title: Natural history of moderate aplastic anemia in children.
abstract: BACKGROUND
  Moderate aplastic anemia (MAA) in children is a rare, idiopathic condition of bone marrow insufficiency that can resolve spontaneously, persist for months or years, or progress to severe aplastic anemia (SAA). We evaluated the rate of progression to SAA.
  
  
  METHODS
  We reviewed the records of 136 children referred for evaluation of bone marrow failure from 1978 to 2002 at St. Jude Children's Research Hospital. MAA was defined by a hypocellular bone marrow (<50%) and 2 or 3 cytopenias (absolute neutrophil count <1,500/mm(3), absolute reticulocyte count <40,000/mm(3), platelet count <100,000/mm(3)) lasting at least 6 weeks.
  
  
  RESULTS
  Twenty-four patients met the criteria for MAA. At a median follow-up of 66 months (range, 10-293), 16 patients (67%) progressed to SAA, 5 (21%) had persistent MAA, and 3 (12%) had complete resolution of MAA. No risk factors for progression could be identified.
  
  
  CONCLUSIONS
  When childhood MAA is treated with supportive care alone, 2/3 of patients progress to SAA.
authors.affiliation: Department of Hematology-Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA. scott.howard@stjude.org
authors.forename: Scott C
authors.initials: SC
authors.lastname: Howard
authors.forename: Paula E
authors.initials: PE
authors.lastname: Naidu
authors.forename: X Joan
authors.initials: XJ
authors.lastname: Hu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jeng
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodriguez-Galindo
authors.forename: Martha D
authors.initials: MD
authors.lastname: Rieman
authors.forename: Winfred C
authors.initials: WC
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000741:Anemia, Aplastic / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis