Interleukin-18 Polymorphisms Deficiency Association with Asthma Risk: An Update Meta-analysis

Area of Science:

• Genetics
• Immunology
• Respiratory Medicine

Background:

• Conflicting evidence exists regarding the association between Interleukin-18 (IL-18) promoter polymorphisms and asthma risk.
• Specific polymorphisms, including rs1946518 (A-607C), rs187238 (G-137C), and rs549908 (A-105C), have been implicated but require comprehensive evaluation.

Purpose of the Study:

• To conduct a systematic review and meta-analysis to comprehensively evaluate the association between IL-18 promoter polymorphisms and asthma risk.
• To clarify the role of specific IL-18 gene variants in asthma susceptibility.

Main Methods:

• Systematic review and meta-analysis of 12 published studies (up to Dec 30, 2017).
• Examined associations for IL-18 polymorphisms: A-607C (8 studies), G-137C (8 studies), and A-105C (4 studies).
• Utilized fixed- and random-effects models to calculate summary odds ratios (ORs) and 95% confidence intervals (CIs), assessing heterogeneity and publication bias.

Main Results:

• No statistically significant association was found between allele frequencies of IL-18 polymorphisms (A-607C, G-137C, A-105C) and asthma risk (p>0.05).
• Genotype frequencies of these polymorphisms also showed no significant association with asthma under various genetic models (p>0.05).
• Subgroup analyses by ethnicity, sample size, genotyping methods, and other factors yielded consistent results, with no evidence of publication bias.

Conclusions:

• The meta-analysis suggests that the investigated IL-18 promoter polymorphisms (A-607C, G-137C, and A-105C) are unlikely to be associated with asthma risk.
• These findings contribute to a clearer understanding of the genetic factors influencing asthma development.