Tocilizumab for severe COVID-19 related illness - A community academic medical center experience.

The SARS-CoV-2 virus responsible for the COVID-19 pandemic can result in severe or fatal disease in a subset of infected patients. While the pathogenesis of severe COVID-19 disease has yet to be fully elucidated, an overexuberant and harmful immune response to the SARS-CoV-2 virus may be a pivotal aspect of critical illness in this patient population. The inflammatory cytokine, IL-6, has been found to be consistently elevated in severely ill COVID-19 patients, prompting speculation that IL-6 is an important driver of the pathologic process. The inappropriately elevated levels of inflammatory cytokines in COVID-19 patients is similar to cytokine release syndrome (CRS) observed in cell therapy patients. We sought to describe outcomes in a series of severely ill patients with COVID-19 CRS following treatment with anti-IL-6/IL-6-Receptor (anti-IL-6/IL-6-R) therapy, including tocilizumab or siltuximab. At our academic community medical center, we formed a multi-disciplinary committee for selecting severely ill COVID-19 patients for therapy with anti-IL-6 or IL-6-R agents. Key selection criteria included evidence of hyperinflammation, most notably elevated levels of C-reactive protein (CRP) and ferritin, and an increasing oxygen requirement. By the data cutoff point, we treated 31 patients with anti-IL-6/IL-6-R agents including 12 who had already been intubated. Overall, 27 (87%) patients are alive and 24 (77%) have been discharged from the hospital. Clinical responses to anti-IL-6/IL-6-R therapy were accompanied by significant decreases in temperature, oxygen requirement, CRP, IL-6, and IL-10 levels. Based on these data, we believe anti-IL-6/IL-6-R therapy can be effective in managing early CRS related to COVID-19 disease. Further study of anti-IL-6/IL-6-R therapy alone and in combination with other classes of therapeutics is warranted and trials are underway.

Incidental discovery of a large complicated arteriovenous haemangioma.

Arteriovenous haemangiomas within the chest are rare and uncommonly documented. After a 60-year-old woman with a history of smoking underwent a routine chest X-ray revealing a right apical mass, further investigations led to the discovery of a large extrapulmonary arteriovenous haemangioma in the superior mediastinum. Additionally, this case became complicated when the hemangioma was found to not only be compressing adjacent major arteries and veins, but also invading into the spinal canal and displacing the spinal cord. With multidisciplinary planning, the arteriovenous haemangioma was embolised and successfully resected. Thus, we present a case of an arteriovenous haemangioma in the superior mediastinum and discuss the importance of the case.

Induction of pulmonary hypertensive changes by extracellular vesicles from monocrotaline-treated mice.

AIMS: Circulating endothelium-derived extracellular vesicles (EV) levels are altered in pulmonary arterial hypertension (PAH) but whether they are biomarkers of cellular injury or participants in disease pathogenesis is unknown. Previously, we found that lung-derived EVs (LEVs) induce bone marrow-derived progenitor cells to express lung-specific mRNA and protein. In this study, we sought to determine whether LEV or plasma-derived EV (PEV) alter pulmonary vascular endothelial or marrow progenitor cell phenotype to induce pulmonary vascular remodelling. METHODS AND RESULTS: LEV, PEV isolated from monocrotaline (MCT-EV)- or vehicle-treated mice (vehicle-EV) were injected into healthy mice. Right ventricular (RV) hypertrophy and pulmonary vascular remodelling were assessed by RV-to-body weight (RV/BW) and blood vessel wall thickness-to-diameter (WT/D) ratios. RV/BW, WT/D ratios were elevated in MCT- vs. vehicle-injected mice (1.99 ± 0.09 vs. 1.04 ± 0.09 mg/g; 0.159 ± 0.002 vs. 0.062 ± 0.009%). RV/BW, WT/D ratios were higher in mice injected with MCT-EV vs. mice injected with vehicle-EV (1.63 ± 0.09 vs. 1.08 ± 0.09 mg/g; 0.113 ± 0.02 vs. 0.056 ± 0.01%). Lineage-depleted bone marrow cells incubated with MCT-EV and marrow cells isolated from mice infused with MCT-EV had greater expression of endothelial progenitor cell mRNAs and mRNAs abnormally expressed in PAH than cells incubated with vehicle-EV or isolated from vehicle-EV infused mice. MCT-EV induced an apoptosis-resistant phenotype in murine pulmonary endothelial cells and lineage-depleted bone marrow cells incubated with MCT-EV induced pulmonary hypertension when injected into healthy mice. CONCLUSIONS: EV from MCT-injured mice contribute to the development of MCT-induced pulmonary hypertension. This effect may be mediated directly by EV on the pulmonary vasculature or by differentiation of bone marrow cells to endothelial progenitor cells that induce pulmonary vascular remodelling.