THE ASSOCIATION BETWEEN TUMOR NECROSIS FACTORαGENE POLYMORPHISM AND ASTHMA

Objective.In this study,we investigated the hypothesis that tumor necrosis factor(TNF)α-308gene polymorphism might be of the genetic predisposition to asthma and asthma phenotypes.Methods.TNFα-308gene polymorphism was genotyped in221random unrelated Northern Chinese population(comprising125asthmatics and96healthy controls)and52individuals from12asthmatic families with Han ethnic by using polymerase chain reaction(PCR)-restriction fragment length polymor-phism(RFLP).Methacholine(Mch)broncho-challenge test,bronchial reversibility test and lung function were underwent in all asthmatics.Results.TNFα-3082homozygosity was present at a significantly higher frequency in asthmatics than that in controls(20.8%vs11.4%,P<0.05,OR2.259),the TNF allele2was also higher in asthmatics compared with controls(0.42vs0.33,P<0.01).TNFα-3082homozygosity was an weak independent risk factor for asthma etiology(OR0.226,P<0.05).Moreover,patients carrying TNFα-3082homozy-gosity had less responsive to inhaledβ 2 -agonist in20minutes than patients carrying other two genotypes(24.1%vs29.5%vs38.8%,P<0.05).Linkage analysis didn't support that TNFαgene was linked to asthma (Likelihood of odds,LOD<1)based on familial data.Conclusion These results suggest that TNFα-3082homozygosity may be of a component contribut-ing to the genetic predisposition to asthma ,and airway responsiveness toβ2 -agonist.