Heat shock protein 70-2 and tumor necrosis factor-α gene polymorphisms in Chinese children with Henoch- Schönlein purpura

Background:Henoch-Schönlein purpura(HSP)or IgAassociated vasculitis is related to immune disturbances.Polymorphisms of the heat shock protein 70-2 gene(HSP70-2)and the tumor necrosis factor-αgene(TNF-α)are known to be associated with immune diseases.The purpose of this study was to investigate the likely association of HSP70-2(+1267A/G)and TNF-α(+308A/G)gene polymorphisms with HSP in children.Methods:The polymerase chain reaction restriction fragment length polymorphism method was used to detect the HSP70-2 and TNF-αpolymorphisms in 205 cases of children with HSP and 53 controls;and the association of these polymorphisms with HSP and HSP nephritis(HSPN)was analyzed.Results:The G/G genotypic frequencies at the+1267A/G position of HSP70-2 in the HSP group(22.9%)were signifi cantly higher than those in the healthy control group(9.4%)(χ^(2)=4.764,P<0.05).The frequencies of the A/A,A/G and G/G genotypes of HSP70-2 in patients in the nephritis-free group and the HSPN group showed no statistically significant difference.The A/A genotype frequency at the+308G/A position of TNF-αin the HSP group was 8.3%,which was higher than that in the control group(χ^(2)=6.447,P<0.05).The A allele frequency of TNF-αin the HSP group was higher than that in the control group,with a statistically significant difference(χ^(2)=7.241,P<0.05).Conclusions:The HSP70-2(+1267A/G)and TNF-α(+308G/A)gene polymorphisms were associated with HSP in children.The G/G homozygosity of HSP70-2 and the A/A homozygosity of TNF-αmay be genetic predisposing factors for HSP.