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Abstract: Background: Immunomagnetic cell selection (ICS) cells is increasingly used in allogeneic hematopoietic transplantation in order to reduce the T cells quantity. The aim of this study was to evaluate an protocol based on Ficoll method before ICS. Study design and methods: The automated procedure was compared with the standard method. In the group 1 the cell processing involves the extraction of the buffy-coat by Ficoll before incubation with antibodies. This procedure was performed with the Sepax S-100 device. The efficacy of this automated procedure was compared with the group 2. In this group, the cell washing and the incubation were performed through the standard method. The CD34+ cells collected by apheresis (HPC-A) were selected with ICS. Results: The results obtained after Ficoll procedure, showed a total nucleated cells (TNCs) and CD34+ cells recovery of 85.73% (75.90–90.63; SD 4.25) and 79.31% (51.77–112.31; SD 18.40), respectively. The TNC and CD34+ cells recovery after the pre-incubation washing performed through the standard method, was 75.54% (38.36–97.76; SD 22.5) and 61.51% (30.87–81.79; SD 19.3), respectively. The CD34+ cells recovery after ICS was 79% (51.77–100; SD 18.40) and 44% (15.57–88.24; SD 25.91) in the group 1 and the group 2, respectively. This difference was statistically significant (p =0.001). Conclusion: The efficacy of the ICS which resulted to be higher in the group 1 compared to the group 2. Overall, our data suggest that the Ficoll procedure before incubation is suitable for the clinical routine in the ICS for haploidentical transplantation in patients affected by thalassemia. [Copyright &y& Elsevier]

Abstract: γ/δ T cells represent a subset of T cells expressing a T cell receptor (TCR) variant composed of gamma and delta chains. The γ/δ TCR is expressed by 2–10% of all T cells in human peripheral blood, whereas the majority of T cells express α/β TCRs. γ/δ T cells display a range of innate effector functions including rapid secretion of chemokines and cytokines, as well as target cell lysis. Recent interest has focused on the function of γ/δ T lymphocytes in allogeneic transplantation in the onco-hematology field. Several studies, in vitro and in vivo, suggest that γ/δ T lymphocytes are potential beneficial effector cells in the context of hematopoietic stem cell transplantation (HSCT). In addition, in this review, we discuss the depletion of α/β T lymphocytes in the graft for allogeneic transplantation. In fact, an efficient TCR α/β cell depletion potentially reduces the risk of GvHD. Furthermore, TCR α/β T cell depletion, especially with immunomagnetic negative selection, retains other potential beneficial effector cells in the graft, such as γ/δ T cells, NK cells, and stem cells. These “facilitating” cells might facilitate engraftment, exert GvL effects, and reduce the risk for infections. [Copyright &y& Elsevier]

Abstract: T regulatory cells are fundamental in the maintenance of immune homeostasis and self-tolerance. Experimental models suggest the existence of two functional types of Treg cells designated naturally occurring and induced. Interest in Treg cells increased with evidence from experimental mouse and human models demonstrating that the immunosuppressive potential of these cells can be utilized in the treatment of various pathological conditions. The existence of a subpopulation of suppressive T cells was the subject of significant controversy among immunologists for many years. T regulatory cells limit immune activation through a variety of direct and indirect interactions, many of which are yet to be determined. Fully understanding Treg cells biology will lead us to harnessing the capacity of these cells in order to develop strategies to prevent autoimmune disorders and tolerance to transplantation. Efficient isolation, expansion and cryopreservation strategies that comply with Good Manufacturing Practice (GMP) guidelines are prerequisites for the clinical application of human CD4+ CD25+ CD127low FOXP3+ regulatory T cells. [Copyright &y& Elsevier]

Abstract: The aim of our study is to assess the mortality of leukocytes during extracorporeal photopheresis. Sixty-three photopheresis performed on 13 patients affected by chronic GvHD were evaluated. Samples were analyzed using a FACSCalibur flow cytometer. Apoptosis and necrosis of limphomononuclear cells dramatically increased after the apheretic procedure. We found a further increase of apoptotic and necrotic limphomononuclear cells after treatment with 8-MOP and UVA (p ⩽0.05). Our data suggested that the immunomodulatory effects of extracorporeal photopheresis, triggered by circulating apoptotic or necrotic cells, could play an important role in the treatment of GvHD with this procedure. [Copyright &y& Elsevier]