title: New clinical score for disease activity at diagnosis in Langerhans cell histiocytosis.
abstract: BACKGROUND
  The clinical presentation and course of Langerhans cell histiocytosis (LCH) are variable, ranging from an isolated, spontaneously remitting bone lesion to multisystem disease with risk organ involvement. Treatment of LCH ranges from a wait-and-see attitude to intensive multidrug therapy and, in some cases, bone marrow transplantation. It is necessary to develop an objective score for assessing disease activity in patients with LCH. We propose a new clinical scoring system to evaluate disease activity at diagnosis that can predict the clinical outcomes of LCH and correlate it with clinical courses.
  
  
  METHODS
  Clinical data, obtained from children diagnosed with LCH at Asan Medical Center and Hanyang University Hospital between March 1998 and February 2009, were studied retrospectively. The scoring system was developed according to the basic biological data, radiological findings, and physical findings and applied to a database containing information on 133 patients.
  
  
  RESULTS
  The median age of the 133 patients (74 male, 59 female) was 52 months (range, 0.6-178 months), and LCH was diagnosed based on CD1a positivity. At diagnosis, the score distributions were highly asymmetrical: the score was between 1 and 2 in 75.9% of cases, 3-6 in 15.8%, and greater than 6 in 8.3%. Initial scores above 6 were highly predictive of reactivation and late complications.
  
  
  CONCLUSIONS
  This new LCH disease activity score provides an objective tool for assessing disease severity, both at diagnosis and during follow-up.
authors: Department of Pediatrics, College of Medicine, Hanyang University Hospital, Seoul, Korea.
authors: Won-Ik
authors: WI
authors: Choi
authors: You Cheol
authors: YC
authors: Jeong
authors: Sun Young
authors: SY
authors: Kim
authors: So Dam
authors: SD
authors: Kim
authors: John Paul
authors: JP
authors: Pribis
authors: Hee-Jin
authors: HJ
authors: Kim
authors: Kyung-Nam
authors: KN
authors: Koh
authors: Ho-Joon
authors: HJ
authors: Im
authors: Young-Ho
authors: YH
authors: Lee
authors: Jong-Jin
authors: JJ
authors: Seo