Association between interferon-gamma (IFN-γ) gene polymorphisms (+874A/T and +2109A/G), and susceptibility to hepatitis B viral infection (HBV).

BACKGROUND: Interferon-gamma (IFN-γ) is a chief proinflammatory cytokine with a significant role in the immune response against viral infections. Today there is increasing evidence about the association between individual genetic polymorphisms and cytokines in predicting HBV infection susceptibility. AIM: This study aimed to investigate the association between IFN-γ gene polymorphisms and susceptibility to hepatitis B viral infection (HBV), and the impact of these genetic polymorphisms on IFN-γ production. IFN-γ (+874A/T, rs2430561, and +2109A/G, rs1861494) was genotyped by single-stranded polymorphism-polymerase chain reaction (SSP-PCR) in 126 Egyptians with chronic HBV infection and in 100 healthy control subjects. The plasma levels of IFN-γ were measured by Enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared to the control subjects there was a slight increase in +874TT genotype frequency in HBV patients. However, no statistical significance in IFN-γ (+874A/T and +2109A/G) genotype/allele distribution was demonstrated, indicating the lack of association between these SNPs and susceptibility to HBV infection. In +2109A/G, only AG genotype was observed with a complete abrogation of GG and AA genotypes. Haplotypes between different loci on selected genes showed insignificant changes in their frequency in patients and control subjects. HBV patients had a significantly higher level of IFN-γ (P < 0.001) compared to controls. The maximum significant increase in IFN-γ production was observed in subjects harboring the +874TA genotype. CONCLUSIONS: As no association could be characterized between the polymorphism in IFN-γ (+874A/T and +2109A/G) and susceptibility to chronic HBV infection, our data support the concept that IFN-γ gene polymorphisms are not predictors of HBV susceptibility in this segment of the Egyptian population.

Association between IL-10 gene promoter polymorphism and hepatitis B viral infection in an Egyptian population.

Cytokines play critical roles in the pathogenesis of hepatitis B virus infection (HBV). This work was designed to study the effect of IL-10 gene polymorphisms (-1082G/A and -819C/T) on susceptibility of Egyptians to HBV. Genotyping was performed using single-stranded polymorphism-polymerase chain reaction in 118 Egyptian hepatitis B patients and 119 healthy controls, and IL-10 serum levels were measured using ELISA. The frequency of IL-10 -1082G/G was significantly higher in HBV patients than in healthy controls, and G/A and A/A were not significantly different between groups. The distribution of IL-10 -819 genotypes was not significantly different between the HBV and healthy control groups. Although AT was significantly different between controls and patients, the distribution of the other haplotypes was not. IL-10 levels were significantly lower among hepatitis B patients. Our data stress the importance of IL-10 gene polymorphism in HBV infection. Depending on our preliminary work, IL-10 -1082G/G may act as a host genetic factor in the susceptibility to HBV infection in Egyptians.

Transforming Growth Factor- ß 1 Gene Polymorphism (T29C) in Egyptian Patients with Hepatitis B Virus Infection: A Preliminary Study.

The interindividual variations in the capacity of transforming growth factor- ß 1 (TGF- ß 1) production have been ascribed to genetic polymorphisms in TGF- ß 1 gene. As pathogenesis of HBV has a genetic background, this preliminary study was designed to assess the impact of TGF- ß 1 (T29C) on the susceptibility of Egyptians to HBV infection. Genotyping was performed using single stranded polymorphism-polymerase chain reaction (SSP-PCR) in 65 Egyptian hepatitis B patients and 50 healthy controls. TGF- ß 1 plasma levels were measured using Enzyme-linked immunosorbent assay (ELISA). The frequency of CC genotype was significantly higher (P < 0.05) in HBV patients compared to controls. On the contrary, TC genotype did not show significant difference in both groups. TT genotype was significantly higher (P < 0.01) in controls than HBV patients. Our current preliminary data revealed that the frequency of the genotypes in the controls were within Hardy-Weinberg equilibrium (HWE) while the patients group was out of HWE (P < 0.01). TGF- ß 1 was significantly (r = -0.684; P < 0.001) deceased in the sera of patients as compared to normal subjects. Depending on our preliminary work, CC genotype may act as a host genetic factor in the susceptibility to HBV infection in Egyptians. Taken together, the current data pointed to the importance of polymorphism of TGF- ß 1 gene (T29C) in HBV infection.