Allergy Asthma Immunol Res.  2013 Mar;5(2):106-109. 10.4168/aair.2013.5.2.106.

IL-5 Promoter Polymorphism Enhances IgE Responses to Staphylococcal Superantigens in Adult Asthmatics

• Losol P
• Kim SH
• Hwang EK
• Shin YS
• Park HS

• KMID: 2260346
• DOI: http://doi.org/10.4168/aair.2013.5.2.106

Abstract

Interleukin 5 (IL-5) is a key cytokine involved in the induction of T-helper type 2 (Th2) responses in the asthmatic airway. We investigated IL-5 genetic polymorphisms associated with asthma phenotypes, including IgE responses to staphylococcal enterotoxins A and B (SEA and SEB, respectively), in asthmatics. Adult asthmatics (n=310) and normal controls (n=160) were enrolled in the present study. Serum total and specific IgE to SEA and SEB were measured. Two IL-5 polymorphisms, -746A>G and +4499T>G, were genotyped using the primer-extension method. There were no significant differences in genotype or haplotype frequencies of these polymorphisms between the two groups. Asthmatics carrying the AG/GG genotype at -746A>G had a significantly higher prevalence of serum specific IgE to SEA (P=0.008), higher total IgE levels (P=0.014), and lower PC20 methacholine levels (P=0.002) compared to those with the AA genotype. These findings suggest that the IL-5 promoter polymorphism at -746A>G enhances serum total and specific IgE responses to SEA, which may augment airway hyperresponsiveness in adult asthmatics.

Keyword

Asthma; eosinophilic inflammation; IL-5; polymorphism; staphylococcal enterotoxin

MeSH Terms

Adult
Asthma
Enterotoxins
Genotype
Haplotypes
Humans
Immunoglobulin E
Interleukin-5
Lifting
Methacholine Chloride
Phenotype
Polymorphism, Genetic
Prevalence
Superantigens
Enterotoxins
Immunoglobulin E
Interleukin-5
Methacholine Chloride
Superantigens