title: Reduction in peripheral regulatory T cell population in childhood ocular type myasthenia gravis.
abstract: OBJECTIVE
  Myasthenia gravis (MG) is a T-cell dependent and antibody mediated autoimmune disease. Recent studies of adult patients and animal models have shown that regulatory T cells (Tregs) play an important role in the pathogenesis of MG, but little is known about MG in children. This study evaluated the role of peripheral blood Tregs in childhood ocular MG and assessed if Tregs could be an index for estimating immunological status.
  
  
  METHODS
  Clinical data and peripheral lymphocytes were obtained from 13 children with serum AChR antibody-positive ocular type MG and 18 age-matched controls. Committed cells from MG patients were divided into two clinical stages: active (n=12) and remission (n=11). Tregs and Th17 cells were analyzed by flow cytometric analysis based on CD4(+)CD25(+) intracellular Foxp3(+) and CD4(+) intracellular IL-17A(+) fractions, respectively.
  
  
  RESULTS
  The percentage of Tregs among peripheral blood CD4(+) T cells in active stage, remission stage, and control groups was 3.3±1.3%, 4.8±1.7%, and 5.0±0.6%, respectively. The Treg population was significantly lower in the active stage than in the remission stage and controls. Furthermore, Treg percentage was significantly lower during relapse of myasthenia symptoms. We witnessed no remarkable associations between the percentage of Tregs and immune suppressant dosages.
  
  
  CONCLUSIONS
  A significant reduction in the peripheral Treg population is considered to contribute to the pathophysiology of ocular type childhood MG and may be a marker of immunological state in these patients.
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Nishimura
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan. Electronic address: inabay@shinshu-u.ac.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Inaba
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Yozo
authors.initials: Y
authors.lastname: Nakazawa
authors.affiliation: Division of Child Neurology, Chiba Children's Hospital, Chiba, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Omata
authors.affiliation: Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Manami
authors.initials: M
authors.lastname: Akasaka
authors.affiliation: Department of Neuropediatrics, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Shirai
authors.affiliation: Child and Women's Health Sciences, Graduate School of Medicine, Shinshu University, Matsumoto, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Ichikawa
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D009157:Myasthenia Gravis / Q000097:blood / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology
keywords: Childhood; Myasthenia gravis; Ocular type; Regulatory T cell (Treg); Relapse; Th17 cell