Objectives: To determine: Incidence and severity of acute GVHD according to the type of donor, their age and/or the source of hematopoietic progenitor cells (HPC). MRT according to type of donor and age range Incidence and extension of chronic GVHD according to type of donor, age and/or source of CPH.

Materials and methods: Prospective study comparing the results in 161 (pediatric and adults) correlative patients undergoing HSCT between May 2015 and August 2020, establishing 4 cohorts according to the donor:

• HLA-identical related transplant (MSD) (n = 45) (26 adults and 19 pediatric).
• Haploidentical transplant (HAPLO) (n = 36) (19 adults and 17 pediatrics).
• HLA-identical unrelated transplant (MUD) (n = 51) (20 adults and 31 pediatrics).
• Unrelated transplant with 1 missmatch (MMUD) (n = 29) (14 adults and 15 pediatrics).

Results: Diagnosis: AML-MDS: 36% (n: 59), ALL 27 (n: 44) aplastic anemia: 8% (n: 14) 8% (n: 13) primary immunodeficiency (ID) and others. The most frequent diagnosis in pediatrics was ALL and in adults AML - MDS. 13 of 79 adults were older than 60 years (16%). The source of CPH was bone marrow (BM) in 68 patients (42%) and peripheral blood (PB) in 93 (58%). In pediatrics, 79% used MO and in adults, 91% SP. The incidence of acute GVHD varies according to the type of donor used, as assessed in table1. There are no significant differences in the incidence of acute GVHD comparing the source of CPH (MO versus SP) nor the pediatric versus adult population. The MRT also varies according to the type of donor, as can be seen in table 1.

Conclusions: Acute leukemias are the main indication for allogeneic HSCT in both the pediatric population and the adult population. Bone marrow as a source of CPH is the most frequent option in pediatrics, while SP is in adults. HSCT with MSD is the one associated with the lowest incidence of acute GVHD, followed by MUD.