ORIGINAL ARTICLE 413 0021-7557/03/79-05/413 Jornal de Pediatria Copyright © 2003 by Sociedade Brasileira de Pediatria Abstract Objective: To describe the demographics and the most important acute clinical complications in patients undergoing bone marrow transplantation in the Pediatric Oncology Unit at Hospital de Clínicas de Porto Alegre, Brazil. Material and methods: A retrospective analysis was performed including 41 patients treated between August 1997 and June 2002. Twenty patients received allogeneic transplants (AG) and 21 received autologous transplants (AT). Results: The mean age of AG patients was 8.9 +5.4 years. Twelve patients were male. Stem cell sources were: bone marrow in 12 patients; peripheral blood in five; and unrelated cord blood in three. The diseases were acute lymphoid leukemia in seven patients; acute myeloid leukemia in four; chronic myeloid leukemia in two; myelodysplastic syndrome in two; Burkitt’s lymphoma in one; severe combined immunodeficiency in one; Chediaki-Higashi syndrome in one; Fanconi anemia in one; and aplastic anemia in one. One patient developed grade II acute graft-versus-host-disease (GVHD), and three patients had grade IV GVHD. Three patients developed chronic GVHD. In all of them, the cell source was peripheral blood. Survival in this group was 70.0 +10.3%. The main cause of death was GVHD in three patients and sepsis in another three. All deaths occurred before day 100. One of the patients who received unrelated cord blood is alive 3.5 years after the transplantation. In AG patients, mean age was 8.7 +4.3 years. Eleven patients were male. The stem cell sources were: peripheral blood in 16; bone marrow in three; and peripheral blood + bone marrow in two. The diseases were: Wilms’ tumor in five patients; Ewing’s sarcoma family tumors in four; neuroblastoma in three; Hodgkin’s disease in three; non-Hodgkin’s lymphoma in one; rhabdomyosarcoma in two; neuroectodermic tumor of the central nervous system in two; acute myeloid leukemia in one. Survival in this group was 59.4 +11.7%. Five patients died due to tumor relapse, two patients due to sepsis and one patient died in remission 20 months after bone marrow transplantation due to infection. In the whole group, the most common toxicities were vomiting, mucositis, diarrhea and abdominal pain. Infections were recorded in 58.5% of the patients. In 46.9%, at least one pathogen was isolated in the blood culture. The time required for neutrophil and platelet engraftment was correlated to the number of hematopoietic stem cell infused. Conclusions: The overall survival in our patients is similar to that reported in the literature. We did not find differences between AT and AG patients regarding acute toxicities and infections. J Pediatr (Rio J) 2003;79(5):413-22: Bone marrow transplantation, pediatric cancer, umbilical cord blood, hematopoietic stem cell. Clinical and epidemiological analysis of bone marrow transplantation in a pediatric oncology unit Cláudio Galvão de Castro Jr., 1 Lauro José Gregianin, 2 Algemir Lunardi Brunetto 3 1. Master’s Degree. MD, Specialist in Pediatric Oncology, School of Medicine, Universidade Federal do Rio Grande do Sul. 2. PhD. MD, Specialist in Pediatric Oncology; School of Medicine, Universidade Federal do Rio Grande do Sul. 3. Chief of the Pediatric Oncology Service, HCPA; associate professor, School of Medicine, UFRGS; professor, School of Medicine, Universidade Luterana do Brasil; MSc and Ph.D., University of Newcastle upon Tyne - England. Manuscript received Dec 12 2002, accepted for publication Jun 25 2003.