Soluble urokinase Plasminogen Activator Receptor (suPAR) levels are predictive of COVID-19 severity: an Italian experience.

BACKGROUND: The soluble urokinase Plasminogen Activator Receptor (suPAR) has been identified as a reliable marker of COVID-19 severity, helping in personalizing COVID-19 therapy. This study aims to evaluate the correlation between suPAR levels and COVID-19 severity, in relation to the traditional inflammatory markers. METHODS: Sera from 71 COVID-19 patients were tested for suPAR levels using Chorus suPAR assay (Diesse Diagnostica Senese SpA, Italy). suPAR levels were compared with other inflammatory markers: IL-1ß, IL-6, TNF-α, circulating calprotectin, neutrophil and lymphocyte counts, and Neutrophil/Lymphocytes Ratio (NLR). Respiratory failure, expressed as P/F ratio, and mortality rate were used as indicators of disease severity. RESULTS: A positive correlation of suPAR levels with IL-6 (r = 0.479, p = 0.000), TNF-α (r = 0.348, p = 0.003), circulating calprotectin (r = 0.369, p = 0.002), neutrophil counts (r = 0.447, p = 0.001), NLR (r = 0.492, p = 0.001) has been shown. Stratifying COVID-19 population by suPAR concentration above and below 6 ng/mL, we observed higher levels of circulating calprotectin (10.1 µg/mL, SD 7.9 versus 6.4 µg/mL, SD 7.5, p < 0.001), higher levels of P/F ratio (207.5 IQR 188.3 vs 312.0 IQR 127.8, p = 0.013) and higher mortality rate. Median levels of suPAR were increased in all COVID-19 patients requiring additional respiratory support (Nasal Cannula, Venturi Mask, BPAP and CPAP) (6.5 IQR = 4.9) compared to the group at room air (4.6 IQR = 4.2). CONCLUSION: suPAR levels correlate with disease severity and survival rate of COVID-19 patients, representing a promising prognostic biomarker for the risk assessment of the disease.

Interleukin-6 Elevation Is a Key Pathogenic Factor Underlying COVID-19-Associated Heart Rate-Corrected QT Interval Prolongation.

Background: Heart rate-corrected QT interval (QTc) prolongation is prevalent in patients with severe coronavirus disease 2019 (COVID-19) and is associated with poor outcomes. Recent evidence suggests that the exaggerated host immune-inflammatory response characterizing the disease, specifically interleukin-6 (IL-6) increase, may have an important role, possibly via direct effects on cardiac electrophysiology. The aim of this study was to dissect the short-term discrete impact of IL-6 elevation on QTc in patients with severe COVID-19 infection and explore the underlying mechanisms. Methods: We investigated the following mechanisms: (1) the QTc duration in patients with COVID-19 during the active phase and recovery, and its association with C-reactive protein (CRP) and IL-6 levels; (2) the acute impact of IL-6 administration on QTc in an in vivo guinea pig model; and (3) the electrophysiological effects of IL-6 on ventricular myocytes in vitro. Results: In patients with active severe COVID-19 and elevated IL-6 levels, regardless of acute myocardial injury/strain and concomitant QT-prolonging risk factors, QTc was significantly prolonged and rapidly normalized in correlation with IL-6 decrease. The direct administration of IL-6 in an in vivo guinea pig model acutely prolongs QTc duration. Moreover, ventricular myocytes incubated in vitro with IL-6 show evident prolongation in the action potential, along with significant inhibition in the rapid delayed rectifier potassium current (IKr). Conclusion: For the first time, we demonstrated that in severe COVID-19, systemic inflammatory activation can per se promote QTc prolongation via IL-6 elevation, leading to ventricular electric remodeling. Despite being transitory, such modifications may significantly contribute to arrhythmic events and associated poor outcomes in COVID-19. These findings provide a further rationale for current anti-inflammatory treatments for COVID-19, including IL-6-targeted therapies.

Transient Hypogonadism Is Associated With Heart Rate-Corrected QT Prolongation and Torsades de Pointes Risk During Active Systemic Inflammation in Men.

Background Systemic inflammation and male hypogonadism are 2 increasingly recognized "nonconventional" risk factors for long-QT syndrome and torsades de pointes (TdP). Specifically, inflammatory cytokines prolong, while testosterone shortens the heart rate-corrected QT interval (QTc) via direct electrophysiological effects on cardiomyocytes. Moreover, several studies demonstrated important interplays between inflammation and reduced gonad function in men. We hypothesized that, during inflammatory activation in men, testosterone levels decrease and that this enhances TdP risk by contributing to the overall prolonging effect of inflammation on QTc. Methods and Results We investigated (1) the levels of sex hormones and their relationship with inflammatory markers and QTc in male patients with different types of inflammatory diseases, during active phase and recovery; and (2) the association between inflammatory markers and sex hormones in a cohort of male patients who developed extreme QTc prolongation and TdP, consecutively collected over 10 years. In men with active inflammatory diseases, testosterone levels were significantly reduced, but promptly normalized in association with the decrease in C-reactive protein and interleukin-6 levels. Reduction of testosterone levels, which also inversely correlated with 17-ß estradiol over time, significantly contributed to inflammation-induced QTc prolongation. In men with TdP, both active systemic inflammation and hypogonadism were frequently present, with significant correlations between C-reactive protein, testosterone, and 17-ß estradiol levels; in these patients, increased C-reactive protein and reduced testosterone were associated with a worse short-term outcome of the arrhythmia. Conclusions During systemic inflammatory activation, interleukin-6 elevation is associated with reduced testosterone levels in males, possibly deriving from an enhanced androgen-to-estrogen conversion. While transient, inflammatory hypotestosteronemia is significantly associated with an increased long-QT syndrome/TdP risk in men.

