Association of polymorphism of tumor necrosis factor-alpha gene promoter region with outcome of hepatitis B virus infection

AIM： To determine whether -238G/A and -857C/T polymorphisms of tumor necrosis factor-alpha （TNF-α）, gene promoter and hepatitis B （HB） viral genotypes were associated with outcomes of HBV infection. METHODS： A total of 244 HBV self-limited infected subjects, 208 asymptomatic carriers, and 443 chronic HB patients were recruited to conduct a case-control study. TNF-α -238G/A and -857C/T gene promoter polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）, and HBV genotypes were examined by nested PCR. RESULTS： The positive rate of HBV DNA in asymptomatic carder group and chronic HB group was 46.6% and 49.9%, respectively. HBV genotype proportion among the asymptomatic carriers was 2.1% for genotype A, 25.8% for genotype B, 68.0% for genotype C, and 4.1% for genotype B＋C mixed infection, and 0.9% for genotype A, 21.7% for genotype B, 71.5% for genotype C, 5.9% for genotype B＋C mixed infection in chronic HB group. There was no significant difference in genotype distribution between the asymptomatic carrier group and chronic HB group （X^2 = 1.66, P = 0.647）. The frequency of -238GG genotype in self-limited group was 95.1%, significantly higher than 90.7% in chronic HB group and 89.0% in asymptomatic carrier group （P = 0.041 and P = 0.016, respectively）.The frequency of TNF-α-857 CC in chronic HB group was 79.7%, significantly higher than 64.4% in asymptomatic carrier group and 70.9% in self-limited group （P〈0.001 and P = 0.023, respectively）. A multiple logistic regression analysis revealed that TNF-α-238GA and -857CC were independently associated with chronic HB after gender and age were adjusted.CONCLUSION： TNF-α promoter variants are likely to play a substantial role in the outcome of HBV infection.

Endothelial Nitric Oxide Synthase Gene Polymorphisms Associated with Susceptibility to High Altitude Pulmonary Edema in Chinese Railway Construction Workers at Qinghai-Tibet over 4500 Meters above Sea Level

Objective To examine whether the polymorphisms of endothelial nitric oxide synthase (eNOS) gene are associated with the susceptibility to high altitude pulmonary edema (HAPE) in Chinese railway construction workers at Qinghai-Tibet where the altitude is over 4 500 m above sea level. Methods A case-control study was conducted including 149 HAPE patients in the construction workers and 160 healthy controls randomly recruited from their co-workers, matching the patients in ethnicity, age, sex, lifestyle, and working conditions. Three polymorphisms of eNOS gene, T-786C in promoter, 894G/T in exon 7, and 27bp variable number tandem repeat (VNTR) in intron 4, were genotyped using polymerase chain reaction (PCR) and confirmed with DNA sequencing. Results The frequencies of 894T allele and heterozygous G/T of the 894G/T variant were significantly higher in HAPE patients group than in the control group (P=0.0028 and P=0.0047, respectively). However, the frequencies of the T-786C in promoter and the 27bp VNTR in intron 4 were not significantly different between the two groups. Haplotypic analysis revealed that the frequencies of two haplotypes (H3,T-T-b, b indicates 5 repeats of 27 bp VNTR; H6, C-G-a, a indicates 4 repeats of 27 bp VNTR) were significantly higher in HAPE patients (both P<0.0001). On the contrary, the frequencies of H1 (T-G-b) and H2 (T-G-a) were lower in HAPE patients than in healthy controls (both P<0.001). Conclusions Two haplotypes (T-T-b and C-G-a) may be strongly associated with susceptibility to HAPE. Compared with the individual alleles of eNOS gene, the interaction of multiple genetic markers within a haplotype may be a major determinant for the susceptibility to HAPE.

Association of-238G/A and -857C/T Polymorphisms of Tumor Necrosis Factor-Alpha Gene Promoter Region With Outcomes of Hepatitis B Virus Infection

Objectives To determine whether -238G/A and -857C/T polymorphisms of tumor necrosis factor-alpha （TNF-o0 gene promoter were associated with outcomes of hepatitis B virus infection. Methods A total of 246 HBV self-limited infected subjects and 443 chronic hepatitis B （HB） patients were recruited in this case-control study. TNF-α-238G/A and -857C/T gene promoter polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）. Results The frequency of TNF-α-238 GG （90.7%） in chronic HB group was significantly lower than that （95.1%） in self-limited group （P=0.041）. The frequency of TNF-oc-857 CC （79.7%） in chronic HB patients was significantly higher than that （70.9%） in self-limited infected subjects （P=0.021）. Multiple logistic regression analysis revealed that both TNF-oc-238GA and -857CC were independently associated with chronic HB. Conclusions TNF-α promoter variants are likely to play a substantial role in influencing the outcomes of HBV infection.