Prevalence, specificity, and clinical association of anti-phospholipid antibodies in COVID-19 patients: are the antibodies really guilty?

BackgroundCritically 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 (aPL) 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 anti-cardiolipin (aCL), anti-beta2-glycoprotein I (anti-{beta}2GPI) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies was not investigated systematically. Epitope specificity of anti-{beta}2GPI antibodies was not reported. ObjectiveTo 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-{beta}2GPI antibodies. MethodsELISA and chemiluminescence assays were used to test 122 sera of patients suffering from severe COVID-19. Of them, 16 displayed major thrombotic events. ResultsAnti-{beta}2GPI IgG/IgA/IgM were the most frequent in 15.6/6.6/9.0% of patients, while aCL IgG/IgM were detected in 5.7/6.6% by ELISA. Comparable values were found by chemiluminescence. aPS/PT IgG/IgM were detectable in 2.5 and 9.8% by ELISA. No association between thrombosis and aPL was found. Reactivity against domain 1 and 4-5 of {beta}2GPI was limited to 3/58 (5.2%) tested sera for each domain and did not correlate with aCL/anti-{beta}2GPI nor with thrombosis. ConclusionsaPL show a low prevalence in COVID-19 patients and are not associated with major thrombotic events. aPL in COVID-19 patients are mainly directed against {beta}2GPI but display an epitope specificity different from antibodies in antiphospholipid syndrome.

Tocilizumab for patients with COVID-19 pneumonia. The TOCIVID-19 phase 2 trial

BackgroundTocilizumab blocks pro-inflammatory activity of interleukin-6 (IL-6), involved in pathogenesis of pneumonia the most frequent cause of death in COVID-19 patients. MethodsA multicentre, single-arm, hypothesis-driven phase 2 trial was planned to study the effect of Tocilizumab on lethality rates at 14 and 30 days (co-primary endpoints). A cohort of patients consecutively enrolled after phase 2 was used as a validation dataset. A multivariable logistic regression was performed to generate hypotheses, while controlling for possible confounders. Resultsout of 301 patients in phase 2 intention-to-treat (ITT) analysis, 180 (59.8%) received tocilizumab. With 67 death events, lethality rates were 18.4% (97.5%CI: 13.6-24.0, P=0.52) and 22.4% (97.5%CI: 17.2-28.3, P<0.001) at 14 and 30 days. Lethality rates were lower in the validation dataset, including 920 patients. No signal of specific drug toxicity was reported. The multivariable logistic regression suggests tocilizumab might be more effective in patients not requiring mechanical respiratory support at baseline. Also, it supports a positive effect on lethality rate of the use of corticosteroids. ConclusionsTocilizumab reduced lethality rate at 30 days compared with null hypothesis, without significant toxicity. Such result support the use of tocilizumab while waiting for ongoing phase 3 trials. RegistrationEudraCT (2020-001110-38); clinicaltrials.gov (NCT04317092)