Rationale: Coronavirus disease (COVID-19) is a global threat to health. Its inflammatory characteristics are incompletely understood. Objectives: To define the cytokine profile of COVID-19 and to identify evidence of immunometabolic alterations in those with severe illness. Methods: Levels of IL-1β, IL-6, IL-8, IL-10, and sTNFR1 (soluble tumor necrosis factor receptor 1) were assessed in plasma from healthy volunteers, hospitalized but stable patients with COVID-19 (COVID stable patients), patients with COVID-19 requiring ICU admission (COVID ICU patients), and patients with severe community-acquired pneumonia requiring ICU support (CAP ICU patients). Immunometabolic markers were measured in circulating neutrophils from patients with severe COVID-19. The acute phase response of AAT (alpha-1 antitrypsin) to COVID-19 was also evaluated. Measurements and Main Results: IL-1β, IL-6, IL-8, and sTNFR1 were all increased in patients with COVID-19. COVID ICU patients could be clearly differentiated from COVID stable patients, and demonstrated higher levels of IL-1β, IL-6, and sTNFR1 but lower IL-10 than CAP ICU patients. COVID-19 neutrophils displayed altered immunometabolism, with increased cytosolic PKM2 (pyruvate kinase M2), phosphorylated PKM2, HIF-1α (hypoxia-inducible factor-1α), and lactate. The production and sialylation of AAT increased in COVID-19, but this antiinflammatory response was overwhelmed in severe illness, with the IL-6:AAT ratio markedly higher in patients requiring ICU admission ( P < 0.0001). In critically unwell patients with COVID-19, increases in IL-6:AAT predicted prolonged ICU stay and mortality, whereas improvement in IL-6:AAT was associated with clinical resolution ( P < 0.0001). Conclusions: The COVID-19 cytokinemia is distinct from that of other types of pneumonia, leading to organ failure and ICU need. Neutrophils undergo immunometabolic reprogramming in severe COVID-19 illness. Cytokine ratios may predict outcomes in this population.

Background Prognostic tools are required to guide clinical decision-making in COVID-19. Methods We studied the relationship between the ratio of interleukin (IL)-6 to IL-10 and clinical outcome in 80 patients hospitalized for COVID-19, and created a simple 5-point linear score predictor of clinical outcome, the Dublin-Boston score. Clinical outcome was analysed as a three-level ordinal variable (“Improved”, “Unchanged”, or “Declined”). For both IL-6:IL-10 ratio and IL-6 alone, we associated clinical outcome with a) baseline biomarker levels, b) change in biomarker level from day 0 to day 2, c) change in biomarker from day 0 to day 4, and d) slope of biomarker change throughout the study. The associations between ordinal clinical outcome and each of the different predictors were performed with proportional odds logistic regression. Associations were run both “unadjusted” and adjusted for age and sex. Nested cross-validation was used to identify the model for incorporation into the Dublin-Boston score. Findings The 4-day change in IL-6:IL-10 ratio was chosen to derive the Dublin-Boston score. Each 1 point increase in the score was associated with a 5.6 times increased odds for a more severe outcome (OR 5.62, 95% CI -3.22–9.81, P = 1.2 × 10 −9 ). Both the Dublin-Boston score and the 4-day change in IL-6:IL-10 significantly outperformed IL-6 alone in predicting clinical outcome at day 7. Interpretation The Dublin-Boston score is easily calculated and can be applied to a spectrum of hospitalized COVID-19 patients. More informed prognosis could help determine when to escalate care, institute or remove mechanical ventilation, or drive considerations for therapies. Funding Funding was received from the Elaine Galwey Research Fellowship, American Thoracic Society, National Institutes of Health and the Parker B Francis Research Opportunity Award.

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by neutrophil-driven lung destruction and early emphysema in a low AAT, and high neutrophil elastase environment in the lungs of affected individuals. In this study, we examined peripheral blood neutrophil apoptosis and showed it to be accelerated in individuals with AATD by a mechanism involving endoplasmic reticulum stress and aberrant TNF-α signaling. We reveal that neutrophil apoptosis in individuals homozygous for the Z allele (PiZZ) is increased nearly 2-fold compared with healthy controls and is associated with activation of the external death pathway. We demonstrate that in AATD, misfolded AAT protein accumulates in the endoplasmic reticulum of neutrophils, leading to endoplasmic reticulum stress and the expression of proapoptotic signals, including TNF-α, resulting in increased apoptosis and defective bacterial killing. In addition, treatment of AATD individuals with AAT augmentation therapy decreased neutrophil ADAM-17 activity and apoptosis in vivo and increased bacterial killing by treated cells. In summary, this study demonstrates that AAT can regulate neutrophil apoptosis by a previously unidentified and novel mechanism and highlights the role of AAT augmentation therapy in ameliorating inflammation in AATD.