Efferocytosis of SARS-CoV-2-infected dying cells impairs macrophage anti-inflammatory functions and clearance of apoptotic cells

COVID-19 is a disease of dysfunctional immune responses, but the mechanisms triggering immunopathogenesis are not established. The functional plasticity of macrophages allows this cell type to promote pathogen elimination and inflammation or suppress inflammation and promote tissue remodeling and injury repair. During an infection, the clearance of dead and dying cells, a process named efferocytosis, can modulate the interplay between these contrasting functions. Here, we show that engulfment of SARS-CoV-2-infected apoptotic cells exacerbates inflammatory cytokine production, inhibits the expression of efferocytic receptors, and impairs continual efferocytosis by macrophages. We also provide evidence supporting that lung monocytes and macrophages from severe COVID-19 patients have compromised efferocytic capacity. Our findings reveal that dysfunctional efferocytosis of SARS-CoV-2-infected cell corpses suppresses macrophage anti-inflammation and efficient tissue repair programs and provides mechanistic insights for the excessive production of pro-inflammatory cytokines and accumulation of tissue damage associated with COVID-19 immunopathogenesis

Comparative effectiveness of home blood pressure telemonitoring (HBPTM) plus nurse case management versus HBPTM alone among Black and Hispanic stroke survivors: study protocol for a randomized controlled trial

BACKGROUND: Black and Hispanic stroke survivors experience higher rates of recurrent stroke than whites. This disparity is partly explained by disproportionately higher rates of uncontrolled hypertension in these populations. Home blood pressure telemonitoring (HBPTM) and nurse case management (NCM) have proven efficacy in addressing the multilevel barriers to blood pressure (BP) control and reducing BP. However, the effectiveness of these interventions has not been evaluated in stroke patients. This study is designed to evaluate the comparative effectiveness, cost-effectiveness and sustainability of these two telehealth interventions in reducing BP and recurrent stroke among high-risk Black and Hispanic stroke survivors with uncontrolled hypertension. METHODS/DESIGN: A total of 450 Black and Hispanic patients with recent nondisabling stroke and uncontrolled hypertension are randomly assigned to one of two 12-month interventions: 1) HBPTM with wireless feedback to primary care providers or 2) HBPTM plus individualized, culturally-tailored, telephone-based NCM. Patients are recruited from stroke centers and primary care practices within the Health and Hospital Corporations (HHC) Network in New York City. Study visits occur at baseline, 6, 12 and 24 months. The primary outcomes are within-patient change in systolic BP at 12 months, and the rate of stroke recurrence at 24 months. The secondary outcome is the comparative cost-effectiveness of the interventions at 12 and 24 months; and exploratory outcomes include changes in stroke risk factors, health behaviors and treatment intensification. Recruitment for the stroke telemonitoring hypertension trial is currently ongoing. DISCUSSION: The combination of two established and effective interventions along with the utilization of health information technology supports the sustainability of the HBPTM + NCM intervention and feasibility of its widespread implementation. Results of this trial will provide strong empirical evidence to inform clinical guidelines for management of stroke in minority stroke survivors with uncontrolled hypertension. If effective among Black and Hispanic stroke survivors, these interventions have the potential to substantially mitigate racial and ethnic disparities in stroke recurrence. TRIAL REGISTRATION: ClinicalTrials.gov NCT02011685. Registered 10 December 2013