Summary:Delayed engraftment, graft failure, and adverse transplant-related events have been observed in unrelated umbilical cord blood (UCB) recipients, particularly in those receiving a low leukocyte cell dose and in CML patients. We report the outcomes of two older adult patients with high risk CML who received a low leukocyte cell dose of unmanipulated UCB cells supplemented with ex vivo expanded (AastromReplicell System) UCB cells. Each engrafted promptly and neither patient experienced GVHD or life-threatening infection. Both remain engrafted with cells exclusively of donor origin and are in cytogenetic remission at 19 and 8 months follow-up. Ex vivo expanded UCB cells appear to facilitate hematopoietic recovery and therefore may increase the number of CML patients eligible for unrelated UCB transplant. Bone Marrow Transplantation (2000) 25, 797-799. Keywords: chronic myelogenous leukemia; umbilical cord blood transplant; ex vivo expansion Transplantation of umbilical cord blood (UCB) from related and unrelated donors has been performed in an attempt to increase the number of potential allogeneic stem cell donors. 1,2 The limited availability of unrelated donor UCB units of adequate nucleated cell dose, however, restricts its application in older adult patients. Ex vivo expansion of UCB in small and clinical-scale regulated perfusion experiments (AastromReplicell System, Ann Arbor, MI, USA) has been proven capable of significantly increasing the number of total nucleated cells, CFU-GM, and longterm culture initiating cells. 3 Therefore, the effect of supplementing unrelated donor UCB with ex vivo expanded UCB cells from the same donor was evaluated in two older adult patients with high risk CML and no alternative donor.
Summary:To reduce the number of apheresis procedures and maintain the usual rate of hematopoietic recovery in patients treated with high-dose chemotherapy, we studied the effect of adding a small volume of ex vivo expanded bone marrow to low doses of CD34 + blood stem cells. Thirty-four patients with breast cancer received G-CSF (10 g/kg/day) priming followed by a limited volume (50-100 ml) bone marrow aspiration and standard 10-liter aphereses. Marrow was expanded ex vivo using the AastromReplicell system and infused along with low doses of blood-derived CD34 + cells, collected in one apheresis. Thirty-one evaluable patients received a median CD34 + blood stem cell dose of 0.7 × 10 6 /kg (range, 0.2-2.5) and 4.7 × 10 7 nucleated cells/kg (range, 1.98-8.7) of ex vivo expanded marrow. All patients recovered with normal blood counts and engrafted 500 neutrophils/l and 20 000 platelets/l in a median of 10 and 13 days, respectively. Multivariate analysis revealed that, in addition to CD34 + lineage negative cell quantity, the quantity of stromal progenitors contained in the ex vivo expanded product correlated with engraftment outcome (r = 0.551, P = 0.004
Summary:In comparison to bone marrow, umbilical cord blood has decreased intrinsic immune responsiveness allowing transplantation across HLA barriers with lower rates of graft-versus-host disease. However, laboratory models have also suggested that cord blood may be extremely sensitive to stimulation by cytokines. We report an adult recipient of an ex vivo expanded, HLA-mismatched, unrelated cord blood transplant who experienced a late extramedullary relapse while still in hematologic remission. Despite demonstrating immune tolerance on minimal immunosuppressive agents, a brief course of intravenous interleukin-2 resulted in rapid, aggressive graft-versus-host and graft-versus-leukemia reactions. This case highlights the potential of cytokine immunomodulation following cord blood transplantation, but also suggests caution in stimulating these cells. Bone Marrow Transplantation (2000) 26, 353-355.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.