Hviid Claus Vinter Bødker, Christensen Vibeke Staun, Jensen Klaus Rosenkilde, Møller Julia Roman, Hansen Anja Reinert
Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.
Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
Int J Lab Hematol. 2025 Oct;47(5):808-816. doi: 10.1111/ijlh.14478. Epub 2025 Apr 6.
Neonatal patients present a challenge to the clinical laboratory because of their low blood volume. The Sysmex XN-series features a predilution (PD) mode allowing hematologic measurements with only 20-50 μL of blood. We verified the PD mode for analysis of selected hematologic parameters in 50 μL microsamples.
Microsamples were prepared from adult EDTA blood. White blood cell count (leukocytes, neutrophils, and lymphocytes) and red blood cell parameters (erythrocytes, hemoglobin, hematocrit, mean cell volume, and reticulocytes) were evaluated. The imprecision of the PD mode was evaluated over 3 days, and the accuracy was assessed by method comparison with the standard whole blood mode. The effect of capillary sampling, microsample stability during storage, and pneumatic tube transportation was evaluated. Finally, the bias was reproduced in a small sample of pediatric patients.
For white blood cells, the bias was ≤ 5.4% (95% CI: 4.5-6.2) and imprecision was below 3.5% (except at the lowest levels). Capillary sampling had little effect on PD analytical performance (bias ≤ 0.7% and imprecision ≤ 4.7%) and white blood cell counts were stable for 7 h at room temperature and after pneumatic tube transportation. The red blood cell parameters generally exceeded the allowable bias and imprecision. The bias of the pediatric samples remained within the 95% PI for the method comparison studies.
The PD mode has acceptable analytical performance and preanalytical stability for white blood cell counts but not for red blood cell parameters. It may offer a low-volume alternative for hematologic monitoring.
新生儿患者由于血容量低，给临床实验室带来了挑战。Sysmex XN系列具有预稀释（PD）模式，仅需20 - 50微升血液即可进行血液学检测。我们验证了PD模式在50微升微量样本中分析选定血液学参数的效果。
从成人乙二胺四乙酸（EDTA）抗凝血中制备微量样本。评估白细胞计数（白细胞、中性粒细胞和淋巴细胞）以及红细胞参数（红细胞、血红蛋白、血细胞比容、平均红细胞体积和网织红细胞）。在3天内评估PD模式的不精密度，并通过与标准全血模式进行方法比较来评估准确性。评估毛细管采血、微量样本储存期间的稳定性以及气动管道运输的影响。最后，在一小部分儿科患者样本中重现偏差。
对于白细胞，偏差≤5.4%（95%置信区间：4.5 - 6.2），不精密度低于3.5%（最低水平除外）。毛细管采血对PD分析性能影响很小（偏差≤0.7%，不精密度≤4.7%），白细胞计数在室温下以及气动管道运输后7小时内保持稳定。红细胞参数通常超过了允许的偏差和不精密度。在方法比较研究中，儿科样本的偏差仍在95%预测区间内。
PD模式对于白细胞计数具有可接受的分析性能和分析前稳定性，但对于红细胞参数则不然。它可能为血液学监测提供一种低血量的替代方法。
