title: Microparticles in the blood of patients with systemic lupus erythematosus (SLE): phenotypic characterization and clinical associations.
abstract: Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by circulating autoantibodies and the formation of immune complexes. In these responses, the selecting self-antigens likely derive from the remains of dead and dying cells, as well as from disturbances in clearance. During cell death/activation, microparticles (MPs) can be released to the circulation. Previous MP studies in SLE have been limited in size and differ regarding numbers and phenotypes. Therefore, to characterize MPs more completely, we investigated 280 SLE patients and 280 individually matched controls. MPs were measured with flow cytometry and phenotyped according to phosphatidylserine expression (PS+/PS-), cellular origin and inflammatory markers. MPs, regardless of phenotype, are 2-10 times more abundant in SLE blood compared to controls. PS-MPs predominated in SLE, but not in controls (66% vs. 42%). Selectively in SLE, PS-MPs were more numerous in females and smokers. MP numbers decreased with declining renal function, but no clear association with disease activity was observed. The striking abundance of MPs, especially PS-MPs, suggests a generalized disturbance in SLE. MPs may be regarded as "liquid biopsies" to assess the production and clearance of dead, dying and activated cells, i.e. pivotal events for SLE pathogenesis.
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Fariborz
authors: F
authors: Mobarrez
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Anna
authors: A
authors: Vikerfors
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Johanna T
authors: JT
authors: Gustafsson
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Iva
authors: I
authors: Gunnarsson
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Agneta
authors: A
authors: Zickert
authors: Department of Clinical Chemistry and Pharmacology, Akademiska Hospital, SE-751 85 Uppsala, Sweden.
authors: Anders
authors: A
authors: Larsson
authors: Department of Medicine, Duke University Medical Center; Medical Research Service, Durham VA Hospital, NC, USA.
authors: David S
authors: DS
authors: Pisetsky
authors: Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Division of Cardiovascular Medicine, Stockholm, Sweden.
authors: Håkan
authors: H
authors: Wallén
authors: Unit of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors: Elisabet
authors: E
authors: Svenungsson
mesh_terms: D000936:Antigen-Antibody Complex / Q000097:blood; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001324:Autoantigens / Q000097:blood / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry; D024243:HMGB1 Protein / Q000378:metabolism; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013925:Thromboplastin / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D024243:HMGB1 Protein; C585491:HMGB1 protein, human; D019010:Vascular Cell Adhesion Molecule-1; D023201:CD40 Ligand; D013925:Thromboplastin