Emergence of dysfunctional neutrophils with a defect in arginase-1 release in severe COVID-19.

Neutrophilia occurs in patients infected with SARS-CoV-2 (COVID-19) and is predictive of poor outcomes. Here, we link heterogenous neutrophil populations to disease severity in COVID-19. We identified neutrophils with features of cellular aging and immunosuppressive capacity in mild COVID-19 and features of neutrophil immaturity and activation in severe disease. The low-density neutrophil (LDN) number in circulating blood correlated with COVID-19 severity. Many of the divergent neutrophil phenotypes in COVID-19 were overrepresented in the LDN fraction and were less detectable in normal-density neutrophils. Functionally, neutrophils from patients with severe COVID-19 displayed defects in neutrophil extracellular trap formation and reactive oxygen species production. Soluble factors secreted by neutrophils from these patients inhibited T cell proliferation. Neutrophils from patients with severe COVID-19 had increased expression of arginase-1 protein, a feature that was retained in convalescent patients. Despite this increase in intracellular expression, there was a reduction in arginase-1 release by neutrophils into serum and culture supernatants. Furthermore, neutrophil-mediated T cell suppression was independent of arginase-1. Our results indicate the presence of dysfunctional, activated, and immature neutrophils in severe COVID-19.

Serum autotaxin level: a promising diagnostic biomarker in differentiating Graves' disease and thyroiditis.

BACKGROUND: Recent studies have suggested that serum autotaxin (ATX) may be a promising diagnostic biomarker in differentiating between Graves' disease (GD) and thyroiditis, as well as serving as a monitoring biomarker for GD. This study will evaluate the use of serum ATX as a diagnostic biomarker in these conditions. METHODS: In this prospective interventional study, blood samples were collected from the patients who met both inclusion and exclusion criteria, and serum ATX levels were measured by using the MyBioSource human Autotaxin ELISA kit. RESULTS: A total of 32 patients were enrolled, of which 18.8% were newly diagnosed with GD, 21.9% were thyroiditis, and 59.3% were on treatment for GD. Serum autotaxin antigen was significantly higher in GD patients than in thyroiditis (603.3217 ± 444.24 v/s 214.74 ± 55.91, P = <.005). Serum ATX measurement successfully discriminated GD patients from thyroiditis (AUC = 0.952, 95%CI: 0.00-1.00) with an optimal cutoff value of ≥257.20 ng/L (sensitivity = 100 and specificity = 81.71). Monitoring the efficacy of serum ATX was analyzed and showed a significant difference. CONCLUSION: The serum ATX was higher in subjects with GD as compared to thyroiditis, and ATX levels were found to be decreased during the treatment period. In conclusion, serum ATX can be used as a diagnostic and monitoring biomarker in GD.

Methylene diphenyl diisocyanate occupational exposure data in industry (1998-2020): A descriptive summary from an industrial hygiene perspective.

This paper provides an overview of airborne methylene diphenyl diisocyanate (MDI) concentrations in workplaces across North America and Europe. A total of 7649 samples were collected between 1998 and 2020 by producers of MDI during product stewardship activities at customer sites, primarily using validated OSHA or ISO sampling and analysis techniques. As would be expected from the low vapor pressure of MDI, 80% of the concentrations were less than 0.01 mg/m3 (1 ppb) and 93% were less than 0.05 mg/m3 (5 ppb). Respiratory protection is an integral part of Industrial Hygiene practices; therefore, its use was studied and summarized. While covering a variety of MDI applications, a large number of samples was obtained from composite wood manufacturing facilities, offering specific insight into potential exposures associated with different process sections and job types in this industry sector. Given the potential presence in industrial processes of MDI-containing dust or aerosols, future work should place increased emphasis on also investigating dermal exposure. The data reported in this paper provide valuable information for product stewardship and industrial hygiene purposes throughout the MDI-processing industry.

Characterisation of the pro-inflammatory cytokine signature in severe COVID-19.

Clinical outcomes from infection with SARS-CoV-2, the cause of the COVID-19 pandemic, are remarkably variable ranging from asymptomatic infection to severe pneumonia and death. One of the key drivers of this variability is differing trajectories in the immune response to SARS-CoV-2 infection. Many studies have noted markedly elevated cytokine levels in severe COVID-19, although results vary by cohort, cytokine studied and sensitivity of assay used. We assessed the immune response in acute COVID-19 by measuring 20 inflammatory markers in 118 unvaccinated patients with acute COVID-19 (median age: 70, IQR: 58-79 years; 48.3% female) recruited during the first year of the pandemic and 44 SARS-CoV-2 naïve healthy controls. Acute COVID-19 was associated with marked elevations in nearly all pro-inflammatory markers, whilst eleven markers (namely IL-1ß, IL-2, IL-6, IL-10, IL-18, IL-23, IL-33, TNF-α, IP-10, G-CSF and YKL-40) were associated with disease severity. We observed significant correlations between nearly all markers elevated in those infected with SARS-CoV-2 consistent with widespread immune dysregulation. Principal component analysis highlighted a pro-inflammatory cytokine signature (with strongest contributions from IL-1ß, IL-2, IL-6, IL-10, IL-33, G-CSF, TNF-α and IP-10) which was independently associated with severe COVID-19 (aOR: 1.40, 1.11-1.76, p=0.005), invasive mechanical ventilation (aOR: 1.61, 1.19-2.20, p=0.001) and mortality (aOR 1.57, 1.06-2.32, p = 0.02). Our findings demonstrate elevated cytokines and widespread immune dysregulation in severe COVID-19, adding further evidence for the role of a pro-inflammatory cytokine signature in severe and critical COVID-19.