Unit:
Faculty of MedicineLibrary of the School of Health Sciences
Author:
Nearchakos Nikolaos
Dissertation committee:
Τραυλού Ωραιάνθη, Ομότιμη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Τσαντές Αργύριος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ, Επιβλέπων
Γιαλεράκη Αργυρή, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Πολίτου Μαριάννα, Αναπληρώτρια Καθηγήτρια , Ιατρική Σχολή, ΕΚΠΑ
Κοκόρη Στυλιανή, Επίκουρη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Βαλσάμη Σερένα, Επίκουρη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Πιτταράς Θεόδωρος, Επικουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Original Title:
Σύγκριση κυτταρομετρίας ροής και μεθόδου Nageotte στην καταμέτρηση των υπολειπόμενων λευκοκυττάρων σε λευκαφαιρεμένα παράγωγα αίματος πριν την αποθήκευσή τους
Translated title:
Comparison between Nageotte and flow cytometric counting of residual leucocytes in freshly prepared leucocyte-reduced red blood cell components before prestorage
Summary:
Background: Flow cytometry (FC) and Nageotte hemocytometry represent the most widely accepted methods for counting residual white blood cells (rWBCs) in leucocyte-reduced (LR) blood components. Our aim was to study the agreement between the two methods, under real working blood bank conditions.
Materials and methods: 94 freshly produced LR red blood cell (RBC) units were tested for rWBC concentrations by FC and Nageotte. To assess the precision of each method, we calculated the intra-assay coefficients of variation (CV), and followed the Bland-Altman methodology to study the agreement between the two methods.
Results: CV was 18.5% and 26.2% for the Nageotte and the FC, respectively. However, the agreement between the duplicate observations, using the binary cut-off threshold of 1×106 WBCs per unit to define the results as “pass/fail”, was 71.9% for the Nageotte and 93.3% for the FC. Linear regression analysis did not show any correlation (R-squared=0.01, p=0.35) between the two methods, while the Bland-Altman analysis for the measuring agreement showed a bias toward a higher Nageotte count of 0.77×106 leucocytes per unit (p < 0.001) with the 95% limits of agreement (d±2 sd) ranging from –0.40×106 to 1.94×106 leucocytes per unit.
Conclusion: The absence of agreement between Nageotte and FC method, with the differences within d±2 sd being of high clinical importance, suggests that the two methods cannot be used for clinical purposes interchangeably. The Nageotte seems unsuitable for quality control even with a pass-fail criterion, under real working blood bank conditions.
Main subject category:
Health Sciences
Keywords:
Flow cytometry, Nageotte, Residual leucocytes, Leucocyte-reduced, Blood
