Study Of The Functions Of Peripheral Blood Dendritic Cells And The Balances Of Th1/Th2 In Children With Henoch-Schonlein Purpura

Objective To study the correlation of the changes of the functions of dendritic cells (DC) in peripheral blood mononuclear cells (PBMC) and the impacts of dysfunction of Thl/Th2 subsets in children with Henoch-Schonlein Purpura (HSP), and to explore their role in the pathogenesis of HSP.Methods The levels of IFN-γ,IL-4, IL-12 in plasma were determined by ELISA in 60 children with HSP and 21 normal children. Peripheral blood mononuclear cells (PBMC) of 22 HSP children and 21 normal children were induced with rhGM-CSF and rhIL-4 to make them transform into DC and culture in vitro for 7 days. The levels of Interleukin-12(IL-12) in the supematants of DC were detected by ELISA. The positive expression of CD la on the surface of DC was detected by indirect im-munofluorescence procedure.Results (1)The levels of IFN-γ and the ratio of IFN-γ/IL-4 in plasma of HSP children were significantly lower than those of the controls, respectively (t'=2.88, 4.85, P<0.01); the IL-12 levels were much lower than those of the controls (t' = 4.53, P<0.01); while the levels of IL-4 were remarkably higher than those of the controls (t=5.49, P<0.01). The levels of IL-12 in plasma of HSP children had positive correlation with the levels of IFN-γ (r=0.52, PO.01) and the ratio of IFN-γ/IL-4 (r=0.43, P<0.01), but had no correlation with the levels of IL-4 (r=0.07, P>0.05). The levels of IL-12 in plasma of the controls were positively correlated with the IFN-γ levels (r=0.54, P<0.05) and the ratio of IFN-γ/IL-4 (r=0.58, P<0.01), but weren't correlated with the levels of IL-4 (r=0.22, P>0.05). (2)The levels of IL-12 in the supematants of DC from HSP children were lower than those of the control (t=2.27, P<0.05), and they had positive correlation with the IL-12 levels in plasma (r=0.74, P<0.01). The levels of IL-12 in the supematants of DC from the controls were also positively correlated with the IL-12 levels in plasma (r=0.69, P<0.01). (3)The positive expression rates of CD1a as the surface marker of DC in HSP children were lower than that of the controls (t=2.38, P<0.05), and they had positive correlation with the IL-12 levels in the supematants of DC and in plasma (r= 0.57, 0.68, P<0.01); The positive expression rates of CD1a of the controls were also positively correlated with the supematants and the plasma levels of IL-12, respectively (r=0.60, P<0.01; 0.46, P<0.05).Conclusions The study showed that there was imbalance of Th1/Th2 in HSP children, and the function of Th2 relatively prevailed over Th1. The decrease of Th1 functions correlated closely with the low levels of IL-12 in plasma. The IL-12 levels in plasma of HSP children had positive correlation with the IL-12 levels in the supematants and they were both lower than those of the controls. The...