Phospholipases A2 and platelet-activating-factor acetylhydrolase in patients with acute respiratory distress syndrome
Phospholipases A2 and platelet-activating-factor acetylhydrolase in patients with acute respiratory distress syndrome
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DOI：
10.1097/01.ccm.0000158519.80090.74
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发表时间：
2005-04-01
影响因子：
8.8
通讯作者：
Lekka, ME
中科院分区：
文献类型：
--
作者：
Nakos, G;Kitsiouli, E;Lekka, ME
目标。磷脂酶A(2)(PLA(2))是一个可能与急性呼吸窘迫综合征(ARDS)发生有关的酶家族。目的：研究ARDS患者支气管肺泡灌洗液(BAL)、BAL细胞和血浆中PLA2的活性和特征。设计：前瞻性对照研究。地点：一所大学医院的14个床位的多价重症监护室。患者：共31例机械通气患者，其中20例合并ARDS，11例不合并ARDS。干预。采用纤维支气管镜对机械通气患者进行BAL检查，测定BAL液、细胞和血浆中的磷脂酶A(2)和血小板活化因子乙酰水解酶。结果：与对照组相比，ARDS患者BAL液、BAL细胞和血浆中的PLA2水平均明显升高。BAL液中的PLA(2)主要为IIA型分泌型和胞浆型。在血浆中，发现IIA型分泌型和胞浆型，以及一种钙非依赖性的聚乳酸(2)。在BAL细胞中，也观察到IIA型分泌型磷脂酶A(2)活性较低，为胞浆形式，可能是一种不依赖于钙离子的胞内形式。总磷脂酶A(2)活性与PaO(2)/FiO(2)比值呈负相关，与死亡率呈正相关。与间接性ARDS患者相比，直接ARDS患者的磷脂酶A(2)活性升高。血小板活化因子乙酰水解酶活性在BAL液和血浆中较高，而在BAL细胞中较低。依赖于钙离子的分泌型、胞浆型和非钙依赖型的磷脂酶A(2)和血小板活化因子乙酰水解酶分别在ARDS炎症反应的发生或下调中发挥重要作用。
Objective. Phospholipases A(2) (PLA(2)) comprise a family of enzymes probably implicated in the development of acute respiratory distress syndrome (ARDS). The aim was to investigate PLA2 activities and characteristics in bronchoalveolar lavage (BAL) fluid, BAL cells, and plasma from patients with ARDS by a fluorometric method.Design: Prospective, controlled study.Setting: Fourteen-bed polyvalent intensive care unit in a university hospital.Patients: A total of 31 mechanically ventilated patients, 20 with and 11 without ARDS, were studied. Intervention. BAL was performed by fiberoptic bronchoscopy in mechanically ventilated patients with a controlled mechanical ventilation mode.Measurements: PLA(2) and platelet-activating-factor acetylhydrolase were determined in BAL fluid, cells, and plasma. For the classification of PLA(2)-specific inhibitors, Western blot analysis and their biochemical characteristics were used.Results: In ARDS patients, increased PLA(2) levels were detected in BAL fluid, BAL cells, and plasma compared with the control patients. PLA(2) in BAL fluid was mainly type IIA secretory and cytosolic types. In plasma, type IIA secretory and cytosolic and a Ca2+-independent PLA(2) were found. In BAL cells, a cytosolic form, probably a Ca2+-independent intracellular form, and a low activity of type IIA secretory PLA(2) was also observed. Total PLA(2) activity correlated inversely with Pao(2)/Fio(2) ratio and positively with the mortality rate. Patients with direct ARDS exhibited higher PLA(2) activity compared with patients with indirect ARDS. Platelet-activating-factor acetylhydrolase activity was higher in BAL fluid and plasma, but it was lower in BAL cells.Conclusion. Ca2+-dependent secretory, cytosolic, and Ca2+-independent forms of PLA(2) and platelet-activating-factor acetylhydrolase could play important roles in the development or down-regulation of inflammation in ARDS, respectively.