Background Cytokine storm is a marker of COVID-19 illness severity and increased mortality. Immunomodulatory treatments have been repurposed to improve mortality outcomes. Research Question To identify if immunomodulatory therapies improve survival in patients with COVID-19 cytokine storm. Study Design and Methods We conducted a retrospective analysis of electronic health records across the Northwell Health system. COVID-19 patients hospitalized between March 1, 2020 and April 24, 2020 were included. Cytokine storm was defined by inflammatory markers: ferritin >700ng/mL, C-reactive protein >30mg/dL or lactate dehydrogenase >300U/L. Patients were subdivided into six groups—no immunomodulatory treatment (standard of care) and five groups that received either corticosteroids, anti-interleukin 6 antibody (tocilizumab) or anti-interleukin-1 therapy (anakinra) alone or in combination with corticosteroids. The primary outcome was hospital mortality. Results 5,776 patients met the inclusion criteria. The most common comorbidities were hypertension (44-59%), diabetes (32-46%) and cardiovascular disease (5-14%). Patients most frequently met criteria with high lactate dehydrogenase (76.2%) alone or in combination, followed by ferritin (63.2%) and C-reactive protein (8.4%). More than 80% of patients had an elevated D-dimer. Patients treated with corticosteroids and tocilizumab combination had lower mortality compared to standard of care (Hazard Ratio (HR):0.44, 95% confidence interval (CI): 0.35-0.55; p <0.0001) and when compared to corticosteroids alone (HR:0.66, 95%CI: 0.53-0.83; p-value=0.004), or in combination with anakinra (HR:0.64, 95%CI:0.50-0.81; p-value=0.003) . Corticosteroids when administered alone (HR:0.66, 95%CI:0.57-0.76; p<0.0001) or in combination with tocilizumab (HR:0.43, 95%CI:0.35-0.55; p<0.0001) or anakinra (HR:0.68, 95%CI:0.57-0.81; p<0.0001) improved hospital survival compared to standard of care. Interpretation The combination of corticosteroids with tocilizumab had superior survival outcome when compared to standard of care and corticosteroids alone or in combination with anakinra. Furthermore, corticosteroid use either alone or in combination with tocilizumab or anakinra was associated with reduced hospital mortality for patients with COVID-19 cytokine storm compared to standard of care.

The clinical progression of the severe acute respiratory syndrome coronavirus 2 infection, coronavirus 2019 (COVID-19), to critical illness is associated with an exaggerated immune response, leading to magnified inflammation termed the "cytokine storm." This response is thought to contribute to the pathogenicity of severe COVID-19. There is an initial weak interferon response and macrophage activation that results in delayed neutrophil recruitment leading to impeded viral clearance. This causes prolonged immune stimulation and the release of proinflammatory cytokines. Elevated levels of inflammatory markers in COVID-19 (e.g., d-dimer, C-reactive protein, lactate dehydrogenase, ferritin, and interleukin-6) are reminiscent of the cytokine storm seen in severe hyperinflammatory macrophage disorders. The dysfunctional immune response in COVID-19 also includes lymphopenia, reduced T cells, reduced natural killer cell maturation, and unmitigated plasmablast proliferation causing aberrant IgG levels. The progression to severe disease is accompanied by endotheliopathy, immunothrombosis, and hypercoagulability. Thus, both parts of the immune system-innate and adaptive-play a significant role in the cytokine storm, multiorgan dysfunction, and coagulopathy. This review highlights the importance of understanding the immunologic mechanisms of COVID-19 as they inform the clinical presentation and suggest potential therapeutic targets.

Liu A, Pichard L, Schneider H, Patil SP, Smith PL, Polotsky V, Schwartz AR. Neuromechanical control of the isolated upper airway of mice. J Appl Physiol 105: 1237-1245, 2008. First published July 24, 2008 doi:10.1152/japplphysiol.90461.2008.-We characterized the passive structural and active neuromuscular control of pharyngeal collapsibility in mice and hypothesized that pharyngeal collapsibility, which is elevated by anatomic loads, is reduced by active neuromuscular responses to airflow obstruction. To address this hypothesis, we examined the dynamic control of upper airway function in the isolated upper airway of anesthetized C57BL/6J mice. Pressures were lowered downstream and upstream to the upper airway to induce inspiratory airflow limitation and critical closure of the upper airway, respectively. After hyperventilating the mice to central apnea, we demonstrated a critical closing pressure (Pcrit) of Ϫ6.2 Ϯ 1.1 cmH2O under passive conditions that was unaltered by the state of lung inflation. After a period of central apnea, lower airway occlusion led to progressive increases in phasic genioglossal electromyographic activity (EMGGG), and in maximal inspiratory airflow (V Imax) through the isolated upper airway, particularly as the nasal pressure was lowered toward the passive Pcrit level. Moreover, the active Pcrit fell during inspiration by 8.2 Ϯ 1.4 cmH2O relative to the passive condition (P Ͻ 0.0005). We conclude that upper airway collapsibility (passive Pcrit) in the C57BL/6J mouse is similar to that in the anesthetized canine, feline, and sleeping human upper airway, and that collapsibility falls markedly under active conditions. Active EMGGG and V Imax responses dissociated at higher upstream pressure levels, suggesting a decrease in the mechanical efficiency of upper airway dilators. Our findings in mice imply that anatomic and neuromuscular factors interact dynamically to modulate upper airway function, and provide a novel approach to modeling the impact of genetic and environmental factors in inbred murine strains. obstructive sleep apnea; upper airway collapsibility; critical closing pressure OBSTRUCTIVE SLEEP APNEA is a common disorder with a wide spectrum of neurocognitive, metabolic, and cardiovascular consequences (28,37,39,52,61). Its clinical sequelae stem from frequent nocturnal arousals and/or oxyhemoglobin desaturations, which result from recurrent episodes of upper airway obstruction during sleep (41). Obstruction has been related to elevations in pharyngeal collapsibility during sleep (12,36,47,53), although the mechanism for these elevations is not well understood.Structural alterations and disturbances in neuromuscular control account for elevations in upper airway collapsibility in sleep apnea patients compared with normal controls (36). Boney and soft tissue defects can increase pharyngeal collapsibility by elevating the pressure in tissues around the pharynx (15-19, 59). The impact of structural alterations on upper airway collapsibility may be mitigated by increases in lung volu...

No abstract

No abstract