目的:观察超高龄老年感染患者循环血微粒（MPs）的变化趋势，探讨MPs对感染的早期预警作用。方法:选择2018年12月至2019年3月解放军总医院第二医学中心收住院的年龄≥85岁的感染患者为观察组，选择同期年龄≥85岁的健康体检者作为对照组。于患者发热2 h、第2天和第7天取静脉血，检测白细胞计数（WBC）、中性粒细胞比例（NEUT）、C-反应蛋白（CRP）和降钙素原（PCT）等炎症指标；采用流式细胞仪检测MPs水平，以膜联蛋白Ⅴ标记CD11b阳性MPs（AnnexinⅤn +/CD11bn + MPs）代表白细胞微粒（LMPs），以AnnexinⅤ标记CD66b阳性MPs（AnnexinⅤn +/CD66bn + MPs）代表中性粒细胞微粒（NMPs）。比较组间不同时间点各指标的差异；采用受试者工作特征曲线（ROC）分析各指标对老龄患者感染的预测价值。n 结果:共纳入38例研究对象，其中观察组28例，对照组10例。观察组发热2 h时LMPs、NMPs即达峰值，且明显高于对照组〔LMPs（个/μL）：55.0（28.8，197.2）比19.0（13.5，28.3），NMPs（个/μL）：226.5（123.3，516.5）比26.5（22.0，48.8），均n P<0.01〕；随着对病情的控制，LMPs、NMPs逐渐下降，第2天时NMPs显著低于发热2 h时〔个/μL：106.0（40.0，309.0）比226.5（123.3，516.5），n P<0.05〕，第7天时LMPs、NMPs均显著低于第2天时〔LMPs（个/μL）：17.0（12.5，43.8）比42.0（13.0，117.0），NMPs（个/μL）：30.0（15.8，62.0）比106.0（40.0，309.0），均n P<0.05〕，且第7天LMPs、NMPs水平与对照组比较差异均无统计学意义。在各项炎症指标中，观察组发热2 h时NEUT明显高于对照组（0.70±0.09比0.59±0.04，n P<0.01），而WBC、CRP及PCT与对照组差异无统计学意义；第2天时观察组各炎症指标升至高峰，且均明显高于对照组〔WBC（×10n 9/L）：9.33±2.44比6.37±1.28，NEUT：0.78±0.08比0.57±0.04，CRP（mg/L）：5.67±2.99比0.33±0.18，PCT（μg/L）：0.80±0.67比0.07±0.03，均n P<0.01〕；而第7天时观察组各炎症指标明显下降，且与对照组比较差异无统计学意义。ROC曲线分析显示，发热当天的LMPs和NMPs预警超高龄老年患者发生感染的ROC曲线下面积（AUC）及95%可信区间（95%n CI）均高于WBC、NEUT、CRP、PCT〔0.888（0.763～1.000）、0.973（0.931～1.000）比0.679（0.346～0.811）、0.829（0.700～0.958）、0.607（0.404～0.811）、0.554（0.358～0.749）〕。n 结论:LMPs和NMPs在发热早期即明显升高，可以预测超高龄老年患者感染的发生。“,”Objective:To investigate the level and changing trend of microparticles (MPs) in super-elderly infected patients, and explore its early warning effect on infection.Methods:The infected patients ≥ 85 years old admitted to the Second Medical Center of Chinese PLA General Hospital from December 2018 to March 2019 were selected as the observation group, and the healthy volunteers ≥ 85 years old in the same period were selected as the control group. Venous blood samples were collected at the 2nd hour, the 2nd day and the 7th day after fever, and the inflammatory markers such as white blood cell count (WBC), neutrophil percentage (NEUT), C-reactive protein (CRP) and procalcitonin (PCT) were measured. The levels of MPs were determined by flow cytometry. AnnexinⅤlabeled CD11b positive MPs (AnnexinⅤn +/CD11bn + MPs) represented leukocyte microparticles (LMPs), and AnnexinⅤlabeled CD66b positive MPs (AnnexinⅤn +/CD66bn + MPs) represented neutrophil microparticle (NMPs). The differences of each index at different time points between the two groups were compared, and the predictive value of each index to the infection of elderly patients was analyzed by receiver operating characteristic (ROC) curve.n Results:A total of 38 subjects were enrolled, including 28 cases in the observation group and 10 cases in the control group. The levels of LMPs and NMPs in the observation group increased to the peak at the 2nd hour after fever, and were significantly higher than those in the control group [LMPs (cells/μL): 55.0 (28.8, 197.2) vs. 19.0 (13.5, 28.3), NMPs (cells/μL): 226.5 (123.3, 516.5) vs. 26.5 (22.0, 48.8), bothn P < 0.01]. With the control of the disease, LMPs and NMPs decreased gradually. The NMPs on the 2nd day was significantly lower than that at the 2nd hour of fever [cells/μL: 106.0 (40.0, 309.0) vs. 226.5 (123.3, 516.5), n P < 0.05], and the LMPs and NMPs on the 7th day were significantly lower than those on the 2nd day [LMPs (cells/μL): 17.0 (12.5, 43.8) vs. 42.0 (13.0, 117.0), NMPs (cells/μL): 30.0 (15.8, 62.0) vs. 106.0 (40.0, 309.0), both n P < 0.05]. There was no significant difference in the levels of LMPs and NMPs between the two groups on the 7th day. Among the inflammatory markers, the NEUT in the observation group was significantly higher than that in the control group at the 2nd hour of fever (0.70±0.09 vs. 0.59±0.04, n P < 0.01), but there was no significant difference in WBC, CRP and PCT between the two groups. On the 2nd day, the inflammatory markers in the observation group reached the peak and were significantly higher than those in the control group [WBC (×10 n 9/L): 9.33±2.44 vs. 6.37±1.28, NEUT: 0.78±0.08 vs. 0.57±0.04, CRP (mg/L): 5.67±2.99 vs. 0.33±0.18, PCT (μg/L): 0.80±0.67 vs. 0.07±0.03, alln P < 0.01]. On the 7th day, the inflammatory markers in the observation group decreased significantly, and there was no significant difference between the observation group and the control group. ROC curve analysis showed that the area under ROC curve (AUC) and 95% confidence interval (95% n CI) of LMPs and NMPs on the day of fever were higher than those of WBC, NEUT, CRP and PCT [0.888 (0.763-1.000), 0.973 (0.931-1.000) vs. 0.679 (0.346-0.811), 0.829 (0.700-0.958), 0.607 (0.404-0.811), 0.554 (0.358-0.749)].n Conclusion:LMPs and NMPs are significantly increased in the early stage of fever, which can predict the incidence of infection in the super-elderly patients.