Lupus Anticoagulant and Abnormal Coagulation Tests in Patients with Covid-19

Abstract

To the Editor: Patients with coronavirus disease 2019 have a profound hypercoagulable state, and complicating venous thrombotic events are common. [1][2][3] Abnormalities in coagulation screening measures, including a prolonged activated partial-thromboplastin time (aPTT), have been reported in patients with This finding could be seen as a reason to avoid the use of anticoagulation at both therapeutic and prophylactic doses.A prolonged aPTT may indicate a clottingfactor deficiency or the presence of an inhibitor of coagulation that is either specific (e.g., antibody to factor VIII) or nonspecific (e.g., lupus anticoagulant). Lupus anticoagulant can affect in vitro tests of blood coagulation but typically is not associated with bleeding. As part of the antiphospholipid syndrome, lupus anticoagulant is associated with a thrombotic risk. We investigated the cause of prolonged aPTT in patients with Covid-19.Blood specimens obtained from 216 patients who were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were received for coagulation screening, and 44 (20%) were found to have a prolonged aPTT. The specimens from 9 patients were excluded, and those from 35 patients were investigated further. (Details of the methods are provided in the Supplementary Appendix, available with the full text of this letter at NEJM.org.)A summary of the results is provided in Table 1. The median age was 57 years, and 24 patients were male. Pulmonary embolism was confirmed in 1 patient, and clinically suspected thrombosis was present in 1 patient. No clinically significant bleeding or arterial thromboses were reported.No patients were found to have deficiencies in factor VIII or factor IX. In 5 patients, marginal reductions in factor XI were found that were un-

Antiphospholipid antibodies in patients with COVID‐19: A relevant observation?

“…As far as interpretable and based on available results in previous studies, 5,7‐9 in none of the patients was triple positivity demonstrated. In our patient cohort, only two patients were triple positive, of whom none showed thrombotic complications.…”

“…Bowles et al described 35 patients in detail, and detected 91% of 35 patients positive for LAC in a workout for prolonged APTT 8 . Six of 35 patients (18%) were positive in the APTT system only.…”

“…In two of the four published studies, COVID‐19 patients were not tested for aCL and aβ2GPI 5,8 . If not all criteria aPL are measured, no antibody profiles could be done that proved to be useful because combining the aPL may improve risk assessment 10,11,43‐45 .…”

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“…22 Reports of lupus-anticoagulant mediated artificial prolongation of the partial thromboplastin time (PTT) in patients with COVID-19 make monitoring of therapeutic anticoagulation using anti-Xa levels ideal. 23 A conservative approach to VTE prophylaxis according to severity of COVID-19 and comorbid disease states is outlined in ►Table 5.…”

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“…Severe COVID-19 is associated with an elevation of in ammatory cytokines, which can increase the expression of tissue factor and the suppression of anticoagulant factors 10 . Recently, lupus anticoagulation has frequently been observed in COVID-19 subjects, and this could also be another possible mechanism of abnormal coagulopathy 11 .…”