Pos0571 the New Occurence of Antiphospolipid Syndrome in Patients With the Most Severe Forms of Covid-19

Background: COVID-19 is characterized with pulmonary artery thrombosis, brain and myocardial infarction [1]. Antiphospholipid antibodies (aPLA) are found in COVID-19 patients [2], suggesting that they might be associated with antiphospholipid syndrome (APS), for which the latest research replaces lupus anticoagulans with anti-phosphatidylserine/ prothrombin (aPS/PT) antibodies in cases where it cannot be determined (taking anticoagulants) [4,5]. Objectives: In individuals with the most severe types of COVID-19 combining: 1. clinical features on arterial/venous thrombosis and pregnancy issues during hospitalization or in the patient's personal history; and 2. laboratory data for 9 different aPLAs: anticardiolipin (aCLA), anti-β2-glycoprotein 1 (anti-β2GPI) and aPS/PT antibodies of IgG, IgM, and IgA classes, measured at four time points (hospital admission, worsening of COVID-19, hospital discharge, and the three-month follow-up). Methods: Patients with COVID-19 pneumonia were enrolled in a systematic manner. Previous inflammatory rheumatic illness and APS diagnosis were exclusion criteria. Data on thrombosis and pregnancy pathology were captured by medical records. aCLA, anti-2GPI and aPS/PT antibodies of the IgG, IgM and IgA class were collected at four time points and sent to the University Medical Center Ljubljana in Slovenia for analysis. Values above the 99th percentile of the healthy control population were regarded as positive. SPSS 21 was used for statistics. Results: 108 people with COVID-19 pneumonia were included; 7 died during hospitalization (not a single was aPL-positive on admission, although 3 had thrombosis of the pulmonary artery). During hospitalization 5 pts had pulmonary artery thromboembolism, but only one was aPL-positive at all time points (newly diagnosed with APS). Two patients developed arterial thrombosis -one cerebral artery thrombosis and was positive for aCLA on admission, but tested negative at discharge and follow-up, the other developed coronary artery thrombosis with myocardial infarction and tested aPLA negative. Five patients developed microthrombosis, one pulmonary microthrombosis and tested aPLA positive at admission but negative at follow-up, the other four tested aPLA negative. Considering 9/101 patients with a history of thrombosis: 5 had arterial thrombosis of coronary and cerebral arteries but none was aPL-positive and 4 had venous thrombosis, 1 was aPL-positive at all time points and was diagnosed with APS. In 9/101 patients with a history of thrombosis, 55.6% were transiently aPLA positive at the time of discharge, compared to 26.1% of patients without history (p=0.042). Two patients had a history of pregnancy obstacles (both miscarried after the 10th week of gestation), but none was aPL positive. Conclusion: In our study, 2/108 patients (1.85%) were newly diagnosed with APS. Although aPLA was expected to be associated with vascular disease in the most severe forms of COVID-19, it was not confirmed by this study. At hospital discharge, 56% of patients with a history of arterial or venous thrombosis had positive aPLA that negativized at the 3-months follow-up checkout (transienlty positive) and therefore could not be diagnosed with APS. This discovery may aid us in recommending anticoagulant therapy following hospitalization. Patients with severe COVID-19 who tested aPLA positive should get the same anticoagulant medication as negatives, since those antibodies are usually not connected to APS. REFERENCES: [1] Cheng NM, Chan YC, Cheng SW. COVID-19 related thrombosis: A mini-review. Phlebology. 2022 Jun;37(5):326-337. [2] Taha, M.; Samavati, L. Antiphospholipid antibodies in COVID-19: A meta-analysis and systematic review. RMD Open 2021, 7: e001580 [3] Miyakis S, Lockshin MD, Atsumi T, Branch DW, Brey RL, et al. 2006. J.Thromb.Haemost. 4: 295-306 [4] Pengo, V. Additional laboratory tests to improve on the diagnosis of antiphospholipid syndrome. J. Thromb. Haemost.2020, 18, 1846–1848. [5] Egri N, Bentow C, Rubio, L. et al. Anti-Phosphatidylserine/Prothrombin Antibodies at Two Points: Correlation with Lupus Anticoagulant and Thrombotic Risk. Front. Immunol.2021, 12, 754469. Acknowledgements: NIL. Disclosure of Interests: None declared.