Comparison of capillary and venous blood in the analysis of concentration and function of leucocyte sub-populations.
OBJECTIVE
Compare capillary and venous blood in the analysis of concentration and function of leucocyte sub-populations. This study hypothesised that capillary samples may be used in a site-specific manner as an alternative source of blood samples for assays of leucocyte concentration and neutrophilic phagocytic function and reactive oxygen species (ROS) production, allowing acquisition of multiple samples to better monitor transient but significant post-exercise immune modulation.


METHODS
Resting blood samples were simultaneously obtained from vein, finger and earlobe of healthy subjects (n = 10, age: 25.1 ± 3.1 years). Leucocyte concentrations were measured using a five-part differential haematological analyser. Leucocyte sub-populations (CD3, CD4, CD8, CD19, CD56, CD14) and granulocytic functional-related (CD11b, CD18, CD16b, CD66b) surface antigen markers, neutrophil phagocytosis (FITC-labelled Escherichia coli) and stimulated ROS production (DHR) were quantified utilizing flow cytometry. A MANOVA (α < 0.05 significance) analysed the effects of the different sampling sites in the concentrations of leucocyte populations, their surface antigen expression and granulocytic functions.


RESULTS
Leucocyte concentration and neutrophilic ROS production yielded non-significant differences between sampling sites. Expression of granulocytic surface antigens was increased in both capillary sites compared to venous site (p = 0.008), particularly for adhesion markers CD11b/CD18. The percentage of neutrophils performing phagocytosis was higher in venous samples compared to finger (p = 0.025). Increased number of E. coli ingested was observed in venous sample compared to finger (p = 0.001) and to earlobe (p = 0.006).


CONCLUSIONS
Whilst attention must be paid for varying neutrophilic surface antigen expression and further studies are needed to establish appropriate reference ranges, this study supports the use of capillary blood samples in a site-specific manner to enhance sampling capabilities field-based research.
Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, 4226, QLD, Australia. ecanetti@bond.edu.au.
Elisa F D
EF
Canetti
Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, 4226, QLD, Australia.
J
J
Keane
Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, 4226, QLD, Australia.
C P
CP
McLellan
Faculty of Health Sciences and Medicine, Bond University, 14 University Drive, Robina, 4226, QLD, Australia.
A B
AB
Gray
D000328:Adult; D002196:Capillaries / Q000166:cytology* / Q000276:immunology; D016207:Cytokines / Q000276:immunology*; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000379:methods*; D007962:Leukocytes / Q000145:classification / Q000166:cytology* / Q000276:immunology*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014680:Veins / Q000166:cytology* / Q000276:immunology
D016207:Cytokines
Blood collection; Capillary; Exercise immunology; In-field; Vein