title: Clinical manifestations of antiphospholipid syndrome (APS) with and without antiphospholipid antibodies (the so-called 'seronegative APS').
abstract: OBJECTIVE
  Although the medical literature currently provides a growing number of isolated case reports of patients with clinically well-defined antiphospholipid syndrome (APS) and persistently negative antiphospholipid antibodies (aPL), there are no studies including a series of patients addressing the clinical features of this condition.
  
  
  METHODS
  The authors assessed clinical manifestations of APS in 154 patients: 87 patients with seropositive APS and 67 patients with thrombosis and/or pregnancy morbidity persistently negative for aPL and presenting with at least two additional non-criteria manifestations of APS (the so-called 'seronegative APS', SN-APS). Patients were interviewed at the time of recruitment, and a retrospective file review was carried out.
  
  
  RESULTS
  There were no significant differences in the frequency of thrombotic events or obstetric morbidity in patients with SN-APS versus patients with seropositive APS: deep vein thrombosis (31.4% vs 31.0%), pulmonary embolism (23.8% vs 28.7%), stroke (14.9% vs 17.2%), transient ischaemic attack (11.9% vs 10.3%), early spontaneous abortions (67.1% vs 52.1%), stillbirths (62.5% vs 59.4%), prematurity (28.1% vs 21.7%) or pre-eclampsia (28.1% vs 23.1%).
  
  
  CONCLUSIONS
  Classic and SN-APS patients show similar clinical profiles. The results suggest that clinical management in patients with APS should not be based only on the presence of conventional aPL.
authors.affiliation: Lupus Research Unit, The Rayne Institute, King's College London School of Medicine, St Thomas' Hospital, UK.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Rodriguez-Garcia
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Bertolaccini
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Cuadrado
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sanna
authors.forename: Oier
authors.initials: O
authors.lastname: Ateka-Barrutia
authors.forename: Munther A
authors.initials: MA
authors.lastname: Khamashta
mesh_terms: D000022:Abortion, Spontaneous / Q000175:diagnosis / Q000276:immunology; D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D016736:Antiphospholipid Syndrome / Q000175:diagnosis* / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000276:immunology; D011256:Pregnancy Outcome; D011655:Pulmonary Embolism / Q000175:diagnosis / Q000276:immunology; D012189:Retrospective Studies; D050497:Stillbirth; D013927:Thrombosis / Q000175:diagnosis / Q000276:immunology
chemical_list: D017152:Antibodies, Antiphospholipid; D015415:Biomarkers