Previous studies evaluated the association of IL-4 C33T polymorphism and risk of bronchial asthma but failed to establish a consistent conclusive association. In the present meta-analysis, we intend to define a more reliable estimate of the association in the presence of filling published literature. An exhaustive search in Web of Science, Scopus, and PubMed databases was performed to identify all relevant publications before September 2020, and 24 publications (28 studies) with 6587 cases and 8408 controls were included in final analysis. The association between polymorphism and risk of asthma were measured by Odd ratios (ORs) and 95% confidence intervals (CIs). Moreover, Cochran’s Q and the I2 statistics were used to evaluate the degree of heterogeneity between studies. In the overall study populations, a significant positive association was detected under all genotype models and announced the IL-4 C33T polymorphism as a potential risk factor in the pathogenesis of asthma. In the subgroup analysis by age, a significant association between IL-4 C33T polymorphism and risk of asthma in different age groups was identified in allelic model, which highlighted the predisposing role of the T allele for the asthma risk in all three age groups. Furthermore, the results of subgroup analysis by continent were heterogenous. Accordingly, IL-4 C33T polymorphism was a risk factor in Europeans (all models except heterozygote comparison), Americans (all models except recessive and homozygote comparison) and Asians (just recessive and allelic model). Finally, the ethnicity-specific analysis disclosed a significant association between IL-4 C33T polymorphism and asthma risk in Caucasians (all genotype models except heterozygote comparison), while this association was not significant in African-Americans. This study suggests that IL-4 C33T polymorphism potentially acts as a risk factor for asthma in different ethnicities and age groups.

中文翻译：

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白介素 4 基因多态性 (C33T) 与哮喘风险：基于 24 篇出版物的荟萃分析


先前的研究评估了 IL-4 C33T 多态性与支气管哮喘风险的关联，但未能建立一致的结论性关联。在目前的荟萃分析中，我们打算在现有已发表文献的情况下定义更可靠的关联估计。对 Web of Science、Scopus 和 PubMed 数据库进行了详尽的检索，以确定 2020 年 9 月之前的所有相关出版物，最终分析中纳入了 24 篇出版物（28 项研究），涉及 6587 个病例和 8408 个对照。多态性与哮喘风险之间的关联通过比值比 (OR) 和 95% 置信区间 (CI) 来衡量。此外，Cochran's Q 和 I2 统计数据用于评估研究之间的异质性程度。在整个研究人群中，所有基因型模型下均检测到显着的正相关，并宣布 IL-4 C33T 多态性是哮喘发病机制中的潜在危险因素。在按年龄进行的亚组分析中，等位基因模型中发现IL-4 C33T多态性与不同年龄组哮喘风险之间存在显着相关性，这凸显了T等位基因对所有三个年龄组哮喘风险的诱发作用。此外，按大陆进行的亚组分析结果也存在差异。因此，IL-4 C33T 多态性是欧洲人（除杂合子比较之外的所有模型）、美国人（除了隐性和纯合子比较之外的所有模型）和亚洲人（仅隐性和等位基因模型）的危险因素。 最后，种族特异性分析揭示了白种人中 IL-4 C33T 多态性与哮喘风险之间存在显着关联（除杂合子比较之外的所有基因型模型），而这种关联在非裔美国人中并不显着。这项研究表明，IL-4 C33T 多态性可能是不同种族和年龄组哮喘的危险因素。