原发免疫性血小板减少症患者出血风险与血小板活化的相关性分析

OBJECTIVE: To study the relationship between platelet activation and the degree of bleeding in patients with primary immune thrombocytopenia (ITP). METHODS: 43 patients with ITP were assessed based on ITP-BAT bleeding grading system. Platelet membrane glycoproteins (GP) Ⅰb, GPⅡb/Ⅲa and P-selectin expression were detected by flow cytometry analysis with and without adenosine diphosphate (ADP) stimulation. Association of platelet activation with platelet count, immature platelet fraction (IPF), bleeding severity were evaluated. RESULTS: GPⅡb/Ⅲa and P-selection expressions on unstimulated platelet in ITP patients were higher than those in healthy controls (65.69±10.73 vs 7.16±0.99, t=4.130, P<0.001; 15.43±1.41 vs 12.55±1.03, t=2.070, P=0.043, respectively), and GPⅠb expression was lower than that in healthy controls (240.11±24.93 vs 295.11±22.15, t=2.417, P=0.020). Comparatively to healthy individuals, following ADP stimulation, GPⅡb/Ⅲa expression in ITP patients increased (133.96±12.17 vs 39.67±4.99, t=5.256, P<0.001), whereas GPⅠb and P-selection expressions decreased (37.09±3.94 vs 109.77±23.66, t=3.901, P<0.001; 149.06±19.14 vs 205.73±21.00, t=2.070, P=0.043, respectively). ADP-stimulated GPⅠb, ADP-stimulated and unstimulated P-selection, proportion of GPⅠb, P-selection levels with/without ADP stimulation were significantly associated with platelet counts (P<0.05). ADP-stimulated P-selection and proportion of P-selection levels with/without ADP stimulation were significantly associated with IPF (P<0.05). There were significant differences in the expressions of unstimulated P-selection, ADP-stimulated P-selection, ADP-stimulated GPⅠb stratified by bleeding grades (P<0.05). The ratios of P-selection, GPⅡb/Ⅲa and GPⅠb with/without ADP stimulation in ITP patients were significantly different among various bleeding grades (P<0.05). Higher proportion of GPⅠb with/without ADP stimulation was associated with higher risk of bleeding (OR=3.05, P=0.011). Lower proportion of GPⅡb/Ⅲa and P-selection with/without ADP was associated with higher risk of bleeding (OR=0.32, P=0.023; OR=0.04, P=0.006, respectively). CONCLUSION: Platelet activation index could accurately assess the degree of bleeding in patients with ITP, and also be used as the observation index and reference index for treatment.