title: Serum complement activation on heterologous platelets is associated with arterial thrombosis in patients with systemic lupus erythematosus and antiphospholipid antibodies.
abstract: Complement plays a major role in inflammation and thrombosis associated with systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). A cross-sectional retrospective analysis was performed to evaluate serum complement fixation on platelets and thrombotic incidence using banked sera and clinical data from patients with SLE (n = 91), SLE with antiphospholipid antibodies (aPL) or APS (n = 78) and primary aPL (n = 57) or APS (n = 96). In-situ complement fixation was measured as C1q and C4d deposition on heterologous platelets using an enzyme-linked immunosorbent assay approach. Platelet activation by patient serum in the fluid phase was assessed via serotonin release assay. Enhanced in-situ complement fixation was associated with the presence of IgG aPL and IgG anti-beta2 glycoprotein 1 antibodies (P < 0.05) and increased platelet activation (P < 0.005). Moreover, enhanced complement fixation, especially C4d deposition on heterologous platelets, was positively associated with arterial thrombotic events in patients with SLE and aPL (P = 0.039). Sera from patients with aPL possess an enhanced capacity for in-situ complement fixation on platelets. This capacity may influence arterial thrombosis risk in patients with SLE.
authors.affiliation: Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, New York 10029, USA. ellinor.peerschke@mountsinai.org
authors.forename: E I B
authors.initials: EI
authors.lastname: Peerschke
authors.forename: W
authors.initials: W
authors.lastname: Yin
authors.forename: D R
authors.initials: DR
authors.lastname: Alpert
authors.forename: R A S
authors.initials: RA
authors.lastname: Roubey
authors.forename: J E
authors.initials: JE
authors.lastname: Salmon
authors.forename: B
authors.initials: B
authors.lastname: Ghebrehiwet
mesh_terms: D000328:Adult; D016736:Antiphospholipid Syndrome / Q000097:blood* / Q000150:complications; D001157:Arterial Occlusive Diseases / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D001792:Blood Platelets / Q000378:metabolism*; D003167:Complement Activation / Q000502:physiology*; D015922:Complement C1q / Q000378:metabolism; D003181:Complement C4 / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007118:Immunoassay; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D014481:United States / Q000453:epidemiology
chemical_list: D003181:Complement C4; D015922:Complement C1q