title: Natural course of childhood chronic immune thrombocytopenia using the revised terminology and definitions of the international working group: a single center experience.
abstract: BACKGROUND
  The immune thrombocytopenia (ITP) criteria were newly standardized by the International Working Group. Thus, we analyzed the natural course of childhood chronic ITP to predict the prognosis based on the revised criteria.
  
  
  METHODS
  The medical records of children with chronic ITP from May 2000 to February 2013 in our institute were reviewed.
  
  
  RESULTS
  Forty-seven children with chronic ITP who were not undergoing corticosteroid therapy were included. Their initial platelet count was 23±25×10(9)/L, and age at diagnosis was 6.3±4.1 years. The follow-up period was 5.4±3.7 years. Among them, 44.7% (21/47) showed spontaneous remission and maintained a platelet count ≥100×10(9)/L. And 66.0% (31/47) maintained a platelet count ≥50×10(9)/L until the last follow-up date. The time periods required for the platelet count to be maintained ≥50×10(9)/L and ≥100 ×10(9)/L were 3.1±2.7 and 3.6±2.7 years. Age at diagnosis in the ≥50×10(9)/L group (5.7±4.4 years) was significantly lower than the age at diagnosis in the <50×10(9)/L group (7.4±3.3 years) (P=0.040). And follow-up period was the factor influencing prognosis between the ≥100×10(9)/L group and <50×10(9)/L group (P=0.022).
  
  
  CONCLUSIONS
  Approximately 45% of children with chronic ITP recovered spontaneously about 3-4 years after the diagnosis and 2/3 of patients maintained a platelet count ≥50×10(9)/L, relatively safe state. Age at diagnosis of ITP and follow-up period were the factors influencing prognosis in this study.
authors.affiliation: Hanyoung Children's Hospital, Daegu, Korea.
authors.forename: Ye Jee
authors.initials: YJ
authors.lastname: Shim
authors.affiliation: Incheon Medical Center Beakryung Hospital, Beakryung-do, Korea.
authors.forename: Uk Hyun
authors.initials: UH
authors.lastname: Kim
authors.affiliation: Division of Pediatric Hematology/Oncology, Asan Medical Center Children's Hospital, Department of Pediatrics, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Suh
authors.affiliation: Department of Pediatrics, Kyungpook National University Hospital and Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Kun Soo
authors.initials: KS
authors.lastname: Lee
keywords: Children; Chronic immune thrombocytopenia; Prognosis