J Gao1, G Shan, B Sun, P J Thompson, X Gao. 1. Department of Respiratory Diseases, Peking Union Medical College Hospital, 1 Shuaifuyuan, Dongcheng District, Beijing 100730, China. gaojm@pumch.ac.cn
Abstract
BACKGROUND: Asthma is a complex polygenic disease in which gene-environment interactions are important. The gene encoding tumour necrosis factor alpha (TNFalpha) is one of several candidate loci for asthma pathogenesis and is highly polymorphic. A number of studies have investigated the polymorphism of TNFalpha-308 gene promoter (substitution G-->A, designated as TNF1 and TNF2) in relation to asthma susceptibility in different populations. However, the results of individual studies have been inconsistent. METHODS: To address the inconsistent findings in studies of the association of the polymorphism of TNFalpha-308 gene promoter with susceptibility to asthma, a systematic review was undertaken of the published data and a meta-analysis was performed. The MEDLINE database was searched for case-control studies published in English language journals from 1966 to October 2005. Data were extracted using standardised forms and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: Fifteen eligible studies, comprising 2409 patients with asthma and 3266 controls, were included in the meta-analysis. Using the random effects model, the pooled result showed that the TNF2 allele is associated with overall susceptibility to asthma (OR 1.37, 95% CI 1.02 to 1.84, p=0.04). The ORs for asthma susceptibility in TNF2 homozygote individuals were significantly increased at 2.01 (95% CI 1.26 to 3.20, p=0.009) and 1.51 (95% CI 1.02 to 2.22, p=0.041) compared with TNF1 homozygotes and TNF2/1 heterozygotes, respectively. In addition, the pooled OR for asthma risk in TNF2/1 heterozygotes was also significantly higher than that in TNF1/1 homozygotes (OR 1.47, 95% CI 1.01 to 2.13, p=0.045). CONCLUSIONS: The TNF2 allele confers a significant risk for developing asthma. A large scale case-control study is needed to clarify the functional effect of the polymorphism of the TNFalpha gene in the pathogenesis of asthma.
BACKGROUND:Asthma is a complex polygenic disease in which gene-environment interactions are important. The gene encoding tumour necrosis factor alpha (TNFalpha) is one of several candidate loci for asthma pathogenesis and is highly polymorphic. A number of studies have investigated the polymorphism of TNFalpha-308 gene promoter (substitution G-->A, designated as TNF1 and TNF2) in relation to asthma susceptibility in different populations. However, the results of individual studies have been inconsistent. METHODS: To address the inconsistent findings in studies of the association of the polymorphism of TNFalpha-308 gene promoter with susceptibility to asthma, a systematic review was undertaken of the published data and a meta-analysis was performed. The MEDLINE database was searched for case-control studies published in English language journals from 1966 to October 2005. Data were extracted using standardised forms and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: Fifteen eligible studies, comprising 2409 patients with asthma and 3266 controls, were included in the meta-analysis. Using the random effects model, the pooled result showed that the TNF2 allele is associated with overall susceptibility to asthma (OR 1.37, 95% CI 1.02 to 1.84, p=0.04). The ORs for asthma susceptibility in TNF2 homozygote individuals were significantly increased at 2.01 (95% CI 1.26 to 3.20, p=0.009) and 1.51 (95% CI 1.02 to 2.22, p=0.041) compared with TNF1 homozygotes and TNF2/1 heterozygotes, respectively. In addition, the pooled OR for asthma risk in TNF2/1 heterozygotes was also significantly higher than that in TNF1/1 homozygotes (OR 1.47, 95% CI 1.01 to 2.13, p=0.045). CONCLUSIONS: The TNF2 allele confers a significant risk for developing asthma. A large scale case-control study is needed to clarify the functional effect of the polymorphism of the TNFalpha gene in the pathogenesis of asthma.
Authors: T Chagani; P D Paré; S Zhu; T D Weir; T R Bai; N A Behbehani; J M Fitzgerald; A J Sandford Journal: Am J Respir Crit Care Med Date: 1999-07 Impact factor: 21.405
Authors: T C Li Kam Wa; A H Mansur; J Britton; G Williams; I Pavord; K Richards; D A Campbell; N Morton; S T Holgate; J F Morrison Journal: Clin Exp Allergy Date: 1999-09 Impact factor: 5.018
Authors: Xiaobo Li; Yonggang Zhang; Jie Zhang; Yuling Xiao; Jin Huang; Can Tian; Chao He; Yao Deng; Yingying Yang; Hong Fan Journal: Respir Res Date: 2010-09-24
Authors: Dawn L Demeo; Edward J Campbell; Alan F Barker; Mark L Brantly; Edward Eden; N Gerard McElvaney; Stephen I Rennard; Robert A Sandhaus; James M Stocks; James K Stoller; Charlie Strange; Gerard Turino; Edwin K Silverman Journal: Am J Respir Cell Mol Biol Date: 2007-08-09 Impact factor: 6.914