[Expression of leukocyte-associated Ig-like receptor-1 in children with immune thrombocytopenia]

To study the expression of leukocyte-associated Ig-like receptor-1(LAIR-1) in children with immune thrombocytopenia (ITP), in order to explore the possible role of LAIR-1 in the pathogenesis of childhood ITP.

Expression levels of LAIR-1 on CD4(+) T cells, CD8(+) T cells and CD19(+)CD20(+) B cells of peripheral blood were measured in 40 children with ITP by flow cytometry. Serum level of solubility LAIR-1 (sLAIR-1) was measured using ELISA. Real-time PCR was used to measure LAIR-1 mRNA expression. Thirty-two healthy children served as the control group.

The percentages of CD19(+)CD20(+) B cells in the ITP group were significantly higher than in the control group (P<0.05). In contrast, the percentage of CD4(+) T cells in the ITP group was significantly lower than in the control group (P<0.05). The expression levels of LAIR-1 on CD4(+) T cells and CD8(+) T cells were significantly lower in the ITP group than in the control group (P<0.05). Serum sLAIR-1 level and LAIR-1 mRNA expression in the ITP group significantly increased compared with the control group (P<0.05).

LAIR-1 expression on CD4(+) and CD8(+) T cells decreases and serum sLAIR-1 level increases in children with ITP, suggesting that LAIR-1 may play an important role in immune imbalance in these children.