RESUMEN
BACKGROUND: Most blood products are infused at the time of transfusion through a standard blood filter, designed to capture macroaggregates and cellular debris that might be harmful to the patient if infused. Hematopoietic stem cell products are not universally filtered, likely due to concern about loss of viable stem cells in the filtration process. STUDY DESIGN AND METHODS: We conducted a two-phase study to better understand the safety of routine filtration. First, surplus cryopreserved stem cell products were thawed and filtered, with markers of viability and potency measured. Second, routine filtration was implemented as part of routine practice at our center, and date of neutrophil and platelet (PLT) recovery was compared to historical controls. RESULTS: In the first phase, there was no difference seen in any markers of viability or potency for products after routine filtration. Based on those results, routine filtration was implemented. There was no difference in neutrophil or PLT engraftment. Thus, in this study, routine filtration did not impact the number of viable stem cells and did not delay engraftment. CONCLUSION: Given the very real harm posed by infusion of macroaggregates and cellular debris, and no clear disadvantage to filtration, routine filtration of stem cell products should be considered the standard of care.
Asunto(s)
Filtración , Células Madre Hematopoyéticas/citología , Trasplante de Células Madre de Sangre Periférica/métodos , Aloinjertos , Plaquetas/citología , Conservación de la Sangre , Agregación Celular , Supervivencia Celular , Centrifugación , Ensayo de Unidades Formadoras de Colonias , Criopreservación , Filtración/instrumentación , Supervivencia de Injerto , Humanos , Neutrófilos/citología , Tamaño de la Partícula , Trasplante de Células Madre de Sangre Periférica/efectos adversos , Sistemas de Atención de Punto , Trastornos Respiratorios/etiología , Trasplante AutólogoRESUMEN
The interaction of myeloid-derived suppressor cells (MDSCs) with T cells within G-CSF-mobilized peripheral blood stem cell (PBSC) grafts in patients undergoing autologous or allogeneic hematopoietic stem cell transplantation remains to be elucidated. Through studying allo- and auto-PBSC grafts, we observed grafts containing large numbers of T cells and MDSCs with intergraft variability in their percentage and number. T cells from autologous grafts compared to allografts expressed relative higher percentages of inhibitory receptors PD-1, CTLA-4, TIM-3, LAG-3, TIGIT and BTLA. Autograft T cells had decreased cell proliferation and IFN-γ secretion, which supported the possible presence of T cell exhaustion. On the contrary, graft monocytic MDSCs (M-MDSCs) expressed multiple inhibitory receptor ligands, including PD-L1, CD86, Galectin-9, HVEM and CD155. The expression of inhibitory receptor ligands on M-MDSCs was correlated with their corresponding inhibitory receptors on T cells in the grafts. Isolated M-MDSCs had the ability to suppress T cell proliferation and IFN-γ secretion and/or promote Treg expansion. Blocking the PD-L1-PD-1 signaling pathway partially reversed the functions of M-MDSCs. Taken together, our data indicated that T cells and M-MDSCs in PBSC grafts express complementary inhibitory receptor-ligand pairing, which may impact the quality of immune recovery and clinical outcome post transplantation.