title: Distinct features of circulating microparticles and their relationship with disease activity in inflammatory bowel disease.
abstract: BACKGROUND
  There is evidence that circulating microparticles (MPs) and annexin (+) platelet-derived MPs (PDMPs) are increased in inflammatory bowel disease (IBD). The aim of our study was to characterize the abundance, origin, and annexin V binding of MPs in patients with IBD and correlate them with the disease characteristics.
  
  
  METHODS
  Case-control study of 46 IBD patients (23 Crohn's disease, 23 ulcerative colitis) and 40 matched healthy controls (HC). MPs were divided according to annexin V binding, their origin was estimated based on specific cell membrane markers in plasma samples and their number was calculated via flow cytometry. Clinical and laboratory activity indices were also analyzed.
  
  
  RESULTS
  Annexin (-) PDMPs (P=0.0004), total (P=0.04) and annexin (+) monocyte-derived MPs (P=0.02) were increased and annexin (-) total MPs (P=0.0007) were decreased in IBD patients compared to HC. The annexin (+)/(-) ratio of all MP types were significantly elevated in IBD patients compared to HC (P<0.003). IBD patients with active disease displayed elevated total and annexin (+) total MPs, total, annexin (+) and (-) PDMPs compared with those in remission (P<0.05). Annexin (-) PDMPs were considerably increased in IBD patients with active compared to those with inactive disease (P=0.0013). Total and annexin (-) PDMPs were significantly correlated with most of the disease activity indices (P<0.05).
  
  
  CONCLUSIONS
  The majority of circulating MPs, their counterparts and particularly annexin (-) PDMPs are increased in active IBD patients. Annexin (+)/(-) ratio proved to be the most reliable distinctive MP index between HC and IBD patients.
authors.affiliation: Department of Gastroenterology, Venizelion General Hospital (Evangelos Voudoukis, Konstantina Giannakopoulou, Konstantinos Karmiris, Angeliki Theodoropoulou, Gregorios A. Paspatis), Crete, Greece.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Voudoukis
authors.affiliation: Laboratory of Tumor Biology, School of Medicine, University of Crete (Eleni-Kyriaki Vetsika, Vassilis Georgoulias), Crete, Greece.
authors.forename: Eleni-Kyriaki
authors.initials: EK
authors.lastname: Vetsika
authors.affiliation: Department of Gastroenterology, Venizelion General Hospital (Evangelos Voudoukis, Konstantina Giannakopoulou, Konstantinos Karmiris, Angeliki Theodoropoulou, Gregorios A. Paspatis), Crete, Greece.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Giannakopoulou
authors.affiliation: Department of Gastroenterology, Venizelion General Hospital (Evangelos Voudoukis, Konstantina Giannakopoulou, Konstantinos Karmiris, Angeliki Theodoropoulou, Gregorios A. Paspatis), Crete, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Karmiris
authors.affiliation: Department of Gastroenterology, Venizelion General Hospital (Evangelos Voudoukis, Konstantina Giannakopoulou, Konstantinos Karmiris, Angeliki Theodoropoulou, Gregorios A. Paspatis), Crete, Greece.
authors.forename: Angeliki
authors.initials: A
authors.lastname: Theodoropoulou
authors.affiliation: Blood Bank, Venizelion General Hospital (Aekaterini Sfiridaki), Crete, Greece.
authors.forename: Aekaterini
authors.initials: A
authors.lastname: Sfiridaki
authors.affiliation: Laboratory of Tumor Biology, School of Medicine, University of Crete (Eleni-Kyriaki Vetsika, Vassilis Georgoulias), Crete, Greece.
authors.forename: Vassilis
authors.initials: V
authors.lastname: Georgoulias
authors.affiliation: Department of Gastroenterology, Venizelion General Hospital (Evangelos Voudoukis, Konstantina Giannakopoulou, Konstantinos Karmiris, Angeliki Theodoropoulou, Gregorios A. Paspatis), Crete, Greece.
authors.forename: Gregorios A
authors.initials: GA
authors.lastname: Paspatis
authors.affiliation: Department of Gastroenterology, University Hospital, Heraklion (Ioannis E. Koutroubakis), Crete, Greece.
authors.forename: Ioannis E
authors.initials: IE
authors.lastname: Koutroubakis
keywords: Crohn’s disease; Microparticles; inflammatory bowel disease; ulcerative colitis