Improving the outcome of cord blood transplantation: use of mobilized HSC and other cells from third party donors.
We developed the strategy of umbilical cord blood transplants (UCBT) with co-infusion of a limited number of highly purified mobilized haematopoietic stem cells (MHSC) from a human leucocyte antigen (HLA) unrestricted third party donor (TPD). Short post-transplant periods of neutropenia were usually observed in adults with haematological neoplasms receiving UCBT with a relatively low cell content and 0-3 HLA mismatches after myeloablative conditioning. This resulted from an early and initially predominant engraftment of the TPD-MHSC. After a variable period of double complete TPD + UCB chimerism, final full UCB chimerism was achieved (cumulative incidence >90%) within 100 d. Early recovery of the circulating neutrophils resulting from the 'bridge transplant' of the TPD-MHSC reduced the incidence of serious neutropenia-related infections, also facilitating the use of drugs with myelosuppressive side effects to combat other infections. The observed incidence of graft-versus-host disease and relapses was low, with overall and disease-free survival curves comparable to those of HLA identical sibling transplants. Post-transplant recovery of natural killer cells occurred soon after the transplant and B cells recovered around 6 months, but T-cell recovery took more than 1 year. Available data show that T cell recovery derives from UCB-HSC through thymic differentiation and that cytomegalovirus (CMV)-specific lymphocytes develop following CMV reactivations.
School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain. manueln.fernandez@uam.es
Manuel N
MN
Fernández
D036101:Cord Blood Stem Cell Transplantation / Q000379:methods*; D006084:Graft Rejection; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006650:Histocompatibility Testing; D006801:Humans; D016019:Survival Analysis; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014019:Tissue Donors; D016896:Treatment Outcome