Abstract Number: PB1933
Meeting: ISTH 2020 Congress
Background: Seronegative antiphospholipid syndrome (APS SN) is a term used to describe patients who have clinical manifestations higly suggestive of antiphospholipid syndrome (APS) but with persistently negative criteria antiphospholipid antibodies (aPL). Several considerations can be explain APS-SN.
Recently, new antigenic targets for aPL have been investigated and the value of isolated B2GP1 IgA antibodies in APS diagnosis is controversy.
Aims: This study aimed to report the pathogenic significance of B2GP1 IgA testing in patients with cerebral thrombotic manifestations (arterial and venous) and persistently negative thrombophilia testing including criteria aPL assays (anticardiolipin, aβ2GPI, and Lupus Anticoagulant).
Methods: It is about a 3 years retrospective study (2017 to 2019) include 21 patients adressed for thrombophilia testing. Stroke was found in 12 patients and cerebral venous thrombosis in 9 patients.
Thrombophilia testing include proteins S, C and antithrombin functional tests, the activated protein C resistance (APCR) for factor V Leiden and criteria antiphospholipid antibodies: Lupus Anticoagulant and aCL, aβ2GPI IgM/IgG ELISA. All thrombophilia testing is realised according international recommendations.
Four non-criteria antiphospholipid antibodies was determined: anti B2GP1 IgA, anticardiolipin IgA et antiprothrombin-phosphatidylserin IgM and IgG ELISA.
Results: Results shows that thrombophilia testing was negative for all patients and 100% of them (21/21) had IgA anti-β2GPI without other aPL, criteria and other non criteria (anticardiolipin IgA, anti prothrombin phosphatidyl serine IgM IgG).
Conclusions: Beta2Glycorpotein IgA research could explain cerebral thrombosis for these patients. Over the past few years much attention has been focused on the diagnostic value of IgA isotype. Studies has previously report a link between anti-β2-GPI antibodies to cerebral infarction.
No consensus exists for non-criteria aPL but we have adopted a sequential approach that improves seronegative-APS diagnosis.
To cite this abstract in AMA style:Hocine I, Ferhat-Hamida Y, Hariti G. Contribution of Beta2 Glycoprotein1 IgA (B2GP1 IgA) Antibodies Research in Diagnosis of Seronegative Antiphospholipid Syndrome in Cerebral Thrombosis: A Case Series of 21 Patients [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/contribution-of-beta2-glycoprotein1-iga-b2gp1-iga-antibodies-research-in-diagnosis-of-seronegative-antiphospholipid-syndrome-in-cerebral-thrombosis-a-case-series-of-21-patients/. Accessed January 27, 2022.
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