Association of TNF-α gene promoter polymorphisms with outcome of hepatitis B virus infection

The relationship between tumour necrosis factor-α gene polymorphism and susceptibility and clearance of the persistent hepatitis B virus infection in a Chinese population: a meta-analysis

To date, many studies conducted in the Chinese population have determined the correlation between the tumour necrosis factor-α (TNF-α)-238G/A, -308G/A, -857C/T and -863C/A polymorphisms and persistent hepatitis B virus (HBV) infection. However, their results remain inconclusive. With the aim of confirming this correlation, we performed a meta-analysis of 19 studies. The dichotomous data are presented as the OR with a 95% CI. The results of our study indicate that carriers of the TNF-α-857T allele among the pooled Chinese population were more likely to show spontaneous clearance of HBV (T vs C: OR = 0.824, 95% CI = 0.713-0.953, p 0.009; TT vs CC: OR = 0.701, 95% CI = 0.507-0.970, p 0.032; TC vs CC: OR = 0.804, 95% CI = 0.683-0.947, p 0.009; TT + TC vs CC: OR = 0.835, 95% CI = 0.716-0.974, p 0.021). The TNF-α-308A allele was associated with significantly reduced persistent HBV infection risk in the Chinese (A vs G: OR = 0.585, 95% CI = 0.456-0.751, p 0.002; AG vs GG: OR = 0.519, 95% CI = 0.341-0.789, p <0.000; AA + AG vs GG: OR = 0.512, 95% CI = 0.339-0.772, p 0.001). Persistent HBV infection susceptibility is associated with the TNF-α-308G/A gene polymorphism in the Chinese population, whereas HBV clearance is associated with the TNF-α-857C/T gene polymorphism.

The TNF-α -308 Promoter Gene Polymorphism and Chronic HBV Infection

Background and Aims. TNF-α -308 allele promoter polymorphism has been known to be a potential prognostic factor in patients with chronic HBV infection. We tried to determine how TNF-α -308 allele promoter polymorphism would affect the prognosis in patients with chronic HBV infection. Methods. We searched MEDLINE, EMBASE, and reference lists of relevant review articles related to the association between “TNF-α G-308A promoter polymorphism” with “chronic HBV infection”. We only focused on searching -308 locus in published studies. We reviewed 21 original articles about TNF-α -308 allele polymorphism and its effect on prognosis in patients with chronic HBV infection and discussed the results. Results. conflicting results were observed. The results were divided into 3 groups including neutral, negative, and positive associations between TNF-α -308 allele polymorphism and prognosis in patients with chronic HBV infection. We summarized the primary data as a table. Conclusions. Authors concluded that although there is an upward trend in evidence to claim that there is a positive relation between TNF-α G-308A promoter polymorphisms and resolution of chronic HBV infection, due to many biases and limitations observed in reviewed studies, an organized well-designed study is needed for clarifying the real association.

Relationship between TNF-<alpha> gene promoter polymorphisms and outcomes of hepatitis B virus infections: a meta-analysis

Background

The clearance of hepatitis B virus (HBV) is a complex process which may be influenced by many factors including polymorphisms in the tumor necrosis factor <alpha> (TNF-<alpha>) gene promoter. However, previous reports regarding the relationship between polymorphisms in the TNF-<alpha> promoter and HBV clearance have been inconsistent. Therefore, we performed a meta-analysis on a large population to address this inconsistency.

Methods

A meta-analysis was performed to examine the association between TNF-<alpha> promoter polymorphisms (-1031T/C, -863C/A, -857C/T, -308G/A and-238G/A) and chronic hepatitis B infection. Odds ratio (OR) and its 95 % confidence interval (CI) were used.

Results

Twelve studies were chosen in our meta-analysis, involving 2,754 chronic HBV infection cases and 1,630 HBV clearance cases. The data showed that TNF-<alpha>-863 CC genotype was significantly associated with HBV clearance (-863 CC vs. AA: OR, 0.64; 95% CI, [0.42, 0.97]; p = 0.04) while patients carrying -308 GG genotype had a significantly increased risk of HBV persistence compared with those with GA or AA genotype (GG vs. GA+AA: OR, 1.35; 95% CI, [1.08, 1.70]; p = 0.01). For the other polymorphisms, no association with HBV infection outcome was found.

Conclusions

The data showed that polymorphisms -863 A and -308 G in the TNF-<alpha> gene promoter region might be risk factors for HBV persistence. Furthermore, ethnicity might play an important role in HBV infection outcome, leading to conflicting results. More studies on individuals from various ethnic groups will be necessary to determine the role of TNF-<alpha> promoter polymorphisms in the outcome of HBV infection.

Tumor necrosis factor-alpha-308A allele may have a protective effect for chronic hepatitis B virus infection in Mongoloid populations

OBJECTIVES

Previous studies on the tumor necrosis factor-alpha (TNF-alpha)-308 gene promoter polymorphism in chronic hepatitis B virus (HBV) infection have reported conflicting results.

METHODS

We carried out a meta-analysis of 21 studies in relation to the TNF-alpha-308 gene promoter, involving a total of 4230 chronic HBV infection cases and 2905 controls.

RESULTS

The overall meta-analysis indicated that -308A heterozygotes (GA) had a significant 27% decreased risk of developing chronic hepatitis B (CHB) (odds ratio (OR) 0.73; 95% confidence interval (CI) 0.57-0.93; p=0.012). For -308A allele homozygotes (AA) and carriers (GA+AA), the pooled odd ratios both indicated a significantly decreased risk of CHB (OR 0.28; 95% CI 0.19-0.43; p=0.0001; and OR 0.70; 95% CI 0.55-0.89; p=0.004, respectively). In subgroup analyses by ethnicity, a significantly decreased risk was associated with -308 variant genotypes (GA and AA) in Mongoloid populations in all genetic models. However, no significant associations were found in Caucasoids. Moreover, in the subgroup analyses by control group, significantly decreased risk was associated with -308 variant genotypes (GA and AA) in the group of spontaneously recovered cases in all genetic models; however, no significant associations were found in the group of healthy cases.

CONCLUSIONS

The TNF-alpha-308A allele is a protective factor for chronic HBV infection, especially in Mongoloids.