Expression of interleukin-18 and interleuldn-18 receptor a chain of the peripheral white blood cells in immune thrombocytopeula / 中华内科杂志

ABSTRACT

Objective To detect the expression of interleukin (IL)-18 of the peripheral blood cells and IL-18 receptor α chain(IL-18Rα) on the surface of CD_3~+ cells in patients newly diagnosed as immune thrombocytopenia (ITP) before medication and to explore the roles of IL-18 and IL-18Rα in the development of ITP. Methods Eighteen out-patients or inpatients with acute ITP accepting treatment in Qilu Hospital were enrolled in this study and 15 matching healthy subjects were taken as control. Plasma IL-18 level was detected with enzyme linked immunosorbent assay (ELISA), the expression of IL-18Rα on CD_3~+ lymphocytes and total lymphoeytes were measured with flow cytometry; T-bet and GATA-3 mRNA were measured with reverse transcriptase polymcrase chain reaction (RT-PCR). Results The expression of IL-18 in acute ITP plasma was (468. 57 ± 141.62) ng/L and IL-18Rα on the surface of CD_3~+ cells and lymphocytes were (8.50 ±3. 16)% and (9. 16±2.98)% respectively. The levels of IL-18 and IL-18Rα were increased in active ITP patients as compared with those in the controls (P <0. 05). The levels of IL-18 mRNA (0. 12 ±0. 02) and T-bet mRNA (0. 07 ±0. 02) were significantly increased in patients with active ITP as compared with those in the controls (P <0.05), while GATA-3 mRNA (0.0039±0.0014) were significantly decreased in patients with active ITP (P < 0. 05). The balance between T-bet and GATA-3 was significantly disturbed in ITP. Conclusions Through the variation of the levels of gene and protein, our study showed that IL-18 and IL-18Rα might upregulate the expression of Th1-cytokines in ITP patients. It is also suggested that IL-18 has potential association with the development of ITP. Especially, it may provide a new treatment method for ITP by regulating the ratio of T-bet and GATA-3 and resuming the balance of Th1/ Th2.