Association of gene polymorphism in interleukin-4 and interleukin-13 gene with Henoch-Schonlein purpura

Abstract

Objective To investigate the association between 2 single nucleotide polymorphisms(SNPs) [rs2243250 in interleukin(IL)-4 gene and rs1800925 in IL-13 gene] in Henoch-Schonlein purpura (HSP)and Henoch-Schonlein purpura nephritis (HSPN) in Han Chinese children.The level of IL-4 and IL-13 in serum were compared between HSP and HSPN. Methods A case-control study was adopted in this research, and 383 children with HSP or HSPN were recruited in this study, 409 normal children served as controls.The genotypes of 2 SNPs were detected by using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP), and the serum levels of IL-4 and IL-13 in HSP and HSPN patients were detected by using enzyme linked immunosorbent assay(ELISA). All the data were analyzed by SPSS 16.0 software. Results (1)There was no association (polymorphism of SNP rs2243250 in IL-4 gene) in HSP group and HSPN group compared with the healthy control group (P>0.05); and the polymorphism of another SNP(rs1800925 in IL-13 gene) was associated with HSP (P=0.037), and the frequency of T allele of the study group was higher than that of the healthy control group (P=0.027). But there was no difference between the study group (HSP group and HSPN group) and the healthy control group in frequency of TT genotype(P=0.132), and there was no association between HSPN group and healthy control group (P=0.487); also there was no association between polymorphism of this SNP in HSP group and HSPN group (P=0.129). (2)There was an association between polymorphism of IL-13 gene and IL-13 level in serum, patients with TT genotype had a higher serum IL-13 level than any other genotypes(P 0.05). (3)There was an association between polymorphism of IL-13 gene and IL-13 level in serum patients with HSPN who had a higher level of serum IL-13 than the patients with HSP (P<0.05), but there was no difference in serum IL-4 level between HSP group and HSPN group. Conclusions The polymorphism of SNP (rs1800925 in IL-13 gene) was associated with HSP group, and the polymorphism of this SNP might affect the level of IL-13 in serum.The patients with HSPN have a higher level of serum IL-13 than the patients with HSP, and high level of IL-13 may be a risk factor in the progression from HSP to HSPN. Key words: Henoch-Schonlein purpura; Henoch-Schonlein purpura nephritis; Interleukin-4; Interleukin-13; Gene polymorphism