Anti-severe acute respiratory syndrome coronavirus-2 adenoviral-vector vaccines trigger subclinical antiplatelet autoimmunity and increase of soluble platelet activation markers.

To slow down the coronavirus disease 2019 (COVID-19) pandemic an unequalled vaccination campaign was initiated. Despite proven efficacy and safety, a rare but potentially fatal complication of adenoviral-vector vaccines, called vaccine-induced immune thrombotic thrombocytopenia (VITT), has emerged the pathogenesis of which seems to be related to the development of platelet-activating anti-platelet factor 4 (PF4) antibodies. While a few studies have evaluated the incidence of anti-PF4 positivity in anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine recipients, to date no studies have assessed whether an antiplatelet immunological response develops and if this associates with platelet and blood clotting activation. We carried out a prospective study in healthy subjects who received the first dose of ChAdOx1 or Ad26.COV2.S or BNT162b2 vaccines to evaluate platelet-specific and non-specific immune response and in vivo platelet activation and blood clotting activation. Individuals receiving ChAdOx1 and, less so, Ad26.COV2.S developed with high frequency auto- or alloantiplatelet antibodies, increased circulating platelet-derived microvesicles and soluble P-selectin associated with mild blood clotting activation. Our study shows that an immunological reaction involving platelets is not uncommon in individuals receiving anti-SARS-CoV-2 vaccination, especially after ChAdOx1 and Ad26.COV2.S, and that it associates with in vivo platelet and blood clotting activation.

Effectiveness of Tocilizumab in hospitalized moderate-to-severe COVID-19 patients: a real life study.

BACKGROUND: To assess the clinical effectiveness of Tocilizumab (TCZ) in moderate-to-severe hospitalized COVID-19 patients and factors associated with clinical response. METHODS: 508 inpatients with moderate-to-severe SARS-CoV-2 infection were enrolled. TCZ effect in addition to standard medical therapy was evaluated in terms of death during hospital stay. Unadjusted and adjusted risk of mortality for TCZ treated patients versus TCZ untreated ones was estimated using robust Cox regression model. We considered the combination of TCZ and ICU as time-dependent exposure and created a model using duplication method to assess the TCZ effect in very severe COVID-19 patients. RESULTS: TCZ REDUCED DEATH DURING HOSPITAL STAY IN THE UNADJUSTED MODEL (HR 0.54, 95%CI 0.33- 0.88) and also in the adjusted model, although with loss of statistical significance (HR 0.72, 0.43- 1.20). Better effectiveness was observed in patients with low SpO2/FiO2 ratio (HR 0.35, 0.21-0.61 vs 1.61, 0.54-4.82, p<0.05), and, without statistical significance, in patients with high CRP (HR 0.51, 0.30-0.87 vs 0.41, 0.12-1.37, p =NS) and high IL-6 (HR 0.49, 0.29-0.82 vs 1.00, 0.28-3.55, p=NS). TCZ was effective in patients not admitted to ICU, both in the unadjusted (HR 0.33, 0.14-0.74) and in the adjusted (HR 0.39, 0.17-0.91) model but no benefit was observed in critical ICU-admitted patients both in the unadjusted (HR 0.66, 0.37-1.15) and in the adjusted model (HR 0.95, 0.54-1.68). CONCLUSIONS: our real-life study suggests clinical efficacy of TCZ in moderate-to-severe COVID-19 patients but not in end-stage disease. Thus, to enhance TCZ effectiveness, patients should be selected before grave compromise of clinical conditions.

Can SSRI/SNRI antidepressants decrease the 'cytokine storm' in the course of COVID-19 pneumonia?

