Severe Acute Respiratory Syndrome Coronavirus 2, COVID-19, and the Renin-Angiotensin System: Pressing Needs and Best Research Practices.

The coronavirus disease 2019 (COVID-19) pandemic is associated with significant morbidity and mortality throughout the world, predominantly due to lung and cardiovascular injury. The virus responsible for COVID-19-severe acute respiratory syndrome coronavirus 2-gains entry into host cells via ACE2 (angiotensin-converting enzyme 2). ACE2 is a primary enzyme within the key counter-regulatory pathway of the renin-angiotensin system (RAS), which acts to oppose the actions of Ang (angiotensin) II by generating Ang-(1-7) to reduce inflammation and fibrosis and mitigate end organ damage. As COVID-19 spans multiple organ systems linked to the cardiovascular system, it is imperative to understand clearly how severe acute respiratory syndrome coronavirus 2 may affect the multifaceted RAS. In addition, recognition of the role of ACE2 and the RAS in COVID-19 has renewed interest in its role in the pathophysiology of cardiovascular disease in general. We provide researchers with a framework of best practices in basic and clinical research to interrogate the RAS using appropriate methodology, especially those who are relatively new to the field. This is crucial, as there are many limitations inherent in investigating the RAS in experimental models and in humans. We discuss sound methodological approaches to quantifying enzyme content and activity (ACE, ACE2), peptides (Ang II, Ang-[1-7]), and receptors (types 1 and 2 Ang II receptors, Mas receptor). Our goal is to ensure appropriate research methodology for investigations of the RAS in patients with severe acute respiratory syndrome coronavirus 2 and COVID-19 to ensure optimal rigor and reproducibility and appropriate interpretation of results from these investigations.

Risk of Severe Covid-19 in Patients with Celiac Disease: A Population-Based Cohort Study.

BACKGROUND: Patients with celiac disease (CeD) are at increased risk of certain viral infections and of pneumococcal pneumonia, raising concerns that they may be susceptible to severe coronavirus disease 2019 (Covid-19). We aimed to quantify the association between CeD and severe outcomes related to Covid-19. METHODS: We performed a population-based cohort study, identifying individuals with CeD in Sweden, as defined by small intestinal villus atrophy diagnosed at all (n=28) Swedish pathology departments during the years spanning 1969-2017, and alive on February 1, 2020. We compared these patients to controls matched by sex, age, county, and calendar period. We performed Cox proportional hazards with follow-up through July 31, 2020, assessing risk of 1) hospital admission with a primary diagnosis of laboratory-confirmed Covid-19 (co-primary outcome); and 2) severe disease as defined by admission to intensive care unit and/or death attributed to Covid-19 (co-primary outcome). RESULTS: Among patients with CeD (n=40,963) and controls (n=183,892), the risk of hospital admission for Covid-19 was 2.9 and 2.2 per 1000 person-years respectively. After adjusting for comorbidities, the risk of hospitalization for Covid-19 was not significantly increased in patients with CeD (HR 1.10; 95% CI 0.80-1.50), nor was the risk of severe Covid-19 increased (HR 0.97; 95% CI 0.59-1.59). Results were similarly null when we compared CeD patients to their non-CeD siblings with regard to these outcomes. Among all patients with CeD and controls hospitalized with a diagnosis of Covid-19 (n=58 and n=202, respectively), there was no significant difference in mortality (HR for CeD compared to controls 0.96; 95% CI 0.46-2.02). CONCLUSION: In this population-based study, CeD was not associated with an increased risk of hospitalization for Covid-19 or intensive care unit and/or death attributed to Covid-19.

Antibody profiling and prevalence in US patients during the SARS-CoV2 pandemic.

BACKGROUND: Antibody diagnostics play an important role in disease detection and can potentially aid in monitoring of the immune responses to see if an individual has developed immunity. Developing high throughput diagnostics which does not involve handling of infectious material becomes imperative in the case of pandemics such as the recent outbreak of SARS-CoV2. METHODS: A protein microarray technology was used to detect the plurality of antibody response to four novel antigens namely S1 glycoprotein, Receptor binding domain (RBD), S2 glycoprotein and Nucleoprotein of the novel coronavirus named SARS-CoV2 using serum samples. A DBS card was additionally used to compare its performance with a venipuncture-based serum separator tube (SST) draw. RESULTS: The three main subclasses of antibodies IgM, IgA and IgG were analyzed to see the variations in immune responses in the affected population and compared to their microbial RT-PCR based NP swab results. The clinical sensitivity and specificity were determined to be 99.67% and 99.77%. In the matrix comparison study, which would enable patients to test without risk of transmitting the virus, DBS (Dried Blood Spot) matched with higher than 98% accuracy to a venipuncture-based SST collection. CONCLUSION: Multiplex testing enables higher sensitivity and specificity which is essential while establishing exposure on a population scale. This flexible platform along with a discrete collection methodology would be crucial and broadly useful to scale up testing in current and future pandemics. Minimum sample volume that can be collected using DBS cards can be processed in this multiplex pillar plate format enabling the capacity to provide the reliability of high throughput analyzers while having the ease of collection similar to rapid tests.