Granulocyte concentrates: prolonged functional capacity during storage in the presence of phenotypic changes

Abstract

BackgroundGranulocyte transfusion has been proposed as a bridging therapy for patients with prolonged periods of chemotherapy-induced neutropenia, who suffer from severe fungal and bacterial infections. To recover, adequate numbers of granulocytes are required when the patients are refractory to standard treatment. The aim of this study was to assess the functional characteristics and efficacy of granulocyte colony-stimulating factor/dexamethasone-mobilized granulocytes used for transfusions.

Changes in gene expression of granulocytes during in vivo granulocyte colony-stimulating factor/dexamethasone mobilization for transfusion purposes

“…4,10,49,50 However, the life span of those cells is prolonged upon in vitro culture as well as in vivo. In addition, supplementation of the culture medium of previously untreated control cells with G-CSF/dexamethasone also prolongs cell survival.…”

“…[6][7][8] Despite all the aforementioned studies, we and others have found that donor granulocytes, when mobilized for transfusion purposes, show virtually normal functional characteristics in vitro in the presence of some minor phenotypic changes, whereas their life span is consistently prolonged. 9,10 Both G-CSF and dexamethasone are well-established prosurvival factors for neutrophilic granulocytes, [11][12][13] and this effect involves various survival signaling pathways. G-CSF has been shown to increase in neutrophils the mRNA expression of A1/Bfl-1, an antiapoptotic member of the Bcl-2 family of proteins.…”

Impaired killing of Candida albicans by granulocytes mobilized for transfusion purposes: a role for granule components

“…The functional NADPH oxidase activity upon cell activation was also comparable between control and G-CSF/dexamethasone-mobilized neutrophils ( Figure 1B). 14 Furthermore, the mobilization of azurophilic granules was measured by the membrane expression of CD63 and the release of elastase and MPO upon stimulation with cytochalasin-B/fMLP (Figure 2A-C). The mobilization of specific granules was evaluated by the membrane expression of CD66b and the release of lactoferrin upon stimulation with PAF/fMLP ( Figure 2D,E).…”

“…11,12 We and others have shown that neutrophils from G-CSF/dexamethasone-treated donors display prolonged survival rates, intact NADPH oxidase activation and a normal antimicrobial response against gram-positive and gram-negative bacteria. [13][14][15][16] Nevertheless, G-CSFmobilized donor neutrophils have been reported to contain reduced levels of lactoferrin for example, derived from the specific granules, as compared to neutrophils from untreated controls. 17 During granulopoiesis granular proteins are synthesized, and when released by the mature neutrophil these proteins employ cytotoxic activity or limit the availibility of nutrients for the pathogen.…”

Experimental Evidence That Granulocyte Transfusions Are Efficacious in Treatment of Neutropenic Hosts with Pulmonary Aspergillosis

“…Repeated G-CSF administrations have been shown to be superior to single administrations in improving these functional properties (40). It is recommended that the granulocytes be transfused as soon as possible after they are obtained, without storage (41, 42), as we did, although it has been shown that neutrophil functions can be preserved for 24 h ex vivo (43), and viability after G-CSF mobilization is preserved up to 72 h after collection, while interleukin 1 (IL-1) or IL-8, implicated in transfusion reactions, remains low (44). Between collection and transfusion the cells were refrigerated, as is optimal with human cells (41).…”