Department of Hematology, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
J Clin Apher. 2021 Dec;36(6):870-877. doi: 10.1002/jca.21941. Epub 2021 Sep 18.
Monitoring of stem cell concentration in transplantation settings is crucial to determine the optimal time of apheresis and is currently based on enumeration of CD34+ cells by flow cytometry. No surrogate marker has replaced CD34+ cell enumeration to date. The aim of this study was the evaluation of the hematopoietic progenitor cell (HPC) parameter of the Sysmex XN-1000 analyzer in terms of optimizing the peripheral blood stem cell apheresis process.
Results of flow cytometric CD34+ cell and Sysmex HPC count were compared in 208 preharvest samples and 139 apheresis products.
HPC and CD34+ cell counts showed significant differences in the multiple myeloma (MM) group. The correlation between preharvest HPC and CD34+ cell counts was good in the MM group (rho = .613) and strong in the lymphoma group (rho = .802), allogeneic donors (rho = .923), and other group of samples (rho = .816). The HPC positive cutoff demonstrating 100% specificity and positive predictive value for MM patients was high for ≥20/μL and ≥10/μL CD34+ cell counts, and therefore of limited value. The HPC negative cutoff demonstrating 100% sensitivity and negative predictive value was approximately <4/μL, irrespective of diagnosis.
Based on proposed HPC positive cutoffs (≥31/μL in the lymphoma group and ≥11/μL in the other group of samples), routine HPC enumeration could improve the workflow by replacing CD34+ cell counting in allogeneic donors as well as non-MM patients. Furthermore, based on proposed HPC negative cutoff (<4/μL), CD34+ cell counting could be fully omitted in donors and patients that are not adequately mobilized.
在移植环境中监测干细胞浓度对于确定最佳的单采时间至关重要，目前基于流式细胞术对 CD34+细胞进行计数。到目前为止，还没有替代 CD34+细胞计数的替代标志物。本研究旨在评估 Sysmex XN-1000 分析仪的造血祖细胞（HPC）参数，以优化外周血干细胞采集过程。
比较了 208 个预采集样本和 139 个采集产物的流式细胞术 CD34+细胞和 Sysmex HPC 计数结果。
多发性骨髓瘤（MM）组中 HPC 和 CD34+细胞计数存在显著差异。MM 组中预采集 HPC 与 CD34+细胞计数之间的相关性良好（rho=0.613），淋巴瘤组（rho=0.802）、同种异体供体（rho=0.923）和其他样本组（rho=0.816）的相关性较强。对于 MM 患者，HPC 阳性截断值≥20/μL 和≥10/μL CD34+细胞计数具有 100%的特异性和阳性预测值，因此价值有限。HPC 阴性截断值的敏感性和阴性预测值均为 100%，约为<4/μL，与诊断无关。
基于提出的 HPC 阳性截断值（淋巴瘤组≥31/μL，其他样本组≥11/μL），常规 HPC 计数可通过在同种异体供体以及非 MM 患者中替代 CD34+细胞计数来改善工作流程。此外，基于提出的 HPC 阴性截断值（<4/μL），对于动员不足的供体和患者，可以完全省略 CD34+细胞计数。
