Evaluation of the Sysmex XN automated hematopoietic progenitor cell enumeration for timing of peripheral blood stem cell harvest

Background An automated hematopoietic progenitor cell count measurement in Sysmex XN analyzer (XN‐HPC) has been developed to assist flow cytometry CD34+ cell count measurement, which requires technical expertise and a long turnaround time. Here, we evaluated the correlation between XN‐HPC count and flow cytometric CD34+ cell count in pre‐harvest peripheral blood (PB) samples from patients undergoing autologous peripheral blood stem cell (PBSC) transplantation according to diagnosis and investigated the possible cause of the decreased correlation in plasma cell neoplasm patients. Materials and Methods We retrospectively included 399 patient data that had matched PB XN‐HPC count and CD34+ cell count of PB and apheresis product from Samsung Medical Center (SMC) and the Hematopoietic Stem Cell (HSC) registry. We assessed the diagnostic accuracy and the potential cutoff values of XN‐HPC count for predicting adequate PBSC collection. Results The PB XN‐HPC count was 1.6 and 1.3‐fold higher than the CD34+ cell count in SMC (25.0 vs 15.9/μl) and the HSC registry (20.0 vs 15.2/μl), respectively. Overall the correlation between the PB XN‐HPC and CD34+ cell count was moderate (SMC, r = 0.71; HSC registry, r = 0.66). A significant proportional and systemic bias with overestimation of XN‐HPC count were noted in the plasma cell neoplasm patients in both SMC and the HSC registry. However, no significant difference in correlation was observed according to myeloma‐related laboratory parameters in plasma cell neoplasm patients. Conclusion Our results suggest that XN‐HPC count should be interpreted cautiously in cancer patients undergoing autologous PBSC transplantation, especially in those with plasma cell neoplasm.

Section: Discussioncontrasting

confidence: 48%

Section: Introductioncontrasting

confidence: 61%

Section: Discussionmentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Correlation between peripheral blood automated hematopoietic progenitor cell counts and flow cytometric CD34⁺ cell counts differs according to diagnosis in patients undergoing autologous peripheral blood stem cell transplantation

Kim

et al. 2021

Hematopoietic progenitor cell counting can optimize peripheral blood stem cell apheresis process

Reberšek

Furlan

Zver

et al. 2021

Introduction: 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.Materials and Methods: Results of flow cytometric CD34+ cell and Sysmex HPC count were compared in 208 preharvest samples and 139 apheresis products.Results: 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.Conclusions: 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.

Comparison of peripheral blood automated hematopoietic progenitor cell count and flow cytometric CD34+ cell count

Hagenkötter,

Mika,

Ladigan‐Badura

et al. 2024

BackgroundStem cell apheresis in the context of autologous stem cell transplantation requires an accurate cluster of differentiantion 34 (CD34+) count determined by flow cytometry as the current gold standard. Since flow cytometry is a personnel and time‐intensive diagnostic tool, automated stem cell enumeration may provide a promising alternative. Hence, this study aimed to compare automated hematopoietic progenitor enumeration carried out on a Sysmex XN‐20 module compared with conventional flow cytometric measurements.MethodsOne hundred forty‐three blood samples from 41 patients were included in this study. Correlation between the two methods was calculated over all samples, depending on leukocyte count and diagnosis.ResultsOverall, we found a high degree of correlation (r = 0.884). Furthermore, correlation was not impaired by elevated leukocyte counts (>10 000/μL, r = 0.860 vs <10 000/μL, r = 0.849; >20 000/μL, r = 0.843 vs <20 000/μL, r = 0.875). However, correlation was significantly impaired in patients with multiple myeloma (multiple myeloma r = 0.840 vs nonmyeloma r = 0.934).SummaryStem cell measurement carried out on the Sysmex XN‐20 module provides a significant correlation with flow cytometry and might be implemented in clinical practice. In clinical decision‐making, there was discrepancy of under 15% of cases. In multiple myeloma patients, XN‐20 should be used with caution.