title: Haploidentical cord blood transplant contaminated with maternal T cells in a patient with advanced leukaemia.
abstract: Myeloablative treatment followed by lymphohaematopoietic reconstitution with stem cells from umbilical cord blood (UCB) can cure children with leukaemia. The clinical experience of UCB transplantation with HLA 2- and 3-antigen mismatched siblings is rather limited and there are no reports of such patient being given UCB significantly contaminated with maternal T lymphocytes. In this study, we report our experience in treating a child with chronic myeloid leukaemia in blast crisis who was transplanted using UCB cells from mismatched sibling donor containing a significant number of maternal T cells. The patient received 1.17 x 10(8) nucleated cells/kg after conditioning with Ara-C, busulphan, TBI and cyclophosphamide. GVHD prophylaxis was with cyclosporine and an anti-CD25 monoclonal antibody. Although engraftment was somewhat slow it was complete as documented by cytogenetic analysis and DNA studies. Results of minimal residual disease monitoring by RT-PCR for the hybrid BCR/ABL gene showed no evidence of leukaemic mRNA post-transplant. Acute GVHD, skin only, developed on day +14 but promptly responded to low-dose steroids. The technique used for UCB collection may have cell contamination found. In spite of these potential disadvantages: advanced disease, HLA antigen disparate donor and significant maternal T cell contamination, the transplant was successful and at a follow-up of 14 months the child is well with no evidence of chronic GVHD. Immune naivety of cord blood and lack of immunological reactivity of maternal T cells in this context may have played a significant role in the outcome of this case.
authors: Instituto Português de Oncologia de Francisco Gentil, Lisboa, Portugal.
authors: M M
authors: MM
authors: Abecasis
authors: A M
authors: AM
authors: Machado
authors: G
authors: G
authors: Boavida
authors: M G
authors: MG
authors: Silva
authors: P
authors: P
authors: Lúcio
authors: A
authors: A
authors: Ambrósio
authors: M L
authors: ML
authors: Jorge
mesh_terms: D002678:Chimera; D005190:Family; D005260:Female; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006085:Graft Survival; D006239:Haplotypes; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000276:immunology / Q000628:therapy*; D019520:Living Donors; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D013997:Time Factors