Xiao M, et al. Arthritis Rheumatol 2020.
OBJECTIVES: Coagulopathy is one of the characteristics of critically ill patients with Coronavirus Disease 2019 (COVID-19). Antiphospholipid antibodies (aPLs) contribute to coagulopathy, but their role in COVID-19 remains unclear. We aimed to determine the prevalence and characteristics of aPLs in patients with COVID-19.
METHODS: Sera collected from 66 critically ill and 13 non-critically ill patients with COVID-19 were tested for anti-cardiolipin (aCL) and anti-β2-glycoprotein 1 (aβ2GP1) (IgG, IgM, and IgA) and IgG aβ2GP1-D1 by the chemiluminescence assay (CIA) and IgM and IgG anti-phosphatidylserine/prothrombin (aPS/PT) by ELISA.
RESULTS: aPLs were detected in 47.0% of critically ill patients (31/66), but not in patients with non-critical conditions. IgA aβ2GP1 was the most common aPL, present in 28.8% (19/66) critically ill patients, followed by IgA aCL (25.8%,17/66) and IgG aβ2GP1 (18.2%,12/66). For multiple aPLs, IgA aβ2GP1+IgA aCL was the most common type (22.7%, 15/66), followed by IgA aβ2GP1+IgA aCL+ IgG aβ2GP1 (15.2%, 10/66). aPLs emerge around 35-39 days post-disease onset. Dynamic analysis of aPLs revealed 4 patterns based on persistence or transient appearance of the aPLs. Patients with multiple aPLs displayed significantly higher incidence of cerebral infarction (p=0.023).
CONCLUSIONS: aPLs were common in critically ill patients. Multiple medium or high levels aPLs may help identify patients at risk of developing cerebral infarction. aPLs may be transient and disappear within a few weeks, but in genetically predisposed patients, COVID-19 may trigger the development of "COVID-19-induced-APS-like-syndrome". Long-term follow-up on COVID-19 patients positive for aPLs would be of great importance.