The IL-1beta genotype carries asthma susceptibility only in men.
One proinflammatory cytokine possibly implicated in the pathogenesis of asthma is IL-1beta. We analyzed the polymorphism of the IL-1beta gene (single nucleotide exchange at position -511) in a cohort of 245 patients with asthma (mean age, 58 years; age range, 31-84 years) and 405 controls. There were no differences in the allele frequencies. However, in men the genotype distribution differed significantly between asthmatic and control subjects (P =.03). The number of 1.2 heterozygotes was decreased in the patient group (P =.01). In subgroup analysis, the genotype distributions between cases and controls proved significantly different only in men with lower serum IgE (<100 IU/mL; P =.009). The odds ratio of the 1.2 heterozygote men was 0.37 (95% CI, 0.19-0.71). Thus in the case of men the effect of the IL-1beta locus is clear, whereas in women there is no effect. In men this might make a significant contribution to the total asthma prevalence because of the high number of functional genotypes (ie, 50/50 IL-1beta homozygote/heterozygote ratio).
Karjalainen
Jussi
J
Tampere University Hospital, Department of Respiratory Medicine, Finland.
Nieminen
Markku M
MM
Aromaa
Arpo
A
Klaukka
Timo
T
Hurme
Mikko
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001249:Asthma / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012737:Sex Factors
D007375:Interleukin-1