title: Evaluation of tissue factor bearing microparticles as biomarkers in allogeneic stem-cell transplantation.
abstract: BACKGROUND
  There is compelling evidence that blood-borne tissue factor that is predominantly found on circulating microparticles (MPs) plays an important role in both, cancer biology and organ and stem-cell transplantation (SCT). Therefore, we hypothesized that numbers of tissue factor bearing MPs might be associated with complications and outcome in allogeneic SCT (allo-SCT).
  
  
  METHODS
  In a prospective study, we enumerated total, platelet, endothelial, and tissue factor bearing MPs in plasma samples obtained from up to 60 patients with hematologic diseases at different time-points during the course of allo-SCT by flow cytometry. Patient- and transplant-related risk factors were included in statistical analysis.
  
  
  RESULTS
  Mean follow-up time was 968 days (0-1981 days). Thirty-four (56.7%) patients died, 17 due to transplant-related mortality (28.3%). High numbers of tissue factor positive MPs more than 500/μL before conditioning were predictive for shorter overall survival (P=0.017, hazard ratio=4.5) in multivariate analysis. This was mainly caused by an increase in transplant-related mortality (P=0.010, hazard ratio=11.0) with cumulative incidences at 1 year of 68.8% compared with patients with lower values (20.1%; P=0.002).
  
  
  CONCLUSIONS
  Tissue factor bearing MPs might be useful biomarkers for risk stratification in allo-SCT patients and further studies should investigate their origin, functional properties, and optimal cut-off values.
authors.affiliation: Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: De Rop
authors.forename: Michael
authors.initials: M
authors.lastname: Stadler
authors.forename: Stefanie
authors.initials: S
authors.lastname: Buchholz
authors.forename: Roswith
authors.initials: R
authors.lastname: Eisert
authors.forename: Arnold
authors.initials: A
authors.lastname: Ganser
authors.forename: Arne
authors.initials: A
authors.lastname: Trummer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001792:Blood Platelets / Q000378:metabolism; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006086:Graft vs Host Disease / Q000378:metabolism / Q000401:mortality; D006402:Hematologic Diseases / Q000378:metabolism / Q000401:mortality / Q000628:therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D052016:Mucositis / Q000378:metabolism / Q000401:mortality; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D033581:Stem Cell Transplantation / Q000009:adverse effects* / Q000401:mortality*; D013923:Thromboembolism / Q000378:metabolism / Q000401:mortality; D013925:Thromboplastin / Q000378:metabolism*; D014184:Transplantation, Homologous; D055815:Young Adult
chemical_list: D015415:Biomarkers; D013925:Thromboplastin