A quantitative assay for detection of SARS-CoV-2 neutralizing antibodies.

OBJECTIVES: Serological assays for SARS-CoV-2 have a critical role not only in diagnosis of COVID-19, but also in assessing the degree and duration of response of specific antibodies against the virus obtained through infection or vaccination. We present the results obtained with a competitive immunoenzymatic method (Chorus SARS-CoV-2 "Neutralizing" Ab) for quantitative determination of total neutralizing anti-S1 SARS-CoV-2 antibodies (IgG, IgM, and IgA) in human serum obtained on a disposable device with the Chorus TRIO instrument using a recombinant strong neutralizing antibody as tracer. METHODS: A total of 694 sera were evaluated for SARS-CoV-2 neutralizing antibodies: 407 uninfected, 201 symptomatic subjects, 37 post-infection patients, and 49 vaccinated. Sixty-eight of the previous sera were used to compare the Chorus SARS-CoV-2 "Neutralizing" Ab results with those obtained with micro-neutralization of the Alpha and original variants. A set of 74 positive sera for other respiratory infections were analyzed to evaluate the possible cross reaction to SARS-CoV-2 virus. RESULTS: Of the 694 samples, only 3 had discordant results between micro-neutralization and values measured by Chorus SARS-CoV-2 "Neutralizing" Ab: 1 false negative and 2 false positives. Values of sensitivity and specificity were very high: percent positive agreement (sensitivity) 99.6% (95% CI: 97.7 - 99.9) and percent negative agreement (specificity) 99.6% (95% CI: 98.0 -99.9). Concordance was high with a Gwet's Ac1 of 0.992. No significant differences were observed between the alpha and original variants. CONCLUSIONS: The Chorus SARS-CoV-2 "Neutralizing" Ab test was highly sensitive and specific, and varies from most other currently available tests since it analyzes only antibodies with viral-neutralizing capacity.

Unravelling Atrioventricular Block Risk in Inflammatory Diseases: Systemic Inflammation Acutely Delays Atrioventricular Conduction via a Cytokine-Mediated Inhibition of Connexin43 Expression.

Background Recent data suggest that systemic inflammation can negatively affect atrioventricular conduction, regardless of acute cardiac injury. Indeed, gap-junctions containing connexin43 coupling cardiomyocytes and inflammation-related cells (macrophages) are increasingly recognized as important factors regulating the conduction in the atrioventricular node. The aim of this study was to evaluate the acute impact of systemic inflammatory activation on atrioventricular conduction, and elucidate underlying mechanisms. Methods and Results We analyzed: (1) the PR-interval in patients with inflammatory diseases of different origins during active phase and recovery, and its association with inflammatory markers; (2) the existing correlation between connexin43 expression in the cardiac tissue and peripheral blood mononuclear cells (PBMC), and the changes occurring in patients with inflammatory diseases over time; (3) the acute effects of interleukin(IL)-6 on atrioventricular conduction in an in vivo animal model, and on connexin43 expression in vitro. In patients with elevated C-reactive protein levels, atrioventricular conduction indices are increased, but promptly normalized in association with inflammatory markers reduction, particularly IL-6. In these subjects, connexin43 expression in PBMC, which is correlative of that measured in the cardiac tissue, inversely associated with IL-6 changes. Moreover, direct IL-6 administration increased atrioventricular conduction indices in vivo in a guinea pig model, and IL-6 incubation in both cardiomyocytes and macrophages in culture, significantly reduced connexin43 proteins expression. Conclusions The data evidence that systemic inflammation can acutely worsen atrioventricular conduction, and that IL-6-induced down-regulation of cardiac connexin43 is a mechanistic pathway putatively involved in the process. Though reversible, these alterations could significantly increase the risk of severe atrioventricular blocks during active inflammatory processes.

Outcome After Acute Ischemic Stroke Treatment During Covid-19 Outbreak in South-East Tuscany.

