Graft Composition and Post-Thawing Cell Viability Influence the Hematopoietic Recovery in Autologous Hematopoietic Stem Cell Transplantation

Coronavirus disease 2019 pandemic and allogeneic hematopoietic stem cell transplantation: a single center reappraisal

“…One of the main concern related to cryopreservation is represented by the loss of viable cells due to unit processing or during the storage [ 16 , 17 ]. This risk may be exacerbated if products are cryopreserved at cell concentration greater than 2 × 10 8 /ml, or if they contain a large amount of granulocytes [18] , [19] , [20] . In this study, we confirmed that part of viable CD34 + cells was lost with cryopreservation.…”

Hematopoietic Stem Cell Transplantation: The Quality Matters

“…Prior studies have also reported that CD34+ cell survival in the cryopreserved cell preparations was inversely related with the ratio between CD34+ cells and the total nucleated cells including white blood cells and neutrophils; however, the effect of platelets concentration was ignored in the study [5]. Supported by the remarkable experimental data in which increasing concentrations of platelets were cryopreserved with HSCs, Valentini et al have shown adverse effects of higher platelet number on the viable HSC recovery [4]. Therefore, the authors have recommended that platelets should be removed before cryopreservation of HSCs or alternatively the cells ought to be immediately washed after thawing to minimize the unwarranted influence of the platelet-derived factors in terms of their viability and engraftment potential.…”

“…Nevertheless, there is an obvious dearth of literature regarding the composition of the cell graft especially with respect to the presence of platelets that possibly influence the recovery and viability of the cryopreserved HSCs and, their engraftment and function posttransplantation. Valentini et al have addressed this interesting aspect of HSCs research in their recently published study to demonstrate that the higher concentration of platelets in the Peripheral Blood Stem Cells (PBSCs) negatively impacts the survival and recovery rates of the peripheral blood derived autologous HSCs after cryopreservation [4]. Prior studies have also reported that CD34+ cell survival in the cryopreserved cell preparations was inversely related with the ratio between CD34+ cells and the total nucleated cells including white blood cells and neutrophils; however, the effect of platelets concentration was ignored in the study [5].…”

“…It is generally believed that the bioactive molecules from the platelets act on their respective membrane receptors on the HSCs to initiate signaling pathways that regulate various cell functions. Contrarily, the observed detrimental effect of the platelets on the cryopreserved HSCs is intriguing and may be attributed to the release of pro-inflammatory cytokines by the peripheral blood platelets [4]. These data may have widespread implications in the regenerative medicine where both bone marrow as well as peripheral blood derived HSCs have been extensively studied for their reparability [13].…”