Low CD34 collection from a healthy blood progenitor cell donor: A case report

Enumeration of viable CD34+ cells in cord blood using a novel stem cell enumeration kit

OBJECTIVE

To assess the detection performance of the hematopoietic stem cell enumeration kit developed by BD Biosciences.

METHODS

Cord blood samples were prepared using a hematopoietic stem cell enumeration kit developed by BD Biosciences and Stem-Kit reagents from Beckman Coulter. CD34+ cells were enumerated using a BD FACSCanto instrument and FACSDiva software.

RESULTS

A total of 519 samples were analyzed in this study. The hematopoietic stem cell enumeration kit developed by BD Biosciences yielded absolute counts of CD34-positive cells that were on average 8.7% lower than Beckman Coulter Stem-Kit reagents (range: -5.7% to-14.7%). The BD Biosciences kit yielded relative counts that were on average 9.9% higher compared with Beckman Coulter Stem-Kit reagents (range: -2.1% to +13.8%). The intraclass correlation coefficients for absolute and relative counts of CD34-positive cells were 0.9967 (95% confidence interval [CI]: 0.9961-0.9972) and 0.9512 (95% CI: 0.9423-0.9587) for the BD Biosciences and Beckman Coulter kits, respectively.

CONCLUSIONS

The hematopoietic stem cell enumeration kit developed by BD Biosciences can be used to enumerate CD34-positive stem cells from cord blood samples.

Manual color monitoring to optimize hematopoietic progenitor cell collection on the Fenwal Amicus

A technique was developed to improve consistency of MNC transfers from the centrifuge to the collection bag in the Fenwal Amicus. The operator assures that RBCs completely fill the cassette by the end of the transfer by adjusting the RBC offset in succeeding cycles. We compared yields and crosscellular content before and after implementation of the monitoring technique. Retrospective data from 400 consecutive HPC collection procedures (200 for each technique) were compared. In 40 monitored collections, the RBC offset was adjusted to 6-9 mL to ensure that RBCs completely filled the cassette. Collections requiring these adjustments were not associated with a specific diagnosis. Median values were compared between the 40 collections requiring offset adjustment and those performed before implementation of monitoring. Baseline peripheral CD34+ cell (17 vs. 14 cells μL(-1)), lymphocytes (2 vs. 1.3 × 10(9) /L), WBCs, HCT, and PLTs were significantly higher in the group requiring offset changes. The group requiring offset changes had significantly more CD34+ cells per collection (190.8 × 10(6) or 2.04 × 10(6) /kg vs. 84.3 × 10(6) or 0.89 × 10(6) /kg) and more lymphocytes per collection (16.9 × 10(9) vs. 11.6 × 10(9)). Crosscellular content of the group requiring offset changes was significantly higher for WBCs (41.8 vs. 33.1 × 10(9)), granulocytes (9.6 vs. 7.2 × 10(9)), RBCs (23 vs. 17 mL), and PLTs (2.1 vs. 1.2 × 10(11)). Manual monitoring is a simple, inexpensive method to optimize each HPC collection to maximize CD34+ cell and lymphocyte yields.

Enumeration of viable CD34(+) cells by flow cytometry in blood, bone marrow and cord blood: results of a study of the novel BD™ stem cell enumeration kit

BACKGROUND AIMS

Enumeration of CD34(+) cells in leukocyte-rich cell suspensions is important for clinical decision-making in stem cell transplantation. Single-platform flow cytometry assays offer the significant advantages of speed and reproducibility, and have therefore become the gold standard in stem cell enumeration. The clinical community has recently defined the need for stem cell enumeration kits that incorporate viability dyes. The purpose of this study was to evaluate a novel assay, BD Biosciences' (BD) stem cell enumeration kit (SCE kit(‡)), in relation to Beckman Coulter's (BC) commercially available BC Stem-Kit™.

METHODS

Fresh/freeze-thawed samples from leukapheresis, bone marrow and cord blood, and fresh normal/mobilized blood, were analyzed with both assays (simultaneous detection of side/forward scatter and three fluorescence signals) on two flow cytometry platforms, BD FACSCanto II and BD FACSCalibur. Results. Results from both assays were highly congruent, with an overall r(2) ≥ 0.99 (all specimen types included), a linear correlation across all CD34(+) cell frequencies and concentrations, and an almost ideal steepness of the trend line.

CONCLUSIONS

Both assays functioned reliably. Being based on single-platform International Society of Hematotherapy and Graft Engineering (ISHAGE) guidelines and similar staining methods, both assays essentially come to identical results. For most specimen types, the viability of CD34(+) cells was equal to overall leukocyte viability. In summary, in the hands of an experienced technician, the BD™ SCE kit and the BC Stem-Kit are equivalent. The infrequent user might derive benefit from the fact that counting spheres are pre-pipetted into the Trucount tube for the SCE kit, making this assay less susceptible to pipetting inaccuracy.