title: Endothelial cell-derived microparticles in allogeneic hematopoietic stem cell recipients.
abstract: BACKGROUND
  Alterations of microparticles derived from different cell types are described in a number of diseases associated with inflammation and hemostatic disorders.
  
  
  METHODS
  In this prospective study, we firstly analyzed endothelial cell derived microparticles (EMP) in 19 hematopoietic stem cell recipients. Cultured human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor-alpha (TNF-alpha) served as positive controls. EMP were analyzed by fluorescent activated cell sorting (FACS), detecting the particels via expression of CD62 (E-selectin) and anionic phospholipids binding to annexin V.
  
  
  RESULTS
  EMP were not significantly influenced by conditioning regimens with non-myeloablative chemotherapy and 4 Gy total body irradiation (TBI) or by myeloablative regimens containing 12 Gy TBI. During acute graft versus host disease (aGVHD), significantly higher levels of EMP were detected than in patients without aGVHD (18.5/microl s=10.1 vs. 14.6/microl SD = 11.5; P = 0.004) while infectious complications did not alter EMP levels significantly. Immunosuppressive therapy with corticosteroids tendentially elevated EMP levels. HUVEC treated with TNF-alpha 1 ng/ml, 10 ng/ml and 100 ng/ml released significantly more EMP than unstimulated cultures (30.0/microl ss = 13.6 vs. 126.8/microl SD = 66.9, P = 0.032 / vs. 683.3/microl SD = 349.9; P = 0.03 / vs. 489.3 s = 184.4; P = 0.013).
  
  
  CONCLUSIONS
  Elevation of EMP during aGVHD might express severe endothelial cell injury within this complication after hematopoietic stem cell transplantation and might serve as a diagnostic test for early differentiation of aGVHD from other transplanted related complications.
authors.affiliation: Medizinische Klinik III, Grosshadern, Klinikum der Ludwig Maximilians, Universitaet Muenchen, Germany. verana.pihusch@t-online.de
authors.forename: Verena
authors.initials: V
authors.lastname: Pihusch
authors.forename: Andreas
authors.initials: A
authors.lastname: Rank
authors.forename: Ruth
authors.initials: R
authors.lastname: Steber
authors.forename: Markus
authors.initials: M
authors.lastname: Pihusch
authors.forename: Rudolf
authors.initials: R
authors.lastname: Pihusch
authors.forename: Bettina
authors.initials: B
authors.lastname: Toth
authors.forename: Erhard
authors.initials: E
authors.lastname: Hiller
authors.forename: Hans-Jochem
authors.initials: HJ
authors.lastname: Kolb
mesh_terms: D000293:Adolescent; D000328:Adult; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D006086:Graft vs Host Disease / Q000097:blood; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007938:Leukemia / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019172:Transplantation Conditioning / Q000009:adverse effects*; D014184:Transplantation, Homologous; D014409:Tumor Necrosis Factor-alpha
chemical_list: D014409:Tumor Necrosis Factor-alpha