Early SARS-CoV-2 infection: Platelet-neutrophil complexes and platelet function.

Background: Conflicting results have been reported on platelet activity and responsiveness among patients with COVID-19 with or without thromboembolic complications.

Objectives: To assess platelet reactivity in patients with moderate disease at early stages of COVID-19.

Methods: We performed a prospective, descriptive analysis of 100 consecutive patients presenting with suspected SARS-CoV-2 infection at University Medical Center Freiburg during the first or second wave of the pandemic.

Complement system component dysregulation is a distinctive feature of COVID-19 disease: a prospective and comparative analysis of patients admitted to the emergency department for suspected COVID-19 disease.

The complement system (CS) plays a pivotal role in Coronavirus disease 2019 (COVID-19) pathophysiology. The objective of this study was to provide a comparative, prospective data analysis of CS components in an all-comers cohort and COVID-19 patients. Patients with suspected COVID-19 infection admitted to the Emergency department were grouped for definite diagnosis of COVID-19 and no COVID-19 accordingly.

Serum Protein Profiling Reveals a Specific Upregulation of the Immunomodulatory Protein Progranulin in Coronavirus Disease 2019.

Background: Severe courses of coronavirus disease 2019 (COVID-19) are associated with elevated levels of interleukin 6 (IL-6). However, there is a growing body of evidence pointing to a broad and more complex disorder of proinflammatory and antiviral responses with disturbed interferon signaling in COVID-19.

Methods: In this prospective, single-center registry, we included severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients and patients with similar symptoms and severity of disease but negative for SARS-CoV-2 admitted to the emergency department and compared their serum protein expression profiles.

Serum ACE2, Angiotensin II, and Aldosterone Levels Are Unchanged in Patients With COVID-19.

Background: The role of the renin-angiotensin-aldosterone system (RAAS) in coronavirus disease 2019 (COVID-19) is controversially discussed. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells by binding to angiotensin-converting enzyme 2 (ACE2) and activity of the RAAS may affect susceptibility to SARS-CoV-2 infection and outcome of patients with COVID-19.

Methods: In this prospective single-center study, we determined the serum levels of ACE2, angiotensin II, and aldosterone in patients with COVID-19 compared with control patients presenting with similar symptoms in the emergency unit.

Rate of venous thromboembolism in a prospective all-comers cohort with COVID-19.

COVID-19 is associated with a variety of clinical complications including coagulopathy, which frequently results in venous thromboembolism (VTE). Retrospective analyses reported a markedly increased rate of VTEs in COVID-19. However, most recent studies on coagulopathy in COVID-19 were only focused on critically ill patients, and without suitable control groups.