Objective To evaluate the incidence and characteristics of SARS-CoV-2 infection among patients with systemic lupus erythematosus (SLE) and to compare it to that described in the general population. Methods For 5 weeks, we carried out a cross-sectional study consisting of telephone interviews of SLE patients. We collected epidemiological data, symptoms suggesting COVID-19, results of nasopharyngeal swabs, and ongoing treatments. In those patients who required hospital admission, clinical, radiological, and laboratory features, and outcome were investigated. Results Four hundred patients with SLE completed the survey. Overall, 4 (1.00%, 95%CI 0.02–1.98) patients were classified as confirmed cases of COVID-19 and 26 (6.51%, 95%CI 4.08–8.94) as possible clinical cases. The incidence of confirmed cases in our series was similar to that of the Catalan population (1.00% versus 0.63%; p = 0.456), whereas the incidence of possible cases was higher in our series (6.51% versus 1.29%; p < 0.005). The only difference between SLE patients with confirmed and possible COVID-19 and those without was the percentage of patients who have had contact with a confirmed or possible case of COVID-19 (26.7% versus 9.2%; p = 0.003) Conclusions The incidence of COVID-19 in SLE patients with inactive disease is low and, in our series, all cases with confirmed infection recovered. Key Points • In a cohort of SLE patients with stable and clinical inactive disease, the incidence of COVID-19 is low. • All SLE patients with confirmed SARS-CoV-2 infection recovered.

ObjectivePatients with COVID-19 presented with an elevated prevalence of antiphospholipid antibodies (aPL) but the relationship with thrombosis is controversial. We analysed the persistence of aPL and their association with the clinical outcomes during hospitalisation in a cohort of COVID-19 patients.Patients and MethodsWe conducted a prospective study including consecutive hospitalised patients with COVID-19 from Hospital Clínic of Barcelona between March 28th and April 22nd, 2020. Clinical outcomes during hospitalisation were thrombosis, intensive care unit (ICU) admission, and severe ventilatory failure. We determined both criteria and non-criteria aPL. Of note, in those patients with a positive result in the first determination, a second sample separated by at least 12 weeks was drawn to test the persistence of aPL.ResultsOne hundred and fifty-eight patients (59.5% men) with a mean age of 61.4 ± 14.9 years old were included. Thrombosis was present in 28 (17.7%) patients, severe respiratory failure in 47 (30.5%), and 30 (18.9%) patients were admitted to ICU. Sixteen (28.6%) patients were positive for the criteria aPL at both determinations and only two (3.6%) of them suffered from thrombosis during hospitalisations (both had aCL IgG). However, they presented with low titers of aCL. Of note, aPL were not related to thrombosis, ICU admission or severe respiratory failure.ConclusionAlthough aPL were prevalent in our cohort of hospitalised COVID-19 patients and they were persistent in half of tested patients, most determinations were at low titers and they were not related to worse clinical outcomes.

Antibodies to phospholipids (aPL) and associated proteins are a hallmark in the diagnosis of anti-phospholipid syndrome (APS). Those included in the classification criteria are the lupus anticoagulant (LA) and the IgG and IgM isotypes of anticardiolipin (aCL) and anti-beta-2 glycoprotein I (β2GPI) antibodies. Non-classification criteria markers such as autoantibodies that recognize the phosphatidylserine/prothrombin (aPS/PT) complex have been proposed as biomarkers for APS. Studies of aPS/PT antibodies have shown a strong correlation to clinical manifestations and LA. We aimed to study the value and the persistence of aPS/PT IgG and IgM antibodies in a cohort of consecutive patients with clinical suspicion of APS and their utility as thrombotic risk markers. Our study, with 103 patients, demonstrates that persistently positive results for aPS/PT IgG antibodies were significantly associated with APS classification, thrombosis, triple aPL positivity, LA positive result, and the Global APS Score (GAPSS) &gt; than 9 points (p &lt; 0.01, for each condition). On the other hand, no association was seen with pregnancy morbidity (p = 0.56) and SLE (p = 0.07). Persistence of aPS/PT antibodies, defined according to the current laboratory classification criteria, likely improves the diagnosis and clinical assessment of patients with APS.