Viall Austin K, LeVine Dana N
Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA.
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA.
J Vet Emerg Crit Care (San Antonio). 2020 May;30(3):272-278. doi: 10.1111/vec.12947. Epub 2020 Feb 25.
To evaluate the performances of a manual Nageotte hemocytometer method and commercial fluorescent bead-based flow cytometric assay for quantifying [rWBC] in leukoreduced canine packed red blood cell (pRBC) units.
Prospective study. Five, commercially purchased, double leukoreduced canine pRBC units were spiked with canine leukocytes to create 6 pRBC standards with the following [rWBC]: < 0.1, 0.375, 1.5, 3.0, 6.0, and 24.0 WBC/µL. [rWBC] of each pRBC standard was measured with the Nageotte hemocytometer and flow cytometric techniques. Limit of detection (LoD), linearity, and bias were determined for each method. For each standard, accuracy and precision were calculated; the cumulative accuracy and mean precision for measurements between the LoD and 24.0 WBC/µL were also determined.
University veterinary blood bank and clinical pathology laboratory.
The Nageotte hemocytometer method had an LoD = 1.48 WBC/µL, inadequate linearity (R = 0.92), and a significant negative proportional bias (slope best-fit line = 0.52 ± 0.03). Between [rWBC] 1.5-24 WBC/µL, the technique demonstrated poor cumulative accuracy (6.7%) but acceptable mean precision (17.3%). Relative to a 2 rWBC/µL threshold, at 1.5 WBC/µL the method was inaccurate (6.7%) with acceptable precision (16.6%). The flow cytometric assay had an LoD = 1.3 WBC/µL, acceptable linearity (R = 0.99), and a mild positive proportional bias (slope best-fit line = 1.11 ± 0.01). The technique had acceptable cumulative accuracy (80%) and mean precision (10.7%) for measuring [rWBC] between 1.5 and 24 WBC/µL. At 1.5 WBC/µL, this method was acceptably accurate (86.7%) and precise (16.0%).
The flow cytometric assay demonstrated acceptable performance for quantification of [rWBC] in leukoreduced canine pRBC units. The Nageotte hemocytometer method should be used cautiously due to poor accuracy and significant negative bias.
评估手动纳盖奥特血细胞计数法和基于商业荧光微球的流式细胞术检测法在定量白细胞滤除犬浓缩红细胞（pRBC）单位中残留白细胞（[rWBC]）的性能。
前瞻性研究。从商业渠道购买5个经两次白细胞滤除的犬pRBC单位，加入犬白细胞，制成6个[rWBC]如下的pRBC标准品：<0.1、0.375、1.5、3.0、6.0和24.0个白细胞/微升。用纳盖奥特血细胞计数法和流式细胞术测量每个pRBC标准品的[rWBC]。确定每种方法的检测限（LoD）、线性和偏差。计算每个标准品的准确度和精密度；还确定了LoD与24.0个白细胞/微升之间测量的累积准确度和平均精密度。
大学兽医血库和临床病理实验室。
纳盖奥特血细胞计数法的LoD = 1.48个白细胞/微升，线性不足（R = 0.92），且存在显著的负比例偏差（最佳拟合线斜率 = 0.52 ± 0.03）。在[rWBC]为1.5 - 24个白细胞/微升之间，该技术的累积准确度较差（6.7%），但平均精密度可接受（17.3%）。相对于2个rWBC/微升的阈值，在1.5个白细胞/微升时，该方法不准确（6.7%）但精密度可接受（16.6%）。流式细胞术检测法的LoD = 1.3个白细胞/微升，线性可接受（R = 0.99），且存在轻微的正比例偏差（最佳拟合线斜率 = 1.11 ± 0.01）。该技术在测量1.5至24个白细胞/微升之间的[rWBC]时，累积准确度可接受（80%），平均精密度为10.7%。在1.5个白细胞/微升时，该方法的准确度可接受（86.7%），精密度为16.0%。
流式细胞术检测法在定量白细胞滤除犬pRBC单位中的[rWBC]方面表现出可接受的性能。由于准确度差和显著的负偏差，纳盖奥特血细胞计数法应谨慎使用。