BACKGROUND: Lots of research has been conducted to fight COVID-19 since the outbreak of the pandemic in 2020. The role of 'cytokine storm' in the pathogenesis of COVID-19 pneumonia is well known. Relationship between interleukins and depression is still subject matter of the research, but a correlation between interleukin-6 and depressive disorders is proven by now. The aim of this study is to verify differences among interleukin-6 blood levels of inpatients treated with SSRI and/or SNRI before and during hospitalization and of inpatients not treated with these drugs. METHODS: This is an observational study performed during the first wave of SARS Cov-2 pandemic in Italy for three months. The hospitalized patients of Internal Medicine wards and Infectious and Tropical Diseases ward of Azienda Ospedaliero-Universitaria Careggi of Florence for COVID-19 pneumonia have been divided into two subgroups (treated / not treated with antidepressants). Patients admitted to Intensive Care Unit previously have been excluded. Each patient has been evaluated concerning demographic, clinical and therapeutic features. The first dosage of interleukin-6 detected during hospitalization has been noticed. RESULTS: 8,5% (n=34 patients) of the entire sample (n=402) had been treated with an antidepressant of the two considered categories before admission until discharge from hospital. Significant lower levels of interleukin-6 of recovered patients of the treated subgroup have been highlighted as compared to recovered patients of not-treated subgroup (12,1 vs 25,4 p<0,001). These results have been pointed out in spite of higher mean age and more serious comorbidities of the treated subgroup. Nevertheless the incidence of severe Acute Respiratory Distress Syndrome is significantly lower in the subgroup of patients with antidepressant treatment (20,6% vs 43,2% p<0,02) as well as endotracheal intubation employment (0,0% vs 11,7% p<0,04). The rate of deceased patients of treated-subgroup is not significant lower than the rate of not-treated subgroup (23,5% vs 26,4% p=0,13). CONCLUSIONS: During COVID-19 pneumonia, the production of interleukin-6 seems to be modulated in presence of antidepressant therapy. Further proofs and broader surveys are necessary.

Prompt Predicting of Early Clinical Deterioration of Moderate-to-Severe COVID-19 Patients: Usefulness of a Combined Score Using IL-6 in a Preliminary Study.

BACKGROUND: The early identification of patients at risk of clinical deterioration is of interest considering the timeline of COVID-19 after the onset of symptoms. OBJECTIVE: The aim of our study was to evaluate the usefulness of testing serum IL-6 and other serological and clinical biomarkers, to predict a short-term negative clinical course of patients with noncritical COVID-19. METHODS: A total of 208 patients with noncritical COVID-19 pneumonia at admission were consecutively enrolled. Clinical and laboratory findings obtained on admission were analyzed by using survival analysis and stepwise logistic regression for variable selection. Three-day worsening as outcome in a logistic model to generate a prognostic score was used. RESULTS: Clinical worsening occurred in 63 patients (16 = died; 39 = transferred to intensive care unit; 8 worsening of respiratory failure). Forty-five of them worsened within 3 days after admission. The risk of clinical worsening was progressively enhanced along with increasing quartiles of IL-6 levels. Multivariate analysis showed that IL-6 (P = .005), C-reactive protein (CRP) (P = .003), and SaO2/FiO2 (P = .014) were the best predictors for clinical deterioration in the first 3 days after admission. The combined score yielded an area under the curve = 0.88 (95% confidence interval: 0.83-0.93). A nomogram predicting the probability of 3-day worsening was generated. The score also showed good performance for 7-day and 14- or 21-day worsening and in predicting death occurring during all the follow-up. CONCLUSIONS: Combining IL-6, CRP, and SaO2/FiO2 in a score may help clinicians to identify on admission those patients with COVID-19 who are at high risk for a further 3-day clinical deterioration.

Impaired immune cell cytotoxicity in severe COVID-19 is IL-6 dependent.

BACKGROUNDCoronavirus disease 19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2. Antiviral immune response is crucial to achieve pathogen clearance; however, in some patients an excessive and aberrant host immune response can lead to an acute respiratory distress syndrome. The comprehension of the mechanisms that regulate pathogen elimination, immunity, and pathology is essential to better characterize disease progression and widen the spectrum of therapeutic options.METHODSWe performed a flow cytometric characterization of immune cell subsets from 30 patients with COVID-19 and correlated these data with clinical outcomes.RESULTSPatients with COVID-19 showed decreased numbers of circulating T, B, and NK cells and exhibited a skewing of CD8+ T cells toward a terminally differentiated/senescent phenotype. In agreement, CD4+ T and CD8+ T, but also NK cells, displayed reduced antiviral cytokine production capability. Moreover, a reduced cytotoxic potential was identified in patients with COVID-19, particularly in those who required intensive care. The latter group of patients also showed increased serum IL-6 levels that inversely correlated to the frequency of granzyme A-expressing NK cells. Off-label treatment with tocilizumab restored the cytotoxic potential of NK cells.CONCLUSIONThe association between IL-6 serum levels and the impairment of cytotoxic activity suggests the possibility that targeting this cytokine may restore antiviral mechanisms.FUNDINGThis study was supported by funds from the Department of Experimental and Clinical Medicine of University of Florence (the ex-60% fund and the "Excellence Departments 2018-2022 Project") derived from Ministero dell'Istruzione, dell'Università e della Ricerca (Italy).