Allergic rhinitis and polymorphisms of the interleukin 1 gene complex.
BACKGROUND
Allergic rhinitis is a chronic inflammatory disease with a genetic background. Inflammatory reactions are regulated by cytokines. Cytokine genes are polymorphic and have been implicated as candidate genes in allergy.


OBJECTIVE
To study the significance of the interleukin 1 (IL-1) gene complex in allergic rhinitis.


METHODS
Population-based, cross-sectional study. We studied the polymorphisms of 3 IL-1 gene complex genes, IL1A (+4845G>T), IL1B (-511 degrees C>T), and IL1RN (variable number of tandem repeats; IVS2, 86 bp, duplicates 2 to 5), in patients with allergic rhinitis. The study group consisted of 405 nonasthmatic individuals of whom 56 had allergic rhinitis.


RESULTS
The genotype distribution differed significantly in all cytokine genes studied between subjects with and without allergic rhinitis. The difference was mainly due to an increased number of IL1A allele G homozygotes (67.9% vs 43.2%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.5-5.1), IL1B heterozygotes (72.2% vs 47.4%; OR, 2.8; 95% CI, 1.5-5.3), and IL1RN allele 2 homozygotes (18.5% vs 7.5%; OR, 2.8; 95% CI, 1.3-6.2) in allergic rhinitis. Haplotype analysis revealed a significant difference in the distribution of IL-1 gene complex haplotypes between subjects with and without allergic rhinitis (P = 0.005, 10 df).


CONCLUSIONS
The IL-1 gene complex polymorphism is strongly associated with allergic rhinitis in nonasthmatic individuals.
Joki-Erkkilä
Veli-Pekka
VP
Department of Otorhinolaryngology, Tampere University Hospital, Tampere, Finland. veli-pekka.joki-erkkila@nokianlaakariasema.fi
Karjalainen
Jussi
J
Hulkkonen
Janne
J
Pessi
Tanja
T
Nieminen
Markku M
MM
Aromaa
Arpo
A
Klaukka
Timo
T
Hurme
Mikko
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006720:Homozygote; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012221:Rhinitis, Allergic, Perennial / Q000235:genetics*
D007375:Interleukin-1