Contribution of the Elevated Thrombosis Risk of Males to the Excess Male Mortality Observed in COVID-19: An Observational Study (preprint)

Background: The mortality rate of COVID-19 is elevated in males compared to females. Objective: Determine the extent that the elevated thrombotic risk in males relative to females contributes to excess COVID-19 mortality in males. Design: Observational study. Setting: Data sourced from electronic medical records from over 200 US hospital systems. Participants: 60,877 patients hospitalized with COVID-19. Exposure: Exposure variable: biological sex; key variable of interest: thrombosis. Main outcome measures: Primary outcome was COVID-19 mortality. We measured: 1) mortality rate of males relative to females, 2) rate of thrombotic diagnoses occurring during hospitalization for COVID-19 in both sexes, and 3) mortality rate when evidence of thrombosis was present. Results: : The COVID-19 mortality rate of males was 29.9% higher than that of females. Males had a 35.8% higher rate of receiving a thrombotic diagnosis compared to females. The mortality rate of all patients with a thrombotic diagnosis was 40.0%— over twice that of COVID-19 patients without a thrombotic diagnosis (adjusted OR 2.50 [2.37 to 2.64], p-value < .001). When defining thrombosis as either a documented thrombotic diagnosis or a D-dimer level ≥ 3.0 μg/mL, 16.4% of the excess mortality in male patients could be explained by increased thrombotic risk. Conclusions: and Relevance: Our findings suggest the higher COVID-19 mortality rate in males may be significantly accounted for by the elevated risk for thrombosis among males. Understanding the mechanisms that underlie increased male thrombotic risk may allow for the advancement of effective anticoagulation strategies that reduce COVID-19 mortality in males.

CRISPRa screening with real world evidence identifies potassium channels as neuronal entry factors and druggable targets for SARS-CoV-2 (preprint)

Although vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been successful, there are no good treatments for those who are actively infected and potentially suffer from diverse neurological symptoms. While SARS-CoV-2 primarily infects the respiratory tract, clinical evidence indicates that cells from sensory organs, brain, and heart are also susceptible to infection. An understanding of factors critical for viral infection in these tissues may help identify novel therapeutics. To discover host factors involved in SARS-CoV-2 viral entry, we performed CRISPR activation (CRISPRa) screens targeting all 6000+ human membrane proteins in cells with and without overexpression of ACE2 using Spike-pseudotyped lentiviruses. We identified both novel as well as previously validated host factors. Notably, we used replication-competent SARS-CoV-2 to validate new viral-entry promoting genes, including potassium channel KCNA6, protease LGMN, and MHC-II component HLA-DPB1. We found that the overexpression of KCNA6 led to a marked increase in infection even in cells with undetectable levels of ACE2 expression. Our analysis of human olfactory neuroepithelium scRNA-seq data revealed that OLIG2+ cells--previously identified as sites of infection in COVID-19 autopsy studies--have high KCNA6 expression and minimal levels of ACE2, suggesting that the presence of KCNA6 may explain sensory/neuronal aspects of COVID-19 symptoms. Further, we demonstrate that FDA-approved compound dalfampridine, an inhibitor of KCNA-family potassium channels, suppresses viral entry in a dosage-dependent manner. Finally, we identified common prescription drugs likely to modulate the top screen hits. We then performed a retrospective analysis of insurance claims of ~8 million patients and found a clinical association between screen-identified drug classes, particularly those targeting potassium channels, and COVID-19 severity. We have thus identified the potassium channel KCNA6 as a SARS-CoV-2 host factor, expanded our understanding of potential viral tropism, and identified promising targets for drug repurposing and development.

Association of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers with the Risk of Hospitalization and Death in Hypertensive Patients with Coronavirus Disease-19 (preprint)

BackgroundWhether angiotensin-converting enzyme (ACE) Inhibitors and angiotensin receptor blockers (ARBs) mitigate or exacerbate SARS-CoV-2 infection remains uncertain. In a national study, we evaluated the association of ACE inhibitors and ARB with coronavirus disease-19 (COVID-19) hospitalization and mortality among individuals with hypertension. MethodsAmong Medicare Advantage and commercially insured individuals, we identified 2,263 people with hypertension, receiving [≥]1 antihypertensive agents, and who had a positive outpatient SARS-CoV-2 test (outpatient cohort). In a propensity score-matched analysis, we determined the association of ACE inhibitors and ARBs with the risk of hospitalization for COVID-19. In a second study of 7,933 individuals with hypertension who were hospitalized with COVID-19 (inpatient cohort), we tested the association of these medications with in-hospital mortality. We stratified all our assessments by insurance groups. ResultsAmong individuals in the outpatient and inpatient cohorts, 31.9% and 29.8%, respectively, used ACE inhibitors and 32.3% and 28.1% used ARBs. In the outpatient study, over a median 30.0 (19.0 - 40.0) days after testing positive, 12.7% were hospitalized for COVID-19. In propensity score-matched analyses, neither ACE inhibitors (HR, 0.77 [0.53, 1.13], P = 0.18), nor ARBs (HR, 0.88 [0.61, 1.26], P = 0.48), were significantly associated with risk of hospitalization. In analyses stratified by insurance group, ACE inhibitors, but not ARBs, were associated with a significant lower risk of hospitalization in the Medicare group (HR, 0.61 [0.41, 0.93], P = 0.02), but not the commercially insured group (HR: 2.14 [0.82, 5.60], P = 0.12; P-interaction 0.09). In the inpatient study, 14.2% died, 59.5% survived to discharge, and 26.3% had an ongoing hospitalization. In propensity score-matched analyses, neither use of ACE inhibitor (0.97 [0.81, 1.16]; P = 0.74) nor ARB (1.15 [0.95, 1.38]; P = 0.15) was associated with risk of in-hospital mortality, in total or in the stratified analyses. ConclusionsThe use of ACE inhibitors and ARBs was not associated with the risk of hospitalization or mortality among those infected with SARS-CoV-2. However, there was a nearly 40% lower risk of hospitalization with the use of ACE inhibitors in the Medicare population. This finding merits a clinical trial to evaluate the potential role of ACE inhibitors in reducing the risk of hospitalization among older individuals, who are at an elevated risk of adverse outcomes with the infection.