Nuove strategie manipolative ex vivo per il purging delle unità di cellule staminali ematopoietiche periferiche destinate al trapianto autologo di midollo

Abstract

NEW MANIPULATIVE STRATEGIES EX VIVO FOR PURGING OF PHERIPHERAL HAEMATOPOIETICS STEM CELLS UNITS AIMED FOR AUTOLOGOUS BONE MARROW TRANSPLANTATION This thesis aims to evaluate the possibility of using the Gemtuzumab ozogamicin in ex vivo purging of autologous pheripheral blood mononuclear cells, in order to eliminate possible contaminants leukaemia cells. The use of this drug is subject to verification that the depletion of malignant cells does not cause cytotoxic effects on normal stem cells and normal multi-potential progenitors, which are in charge restocking stable and enduring new bone marrow. Therefore, these experiments were conducted by exposing to Gemtuzumab ozogamicin haematopoietic stem cells mobilized in pheripheral blood and haematopoietic stem cells obtained from cord blood determining their "rate of growth" through clonogenic tests. Based on the above data it can be concluded that: 1) the Gemtuzumab ozogamicin not significantly inhibit the clonal efficiency of subset primitive CD34+/CD38- and mononuclear cells 2) cryopreservation significantly increases the toxic effects of Gemtuzumab ozogamicin probably because of damage to the mambrane, wich promote endocytosis 3) in the clinical purgin, use of Gemtuzumab ozogamicin, should be avoided treatments longer than 24 hs. These data provide the opportunity for future experiments designed to elucidate the phenomena of toxicity found, and allow to plane clinical trials in order to validate the use of Gemtuzumab ozogamicin in haematopoietic stem cells purging obteined with apheresis methods of acute myeloid leukemia patients elect to the autologous bone marrow transplantatio