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-α gene (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.

The polymerase chain reaction restriction fragment length polymorphism method was used to detect the HSP70-2 and TNF-α polymorphisms in 205 cases of children with HSP and 53 controls; and the association of these polymorphisms with HSP and HSP nephritis (HSPN) was analyzed.

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%) (χ2=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-α in the HSP group was 8.3%, which was higher than that in the control group (χ2=6.447, P<0.05). The A allele frequency of TNF-α in the HSP group was higher than that in the control group, with a statistically significant difference (χ2=7.241, P<0.05).

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-α may be genetic predisposing factors for HSP.