title: Clinical course of 63 children with hereditary spherocytosis: a retrospective study.
abstract: BACKGROUND
  Hereditary spherocytosis (HS) is an inherited hemolytic anemia that is caused by deficiency or dysfunction of erythrocyte cytoskeletal proteins.
  
  
  OBJECTIVE
  The aim of this study was to describe the clinical course of hereditary spherocytosis in patients treated in the Pediatric Hematology Unit, Hospital das Clínicas, Universidade Federal de Minas Gerais.
  
  
  METHODS
  Sixty-three under 16-year-old patients with hereditary spherocytosis were retrospectively evaluated between January 1988 and December 2007. Hereditary spherocytosis was diagnosed based on clinical history, physical examination and on a positive osmotic fragility curve. Patients underwent screening for cholelithiasis by ultrasonography. They were classified into three groups: mild, moderate and severe. The events of interest were need for blood transfusion, cholelithiasis, splenic sequestration, aplastic crisis, and splenectomy. Differences between subgroups were evaluated by the two-sided log-rank test.
  
  
  RESULTS
  The mean age at diagnosis was 5.2 years and most patients were classified as moderate (54%). Patients with the severe form of the disease were younger (p-value = 0.001) and needed more blood transfusions (p-value = 0.004). Seventeen patients (27%) developed cholelithiasis, 14 (22.2%) splenic sequestration and three (4.8%) aplastic crises. Twenty-two patients (34.9%) were splenectomized with the main indication being splenic sequestration in nine patients (41%).
  
  
  CONCLUSIONS
  The clinical course of patients with hereditary spherocytosis in this study was relatively benign however cholelithiasis was a common complication.
authors.affiliation: Pediatrics Department, Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors.forename: Maria Christina Lopes Araujo
authors.initials: MC
authors.lastname: Oliveira
authors.forename: Rachel Aparecida Ferreira
authors.initials: RA
authors.lastname: Fernandes
authors.forename: Carolina Lins
authors.initials: CL
authors.lastname: Rodrigues
authors.forename: Daniela Aguiar
authors.initials: DA
authors.lastname: Ribeiro
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Giovanardi
authors.forename: Marcos Borato
authors.initials: MB
authors.lastname: Viana