COVID-19 is a new pandemic, caused by Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-Cov2) infection and characterized by a broad spectrum of clinical manifestations. Inflammation and the innate immune system have been recently recognized as pivotal players in the most severe forms, characterized by significantly elevated levels of pro-inflammatory cytokines. In this setting, several studies have also reported the presence of abnormalities in coagulation parameters and platelets count, possibly identifying a subgroup of patients with poor prognosis. Some reports of full-blown thromboembolic events are emerging. Among the possible mechanisms underlying coagulation dysfunction, the so-called "cytokine storm" seems to play a pivotal role. Other candidate factors include virus-specific mechanisms, related to the virus interaction with renin angiotensin system (RAS) and the fibrinolytic pathway, but also comorbidities affecting these patients. Coagulation dysfunction is therefore a candidate risk factor for adverse outcomes in COVID-19 and should be carefully addressed in clinical practice.

Background: Critically ill patients with coronavirus disease 2019 (COVID-19) have a profound hypercoagulable state and often develop coagulopathy which leads to organ failure and death. Because of a prolonged activated partial-thromboplastin time (aPTT), a relationship with anti-phospholipid antibodies (aPLs) has been proposed, but results are controversial. Functional assays for aPL (i.e., lupus anticoagulant) can be influenced by concomitant anticoagulation and/or high levels of C reactive protein. The presence of anticardiolipin (aCL), anti-beta2-glycoprotein I (anti-b 2 GPI), and anti-phosphatidylserine/ prothrombin (aPS/PT) antibodies was not investigated systematically. Epitope specificity of anti-b 2 GPI antibodies was not reported. Objective: To evaluate the prevalence and the clinical association of aPL in a large cohort of COVID-19 patients, and to characterize the epitope specificity of anti-b 2 GPI antibodies. Methods: ELISA and chemiluminescence assays were used to test 122 sera of patients suffering from severe COVID-19. Of them, 16 displayed major thrombotic events.

Background The highest number of COVID-19 cases in Italy have been reported in Lombardy, a region in northern Italy. We aimed to analyse the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with rheumatic and musculoskeletal diseases living in a district of Lombardy with a high prevalence of COVID-19. MethodsWe did a single-centre observational study at the Azienda Socio Sanitaria Territoriale (ASST) Spedali Civili of Brescia, Italy. We collected data from patients with rheumatic and musculoskeletal diseases enrolled in our outpatient clinic to identify confirmed or possible cases of SARS-CoV-2 infection. Data were collected through a survey that was administered via telephone or in the outpatient clinic by rheumatologists. We also did a case-control study of all patients with confirmed COVID-19 pneumonia and rheumatic and musculoskeletal diseases who were admitted to the ASST Spedali Civili of Brescia during the study period. Cases were matched by age, sex, and month of hospital admission to at least two controls admitted to the same hospital for COVID-19 pneumonia during the study period. Findings Between Feb 24 and May 1, 2020, we collected data from 1525 patients with rheumatic and musculoskeletal diseases: 117 (8%) presented with symptoms that were compatible with COVID-19. 65 patients had a swab confirmation of SARS-CoV-2 infection, whereas 52 presented with a spectrum of symptoms indicative of COVID-19 but were not swab tested. Patients with confirmed COVID-19 were older than those with suspected COVID-19 (median age 68 [IQR 55-76] years vs 57 [49-67] years; p=0•0010) and more likely to have arterial hypertension (33 [51%] vs 14 [27%] patients; odds ratio [OR] 2•8 [95% CI 1•3-6•1]; p=0•031) and obesity (11 [17%] vs 1 [2%]; OR 11•0 [1•3-83•4]; p=0•0059). We found no differences in rheumatological disease or background therapy between confirmed and suspected COVID-19 cases. 47 (72%) of the 65 patients with confirmed COVID-19 developed pneumonia that required admission to hospital. 12 (10%) deaths occurred among the 117 patients with confirmed or suspected COVID-19 (ten in those with confirmed COVID-19 and two in those with suspected COVID-19). Deceased patients with confirmed COVID-19 were older than survivors (median age 78•8 years [IQR 75•3-81•3] vs 65•5 years [53•3-74•0]; p=0•0002). We observed no differences in sex, comorbidities, or therapies between the deceased patients and survivors. The case-control study comprised 26 patients with rheumatic and musculoskeletal diseases and COVID-19 pneumonia and 62 matched controls. We found no significant differences between cases and controls in duration of COVID-19 symptoms before admission, duration of stay in hospital, or the local chest X-ray scoring system. Glucocorticoids were used for severe respiratory manifestations related to lung involvement in 17 (65%) of 26 cases and tocilizumab in six (23%) of 26; thrombotic events occurred in four (15%) of 26 cases. Four (15%) of 26 cases and six (10%) of 62 controls died...