title: New tests to detect antiphospholipid antibodies: anti-domain I beta-2-glycoprotein-I antibodies.
abstract: Beta-2 glycoprotein I (β2GPI) is the main antigenic target for antiphospholipid antibodies (aPL), the serological markers of antiphospholipid syndrome (APS). Domain I (DI) of β2GPI has lately been identified as the main epitope targeted by antibodies reacting against β2GPI. DI is a cryptic epitope, becoming available for autoantibody binding when β2GPI opens from a circular to a fish-hook configuration. Antibodies targeting β2GPI-DI are more frequently detected in patients with a full-blown syndrome than in asymptomatic aPL carriers or in patients with infectious diseases that have reactivity toward the whole molecule. Interestingly, anti-DI antibodies are strongly positively correlated with thrombotic and pregnancy manifestations, enabling identification of patients at higher risk of clinical events. However, available tests to detect anti-DI antibodies still lack standardization. Moreover, some APS patients develop antibodies reacting against β2GPI epitopes other than DI, suggesting that other anti-β2GPI antibody subsets may be clinically relevant. Available evidence on anti-DI antibodies in APS is herein critically reviewed.
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy, cecilia.chighizola@unimi.it.
authors.forename: Cecilia Beatrice
authors.initials: CB
authors.lastname: Chighizola
authors.forename: Maria
authors.initials: M
authors.lastname: Gerosa
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Meroni
mesh_terms: D017152:Antibodies, Antiphospholipid / Q000032:analysis* / Q000276:immunology; D016736:Antiphospholipid Syndrome / Q000175:diagnosis* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D011487:Protein Conformation; D053482:beta 2-Glycoprotein I / Q000276:immunology*
chemical_list: D017152:Antibodies, Antiphospholipid; D001324:Autoantigens; D015415:Biomarkers; D016056:Immunodominant Epitopes; D053482:beta 2-Glycoprotein I