title: Incidence of a first thromboembolic event in carriers of isolated lupus anticoagulant.
abstract: Among the so called antiphospholipid (aPL) antibodies Lupus Anticoagulant (LAC) is considered the strongest risk factor for thromboembolic events. In individuals without a previous thromboembolic event (carriers), LAC is a risk factor when associated with the presence of anticardiolipin (aCL) and aβ2-Glycoprotein I (aβ2GPI) antibodies. On the other hand, data on carriers of isolated LAC positivity are sparse and inconclusive. The aim of this study was to prospectively determine the incidence of thrombosis in a cohort of carriers of isolated LAC positivity. One-hundred seventy-nine carriers of LAC confirmed twelve weeks apart and in a reference laboratory were studied. During a total follow up of 552 person-years, there were seven thromboembolic events (1.3% person-y). All the seven patients had at least one adjunctive major risk factor for thrombosis. The cumulative incidence of thromboembolic events was 3.1% (95% CI 0.6-5.6) after 2years, and 5.9% (95% CI 1.2-10.6) after 5 and 10years. On a multivariate regression analysis considering age, sex, autoimmune disease, risk factors for arterial and venous thrombosis, use of aspirin, only age was found to be an independent predictor of thromboembolic events (HR=1.1, 95% CI 1.0-1.2, p=0.02). These data might be relevant in clinical practice and underline the importance of differentiating LAC carriers in terms of isolated positivity or positivity associated with the presence of antibodies to aCL and β2-glycoprotein I.
authors.affiliation: Clinical Cardiology, University Hospital, Padova, Italy. Electronic address: vittorio.pengo@unipd.it.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pengo
authors.affiliation: Laboratory Medicine, District Hospital, Cremona, Italy.
authors.forename: Sophie
authors.initials: S
authors.lastname: Testa
authors.affiliation: A.Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Martinelli
authors.affiliation: Angiology Unit, Department of Internal Medicine, Santa Maria Nuova Hospital, Reggio Emilia, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Ghirarduzzi
authors.affiliation: Department of Angiology and Blood Coagulation "Marino Golinelli", University Hospital, Bologna, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Legnani
authors.affiliation: Internal and Vascular Medicine, University Hospital, Perugia, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gresele
authors.affiliation: A.Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Serena M
authors.initials: SM
authors.lastname: Passamonti
authors.affiliation: Clinical Cardiology, University Hospital, Padova, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bison
authors.affiliation: Clinical Cardiology, University Hospital, Padova, Italy.
authors.forename: Gentian
authors.initials: G
authors.lastname: Denas
authors.affiliation: Clinical Cardiology, University Hospital, Padova, Italy.
authors.forename: Seena Padayattil
authors.initials: SP
authors.lastname: Jose
authors.affiliation: Clinical Cardiology, University Hospital, Padova, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Banzato
authors.affiliation: Rheumatology, University Hospital, Padova, Italy.
authors.forename: Amelia
authors.initials: A
authors.lastname: Ruffatti
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies; D017153:Antibodies, Anticardiolipin / Q000097:blood; D005260:Female; D006801:Humans; D015994:Incidence; D016682:Lupus Coagulation Inhibitor / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000097:blood* / Q000453:epidemiology; D013927:Thrombosis / Q000097:blood / Q000276:immunology*; D013997:Time Factors; D016896:Treatment Outcome; D053482:beta 2-Glycoprotein I / Q000097:blood / Q000276:immunology*
chemical_list: D000906:Antibodies; D017153:Antibodies, Anticardiolipin; D016682:Lupus Coagulation Inhibitor; D053482:beta 2-Glycoprotein I