title: A new cytofluorimetric approach to evaluate the circulating microparticles in subjects with antiphospholipid antibodies.
abstract: BACKGROUND
  Growing evidence supports the idea that microparticles (MPs) could contribute to the pathogenesis of the thrombotic phenomena associated with antiphospholipid antibody syndrome (APS), inducing a hypercoagulable state. But, to date, different approaches to evaluate circulating MPs and conflicting results have been reported.
  
  
  METHODS
  We have characterized the different circulating subpopulations of MPs in APS patients, and in asymptomatic aPL-positive subjects (carriers) by examining the correlation between the amount and phenotype of MPs and the clinical parameters. Forty-eight subjects were enrolled: 16 with primary APS, 16 aPL-positive, but without clinical criteria for APS (carriers), and 16 healthy subjects. The levels of MPs were evaluated using a new cytofluorimetric approach based on BD Horizon Violet Proliferation dye (VPD) 450.
  
  
  CONCLUSIONS
  Using a new detection cytofluorimetric approach, we demonstrated that the AnnV-negative MPs, underestimated/or excluded in the previous studies, are a large subset of circulating MPs. Also, the levels of MPs in the plasma of aPL positive subjects indicate a state of cellular activation, which is much more pronounced in patients with APS compared to aPL carriers. Moreover, the preliminary data of our pilot study suggest that the evaluation of circulating MPs, in particular PMPs and EMPs, could be used as a surrogate biomarker for platelet and vascular damage monitoring and, if confirmed in a more numerous cohort of patients, it could be used as a prognostic factor to identify aPL positive subjects at higher risk of developing thrombosis.
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Niccolai
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Squatrito
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Emmi
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Silvestri
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy; SOD Interdisciplinary Internal Medicine, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Emmi
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Ciucciarelli
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ricci
authors.affiliation: BD Biosciences Italy S.p.A, Buccinasco, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Manganaro
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy; SOD Interdisciplinary Internal Medicine, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy. Electronic address: aamedei@unifi.it.
authors.forename: Amedeo
authors.initials: A
authors.lastname: Amedei
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Italy; SOD Interdisciplinary Internal Medicine, Center for Autoimmune Systemic Diseases, Behçet Center and Lupus Clinic, AOU Careggi, Florence, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Prisco
mesh_terms: D000328:Adult; D000368:Aged; D017152:Antibodies, Antiphospholipid / Q000097:blood; D000911:Antibodies, Monoclonal / Q000737:chemistry; D016736:Antiphospholipid Syndrome / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation; D001792:Blood Platelets / Q000378:metabolism; D016022:Case-Control Studies; D049109:Cell Proliferation; D055252:Cell-Derived Microparticles; D004396:Coloring Agents / Q000737:chemistry; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D010865:Pilot Projects; D012984:Software; D013927:Thrombosis / Q000097:blood / Q000175:diagnosis
chemical_list: D017152:Antibodies, Antiphospholipid; D000911:Antibodies, Monoclonal; D015415:Biomarkers; D004396:Coloring Agents
keywords: Antiphospholipid antibodies; Antiphospholipid syndrome; Circulating cell-derived microparticles; Flow cytometry; Thrombosis