title: Association between the interleukin-4 gene C-589T and C+33T polymorphisms and asthma risk: a meta-analysis.
abstract: OBJECTIVE
  A large number of studies have investigated the correlation between the interleukin (IL)-4 C-589T and C+33T polymorphisms and asthma susceptibility. However, the results are inconsistent. The objective of this study is to explore the association between the IL-4 C-589T and C+33T polymorphisms and asthma risk using meta-analysis.
  
  
  METHODS
  A total of 35 studies (31 concerning C-589T polymorphism and asthma risk with 4737 asthmatics and 6389 controls and 14 studies regarding C+33T polymorphism and asthma risk with 2544 asthmatics and 4049 controls) were included in this meta-analysis.
  
  
  RESULTS
  The IL-4 C-589T polymorphism was associated with increased asthma risk in a dominant genetic model (odds ratio [OR] [95% confidence interval (CI)] = 1.284 [1.131-1.459] for TT + TC vs. CC). In the subgroup analyses by ethnicity, age and atopic status of asthmatics, significantly increased risks of asthma were found both in Asians (OR [95% CI] = 1.301 [1.003-1.689]) and Caucasians (OR [95% CI] = 1.314 [1.061-1.628]) and in both adults (OR [95% CI] = 1.299 [1.098-1.537]) and children (OR [95% CI] = 1.464 [1.044-2.052]). As for the C+33T polymorphism, the results showed that it was correlated with elevated asthma risk in a recessive genetic model (OR [95% CI] = 1.744 [1.215-2.504] for TT vs. CT + CC). After stratifying analyses by ethnicity, age and atopic status of asthmatics, significantly increased asthma risks were observed in Asians (OR [95% CI] = 1.223 [1.037-1.442]), Caucasians (OR [95% CI] = 3.036 [1.224-7.529]), and children (OR [95% CI] = 1.300 [1.075-1.573]) in a recessive genetic model.
  
  
  CONCLUSIONS
  This meta-analysis suggests that the IL-4 C-589T and C+33T polymorphisms may be risk factors for asthma.
authors: Department of Preventive Medicine, College of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan, PR China. haijyang@yahoo.cn
authors: Hai-Jun
authors: HJ
authors: Yang
mesh_terms: D000328:Adult; D000367:Age Factors; D044466:Asian People; D001249:Asthma / Q000208:ethnology / Q000235:genetics*; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012306:Risk; D012307:Risk Factors; D013224:Status Asthmaticus / Q000235:genetics; D044465:White People
chemical_list: D015847:Interleukin-4