急性肺损伤患者中性粒细胞凋亡变化的研究

目的观察急性肺损伤(ALI)患者中性粒细胞(PMN)凋亡的发生以及与肺损伤的关系,并探讨其临床意义。方法对37例符合ALI诊断标准的患者,分离纯化肺灌洗液中的PMN,应用流式细胞术测定PMN凋亡、坏死、存活细胞比例及呼吸瀑发功能的变化,设健康对照组,并观察与乳酸脱氢酶(LDH)和胞浆游离Ca2 变化之间的关系。结果灌洗液中PMN凋亡比例显著降低,24h持续在低水平(P<0.05或P<0.01);各检测点活细胞增多(P<0.05或P<0.01);而灌洗液PMN的呼吸瀑发明显升高,8h达峰值,并持续升高(P<0.01)。灌洗液中LDH水平2～24h明显高于正常对照组(P<0.05或P<0.01);PMN胞浆游离Ca2 各检测点显著增高(P<0.05或P<0.01)。PMN凋亡与LDH水平有相关性(r=-0.7151,P<0.01),PMN凋亡与胞浆游离Ca2 水平有相关性(r=-0.6039,P<0.01)。结论ALI时PMN在肺组织中大量扣押,且正常的凋亡途径发生障碍,造成PMN持续处于激活状态及毒性内容物持续释放,与肺组织的损伤有密切关系,并且PMN凋亡延迟可能与LDH、胞浆游离Ca2 的升高有关。

Study on the apoptosis of polymorphonuclear neutrophil in the patients with acute lung injury

Objective To investigate the relationship between polymorphonuclear neutrophil (PMN) apoptosis and the lung injury in the patients with acute lung injury (ALI) and evaluate the clinical significance. Methods 37 patients were diagnosed as ALI in this study. PMNs were purified from bronchoalveolar lavage fluid. Their apoptosis, necrosis and survival ratios and respiratory burst were detected by flow cytometry. Meanwhile, lactate dehydrogenase (LDH) and intracellular free Ca2 level in PMN were also measured. The healthy people were grouped as the control. Results The apoptosis ratio of PMN in bronchoalveolar lavage fluid was decreased significantly and kept lower level during 24-hour observation period (P<0.05, P<0.01), and the number of living cells was increased obviously (P<0.05, P<0.01). Respiratory burst of PMN in bronchoalveolar lavage fluid was significantly increased, and the peak value appeared at 8th hour, then kept increasing persistently (P<0.01). Meanwhile, LDH level in bronchoalveolar lavage fluid was higher than that in the control group from 2~24 hours (P<0.05, P<0.01), and intracellular free Ca2 in PMN was increased at all observation points (P<0.05, P<0.01). Apoptosis of PMN was significantly related to not only LDH level (r=-0.7151, P<0.01) but also intracellular free Ca2 levels (r=-0.6039, P<0.01). Conclusions In ALI, generous PMN are detained in lung and normal apoptotic pathway is disturbed, which might result in persistent activation of PMN and excessive release of toxic substances, eventually lead to lung tissue injury. The increase of LDH and intracellular free Ca2 could be responsible for delayed apoptosis of PMN.