特发性血小板减少性紫癜患者外周血淋巴细胞共刺激分子的表达及白介素18的作用

本研究探讨特发性血小板减少性紫癜（ITP）患者外周血淋巴细胞共刺激分子CD80、CD86及其配体CD28的表达水平及白介素18的作用。应用免疫荧光标记和流式细胞技术检测34例ITP患者和34名正常人外周血淋巴细胞共刺激分子CD80、CD86及其配体CD28的表达,酶联免疫（ELISA）法测定血浆IL-18。结果表明：ITP患者外周血淋巴细胞CD80、CD86表达率（4.21±2.27%,7.19±5.16%）均明显高于正常对照组（2.34±0.87%,4.08±1.96%,P〈0.01）。ITP组血浆IL-18含量为（538.31±111.33）pg/ml,正常对照组血浆IL-18含量为（489.44±49.07）pg/ml。IL-18含量与血小板数量呈显著性负相关（r=-0.395,P〈0.05）。结论：ITP患者CD80和CD86共刺激分子过度表达,患者血浆中IL-18水平比正常对照组明显升高（P〈0.05）,共刺激分子CD80、CD86与ITP发病密切相关,IL-18在ITP发病机理中起重要作用。

Expression of Co-stimulatory Molecules and Role of Interleukin 18 in Peripheral Lymphocytes of Patients with Idiopathic Thrombocytopenic Purpura

The objective of study was to investigate the expressions of CD80, CD86 and its ligand CD28 on peripheral lymphocytes in patients with idiopathic thrombocytopenic purpura (ITP), to explore the effect of interleukin 18 (IL-18) and its clinical significance in ITP. The expressions of co-stimulatory molecules (CD80, CD86 and its ligand CD28) on peripheral lymphocytes from 34 ITP patients and 34 normal humans were detected by immunofluorescence and flow cytometry. The IL-18 in the plasma was detected by using enzyme linked immunosorbent assay (ELISA). The results showed that the expressions of CD80 and CD86 on peripheral lymphocytes from ITP patients were higher than that of the normal control (4.21 +/- 2.27%, 7.19 +/- 5.16% vs 2.34 +/- 0.87%, 4.08 +/- 1.96%) (P < 0.01); the concentration of IL-18 in plasma of ITP patients was (538.31 +/- 111.33) pg/ml, but the concentration of IL-18 in plasma of controls was (489.44 +/- 49.07) pg/ml. The level of IL-18 negatively correlated with the platelet counts in peripheral blood (r = -0.395, P < 0.05). It is concluded that the CD28/CD80 and CD28/CD86 costimulatory molecules are overexpressed, when the IL-18 level in ITP patients is obviously higher than that in normal controls. When ITP occurred, and the co-stimulatory molecules CD80 and CD86 are closely associated with ITP, it seems that IL-18 may play an important role in ITP pathogenesis.