Introduction
The BD Stem Cell Enumeration Kit has garnered significant attention in the field of flow cytometry for its ability to accurately enumerate CD34+ cells. To validate its efficacy and establish its equivalence to existing methods, a multi-site evaluation was conducted involving four clinical sites specializing in flow cytometry CD34+ enumeration.
This comprehensive study aimed to assess the agreement between the BD FACSCanto II and BD FACSCalibur systems with the predicate method, which utilized the Beckman Coulter StemKit and StemTrol. By analyzing leftover and delinked specimens from clinical flow cytometry testing, the researchers sought to determine the reliability and consistency of the BD Stem Cell Enumeration Kit across various sample types and preparation methods.
Methods and Materials
A total of 1032 specimens were collected from normal and mobilized blood, frozen and thawed bone marrow, leucopheresis, and cord blood. These samples were anticoagulated with a variety of substances, including citrate phosphate dextrose, anticoagulant citrate dextrose-solution A, heparin, and ethylenediaminetetraacetate, either alone or in combination.
To ensure site equivalency for sample preparation, testing, and analysis, fresh leucopheresis samples were analyzed. The BD FACSCanto II and BD FACSCalibur systems were utilized to analyze the specimens, with optimal gating parameters established for the BD FACSCanto II and manual gating for the BD FACSCalibur.
Results
The mean relative bias demonstrated agreement within predefined parameters for both the BD FACSCanto II (-2.81 to 4.31 ±7.1) and BD FACSCalibur (-2.69 to 5.2 ±7.9). These results indicate that the BD Stem Cell Enumeration Kit provides accurate and consistent CD34+ cell enumeration comparable to the predicate method.
Bias analyses of the distribution of the predicate low, mid, and high bin values showed agreement using both investigational methods. Deming regression analyses revealed a linear relationship with R(2) > 0.92 for both methods, further supporting the reliability and consistency of the BD Stem Cell Enumeration Kit.
Discussion
The findings of this multi-site evaluation provide strong evidence that the BD Stem Cell Enumeration Kit is a valuable tool for CD34+ cell enumeration. Its accuracy and consistency across different sample types and preparation methods make it a reliable choice for clinical laboratories and research institutions.
The kit’s ability to enumerate viable CD34+ cells, as well as the percentage of viable CD34+ cells in CD45+ and viable CD45+ populations, makes it particularly useful for assessing hematopoietic stem cell transplantation outcomes and monitoring disease progression in hematological malignancies.
Overall, the BD Stem Cell Enumeration Kit has proven to be an effective and reliable method for CD34+ cell enumeration, providing valuable insights into hematopoietic stem cell biology and clinical applications.
