Study on the association between cytokine gene polymorphisms and acute respiratory distress syndrome

Objective To investigate the correlations between the polymorphisms of TNFα,TNFβ,IL-1β and IL-1ra gene and the susceptibility or outcome of ARDS.Methods A prospective,consecutive entry study was made among 27 patients with ARDS admitted in ICU between 2001 and 2002.The genomic DNA of peripheral blood nucleated was extracted.The region containing the polymorphism sites of TNFα,TNFβ and IL-1β gene was amplified by polymerase chain reaction (PCR) and restrictive fragment length polymorphism (RFLP).The polymorphic region within intron 2 of the IL-1ra gene was amplified by PCR.Results The polymorphisms of TNFα,TNFβ,and IL-1β did not differ between the patients with ARDS and normals(P0.05).The frequency of allele A2 of IL-1ra was 7.5% in normal,with an increase trend in ARDS(16.7%),however the polymorphism of IL-1ra did not differ between the patients with ARDS and normals(P0.05).The frequency of allele 1 of TNFβ was 80% in the nonsurvivors,higher than in the survivors (P=0.017),with an odds ratio of 4.5.However,no differences were observed when the genotype of TNFα,TNFβ,IL-1β and IL-1ra between nonsurvivors and survivors were compared(P 0.05).Conclusion No significant associations of TNFα,IL-1β and IL-1ra gene polymorphisms with susceptibility or outcome of ARDS were detected,allele 1 and allele 2 of TNFβ may have some role in determining the outcome of ARDS.