Environmental tobacco smoke and interleukin 4 polymorphism (C-589T) gene: environment interaction increases risk of wheezing in African-American infants.
OBJECTIVE
To determine whether infants exposed to environmental tobacco smoke (ETS) having the interleukin 4 (IL-4) or interleukin 13 (IL-13) gene polymorphisms were at increased risk of wheezing.


METHODS
A birth cohort of 758 infants was evaluated annually by a questionnaire, physical examination, and skin prick testing. DNA samples from 560 children were genotyped for IL-4 C-589T and IL-13 C-1112T. The relationship of ETS exposure and genotype with the outcome of wheezing was analyzed.


RESULTS
At the time of evaluation, mean age was 13.4 +/- 2.2 months. The prevalence of sensitization was 29%, and wheezing without a cold was 26.2%. The interaction of ETS exposure and the CT/TT genotypes for IL-4 C-589T showed a significant association with wheezing (odds ratio: 10.84; 95% confidence interval: 1.12-104.64, P = .04) in African-American infants.


CONCLUSIONS
In African-American infants with a family history of atopy, the interaction of ETS and IL-4 C-589T demonstrated a 10-fold risk associated with wheezing without a cold.
Smith
Andrew M
AM
Department of Internal Medicine, Division of Immunology, University of Cincinnati, Cincinnati, Ohio 45267-0563, USA. sa6@email.uc.edu
Bernstein
David I
DI
LeMasters
Grace K
GK
Huey
Nanette L
NL
Ericksen
Mark
M
Villareal
Manuel
M
Lockey
James
J
Khurana Hershey
Gurjit K
GK
D001741:Black or African American; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000208:ethnology; D006801:Humans; D007223:Infant; D018793:Interleukin-13 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012135:Respiratory Sounds / Q000209:etiology*; D012959:Socioeconomic Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D018793:Interleukin-13; D014028:Tobacco Smoke Pollution; D015847:Interleukin-4