胸腺肽α1降低脓毒症单核细胞PD-L1表达

Thymosin alpha 1 reduces the expression of PD-L1 on monocyte of septic patients

目的探究胸腺肽α1对脓毒症受试者单核细胞表面共刺激分子(CD86)及负性共刺激分子(PD-L1)表达的影响。方法随机收集2016年3-9月间符合纳入标准的脓毒症受试者,分别在入组前(第0天)、入组后第3天和第7天计算和检测序贯性器官功能衰竭评分(SOFA评分)、降钙素原(PCT)和单核细胞CD86和PD-L1的表达量,同时观察28 d内入住ICU时间和器官功能支持时间。结果研究期间共收集20例(实验组:10例;对照组:10例,脓毒症受试者,两组受试者在入组前(第0天)的各项统计指标差异均无统计学意义;入组后第7天,实验组PD-L1平均荧光强度(MFI)表达低于对照组(2.2[1.5,3.0]vs.3.7[2.7,4.8],P<0.05),差异有统计学意义;入组后28 d的生存和器官功能支持分析显示:实验组受试者继发感染发生率低于对照组[0.00%(0/10)vs.30.00%(3/10),P<0.05],差异有统计学意义;但两组入住ICU时间、28 d呼吸机使用时间、28 d使用血管活性药物时间和28 d生存率的差异均无统计学意义(P>0.05)。结论胸腺肽α1可以通过抑制单核细胞PD-L1表达,有利于抗原提呈抑制状态的改善,减少继发感染的发生率。

Objective To investigate the effect of thymosin α1 on the expression of CD86 and PD-L1 on monocytes of septic patients. Methods Septic patients who met the inclusion criteria between March 2016 and September 2016 were enrolled in this study. Sequential organ failure assessment （SOFA） score, proealcitonin （PCT） , monocyte costimulatory molecule （CD86） and negative costimulatory molecule （PD-L1） were determined before （day O） and after enrollment （ day 3 and day 7 ）. The time of ICU stay and organ function support were observed within 28 days. Results During the study period, 20 sepsis subjects （10 subjects in experimental group and 10 subjects in control） were enrolled in this study. There were no statistical differences in the parameters between the two groups before enrollment （day 0）. On the 7th day, the level of PD- L1 MFI in the experimental group was lower than that in the control group （2.2 [1.5,3.0] vs. 3.7 [2.7,4.8] , P〈0.05）. Analysis of survival and organ function support after 28 days of enrollment showed that the incidence of secondary infection in the experimental group was lower than that in the control group [0.00% （0/10） vs. 30.00% （3/10）, P〈0.051. Because of small sample size, the time of ICU stay, 28-day survival rate, total ventilation time and vasoactive agents using time after enrollment had no significant differences between two groups. Conclusion Thymosin α1 could inhibit the expression of PD- L1 on monocytes of septic patients, which was beneficial to improve the inhibition state of antigen presenting and reduce the incidence of secondary infection.