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American Journal of Respiratory and Critical Care Medicine ; 205(1), 2022.
Article in English | EMBASE | ID: covidwho-1927902


Introduction: Dexamethasone decreases mortality in patients with severe COVID-19. The effects of dexamethasone on inflammation and repair in patients with severe COVID-19 are not well understood. We integrated tracheal aspirate (TA) and peripheral blood bulk/single-cell RNA sequencing to study the effect of dexamethasone on patients with COVID-19 ARDS. Methods: We studied selected patients from a cohort of adults with COVID-19 admitted to three hospitals in San Francisco, California from April 2020 to February 2021. Immunosuppression was not used to treat COVID-19 ARDS at these hospitals prior to July 2020, but was routinely used in these patients after this date. For this analysis, we included patients who were mechanically ventilated for COVID-19 ARDS for whom sequencing samples were available within four days of intubation. We excluded patients who received steroids prior to July 2020, subjects who received immunosuppression other than dexamethasone (e.g., tocilizumab) prior to sample collection, and chronically immunosuppressed subjects. We compared bulk RNASeq from TA and single cell RNASeq from TA and whole blood from subjects who received dexamethasone to subjects who did not receive dexamethasone. In addition, we studied the effect of dexamethasone on peripheral blood cytokine concentrations to confirm the effects of observed changes in gene expression. Results: TA bulk RNASeq was available from 20 subjects (six dexamethasone, 14 non-dexamethasone). There was no significant difference in age, sex, smoking, or BMI between groups. After correcting for multiple comparisons, 947 genes were differentially expressed in TA from subjects who received dexamethasone. Ingenuity Pathway Analysis predicted decreased activation of interferon, JAK/STAT, and NLRP12 signaling in subjects who received dexamethasone (Figure 1A). TA scRNASeq samples were available from ten dexamethasone-treated subjects and nine non-dexamethasone subjects. Whole blood scRNAseq samples were available for seven dexamethasone and eight non-dexamethasone subjects (Figure 1B). Eight subjects (three treated with dexamethasone) had both TA and whole blood scRNAseq samples available for analysis. Dexamethasone had distinct effects on the proportions of immune cells in tracheal aspirates and whole blood (Figure 1C). In 36 dexamethasone vs 42 non-dexamethasone subjects, treatment with dexamethasone was associated with significantly increased concentrations of IL-10 and decreased concentrations of IL-6 (Figure 1D). Conclusions: Dexamethasone decreases pro-inflammatory gene expression in the respiratory tract and peripheral blood of patients with COVID-19 ARDS. The effect of dexamethasone on specific cell populations may be distinct in the respiratory tract and peripheral blood.

PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-333583


While SARS-CoV-2 infection has pleiotropic and systemic effects in some patients, many others experience milder symptoms. We sought a holistic understanding of the severe/mild distinction in COVID-19 pathology, and its origins. We performed a whole-blood preserving single-cell analysis protocol to integrate contributions from all major cell types including neutrophils, monocytes, platelets, lymphocytes and the contents of serum. Patients with mild COVID-19 disease display a coordinated pattern of interferon-stimulated gene (ISG) expression across every cell population and these cells are systemically absent in patients with severe disease. Severe COVID-19 patients also paradoxically produce very high anti-SARS-CoV-2 antibody titers and have lower viral load as compared to mild disease. Examination of the serum from severe patients demonstrates that they uniquely produce antibodies with multiple patterns of specificity against interferon-stimulated cells and that those antibodies functionally block the production of the mild disease-associated ISG-expressing cells. Overzealous and auto-directed antibody responses pit the immune system against itself in many COVID-19 patients and this defines targets for immunotherapies to allow immune systems to provide viral defense. ONE SENTENCE SUMMARY: In severe COVID-19 patients, the immune system fails to generate cells that define mild disease;antibodies in their serum actively prevents the successful production of those cells.