PD-L1在急性白血病中的表达及其临床意义

Expression of Programmed Death Ligand-1(PD-L1) in Human Acute Leukemia and Its Clinical Significance

目的:探索PD-L1在急性白血病中的表达情况,探讨PD-L1的表达与与患者的临床特征及预后之间的关系。方法:应用流式细胞术检测75例患者(包括59例初治患者和16例复发难治患者)骨髓原始细胞中PD-L1的表达情况,并搜集患者的临床资料,追踪初治组患者的治疗效果。结果:PD-L1在白血病细胞中表达的总体阳性率为32.0%(24/75),其中在急性单核细胞白血病中的表达高于在其他白血病类型中的表达水平[56.3%(9/16)vs25.4%(15/59)],其差异有统计学意义(P=0.019),在复发难治组中PD-L1阳性率高于初治组[56.3%(9/16)vs25.4%(15/59)],其差异具有统计学意义(P=0.019);在59例初治患者中PD-L1阳性组1个疗程CR率低于PDL1阴性组(66.7%vs 71.4%),2个疗程CR率低于PD-L1阴性组(70%vs 88.6%),PD-L1阳性组半年复发率高于PD-L1阴性组(20%vs 8.82%),阳性组难治患者比例高于PD-L1阴性组(30%vs 14.3%);PD-L1的表达与患者的性别、年龄、髓外浸润、骨髓中原始细胞比例、初诊血象(白细胞、血红蛋白、血小板水平)等临床特征无显著相关性,与AML患者的分子生物学突变及细胞遗传学危险度分组之间也无显著相关性。结论:PD-L1在急性白血病中有表达,可能参与白血病细胞的免疫逃逸及原发耐药机制,并可能成为评估患者预后及复发的指标。

Objective: To explore the expression of PD-L1 in acute leukemia patients,and to analyze the relationship of PD-L1 expression with the patients' clinical characteristics and prognosis. Methods: The expression of PD-L1 in leukemia cells of 75 patients including 59 de novo patients and 16 relapse / refractory patients with acute leukemia was detected by the flowcytometry,the clinical information was collected,and the therapeutic efficacy of de novo patients was analyzed. Results: The PD-L1 was expressed in human acute leukemia cells with total expression rate 32%( 24 /75),and its expression level in AM L-M5 was higher than that in other leukemias [56. 3%( 9 /16) vs 25. 4%( 15 /59) ],there was statistical significance( P = 0. 019). The PD-L1 possitive rate in relapse / refractory group was higher than that in de novo patient group[( 56. 3%( 9 /16) vs 25. 4%( 15 /59) ],and there was statistical significance( P = 0. 019). In 59 de novo patients,the CR rate of PD-L1 positive group after 1 course of chemotherapy was lower than that in PD-L1 negative group( 66. 7% vs 71. 4%),the CR rate of PD-L1 positive group after 2 courses of chemotherapy was also lower than that in PD-L1 negative group( 70% vs 88. 6%). The relapse rate and the proportion of refractory patients in PD-L1 possitive group were higher than those in PD-L1 negative group. The expression of PD-L1 did not correlated with the clinical parameters,such as sex,age,extramedullary infiltration,percentage of blast cells in bone marrow,counts of WBC,RBC and platelet,as well as molecular biological features and cytogenetical characteristics. Conclusion: PD-L1 is expressed in human acute leukemia cells, and may be involved in the immune escape and primary resistant mechanisms,PD-L1 may be used as an indicator for evaluation of the the patients' prognosis and reocurrence.