BACKGROUND: During Covid-19 pandemic, the Italian National Healthcare Service has faced increasing pressure, especially in Northern Italy. Even in less-affected regions, such as Tuscany, the changes in the healthcare system to prevent Covid-19 spread resulted in difficulty in treating time-dependent disorders like ischemic stroke rapidly. OBJECTIVE: The aim of our study was to assess the outcome after acute ischemic stroke treatments during the Covid-19 spread in comparison with a similar period of the previous year in Siena-Hospital (Hub center in the South-East Tuscany). METHODS: We enrolled all patients admitted to Siena-Hospital for ischemic stroke and submitted them to acute treatments (intravenous and/or mechanical thrombolysis) between February 21st and May 18th, 2020 (study group, n:38) and compared the results with ischemic strokes acutely treated in a similar period in 2019 (control group, n:39). The modified Rankin scale score was assessed at 90 days to evaluate a 3-month clinical outcome. RESULTS: In the study group, the time from symptoms onset to hospital arrival and the door-to-groin puncture time were significantly more prolonged than in the control group. In moderate-severe strokes, the 3-month mortality was significantly higher in the study group (31% vs. 6%; p=0.01), and the number of patients with poor functional outcomes was significantly higher in the study group (73% vs. 44%; p=0.03). CONCLUSION: During the lockdown period due to Covid-19 pandemic, patients with acute ischemic stroke had a worse prognosis. These findings suggest the need to improve the health system organization to guarantee an appropriate treatment during the pandemic, including the patients that are not affected by Covid-19.

A compartment modeling approach to reconstruct and analyze gender and age-grouped CoViD-19 Italian data for decision-making strategies.

BACKGROUND: Available national public data are often too incomplete and noisy to be used directly to interpret the evolution of epidemics over time, which is essential for making timely and appropriate decisions. The use of compartment models can be a worthwhile and attractive approach to address this problem. The present study proposes a model compartmentalized by sex and age groups that allows for more complete information on the evolution of the CoViD-19 pandemic in Italy. MATERIAL AND METHODS: Italian public data on CoViD-19 were pre-treated with a 7-day moving average filter to reduce noise. A time-varying susceptible-infected-recovered-deceased (SIRD) model distributed by age and sex groups was then proposed. Recovered and infected individuals distributed by groups were reconstructed through the SIRD model, which was also used to simulate and identify optimal scenarios of pandemic containment by vaccination. The simulation started from realistic initial conditions based on the SIRD model parameters, estimated from filtered and reconstructed Italian data, at different pandemic times and phases. The following three objective functions, accounting for total infections, total deaths, and total quality-adjusted life years (QALYs) lost, were minimized by optimizing the percentages of vaccinated individuals in five different age groups. RESULTS: The developed SIRD model clearly highlighted those pandemic phases in which younger people, who had more contacts and lower mortality, infected older people, characterized by a significantly higher mortality, especially in males. Optimizing vaccination strategies yielded different results depending on the cost function used. As expected, to reduce total deaths, the suggested strategy was to vaccinate the older age groups, whatever the baseline scenario. In contrast, for QALYs lost and total infections, the optimal vaccine solutions strongly depended on the initial pandemic conditions: during phases of high virus diffusion, the model suggested to vaccinate mainly younger groups with a higher contact rate. CONCLUSION: Because of the poor quality and insufficient availability of stratified public pandemic data, ad hoc information filtering and reconstruction procedures proved essential. The time-varying SIRD model, stratified by age and sex groups, provided insights and additional information on the dynamics of CoViD-19 infection in Italy, also supporting decision making for containment strategies such as vaccination.

Cardiac Arrest Risk During Acute Infections: Systemic Inflammation Directly Prolongs QTc Interval via Cytokine-Mediated Effects on Potassium Channel Expression.

BACKGROUND: During acute infections, the risk of malignant ventricular arrhythmias is increased, partly because of a higher propensity to develop QTc prolongation. Although it is generally believed that QTc changes almost exclusively result from concomitant treatment with QT-prolonging antimicrobials, direct effects of inflammatory cytokines on ventricular repolarization are increasingly recognized. We hypothesized that systemic inflammation per se can significantly prolong QTc during acute infections, via cytokine-mediated changes in K+ channel expression. METHODS: We evaluated (1) the frequency of QTc prolongation and its association with inflammatory markers, in patients with different types of acute infections, during active disease and remission; (2) the prevalence of acute infections in a cohort of consecutive patients with Torsades de Pointes; (3) the relationship between K+ channel mRNA levels in ventricles and peripheral blood mononuclear cells and their changes in patients with acute infection over time. RESULTS: In patients with acute infections, regardless of concomitant QT-prolonging antimicrobial treatments, QTc was significantly prolonged but rapidly normalized in parallel to CRP (C-reactive protein) and cytokine level reduction. Consistently in the Torsades de Pointes cohort, concomitant acute infections were highly prevalent (30%), despite only a minority (25%) of these cases were treated with QT-prolonging antimicrobials. KCNJ2 K+ channel expression in peripheral blood mononuclear cell, which strongly correlated to that in ventricles, inversely associated to CRP and IL (interleukin)-1 changes in acute infection patients. CONCLUSIONS: During acute infections, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless concomitant antimicrobial therapy. Although transient, these changes may significantly increase the risk of life-threatening ventricular arrhythmia in these patients. It is timely and warranted to transpose these findings to the current coronavirus disease 2019 (COVID-19) pandemic, in which both increased amounts of circulating cytokines and cardiac arrhythmias are demonstrated along with a frequent concomitant treatment with several QT-prolonging drugs. Graphic Abstract: A graphic abstract is available for this article.