title: Regulatory T Cells and Vitamin D Status in Children with Chronic Autoimmune Thyroiditis.
abstract: OBJECTIVE
  It is suggested that vitamin D is one of the factors that can regulate the function of Treg cells. In this study, the relationships between Treg cells and vitamin D levels was investigated in pediatric chronic autoimmune thyroiditis (CAT) patients.
  
  
  METHODS
  Thirty-two children with CAT and 24 healthy subjects were studied. FOXP3 expressing CD4+CD25+high Foxp3+T cells were identified as Treg cells. At diagnosis, 25-hydroxycholecalciferol (25OHD3) levels were determined in all patients. FOXP3 expression was measured before and after vitamin D replacement therapy in patients having low levels of 25OHD3.
  
  
  RESULTS
  In the CAT patients, Treg cell levels did not differ from the control group, while the frequency of vitamin D deficiency was higher and FOXP3 molecule expression was lower. FOXP3 molecule expression significantly increased in CAT patients having vitamin D deficiency who were given vitamin D replacement.
  
  
  CONCLUSIONS
  FOXP3 expression is decreased in pediatric CAT patients. This reduction seems to be associated with vitamin D levels. Vitamin D can play a role in enhancing natural Treg cell functions.
authors.affiliation: Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey, E-mail: zeynepsklr@gmail.com.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Şıklar
authors.forename: Deniz
authors.initials: D
authors.lastname: Karataş
authors.forename: Figen
authors.initials: F
authors.lastname: Doğu
authors.forename: Bülent
authors.initials: B
authors.lastname: Hacıhamdioğlu
authors.forename: Aydan
authors.initials: A
authors.lastname: İkincioğulları
authors.forename: Merih
authors.initials: M
authors.lastname: Berberoğlu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000097:blood*; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D013967:Thyroiditis, Autoimmune / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014807:Vitamin D / Q000097:blood* / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood* / Q000188:drug therapy; D014815:Vitamins / Q000097:blood / Q000627:therapeutic use
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D014815:Vitamins; D014284:Triiodothyronine; D014807:Vitamin D; D013972:Thyrotropin; D013974:Thyroxine