EVIDENCE FROM FATAL COVID-19 FOR TARGETING THE BRADYKININ METABOLISM-A SINGLE-CENTER COHORT STUDY.

ABSTRACT: Background: Severe progression of COVID-19 to critical illness, with pulmonary failure, multiple organ failure, and death, is driven by systemic inflammatory responses with overproduction of inflammatory cytokines. In the past years, the potential role of bradykinin, leading to inappropriate immune responses in the pathogenesis of COVID-19, has been raised in a so-called bradykinin storm. However, clinical investigations of bradykinin, its metabolite des-Arg 9 -bradykinin, or substance P, are rare or completely lacking during intensive care of COVID-19 patients. A prospective prolonged cohort study was conducted, including 44 COVID-19 patients (09/2020-02/2021, prevalent wildtype SARS-CoV-2) from the intensive care unit. Plasma levels of bradykinin, des-Arg 9 -bradykinin, and substance P were measured daily by ELISA in survivors (n = 21) and nonsurvivors (n = 23) of COVID-19 from admission until discharge or death. Results: We found significantly higher plasma levels of des-Arg 9 -bradykinin in survivors and nonsurvivors of COVID-19 compared with healthy controls. In addition, plasma des-Arg 9 -bradykinin levels were higher ( P < 0.001, effect size = 0.79) in nonsurvivors compared with survivors of COVID-19 and correlated significantly with disease worsening, and clinical parameters of inflammation, like leukocyte count, IL-6 or lactate dehydrogenase, and outcome. Consequently, compared with healthy controls, bradykinin and substance P plasma levels were significantly reduced in survivors and nonsurvivors of COVID-19. Furthermore, plasma substance P levels were significantly reduced ( P < 0.001, effect size = 0.7) in nonsurvivors compared with survivors of COVID-19, whereas plasma bradykinin levels did not significantly differ between survivors and nonsurvivors of COVID-19. Conclusion: Our data demonstrates that des-Arg 9 -bradykinin is significantly elevated in COVID-19 intensive care unit patients and is associated with disease severity, clinical inflammatory parameters, and survival. These results indicate that des-Arg 9 -bradykinin, not bradykinin, is one of the pivotal peptides of concern for the lethal COVID-19 aggravation and outcome. Further investigations are necessary to evaluate whether des-Arg 9 -bradykinin exhibits potent blood biomarker properties in COVID-19 and offer new treatment approaches.

HIGH HEPARANASE LEVEL IN SURVIVORS OF COVID-19 - INDICATOR OF VASCULAR AND PULMONARY RECOVERY?

ABSTRACT: Background: Severe progression of coronavirus disease 2019 (COVID-19) causes respiratory failure and critical illness. Recently, COVID-19 has been associated with heparanase (HPSE)-induced endothelial barrier dysfunction and inflammation, so called endothelitis, and therapeutic treatment with heparin or low-molecular-weight heparin (LMWH) targeting HPSE has been postulated. Because, up to this date, clinicians are unable to measure the severity of endothelitis, which can lead to multiorgan failure and concomitant death, we investigated plasma levels of HPSE and heparin-binding protein (HBP) in COVID-19 intensive care patients to render a possible link between endothelitis and these plasma parameters. Therefore, a prospective prolonged cohort study was conducted, including 47 COVID-19 patients from the intensive care unit. Plasma levels of HPSE, and HBP were measured daily by enzyme-linked immunosorbent assay in survivors (n = 35) and nonsurvivors (n = 12) of COVID-19 from admission until discharge or death. All patients were either treated with heparin or LMWH, aiming for an activated partial thromboplastin time of ≥60 seconds or an anti-Xa level of >0.8 IU/mL using enoxaparin, depending on the clinical status of the patient (patients with extracorporeal membrane oxygenation or >0.1 µg/kg/min noradrenaline received heparin, all others enoxaparin). Results: We found significantly higher plasma levels of HPSE and HBP in survivors and nonsurvivors of COVID-19, compared with healthy controls. Still, interestingly, plasma HPSE levels were significantly higher ( P < 0.001) in survivors compared with nonsurvivors of COVID-19. In contrast, plasma HBP levels were significantly reduced ( P < 0.001) in survivors compared with nonsurvivors of COVID-19. Furthermore, when patients received heparin, they had significantly lower HPSE ( P = 2.22 e - 16) and significantly higher HBP ( P = 0.00013) plasma levels as when they received LMWH. Conclusion: Our results demonstrated that patients, who recover from COVID-19-induced vascular and pulmonary damage and were discharged from the intensive care unit, have significantly higher plasma HPSE level than patients who succumb to COVID-19. Therefore, HPSE is not suitable as marker for disease severity in COVID-19 but maybe as marker for patient's recovery. In addition, patients receiving therapeutic heparin treatment displayed significantly lower heparanse plasma level than upon therapeutic treatment with LMWH.