OUTCOMES OF PEDIATRIC HEMATOPOIETIC STEM CELL TRANSPLANTS (HSCT) PERFORMED IN BRAZIL BETWEEN 2008 AND 2019

Abstract

HSCT is performed in Brazil since the 70’s, most of them in public centers. Transplant numbers are regularly reported by most centers to the Brazilian Transplant Registry/ Brazilian Solid Organ Association (ABTO/RBT), Latin American Bone Marrow Transplant Group/ Worldwide Network for Blood and Marrow Transplantation (LABMT/WBMT), but transplant outcomes are not available in our country. The objective of this work is to understand HSCT activity and outcomes of Brazilian children. Methods: The Brazilian Society of Bone Marrow Transplant and Cellular Therapy (SBTMO) has developed the initiative to collaborate with the Center for International Blood and Marrow Transplant Research (CIBMTR) to receive back deidentified aggregate nationwide data reported by Brazilian transplant centers. This was approved by the national central IRB in 2019 (Conep CAAE: 65575317.5.1001.0071, principal investigator Dr. Nelson Hamerschlak) as a research project, including data from 2008 through 2027. This is the first report of the Brazilian Pediatric Hematopoietic Stem Cell Transplant activity prepared by the SBTMO Data Managers Working Group with the data reported to the CIBMTR and returned to the country as an enhanced Data Back to Center file. Results: Between 2008 and 2019, 16 of the 19 institutions reporting to the CIBMTR also reported pediatric transplants. A total of 1,929 transplants were reported in children younger than 18 years of age and, different from the adult experience, most of them are allogeneic transplants. Within the past three years, the number of allogeneic transplants from unrelated and mismatched donors have increased and are now performed more often than transplants from matched sibling donors. Unrelated cord blood grafts were rarely used. Marrow was the preferred graft source for all allogeneic transplants. Acute leukemias and severe aplastic anemia were the most common indications for HSCT. Infections were the first cause of death within 100 days post HSCT. The 2-year overall survival after HSCT with HLA-identical sibling, unrelated donors and mismatched related donors for acute lymphoblastic leukemia was 56%, 60% and 37% (p = 0.2) and for acute myelogenous leukemia, 57%, 55% and 62% (p = 0.8), respectively. Pediatric myelodysplastic syndrome and chronic myelogenous leukemia had overall survival over 80%. Severe aplastic anemia was the most common non-malignant HSCT indication and the results with matched related and unrelated transplants are excellent, > 85% survival. In conclusion, this is the first report on transplant outcomes in Brazilian children. The collaboration with the CIBMTR may be a feasible way for Latin American countries to know their transplant outcomes using a mature registry structure with several tools already in place to enhance the collaboration. We would like to acknowledge Dr Nelson Hamerschlak, principal investigator of the National protocol, Dr. Marcelo Pasquini, for his help with the collaboration between CIBMTR and SBTMO, the Brazilian institutions reporting their data, the Data Manager Working Group and the Pediatric Working Group of the SBTMO and SOBOPE.