OBJECTIVETo study the changes and significance of Toll-like receptor-2 (TLR2) and Toll-like receptor-4 (TLR4) on platelets, CD86 on lymphocytes and concentrations of IL-2, IFN-gamma, IL-4 and IL-10 in serum in children with idiopathic thrombocytopenic purpura (ITP).

METHODSPeripheral blood samples were collected from 24 children with acute idiopathic thrombocytopenic purpura (AITP), 21 children with chronic idiopathic thrombocytopenic purpura (CITP) and 20 normal children (control group). Expression of TLR2 and TLR4 on platelets and CD86 on lymphocytes were detected by flow cytometry. Serum concentrations of IL-2, IL-4, IL-10 and IFN-gamma were measured using ABC-ELISA.

RESULTSThe expression of CD41+TLR2+ and CD61+TLR4+ in the AITP and the CITP groups were significantly lower than those in the control group (p<0.01). The AITP group had lower expression of CD41+TLR2+ and CD61+TLR4+ than the CITP group (p<0.01). The expression of CD86+ in the AITP and the CITP groups was significantly higher than that in the control group (p<0.01). The serum concentrations of IL-2, IL-4, IL-10 and IFN-gamma in the AITP and the CITP groups were significantly higher than those in the control group (p<0.05). There was a positive correlation between CD41+TLR2+ and CD61+TLR4+ expression. CD41+TLR2+ and CD61+TLR4+ expression were negatively correlated with CD86+ expression and serum concentrations of IL-2, IL-4 and IL-10.

CONCLUSIONSThe detections of TLR2 and TLR4 on platelets, CD86 on lymphocytes and serum concentrations of IL-2, IFN-gamma, IL-4 and IL-10 are of great value in understanding the pathogenesis and predicting types of ITP in children.