重型再生障碍性贫血CD8^(+)T细胞SLAMF6表达与穿孔素和颗粒酶B的相关性及其临床意义

Correlation between SLAMF6 expression and perforin and granzyme B on circulating CD8^(+)T cells and the clinical significance in patients with severe aplastic anemia

目的探讨初诊重型再生障碍性贫血(SAA)患者外周血CD8^(+)T细胞信号转导淋巴细胞激活分子家族6(SLAMF6)表达与穿孔素、颗粒酶B的相关性及其临床意义。方法收集2016年1月至2019年6月河南省人民医院收治的32例初诊SAA患者的血常规及骨髓象等指标并采集外周血标本进行回顾性分析,采用流式细胞术检测患者初诊时及治疗结束后半年[移植11例,免疫抑制治疗(IST)21例]的标本中CD8^(+)T细胞SLAMF6表达量、穿孔素及颗粒酶B分泌量。采用Pearson法分析临床指标与标本检测结果相关性,并以10名健康人的外周血标本(正常对照组)及13例初诊骨髓增生异常综合征/阵发性睡眠性血红蛋白尿症(MDS/PNH)患者(MDS/PNH组)为对照进行SLAMF6表达量、穿孔素及颗粒酶B分泌量的比较。结果(1)初诊时:SAA组SLAMF6表达量为(56.40±6.37)%,明显低于正常组的(84.34±5.81)%和MDS/PNH组的(82.24±4.98)%(P均<0.001);SAA组穿孔素的表达量为(32.73±8.46)%,高于正常组的(23.75±5.10)%和MDS/PNH组的(26.12±5.53)%(P均<0.05);SAA组颗粒酶B的表达量为(36.23±7.94)%,高于正常对照组的(21.67±5.05)%和MDS/PNH组的(21.79±5.10)%(P均<0.001)。SAA患者SLAMF6表达量与血红蛋白(r=0.804)、网织红细胞绝对值(r=0.656)、骨髓粒系百分比(r=0.643)、骨髓红系百分比(r=0.622)均呈正相关(P均<0.05),与CD8^(+)T细胞穿孔素(r=-0.792)、颗粒酶B(r=-0.908)均呈负相关(P均<0.001)。(2)治疗后:30例SAA存活患者外周血CD8^(+)T细胞SLAMF6表达量高于治疗前[(79.19±12.69)%比(56.40±6.37)%,P<0.001],穿孔素、颗粒酶B表达量均低于治疗前(P均<0.05)。11例移植患者CD8^(+)T细胞SLAMF6表达量高于移植前[(86.54±3.75)%比(56.40±7.35)%,P<0.001],穿孔素、颗粒酶B表达量低于移植前(P均<0.05)。12例IST有效患者CD8^(+)T细胞SLAMF6表达量高于初诊时,其穿孔素、颗粒酶B表达量均低于治疗前(P均<0.05);7例IST无效患者CD8^(+)T细胞SLAMF6表达量、穿孔素、颗粒酶B表达量与治疗前比较,差异无统计学意义(P均>0.05)。结论SLAMF6在初诊SAA患者中低表达,与CD8^(+)T细胞效应因子呈负相关,或作为负性调控因子参与SAA患者CD8^(+)T细胞免疫调控,SLAMF6在造血恢复后明显上调,而治疗无效患者无明显变化,或可作为诊断SAA或评价SAA临床疗效的指标。

Objective To explore the correlation between the expression of signaling lymphocyte activation molecule family 6(SLAMF6)on peripheral blood CD8^(+)T cells and perforin and granzyme B and the clinical significance in patients with newly diagnosed severe aplastic anemia(SAA).Methods The indicators of blood routine and bone marrow and peripheral blood samples of 32 newly diagnosed SAA patients admitted to Henan Provincial People's Hospital from January 2016 to June 2019 were collected for retrospective analysis.Flow cytometry was used to detect the expression of SLAMF6,perforin and granzyme B on samples CD8^(+)T cell before therapy and 6 months after therapy(11 cases received transplantation,21 cases received immunosuppressive therapy[IST]).Spearman correlation analysis was performed to determine the association between clinical indicators and laboratory test results.The expression of SLAMF6,perforin and granzyme B was also detected in 10 healthy people(normal group)and 13 myelodysplastic syndromes/paroxysmal nocturnal hemoglobinuria(MDS/PNH)patients(MDS/PNH group).Results(1)At diagnosis:the expression of SLAMF6 was significantly lower in the SAA group than that in the normal group and the MDS/PNH group([56.40±6.37]%vs[84.34±5.81]%and[82.24±4.98]%(both P<0.001)).The expression of perforin was significantly higher in the SAA group(32.73±8.46)than that in the normal control group(23.75%±5.10%),and the MDS/PNH group(26.12%±5.53%)(both P<0.05).The expression of granzyme B was also significantly higher in the SAA group(36.23%±7.94%)than that in the normal control group(21.67%±5.05%)and the MDS/PNH group(21.79%±5.10%)(both P<0.001).The expression of SLAMF6 was positively correlated with the hemoglobin(r=0.804),and reticulocyte absolute values(r=0.656)in peripheral blood,percentage of granulocytes(r=0.643)and erythrocytes(r=0.622)in bone marrow of SAA patients(all P<0.05).Expression of SLAMF6 was negatively correlated with perforin(r=-0.792)and granzyme B(r=-0.908)on CD8^(+)T cells in patients with SAA(both P<0.001).(2)After treatment:the expression of SLAMF6 in peripheral blood CD8^(+)T cells of 30 surviving patients was higher than pre-treatment([79.19±12.69]%vs[56.40±6.37]%,P<0.001).The expressions of perforin and granzyme B were lower than pre-treatment level(both P<0.05).The expression of SLAMF6 on CD8^(+)T cells in 11 transplanted patients was higher than before transplantation([86.54±3.75]%vs[56.40±7.35]%,P<0.001).The expressions of perforin and granzyme B were lower than before transplantation(both P<0.05).The expression of SLAMF6 on CD8^(+)T cells in 12 IST-respond patients was higher than that before treatment,while the perforin and granzyme B levels were lower than pre-treatment(all P<0.05).The post-treatment expressions of SLAMF6,perforin and granzyme B were similar as before treatment levels in 7 IST-unrespond patients(all P>0.05).Conclusion SLAMF6 is significantly down-regulated on CD8^(+)T cells in newly diagnosed SAA,negatively correlated with the effective factors of CD8^(+)T cells,which might participate in the immune regulatory of CD8^(+)T cells as a negative regulatory factor in patients with SAA.The SLAMF6 is significantly up-regulated after hematopoietic recovery,while there is no significant change in treatment-unrespond patients,which could thus serve as an useful diagnostic and therapeutic index of patients with SAA.