Study On Interleukin-8 Gene Expression And Gene Polymorphisms In Henoch-Schonlein Purpura Nephritis Of Children

BACKGROUND: Recent studies suggest that interleukin-8 (IL-8) may be involved in the pathogenesis of Henoch-Sch?nlein Purpura nephritis(HSPN). Interleukin-8 participate in the pathogenesis of vasculitis, in closely correlation with clinical manifestation in Henoch-Sch?nlein Purpura nephritis(HSPN); and interleukin-8 gene polymorphisms can affect susceptibility to Henoch-Sch?nlein Purpura nephritis. Aim of present study was to investigate association between interleukin-8 gene expression, single nucleotide polymorphisms (SNP) and Henoch-Sch?nlein Purpura nephritis(HSPN) in children patients.METHODSWe identified IL-8 gene expression using real-time polymerase chain reaction in 42 Chinese children with HSPN in acute stage, 28 followed-up in stage of recovery with HSPN and 20 health Chinese as control.We identified polymorphisms in IL-8 gene using Pyrosequencing in 68 Chinese children with HSPN (including patients in acute stage or recovery phase) and 20 Chinese children without HSPN.RESULTS1. 42 patients with HSPN in acute stage had higher IL-8 gene expression in serum than 28 patients with HSPN in stage of recovery and control group(P<0.05). And 28 patients with HSPN in stage of recovery also had higher IL-8 gene expression in serum than normal controls (P<0.05). We found the level of IL-8 gene expression in serum was closely correlation with the phrase in patients with HSPN.2. The frequencies of 68 patients (including patients in acute stage or recovery phase with HSPN) with homozygote (including AA/GG genotype) were higher than normal controls(P<0.05); the allele frequencies of GG genotype were higher in patients than AA genotype in normal controls(P<0.05). We found that Chinese children with homozygote (AA/GG genotype), especially with GG genotype, may be liable to HSPN. And the sample distribution was accorded with Hardy-Weiberg principle.CONCLUSIONSOur results suggest firstly that IL-8 may participate in pathogenesis of HSPN, in closely correlation with clinical manifestation in Chinese children. Our results also suggest that IL-8 homozygote, especially GG genotype may predict susceptibility to HSPN. Our results also suggest that IL-8 gene polymorphisms may play a significant role in HSPN in Chinese children .