Absolute density of different sources of hematopoietic progenitor cells: Bone marrow, peripheral blood stem cell and umbilical cord blood

Volume determination methods for hematopoietic progenitor cell products collected by apheresis

BACKGROUND AIMS

CD34⁺ cell count of hematopoietic progenitor cell products is often first determined using a product sample, with the final reported cell count obtained by multiplying cell count from the sample by the total product volume. Product volume may be determined by apheresis instruments used for collection or calculated based on specific gravity (SG). Here the authors sought to determine the discrepancies between these methods and the impact on patient care.

METHODS

A total of 262 products collected from 176 donors by apheresis were retrospectively reviewed. Volumes calculated by apheresis instruments were compared with volumes calculated based on SG. CD34⁺ cell/kg doses based on volumes from apheresis instruments and SG were also compared. Furthermore, among 42 patients who required multiple collections, the authors determined whether different calculation methods would have changed the number of procedures required.

RESULTS

The volumes for 253 products (96.6%) and CD34⁺ cell/kg doses for 257 products (98.1%) generated from apheresis instruments and SG were similar. Products with discrepant volumes when calculated using different methods were not associated with delayed engraftment. Forty patients who underwent multiple collections (95.2%) were under their collection goals during their first collection and would have required multiple procedures regardless of which method was used to calculate product volumes.

CONCLUSIONS

Volumes determined based on SG did not provide a clear benefit over volumes determined by apheresis instruments. Hence, variation in volume calculation methods across different laboratories is likely to lead to minimal impact on patient care.

Combined Analysis of Endothelial, Hematopoietic, and Mesenchymal Stem Cell Compartments Shows Simultaneous but Independent Effects of Age and Heart Disease

Clinical trials using stem cell therapy for heart diseases have not reproduced the initial positive results obtained with animal models. This might be explained by a decreased regenerative capacity of stem cells collected from the patients. This work aimed at the simultaneous investigation of endothelial stem/progenitor cells (EPCs), mesenchymal stem/progenitor cells (MSCs), and hematopoietic stem/progenitor cells (HSCs) in sternal bone marrow samples of patients with ischemic or valvular heart disease, using flow cytometry and colony assays. The study included 36 patients referred for coronary artery bypass grafting or valve replacement surgery. A decreased frequency of stem cells was observed in both groups of patients. Left ventricular dysfunction, diabetes, and intermediate risk in EuroSCORE and SYNTAX score were associated with lower EPCs frequency, and the use of aspirin and β-blockers correlated with a higher frequency of HSCs and EPCs, respectively. Most importantly, the distribution of frequencies in the three stem cell compartments showed independent patterns. The combined investigation of the three stem cell compartments in patients with cardiovascular diseases showed that they are independently affected by the disease, suggesting the investigation of prognostic factors that may be used to determine when autologous stem cells may be used in cell therapy.