ACE2, the Counter-Regulatory Renin-Angiotensin System Axis and COVID-19 Severity.

Angiotensin (ANG)-converting enzyme (ACE2) is an entry receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). ACE2 also contributes to a deviation of the lung renin-angiotensin system (RAS) towards its counter-regulatory axis, thus transforming harmful ANG II to protective ANG (1-7). Based on this purported ACE2 double function, it has been put forward that the benefit from ACE2 upregulation with renin-angiotensin-aldosterone system inhibitors (RAASi) counterbalances COVID-19 risks due to counter-regulatory RAS axis amplification. In this manuscript we discuss the relationship between ACE2 expression and function in the lungs and other organs and COVID-19 severity. Recent data suggested that the involvement of ACE2 in the lung counter-regulatory RAS axis is limited. In this setting, an augmentation of ACE2 expression and/or a dissociation of ACE2 from the ANG (1-7)/Mas pathways that leaves unopposed the ACE2 function, the SARS-CoV-2 entry receptor, predisposes to more severe disease and it appears to often occur in the relevant risk factors. Further, the effect of RAASi on ACE2 expression and on COVID-19 severity and the overall clinical implications are discussed.

Tocilizumab improves oxidative stress and endothelial glycocalyx: A mechanism that may explain the effects of biological treatment on COVID-19.

We investigated the effects of tocilizumab on endothelial glycocalyx, a determinant of vascular permeability, and myocardial function in rheumatoid arthritis (RA). Eighty RA patients were randomized to tocilizumab (n = 40) or conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and glucocorticoids (GC) (n = 40) for 3 months. Forty healthy subjects with similar age and sex served as controls. We measured: (a)perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), (b)pulse wave velocity (PWV), (c)global LV longitudinal strain (GLS), (d)global work index (GWI) using speckle tracking echocardiography and e)C-reactive protein (CRP), malondialdehyde (MDA) and protein carbonyls (PCs) as oxidative stress markers at baseline and post-treatment. Compared to controls, RA patients had impaired glycocalyx and myocardial deformation markers (P < 0.05). Compared with baseline, tocilizumab reduced PBR(2.14 ± 0.2 versus 1.97 ± 0.2 µm; P < 0.05) while no significant differences were observed post-csDMARDs + GC(P > 0.05). Compared with csDMARDs + GC, tocilizumab achieved a greater increase of GLS, GWI and reduction of MDA, PCs and CRP(P < 0.05). The percent improvement of glycocalyx thickness (PBR) was associated with the percent decrease of PWV, MDA, PCs and the percent improvement of GLS and GWI(P < 0.05). Tocilizumab improves endothelial function leading to a greater increase of effective myocardial work than csDMARDs + GC through a profound reduction of inflammatory burden and oxidative stress. This mechanism may explain the effects of tocilizumab on COVID-19. CLINICAL TRIAL REGISTRATION: url: https://www.clinicaltrials.gov. Unique identifier: NCT03288584.

Effect of Colchicine vs Standard Care on Cardiac and Inflammatory Biomarkers and Clinical Outcomes in Patients Hospitalized With Coronavirus Disease 2019: The GRECCO-19 Randomized Clinical Trial.

Importance: Severe acute respiratory syndrome coronavirus 2 infection has evolved into a global pandemic. Low-dose colchicine combines anti-inflammatory action with a favorable safety profile. Objective: To evaluate the effect of treatment with colchicine on cardiac and inflammatory biomarkers and clinical outcomes in patients hospitalized with coronavirus disease 2019 (COVID-19). Design, Setting, and Participants: In this prospective, open-label, randomized clinical trial (the Greek Study in the Effects of Colchicine in COVID-19 Complications Prevention), 105 patients hospitalized with COVID-19 were randomized in a 1:1 allocation from April 3 to April 27, 2020, to either standard medical treatment or colchicine with standard medical treatment. The study took place in 16 tertiary hospitals in Greece. Intervention: Colchicine administration (1.5-mg loading dose followed by 0.5 mg after 60 min and maintenance doses of 0.5 mg twice daily) with standard medical treatment for as long as 3 weeks. Main Outcomes and Measures: Primary end points were (1) maximum high-sensitivity cardiac troponin level; (2) time for C-reactive protein to reach more than 3 times the upper reference limit; and (3) time to deterioration by 2 points on a 7-grade clinical status scale, ranging from able to resume normal activities to death. Secondary end points were (1) the percentage of participants requiring mechanical ventilation, (2) all-cause mortality, and (3) number, type, severity, and seriousness of adverse events. The primary efficacy analysis was performed on an intention-to-treat basis. Results: A total of 105 patients were evaluated (61 [58.1%] men; median [interquartile range] age, 64 [54-76] years) with 50 (47.6%) randomized to the control group and 55 (52.4%) to the colchicine group. Median (interquartile range) peak high-sensitivity cardiac troponin values were 0.0112 (0.0043-0.0093) ng/mL in the control group and 0.008 (0.004-0.0135) ng/mL in the colchicine group (P = .34). Median (interquartile range) maximum C-reactive protein levels were 4.5 (1.4-8.9) mg/dL vs 3.1 (0.8-9.8) mg/dL (P = .73), respectively. The clinical primary end point rate was 14.0% in the control group (7 of 50 patients) and 1.8% in the colchicine group (1 of 55 patients) (odds ratio, 0.11; 95% CI, 0.01-0.96; P = .02). Mean (SD) event-free survival time was 18.6 (0.83) days the in the control group vs 20.7 (0.31) in the colchicine group (log rank P = .03). Adverse events were similar in the 2 groups, except for diarrhea, which was more frequent with colchicine group than the control group (25 patients [45.5%] vs 9 patients [18.0%]; P = .003). Conclusions and Relevance: In this randomized clinical trial, participants who received colchicine had statistically significantly improved time to clinical deterioration. There were no significant differences in high-sensitivity cardiac troponin or C-reactive protein levels. These findings should be interpreted with caution. Trial Registration: ClinicalTrials.gov Identifier: NCT04326790.

The Greek study in the effects of colchicine in COvid-19 complications prevention (GRECCO-19 study): Rationale and study design.

OBJECTIVE: Colchicine has been utilized safely in a variety of cardiovascular clinical conditions. Among its potential mechanisms of action is the non-selective inhibition of NLRP3 inflammasome which is thought to be a major pathophysiologic component in the clinical course of patients with COVID-19. GRECCO-19 will be a prospective, randomized, open-labeled, controlled study to assess the effects of colchicine in COVID-19 complications prevention. METHODS: Patients with laboratory confirmed SARS-CoV-2 infection (under RT PCR) and clinical picture that involves temperature >37.5 oC and at least two out of the: i. sustained coughing, ii. sustained throat pain, iii. Anosmia and/or ageusia, iv. fatigue/tiredness, v. PaO2<95 mmHg will be included. Patients will be randomised (1:1) in colchicine or control group. RESULTS: Trial results will be disseminated through peer-reviewed publications and conference presentations. CONCLUSION: GRECCO-19 trial aims to identify whether colchicine may positively intervene in the clinical course of COVID-19. (ClinicalTrials.gov Identifier: NCT04326790).