Outcome of Unrelated Umbilical Cord Blood Transplantation in India: A less explored horizon

Introduction:In around 75% patients there is no available matched sibling donors (MSD) for hematopoietic-stem-cell-transplant (HSCT), hence haploidentical-donors, matched-unrelated-donors and umbilical cord blood (UCBT) remain the alternatives.Despite comparable outcomes and low graft-versus-host-disease (GVHD) rate, there is dearth of data on the clinical-outcomes of UCBT in India owing to limited use and experience.Methodology: We analysed the outcomes and possible prognostic factors of UCBTs done at a single institution in India from 2011-2023.Conditioning regimens were based on known triplet combinations of thiotepa, busulfan, treosulfan, melphalan, cyclophosphamide, or fludarabine, along with antithymocyte globulin (ATG).Results: Out of 20 patients transplanted, median age was 4y(0.25-17) with 75% males.While 55% were leukemia (AML/ALL), 45% were benign conditions (hemophagocytic-lymphohistiocytosis in 2 and one each of severe-combined-immunodeficiency, leukocyte-adhesion-defect, Wiskott-Aldrich syndrome, adenosine-deaminase-deficiency, mucopolysaccharidosis, porphyria and muscular-dystrophy).HLA-match was 6/6, 5/6 and 4/6 in 19%, 25% and 56% respectively.The countries of origin of the UCBT units were USA, Taiwan and India in 73%, 20% and 7% respectively.Majority(90%) received myeloablative conditioning.Median volume, CD34 dose, total-nucleated-cell dose and viability were 64ml, 3.3x105/kg, 9.6x107/kg and 95% respectively.Median time for neutrophil-engraftment and hospitalization were 28.5 days and 36.5 days respectively.