Expression of plasmacytoid dendritic cells in peripheral blood and renal tissues in children with Henoch-Schönlein purpura

Abstract

Objective To investigate the expression and distribution of plasmacytoid dendritic cells(pDC) in peripheral blood and renal tissues in children with Henoch-Schonlein purpura(HSP), and explore the role of pDCs in the pathogenesis of Henoch-Schonlein purpura nephritis(HSPN). Methods Among the 40 children with HSP, 28 cases were in the active phase(renal biopsy performed in 8 cases of them)and the other 12 in remission phase.Peripheral blood mononuclear cells were isolated, and the expression of pDC was detected by flow cytometry.The normal control group was established (n=15). Total RNA of peripheral blood was extracted and transcripted into cDNA.Sybr green dye based real-time quantitative PCR method was used to compare the expression(indicated as 2-ΔCt value) of CXC motif chemokine 10 (CXCL10), CC chemokine ligand 5 (CCL5), chemokine CXC subfamily receptor 3(CXCR3), CC chemokine receptor 5(CCR5) in children with HSP and those in the controls.Immunohistochemistry labeling technique was used to detect the distribution of pDC in renal tissues from renal biopsy, and the normal controls were established(n=3). Results The expression percentage of pDC in peripheral blood in active phase was 0.051± 0.039, signi-ficantly lower than those in remission phase(0.181±0.082) and the normal controls(0.166±0.079)(P<0.000 1). Chemokines genes CXCL10 and CCL5 were overexpressed in peripheral blood ceils of acute phase HSP children, but chemokine receptors CXCR3, CCR5 were lowly expressed compared with normal controls.There was almost no expression of pDC in the normal control renal tissues, while pDC was infiltrated in glomeruli of HSPN children. Conclusions The number of pDC and chemokines' expression in peripheral blood is abnormal, and the pathogenesis of nephritis may be involved with the pDC in peripheral blood to migrate to the renal tissues. Key words: Henoch-Schonlein purpura; Plasmacytoid dendritic cells; Chemokines