TY - JOUR
T1 - Effect of blood flow on platelets, leukocytes, and extracellular vesicles in thrombosis of simulated neonatal extracorporeal circulation
AU - Meyer, Andrew D.
AU - Rishmawi, Anjana R.
AU - Kamucheka, Robin
AU - Lafleur, Crystal
AU - Batchinsky, Andriy I.
AU - Mackman, Nigel
AU - Cap, Andrew P.
N1 - Funding Information:
Funding information The NIH/National Heart Lung Blood Institute supported this project with Grant K23 HL124336. The Morrison Trust with the Blood and Coagulation Task Area, U.S. Army Institute of Surgical Research also supplied funding and support. STAGO supplied experimental reagents. The authors would like to acknowledge Ron Bryant, Alia Elkhalili, Neslihan Cingoz, Linda McManus, PhD; Armando Rodriquez; Joshua Walker, CCP; and Kerfoot P. Walker III, who were essential in protocol development, ECMO circuit design, assay and data analysis, manuscript review, and general troubleshooting. The authors would also like to thank Robert William Travis and Xiao Wu MD, for obtaining representative fluorescent images of the oxygenator fibers.
Publisher Copyright:
© 2019 International Society on Thrombosis and Haemostasis
PY - 2020/2/1
Y1 - 2020/2/1
N2 - Background: Extracorporeal membrane oxygenation (ECMO) has frequent and sometimes lethal thrombotic complications. The role that activated platelets, leukocytes, and small (0.3-micron to 1-micron) extracellular vesicles (EVs) play in ECMO thrombosis is not well understood. Objectives: To test the effect of blood flow rate on the generation of activated platelets, leukocytes, and EVs in a simulated neonatal ECMO circuit using heparinized human whole blood. Methods: Simulated neonatal roller pump circuits circulated whole blood at low, nominal, and high flow rates (0.3, 0.5, and 0.7 L/min) for 6 h. Coagulopathy was defined by thromboelastography (TEG), STA®-procoagulant phospholipid clot time (STA®-Procoag-PPL), and calibrated automated thrombogram. High-resolution flow cytometry measured the cellular expression of prothrombotic phospholipids and proteins on platelets, leukocytes, and EV. Results: Despite heparinization, occlusive thrombosis halted flow in two of five circuits at 0.3 L/min and three of five circuits at 0.7 L/min. None of the five circuits at 0.5 L/min exhibited occlusive thrombosis. Phosphatidylserine (PS)-positive platelets and EVs increased at all flow rates more than blood under static conditions (P <.0002). Tissue factor (TF)-positive leukocytes and EVs increased only in low-flow and high-flow circuits (P <.0001). Tissue factor pathway inhibitor (TFPI), at 50 times more than the concentration in healthy adults, failed to suppress thrombin initiation in low-flow and high-flow circuits. Conclusions: This in vitro study informs ECMO specialists to avoid low and high blood flow that increases TF expression on leukocytes and EVs, which likely initiate clot formation. Interventions to decrease TF generated by ECMO may be an effective approach to decrease thrombosis.
AB - Background: Extracorporeal membrane oxygenation (ECMO) has frequent and sometimes lethal thrombotic complications. The role that activated platelets, leukocytes, and small (0.3-micron to 1-micron) extracellular vesicles (EVs) play in ECMO thrombosis is not well understood. Objectives: To test the effect of blood flow rate on the generation of activated platelets, leukocytes, and EVs in a simulated neonatal ECMO circuit using heparinized human whole blood. Methods: Simulated neonatal roller pump circuits circulated whole blood at low, nominal, and high flow rates (0.3, 0.5, and 0.7 L/min) for 6 h. Coagulopathy was defined by thromboelastography (TEG), STA®-procoagulant phospholipid clot time (STA®-Procoag-PPL), and calibrated automated thrombogram. High-resolution flow cytometry measured the cellular expression of prothrombotic phospholipids and proteins on platelets, leukocytes, and EV. Results: Despite heparinization, occlusive thrombosis halted flow in two of five circuits at 0.3 L/min and three of five circuits at 0.7 L/min. None of the five circuits at 0.5 L/min exhibited occlusive thrombosis. Phosphatidylserine (PS)-positive platelets and EVs increased at all flow rates more than blood under static conditions (P <.0002). Tissue factor (TF)-positive leukocytes and EVs increased only in low-flow and high-flow circuits (P <.0001). Tissue factor pathway inhibitor (TFPI), at 50 times more than the concentration in healthy adults, failed to suppress thrombin initiation in low-flow and high-flow circuits. Conclusions: This in vitro study informs ECMO specialists to avoid low and high blood flow that increases TF expression on leukocytes and EVs, which likely initiate clot formation. Interventions to decrease TF generated by ECMO may be an effective approach to decrease thrombosis.
KW - blood cells
KW - extracellular vesicles
KW - extracorporeal membrane oxygenation
KW - thrombosis
KW - tissue factor
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U2 - 10.1111/jth.14661
DO - 10.1111/jth.14661
M3 - Article
C2 - 31628728
AN - SCOPUS:85075121828
SN - 1538-7933
VL - 18
SP - 399
EP - 410
JO - Journal of Thrombosis and Haemostasis
JF - Journal of Thrombosis and Haemostasis
IS - 2
ER -