Sci Transl Med. 2020 Nov 18;12(570):eabd3876. doi: 10.1126/scitranslmed.abd3876. | PubMed

Yu Zuo¹, Shanea K Estes¹, Ramadan A Ali¹, Alex A Gandhi¹, Srilakshmi Yalavarthi¹, Hui Shi^1,2, Gautam Sule¹, Kelsey Gockman¹, Jacqueline A Madison¹, Melanie Zuo³, Vinita Yadav⁴, Jintao Wang⁵, Wrenn Woodard⁶, Sean P Lezak⁶, Njira L Lugogo⁷, Stephanie A Smith⁸, James H Morrissey⁸, Yogendra Kanthi^9,5, Jason S Knight¹⁰

1. Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
2. Division of Rheumatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
3. Division of Geriatric and Palliative Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
4. Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
5. Division of Intramural Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA.
6. Michigan Clinical Research Unit, University of Michigan, Ann Arbor, MI 48109, USA.
7. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
8. Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
9. Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA. yogen.kanthi@nih.gov jsknight@umich.edu.
10. Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA. yogen.kanthi@nih.gov jsknight@umich.edu.

Abstract

Patients with COVID-19 are at high risk for thrombotic arterial and venous occlusions. Lung histopathology often reveals fibrin-based blockages in the small blood vessels of patients who succumb to the disease. Antiphospholipid syndrome is an acquired and potentially life-threatening thrombophilia in which patients develop pathogenic autoantibodies targeting phospholipids and phospholipid-binding proteins (aPL antibodies). Case series have recently detected aPL antibodies in patients with COVID-19. Here, we measured eight types of aPL antibodies in serum samples from 172 patients hospitalized with COVID-19. These aPL antibodies included anticardiolipin IgG, IgM, and IgA; anti-β2 glycoprotein I IgG, IgM, and IgA; and anti-phosphatidylserine/prothrombin (aPS/PT) IgG and IgM. We detected aPS/PT IgG in 24% of serum samples, anticardiolipin IgM in 23% of samples, and aPS/PT IgM in 18% of samples. Antiphospholipid autoantibodies were present in 52% of serum samples using the manufacturer's threshold and in 30% using a more stringent cutoff (≥40 ELISA-specific units). Higher titers of aPL antibodies were associated with neutrophil hyperactivity, including the release of neutrophil extracellular traps (NETs), higher platelet counts, more severe respiratory disease, and lower clinical estimated glomerular filtration rate. Similar to IgG from patients with antiphospholipid syndrome, IgG fractions isolated from patients with COVID-19 promoted NET release from neutrophils isolated from healthy individuals. Furthermore, injection of IgG purified from COVID-19 patient serum into mice accelerated venous thrombosis in two mouse models. These findings suggest that half of patients hospitalized with COVID-19 become at least transiently positive for aPL antibodies and that these autoantibodies are potentially pathogenic.

Presented By Ray Zhuo