Addition of Plerixafor to Mobilization Regimens in Autologous Peripheral Blood Stem Cell Transplants Does Not Affect the Correlation of Preharvest Hematopoietic Precursor Cell Enumeration with First-Harvest CD34+ Stem Cell Yield

Abstract

The CXCR4 antagonist plerixafor is increasingly used in the mobilization regimens for autologous peripheral blood stem cell (PBSC) transplantation. This agent may mobilize a different subset of the stem cell population than traditional regimens, such as growth factors (with and without chemotherapy). Thus, it is important to determine whether plerixafor has an effect on the utility of measurements used to predict the yield of CD34(+) cells, usually either preharvest peripheral blood CD34(+) enumeration by flow cytometry or hematopoietic precursor cell (HPC) enumeration by automated hematology analysis. Although HPC enumeration has a weaker correlation with first-harvest CD34(+) cell yield, this parameter still plays an important role in the timing of apheresis procedures for autologous PBSC transplantation because of its technical simplicity and low cost. In the present study, we retrospectively examined the correlation of HPC measurements with CD34(+) cell yields in patients with multiple myeloma and lymphoma undergoing autologous PBSC transplantation, and investigated how the mobilization regimen affected these results. We found that the correlation coefficients ranged from 0.5877 to 0.7668 and were not significantly impacted by differences in diagnosis or inclusion of plerixafor in the mobilization regimen. The predictive ability of HPC enumeration for various target yields was also examined, and receiver-operating characteristic curves were generated. An HPC cutoff of 20 should result in adequate initial CD34(+) cell yields (>2.5 × 10(6) cell/kg) in >80% of autologous donors with or without plerixafor. This study confirms the utility of HPC enumeration in prediction of adequate initial cell yields, and demonstrates that this utility is maintained regardless of whether or not plerixafor is included in the mobilization regimen.

Multicenter study to evaluate a new enumeration method for hematopoietic stem cell collection management

“…We found very good correlations between peripheral blood XN stem cells and CD34 counts determined by flow cytometry. Our data show that there is an improvement in the correlation of XN stem cells and CD34+ cells in the peripheral blood during stem cell mobilization as well as in stem cell harvests as compared to SE or XE Series analyzers . This has been achieved by adapting reagent composition, cell detection method, and the stem cell identification algorithm in this new version of the Sysmex hematology analyzer, as was also demonstrated in the data of Peerschke and coworkers …”

“…The correlation between preharvest XN stem cell count and the CD34 harvest is good—r = 0.785 (Fig. B)—and the highest published thus far …”

“…4B)-and the highest published thus far. [12][13][14][15][16][17][18][19] DISCUSSION CD34 flow cytometry is a standard method of stem cell enumeration in peripheral blood at the mobilization stage and in the final apheresis product. It requires well-trained and experienced flow cytometer operators and is a technique that can be technically challenging.…”

Decision‐tree algorithm for optimized hematopoietic progenitor cell–based predictions in peripheral blood stem cell mobilization

“…HPC counts have been proven to be a surrogate marker for initiating PBSC collection. The correlation coefficient was 0.446 in our study, which was consistent with previously reported ranges (range, 0.32‐0.78) . The preharvest HPC counts correlated more with the collected CD34+ cell counts than did the MNC and WBC counts; however, the relationship was not as strong.…”

“…The measurement requires less than 3 minutes and can be performed as a part of a routine complete blood cell count in a clinical laboratory. Moderate to strong correlations between preharvest HPC counts and collected CD34+ cell counts have been reported in previous studies . A prospective study conducted by Suh and colleagues demonstrated an excellent harvest success rate guided by using HPC counts.…”