title: Patients with posttraumatic stress disorder exhibit an altered phenotype of regulatory T cells.
abstract: BACKGROUND
  Regulatory T cells (Tregs) play a key role in immune homeostasis in vivo. Tregs have a critical role in preventing the development of autoimmune diseases and defects in Treg function are implicated in various autoimmune disorders. Individuals with posttraumatic stress disorder (PTSD) have higher prevalence of autoimmune disorders than the general population. We hypothesized that war veterans with PTSD would exhibit a decreased number and/or altered phenotype of Tregs.
  
  
  METHODS
  We analyzed peripheral blood mononuclear cells (PBMCs) of patients with PTSD (N = 21) (mean age = 45.9) and age-matched healthy controls (N = 23) (mean age = 45.7) to determine the proportion of Tregs and their phenotype according to the expression of CD127 and HLA-DR markers which describe the differentiation stages of Tregs. In addition, we analyzed the expression of membrane ectoenzyme CD39 on Tregs of the study groups, an important component of the suppressive machinery of Tregs.
  
  
  RESULTS
  We found no differences in the proportion of Tregs between PTSD patients and controls, but PTSD patients had a higher percentage of CD127(-)HLA-DR(-) Tregs and a lower percentage of CD127(lo)HLA-DR(+) Tregs compared to controls. There was no difference in expression of CD39 on Tregs of the study groups.
  
  
  CONCLUSIONS
  Although the proportions of Tregs in PTSD patients were unchanged, we found that they exhibit a different phenotype of Tregs that might be less suppressive. Impaired differentiation and function of Tregs is likely involved in disruption of immune homeostasis in PTSD.
authors: Centre for research and knowledge transfer in biotechnology, University of Zagreb, Zagreb, Croatia ; Department for Cellular Immunology, Institute of Immunology, Rockfellerova ulica 10, Zagreb, Croatia.
authors: Mladen
authors: M
authors: Jergović
authors: Centre for research and knowledge transfer in biotechnology, University of Zagreb, Zagreb, Croatia.
authors: Krešo
authors: K
authors: Bendelja
authors: Department of Psychiatry, University Hospital Dubrava, Zagreb, Croatia.
authors: Anđelko
authors: A
authors: Vidović
authors: Centre for research and knowledge transfer in biotechnology, University of Zagreb, Zagreb, Croatia.
authors: Ana
authors: A
authors: Savić
authors: Centre for research and knowledge transfer in biotechnology, University of Zagreb, Zagreb, Croatia.
authors: Valerija
authors: V
authors: Vojvoda
authors: General hospital "dr. Josip Benčević", Slavonski Brod, Croatia.
authors: Neda
authors: N
authors: Aberle
authors: Department for Cellular Immunology, Institute of Immunology, Rockfellerova ulica 10, Zagreb, Croatia.
authors: Sabina
authors: S
authors: Rabatić
authors: Department of Psychiatry & Behavioral Sciences, Emory University, Atlanta, GA, USA.
authors: Tanja
authors: T
authors: Jovanovic
authors: Department for Cellular Immunology, Institute of Immunology, Rockfellerova ulica 10, Zagreb, Croatia.
authors: Ante
authors: A
authors: Sabioncello
keywords: Autoimmunity; Posttraumatic stress disorder; Regulatory T cells