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Objective: 

Inhaled nitric oxide and glucocorticoids as a combination therapy may attenuate endotoxin-induced inflammatory responses in humans as indicated by levels of cytokines and clinical signs. Since other authors have shown that combined inhaled nitric oxide and steroids improved the histologic damage both in pulmonary and systemic organs in a porcine endotoxin model, we examined if an anti-inflammatory interaction could be demonstrated in humans.

Design: 

Double-blind, crossover, placebo-controlled randomized study.

Setting: 

The intensive care unit in a university hospital.

Subjects: 

Fifteen healthy white volunteers (4 women, 11 men).

Interventions: 

Endotoxin (2 ng/kg) was administered intravenously. Thirty minutes thereafter the volunteers were given glucocorticoids (2 mg/kg) intravenously and inhaled nitric oxide 30 ppm or placebo (nitrogen) administered through a nasal cannula. Blood samples and clinical signs were collected before and up to 5.5 hrs after the endotoxin infusion.

Measurements and Main Result: 

Following endotoxin body temperature and heart rate increased significantly compared with baseline. There were no differences observed between the treatments. Endotoxin challenge also markedly elevated the plasma levels of tumor necrosis factor-α, interleukin (IL)-6, IL-10, and IL1-ra concentrations during the study period. No difference between placebo/glucocorticoids and inhaled nitric oxide/glucocorticoids treatment was seen in the cytokine response.

Conclusions: 

In a human experimental inflammatory model using endotoxin, inhaled nitric oxide and glucocorticoids in low doses given after the endotoxin challenge did not modify the inflammatory cascade as monitored in this study.

Background: Inflammatory reactions arise in reaction to a variety of pathogenic insults. The combination of inhaled nitric oxide (iNO) and glucocorticoids (GC) may attenuate endotoxin-induced inflammatory responses. It has been shown that the combination of iNO (30 p.p.m.) and steroids blunted the inflammatory response in a porcine endotoxin model, but not in humans. Therefore, we investigated whether a clinically ‘maximal’ dose of iNO in combination with GC could modulate the systemic inflammatory response in a human endotoxin model.

Methods: A double-blind, cross-over, placebo-controlled randomized study including 15 healthy Caucasian volunteers (five females, 10 males). Performed at the Intensive Care Unit in a university hospital. iNO 80 p.p.m. or placebo (nitrogen) was started 2 h before administration of endotoxin (2 ng/kg). Thirty minutes later, GC (2 mg/kg, hydrocortisone) was administered intravenously. Blood samples and clinical signs were collected before and up to 24 h after the endotoxin injection.

Results: Body temperature and heart rate increased significantly subsequent to endotoxin challenge. The plasma levels of IFN–γ, IL-1β, IL-2, 4 5, 6, 8, 10, 12, 13 and TNFα were markedly elevated. However, HMGB-1 and sRAGE were unaffected. No difference between placebo/GC and iNO/GC treatment was observed in the clinical or cytokine response, neither was there any difference between the first and the second exposure to endotoxin.

Conclusions: Pre-treatment with iNO 80 p.p.m. along with GC (2 mg/kg) administrated after the endotoxin challenge could not modulate the systemic inflammatory response in this model of human experimental inflammation.

Background: Severe coronavirus disease 2019 (COVID-19) causes a strong inflammatory response. To obtain an overview of inflammatory mediators and effector cells, we studied 25 intensive-care-unit patients during the timeframe after off-label chloroquine treatment and before an introduction of immunomodulatory drugs.

Material and methods: Blood samples were weekly examined with flow cytometry (FCM) for surface and intracytoplasmic markers, cytokine assays were analyzed for circulating interleukins (ILs), and blood smears were evaluated for morphological changes. Samples from healthy volunteers were used for comparison. Organ function data and 30-day mortality were obtained from medical records.

Results: Compared to that of the healthy control group, the expression levels of leukocyte surface markers, i.e., the cluster of differentiation (CD) markers CD2, CD4, CD8, CD158d, CD25, CD127, and CD19, were lower (p < 0.001), while those of leukocytes expressing CD33 were increased (p < 0.05). An aberrant expression of CD158d on granulocytes was found on parts of the granulocyte population. The expression levels of intracellular tumor necrosis factor alpha (TNF alpha) and IL-1 receptor type 2 in leukocytes were higher (p < 0.001) as well as plasma levels of TNF alpha, IL-2, IL-6, IL-8, IL-10 (p < 0.001), interferon gamma (IFN gamma) (p < 0.01), and granulocyte-macrophage colony-stimulating factor (GM-CSF) (p < 0.05). The expression levels of CD33+ leukocytes and circulating IL-6 were higher (p < 0.05) among patients with arterial oxygen partial pressure-to-fractional inspired oxygen (PaO2/FiO(2)) ratios below 13.3 kPa compared to in the remaining patients. The expression levels of TNF alpha, IL-2, IL-4, IL-6, IL-8, and IL-10 were higher in patients treated with continuous renal replacement therapy (CRRT) (p < 0.05), and the levels of the maximum plasma creatinine and TNF alpha Spearman's rank-order correlation coefficient (rho = 0.51, p < 0.05) and IL-8 (rho = 0.44, p < 0.05) correlated. Blood smears revealed neutrophil dysplasia with pseudo-Pelger forms being most common.

Conclusion: These findings suggest that patients with severe COVID-19, in addition to augmented ILs, lymphopenia, and increased granulocytes, also had effects on the bone marrow.