carcinoma (HCC) susceptibility in a Brazilian population. In total, 252 HCV-infected patients (98 with HCV-induced HCC and 154 non-malignant HCV-induced liver cirrhosis) were enrolled and 98 healthy control subjects (negative anti-HCV). The MICA rs2596542 SNP genotypes were determined by real-time PCR assay. No differences in MICA genotype frequencies between HCV-induced cirrhosis patients and controls were observed. However, genotype frequencies of rs2596542A/G SNP were statistically different between HCV-induced HCC patients and controls (p = 0.048), and also between HCC and HCV-induced cirrhosis patients (p = 0.039). The highest frequency of the rs2596542AA genotype was observed in HCC patients (31.6%) when compared with HCV-induced cirrhosis patients (18.8%) and healthy controls (19.4%). Also, rs2596542AA genotype carriers have an increased risk for HCC when compared to HCV-induced cirrhosis status [odds ratio (OR) = 1.99; 95% confidence interval (CI) = 1.06-3.74, p = 0.020)] and healthy individuals (OR = 1.92, 95% CI = 1.00-3.70, p = 0.049). Taken together our study suggest that MICA rs2596542 SNP impacts HCV-induced HCC susceptibility suggesting that genetic variants in MICA are of clinical relevance to hepatocarcinogenesis by impacting host immune response in chronic HCV infection.