title: The role of CD4+CD25bright regulatory T cells in the maintenance of pregnancy, premature rupture of membranes, and labor.
abstract: OBJECTIVE
  The aim of this study was to evaluate the changes of the regulatory T cell subset in peripheral blood caused by gestational age and premature rupture of membranes (PROM) with or without labor to verify the role of regulatory T cells in pregnancy.
  
  
  METHODS
  We investigated regulatory T cell distribution in the peripheral blood of pregnancies during the first trimester (group I, n=2), the second trimester (group II, n=12), and the third trimester without PROM and labor (group III, n=15). In addition, we evaluated pregnancies in the third trimester complicated by PROM (group IV, n=4) and labor with no complication by PROM (Group V, n=5). Comparisons were made with non-pregnant controls (group VI, n=4) using flow cytometry.
  
  
  RESULTS
  During uncomplicated pregnancy, the CD4(+)CD25(bright) regulatory T cell population decreased with advancing gestational age (group I=3.35+/-0.47, group II=2.91+/-1.44, group III=2.81+/-1.36, group VI=2.52+/-0.71, p=NS). When we compared group IV with group III and V to evaluate the changes of the regulatory T cells with PROM, the CD4(+)CD25(bright) regulatory T cell population was significantly decreased in group IV compared to group III (p=0.001) and group V (p=0.026).
  
  
  CONCLUSIONS
  The present results revealed that the regulatory T cell population increased in early pregnancy but decreased in pregnancies complicated by PROM, indicating that regulatory T cells might be related to the maintenance of pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Korea University College of Medicine, Danwon-gu, Ansan-si, Gyeonggi-do, Korea.
authors.forename: Hyun-Joo
authors.initials: HJ
authors.lastname: Seol
authors.forename: Min-Jeong
authors.initials: MJ
authors.lastname: Oh
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Lim
authors.forename: Nan-Hee
authors.initials: NH
authors.lastname: Jung
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Yoon
authors.forename: Hai-Joong
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D015704:CD4 Antigens / Q000276:immunology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000276:immunology* / Q000503:physiopathology; D005865:Gestational Age; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D007743:Labor, Obstetric / Q000276:immunology* / Q000502:physiology; D011247:Pregnancy; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000502:physiology
chemical_list: D015704:CD4 Antigens; D053645:Interleukin-2 Receptor alpha Subunit