Global Journal of Transfusion Medicine (Jan 2022)

Comparison of three methods for enumeration of residual white blood cells in single donor apheresis platelets: A pilot study from Eastern India as a part of quality monitoring process for leukoreduction

  • Nasir Nabi Naikoo,
  • Sabita Basu,
  • Animesh Bajpayee,
  • Deepak Kumar Mishra,
  • Suvro Sankha Datta

DOI
https://doi.org/10.4103/gjtm.gjtm_30_22
Journal volume & issue
Vol. 7, no. 2
pp. 174 – 177

Abstract

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Background and Objectives: The aim of this study was to compare three platforms side-by-side: Nageotte hemocytometer, flow cytometry (FC), and standard hematology analyzer for enumeration of residual white blood cells (rWBCs) in single donor platelets (SDPs) apheresis. Materials and Methods: This was a prospective observational study conducted in a tertiary care oncology center by evaluating 36 units of SDP that were collected and tested in parallel by three different methods for the enumeration of rWBCs. All tests were performed within 24 h of collection according to the manufacturers' recommended methods. Counting by the Nageotte hemocytometer was done by: rWBC/μl = (cells counted × dilution/gridded area volume [50 μl]) and FC calculation was performed by: rWBC/μl = (total beads × total number of leukocyte events/total beads acquired × total sample volume). Results: The number of rWBCs detected by FC was between 1 white blood cell (WBC)/μl and 8 WBCs/μl; whereas, those detected by Nageotte chamber were between 3 WBC/μl and 6 WBCs/μl. The range of rWBC detected by hematology analyzer was 100 WBC/μl to 270 WBCs/μl. There was no correlation observed between the results obtained in standard hematology analyzer with any of the other two methods. The concordance correlation coefficient was measured by kappa analysis and found to be 0.71 between hemocytometry and FC. Linear regression analysis also showed a moderate correlation (R2 = 0.42) between the two methods. However, the coefficient of variation was found to be 49.32% in Nageotte method compared to the 17.55% in FC (P < 0.001). Conclusion: FC followed by Nageotte chamber counting is a better method compared to the standard hematology analyzer for the enumeration of rWBCs. To overcome the cost of FC it is high time to explore the scope and feasibility of a centralized quality monitoring system in India for all leukoreduced blood components.

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