The Expression Of FOXP3 In The Acute Stage Of Hen(?)ch-Sch(?)nlein Purpura In Children

Objective:Hen(o|¨)ch-Sch(o|¨)nlein purpura(HSP) is one of the most common systemic vasculitis in children which mainly affects small vessels and has a high prevalence in Asian countries.HSP is a major cause of childhood secondary renal disease.However the pathogenesis of HSP remains unclear.Most studies hypothesize that HSP is systematic vasculitis generated by IgA-mediated circulating immune complexes depositing in the vessel walls of the involved organs and making the complement activated.Recent data revealed the disorders of decreased Th1 cells and increased Th2 of T lymphocytes,as well as the misbalance of the ratio of Th1 to Th2 existing in the HSP acute stage.Recent reports show that CD4+ CD25+ regulatory T cells have both immunosuppression and immunoregulation functions which play an important role in maintaining the autoimmunity tolerance of body and could be associated with the incidence of many kinds of autoimmune diseases. Transcription factor FOXP3 is not only a specific sign of CD4+CD25+ regulatory T cells but also the key factor of their development and function of immunosuppression.There are some studies showing that the reduced CD4+CD25+regulatory T cells and the decreased expression of FOXP3 mRNA in peripheral blood in patients with HSP acute stage may be related with the immune pathogenesis of HSP.This study aimed to explore the relationship between the gene expression of FOXP3 and the pathogenesis of Hen(o|¨)ch-Sch(o|¨)nlein purpura in children through the study on the expression of transcription factor FOXP3 mRNA in peripheral blood in patients with acute stage HSP.Methods:2ml peripheral blood samples collected from seventeen inpatients with HSP,WBC were isolated and then the RNA was extracted.RNA was changed into cDNA by reverse transcription polymerase chain reaction(RT-PCR).cDNA is used as the template to proceed Real-time Q-PCR,and the simultaneous amplifiableβ-actin is considered to be the internal quod vide.Statistic analysis has been done to detect the expression of FOXP3 in peripheral blood leucocyte. Thirteen age-matched healthy children and fourteen patients with Kawasaki disease(KD) were studied as control. Results:Compared with healthy control subjects,the mRNA expression of FOXP3 in patients with HSP was remarkably decreased,the difference has statistical significance(0.01327±0.004179 vs.0.11921±0.210075,P＜0.05).And the mRNA expression of FOXP3 in patients with KD was also decreased,the difference has statistical significance too(0.02204±0.079844 vs.0.11921±0.210075,P＜0.05).But there was no statistical differences in the mRNA expression of FOXP3 in patients with HSP and KD(0.01327±0.004179 vs.0.02204±0.079844,P＞0.05).Conclusions:Compared with healthy control subjects,the mRNA expression of FOXP3 in patients with HSP was remarkably decreased,and the difference has statistical significance.As in the control group,the mRNA expression of FOXP3 in patients with KD was also decreased compared with healthy control subjects, the difference also has statistical significance.But there was no statistical differences in the mRNA expression of FOXP3 in patients with HSP and KD. The results demonstrated that the decrease of expression of FOXP3 might be the common cause of immune misbalance of systematic vasculitis in children, instead of the specificity alteration of HSP.