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Updated: Aug 21, 2026
Assessing Leukocyte-endothelial Interactions Under Flow Conditions in an Ex Vivo Autoperfused Microflow Chamber Assay
Published on: December 30, 2014
In vivo measurement of circulating leucocyte activation in patients following cardiopulmonary bypass
Hazel A Jones1, Marina Choudhury, David N F Harris
1NHLI and Investigative Science, Faculty of Medicine, Imperial College, Hammersmith Campus, London, W12 0NN, United Kingdom. hazel.jones@imperial.ac.uk
Insights
Researchers developed a simple method to measure white blood cell activation during cardiopulmonary bypass (CPB). This technique accurately detects increased leucocyte activation following CPB surgery.
Area of Science:
- Biomedical Engineering
- Immunology
- Nuclear Medicine
Background:
- Assessing in vivo leucocyte activation is crucial for understanding inflammatory responses.
- Existing methods for measuring leucocyte activation are often complex and time-consuming.
Purpose of the Study:
- To develop and validate a simple, sensitive technique for measuring in vivo activation of circulating leucocytes.
- To assess leucocyte activation in patients undergoing cardiopulmonary bypass (CPB).
Main Methods:
- Developed a novel method using [18F]FDG uptake in whole blood leucocytes.
- Measured [18F]FDG uptake via phosphor imaging of blood-filled capillary tubes.
- Quantified leucocyte radioactivity and normalized it to leucocyte counts.
Main Results:
- [18F]FDG uptake in leucocytes was undetectable before CPB.
- Significantly increased leucocyte [18F]FDG uptake was observed after CPB.
- No significant difference in activation was found between different blood sampling sites.
Conclusions:
- The developed method provides a sensitive index of circulating leucocyte activation in whole blood.
- This technique allows for investigation of white blood cell activation without complex sample handling or cell separation.
- The method is suitable for assessing leucocyte activation in clinical settings like CPB.
Abstract:
We have developed a simple technique to measure in vivo activation of circulating leucocytes and assessed it in 6 patients undergoing cardiopulmonary bypass (CPB). Arterial, mixed venous, and jugular bulb blood samples were taken following i.v. [18F]FDG, before and after CPB. [18F]FDG uptake in leucocytes was measured by phosphor imaging of spun blood-filled capillary tubes. Leucocyte radioactivity was quantified ([(leucocytes-plasma)/plasma radioactivity] and normalised to leucocyte counts. [18F]FDG uptake (mean+/-SEM)) before CPB was undetectable, being -0.014+/-0.007, -0.011+/-0.003, -0.012+/-0.006, -0.010+/-0.005, whereas increased uptake was demonstrated following CPB, 0.006+/-0.006, 0.009+/-0.005, 0.021+/-0.005, 0.034+/-0.006, at 20, 40, 60, and 80 min, respectively. There was no significant difference in activation between sampling sites before or after CPB. This method gives a sensitive index of activation of circulating leucocytes in whole blood, enabling investigation of activation of circulating white cells without the influence of sample handling or the requirement for time-consuming cell separation procedures.
