Department of Cardiothoracic Surgery, University Hospital Regensburg, Regensburg, Germany.
Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany.
Front Immunol. 2024 Feb 21;15:1339235. doi: 10.3389/fimmu.2024.1339235. eCollection 2024.
Neutrophil extracellular traps (NETs) have recently emerged as a potential link between inflammation, immunity, and thrombosis, as well as other coagulation disorders which present a major challenge in the context of extracorporeal membrane oxygenation (ECMO). By examining blood from ECMO patients for NETs and their precursors and correlating them with clinical and laboratory biomarkers of coagulation and inflammation, this study aims to evaluate the association between the presence of NETs in the bloodstream of ECMO patients and the development of potentially severe coagulation disorders during ECMO therapy. Therefore, blood samples were collected from healthy volunteers (n=13) and patients receiving veno-venous (VV) ECMO therapy (n=10). To identify NETs and their precursors, DNA and myeloperoxidase as well as granulocyte marker CD66b were visualized simultaneously by immunofluorescence staining in serial blood smears. Differentiation of DNA-containing objects and identification of NETs and their precursors was performed semiautomatically by a specific algorithm using the shape and size of DNA staining and the intensity of MPO and CD66b signal. Neutrophil extracellular traps and their precursors could be detected in blood smears from patients requiring VV ECMO. Compared to volunteers, ECMO patients presented significantly higher rates of NETs and NET precursors as well as an increased proportion of neutrophil granulocytes in all detected nucleated cells. A high NET rate prior to the initiation of ECMO therapy was associated with both increased IL-6 and TNF-α levels as an expression of a high cytokine burden. These patients with increased NET release also presented an earlier and significantly more pronounced decrease in platelet counts and ATIII activity following initiation of therapy compared with patients with less elevated NETs. These findings provide further indications for the development of immune-mediated acquired thrombocytopenia in ECMO patients.
中性粒细胞胞外诱捕网（NETs）最近被认为是炎症、免疫和血栓形成之间的潜在联系，以及其他凝血障碍，这些在体外膜氧合（ECMO）的背景下构成了主要挑战。通过检查 ECMO 患者的血液中的 NETs 及其前体，并将其与凝血和炎症的临床和实验室生物标志物相关联，本研究旨在评估 ECMO 患者血液中 NETs 的存在与 ECMO 治疗期间潜在严重凝血障碍的发展之间的关联。因此，从健康志愿者（n=13）和接受静脉-静脉（VV）ECMO 治疗的患者（n=10）中采集了血液样本。为了识别 NETs 及其前体，通过免疫荧光染色在连续血涂片上同时可视化 DNA 和髓过氧化物酶以及粒细胞标志物 CD66b。通过使用 DNA 染色的形状和大小以及 MPO 和 CD66b 信号的强度的特定算法，半自动地对包含 DNA 的物体的区分和 NETs 及其前体的识别进行区分。可以在需要 VV ECMO 的患者的血液涂片上检测到 NETs 和其前体。与志愿者相比，ECMO 患者的 NETs 和 NET 前体以及所有检测到的有核细胞中的中性粒细胞的比例明显更高。在开始 ECMO 治疗之前，NET 率高与较高的 IL-6 和 TNF-α 水平相关，这是细胞因子负荷较高的表现。与 NET 升高较少的患者相比，这些 NET 释放增加的患者在开始治疗后血小板计数和 ATIII 活性的下降更早且明显更明显。这些发现为 ECMO 患者中免疫介导的获得性血小板减少症的发展提供了进一步的迹象。
