The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its associated coagulopathy are particularly worrisome in patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS), as these diseases carry an increased risk of thrombotic complications. Mathian et al recently reported the clinical course of COVID-19 in a series of 17 patients with SLE under chronic hydroxychloroquine therapy.1 Of note, only one patient (6%) presented thrombosis despite the fact that four patients (24%) had a history of secondary APS, and five patients (29%) were receiving oral anticoagulants. Antiphospholipid (aPL) antibodies were not measured in these patients during active SARS-CoV-2 infection.1
The American Society of Hematology recently stated that ‘at the current time, there are only very limited data on aPL antibodies in COVID-19 and it is unclear if they represent an epiphenomenon or are actually involved in any haemostatic abnormalities seen in COVID-19 disease’.2 Furthermore, almost all the available information refers to the lupus anticoagulant, with frequencies ranging from 45% to 87%.3 4 This paucity of data led us to test a panel of aPL antibodies in blood specimens from 21 patients hospitalised in the intensive care unit between 12 and 19 April, due to severe or critical COVID-19, and received at our laboratory on 20 April to measure interleukin-6 levels. Anticardiolipin, anti-β2 glycoprotein I, antiprothrombin, antiphosphatidylserine, antiphosphatidylinositol and antiannexin V antibodies were measured, each in IgM and IgG isotypes. Subsequently, demographic and clinical data were obtained from electronic medical records. Sera collected before the SARS-CoV-2 pandemic from 12 healthy individuals, matched for age and sex, were tested as controls.
Pertinent results are summarised in table 1. The median age of patients was 62 years; 43% were men; and a high number of comorbidities were observed (median Charlson Comorbidity Index of 3). A total of 19 patients (90%) had shortness of breath on admission, and 12 (57%) eventually required invasive mechanical ventilation during hospitalisation. Elevated levels of D-dimer, ferritin and C reactive protein were found at presentation.