Ojima Masahiro, Yamamoto Norihisa, Hirose Tomoya, Hamaguchi Shigeto, Tasaki Osamu, Kojima Takashi, Tomono Kazunori, Ogura Hiroshi, Shimazu Takeshi
1Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
2Division of Infection Control and Prevention, Osaka University Hospital, Suita, Osaka, Japan.
J Intensive Care. 2020 Apr 10;8:25. doi: 10.1186/s40560-020-00444-5. eCollection 2020.
Neutrophil extracellular traps (NETs) are fibrous structures released from activated neutrophils. NET formation has been reported to be associated with acute respiratory distress syndrome (ARDS). However, there are no reports dealing with serial changes of NET formation in tracheal aspirate of ARDS patients.
We report three cases of ARDS. Case 1 is a 69-year-old man with necrotizing fasciitis of the buttocks, case 2 is a 49-year-old woman with extensive burns (80% of total body surface), and case 3 is a 73-year-old woman with severe bacterial pneumonia. We found abundant expression of citrullinated histone H3 (Cit-H3) and the formation of NETs at the onset of ARDS in all cases. The amounts of Cit-H3 and NETs decreased with the amelioration of respiratory failure in cases 1 and 2. In case 2, the amounts of Cit-H3 and NETs increased with aggravation of infection and respiratory status. In case 3, the abundant expression of Cit-H3 and NETs persisted; the patient did not recover from ARDS and eventually died. Cit-H3 and NETs were found in tracheal aspirates even if the patients had no direct injury to the lung as in cases 1 and 2.
In these three cases, the formation of NETs was observed in tracheal aspirate of patients with ARDS by either direct or indirect insults to the lung. The amount of NET formation changed dynamically over the clinical course of each patient.
中性粒细胞胞外陷阱（NETs）是活化的中性粒细胞释放的纤维状结构。据报道，NET形成与急性呼吸窘迫综合征（ARDS）有关。然而，尚无关于ARDS患者气管吸出物中NET形成的系列变化的报道。
我们报告了3例ARDS病例。病例1是一名69岁男性，患有臀部坏死性筋膜炎；病例2是一名49岁女性，全身大面积烧伤（占体表面积的80%）；病例3是一名73岁女性，患有严重细菌性肺炎。我们发现，所有病例在ARDS发病时瓜氨酸化组蛋白H3（Cit-H3）表达丰富且有NET形成。病例1和2中，随着呼吸衰竭的改善，Cit-H3和NET的数量减少。在病例2中，随着感染和呼吸状况的加重，Cit-H3和NET的数量增加。在病例3中，Cit-H3和NET持续大量表达；患者未从ARDS中康复，最终死亡。即使患者如病例1和2那样没有肺部直接损伤，在气管吸出物中也发现了Cit-H3和NET。
在这3例病例中，通过对肺部的直接或间接损伤，在ARDS患者的气管吸出物中观察到了NET的形成。NET形成的数量在每个患者的临床过程中动态变化。
