HLA-DQA1 & DQB1 variants associated with hepatitis B virus-related chronic hepatitis, cirrhosis & hepatocellular carcinoma.

Background & objectives: Clinical outcome after hepatitis B virus (HBV) exposure varies extremely from spontaneous clearance to chronic hepatitis B and often progresses to liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Host genetic factor plays an important role in the regulation of immune response. This study was aimed to investigate whether HLA class II DQA1 and DQB1 gene polymorphism were associated with chronic hepatitis B infection and in the development of HBV-related LC and HCC. Methods: DQA1 and DQB1 allele polymorphism were studied in 187 patients with HBV-related liver diseases (which included 73 chronic hepatitis B, 84 LC and 30 HCC patients) and 109 controls who had spontaneously recovered from HBV infection using polymerase chain reaction amplification with sequence-specific primers. Results: Our data suggested that DQA1*0101/2/4 [odds ratio (OR)=2.78; Pc=0.003], DQA1*0103 (OR=2.64; Pc=0.0007) and DQB1*0302/3 (OR=2.15; Pc=0.01) were associated with the protection from chronic HBV infection, whereas DQB1*0402 (OR=0.25; Pc=0.001) showed susceptible effect on chronic HBV infection. DQB1*0601 (OR=3.73; Pc=0.006) conferred protective effect from developing LC; similarly, DQB1*0302/3 (OR=5.53; Pc=0.05) and DQB1*0402 (OR=0.00; Pc=0.001) conferred protective effect from developing HCC. However, DQA1*0601 and DQB1*0503 showed susceptible effect on chronic HBV infection; these associations were no longer significant after Bonferroni correction. Interpretation & conclusions: Our results revealed HLA-DQA1*0101/2/4 - DQA1*0103 - DQB1*0302/3 and DQB1*0601 as protective and DQB1*0402 as risk alleles. The study suggests that various subtypes of HLA-DQA1 and DQB1 are associated with both HBV clearance and development of chronic HBV infections.

Down regulation of TRIF, TLR3, and MAVS in HCV infected liver correlates with the outcome of infection.

In virus-infected cells, pattern recognition receptors (PRRs) recruits their specific adaptor molecules, mitochondrial antiviral signaling protein (MAVS), TIR-domain-containing adapter-inducing interferon-ß (TRIF), and TNF receptor associated factor (TRAF6) which induces interferon. Toll-like receptor 3 (TLR3) induces activation of the NF-kappa B (NF-κB) for interferon production. The study has been designed to assess the correlation of TLR3, MAVS, TRIF, and TRAF6 outcome of HCV infection. The 46 chronic hepatitis C (CHC) patients were screened for LFT (Liver function test), HBsAg, Anti HCV, viral load, histology, and expression of TLR3, MAVS, TRIF, and TRAF6 genes. Out of 46 CHC patients, 7 were on therapy. The 12 healthy controls were screened for LFT, HBsAg, Anti HCV and gene expressions. The gene expressions were studied in liver tissue and measured using semi-quantitative analysis of Western blots. It has been observed that the expression of TRAF6 was independent of HCV infection. The expression of TRIF, TLR3, and MAVS were significantly (P < 0.05) down regulated in CHC (N = 46) compared to healthy controls (N = 12), in high viral load (N = 21) compared to low viral load (N = 25), in HAI (Histology activity index) 1-4 (N = 12), 5-8 (N = 16), 9-12 (N = 8), 13-18 (N = 5) compared to HAI 0 (N = 5) cases. The significant reduction in the expression of TRIF, TLR3, and MAVS was observed in non-responder (N = 3) compared to responder (N = 4) after treatment (P < 0.05). The HCV viral load was positively correlated with the disease severity. The down regulation of TRIF, TLR3, and MAVS expressions in CHC correlates with the disease severity and the outcome of HCV infection.

IL-18 polymorphisms in hepatitis B virus related liver disease.

Interleukine-18 (IL-18) was originally called interferon (INF-γ) inducing factor and plays a critical dual role in Th1 polarization and viral clearance. We aimed to explore whether single-nucleotide promoter polymorphisms (SNPs) are associated with the outcome of hepatitis B virus (HBV) infection. 271 HBV infected patients were recruited in this study out of these 109 were spontaneously recovered and 162 were diagnosed to be having persistent HBV infection which includes 48 chronic hepatitis, 84 liver cirrhosis, 30 HCC cases and were compared with 280 healthy controls. IL-18 promoter genotyping was performed with sequence-specific primers. The results demonstrated the significant involvement of genotype AA at position -607 in healthy controls (38.6%) when compared to cases (26.0%) (OR=0.54 (0.385-0.797)) and also associated with spontaneous clearance (37.6%) compared to persistent HBV infections (17.9%) (OR=2.76 (1.582-4.832)). Whereas, genotype CC at position -607 in cases (18.0%) when compared to healthy controls (6.7%) (OR=3.03 (1.734-5.303)) also associated with persistent HBV infections (24.1%) compared to spontaneous clearance (9.2%) (OR=0.31 (0.151-0.67)). And genotype GC at position -137 in cases (49.5%) compared to healthy controls (38.5%) (OR=1.55 (1.11-2.18)). Whereas, genotype GG at position -137 in healthy controls (56.8%) compared to cases (45.4%) (OR=0.63 (0.451-0.885)). No significant difference at position -137 was observed between spontaneous clearance and persistent HBV infections. These polymorphisms of the IL-18 gene promoter region at position -607 and -137 could be associated with different outcomes of HBV infection. The people with allele A at position -607 may be protected against HBV infection; moreover AA genotype is associated with spontaneous clearance.