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Effects of Oxygen Status on Endotoxemia Induced Inflammation and Hypoxia Inducible Factor-1α

Phase 1
Completed
Conditions
Hyperoxia
Hypoxia
Normoxia
Interventions
Drug: Lipopolysaccharide
Registration Number
NCT01978158
Lead Sponsor
Radboud University Medical Center
Brief Summary

Oxygen is a widely available gas that is cheap, easy to get and extensively used in medicine. From animal studies it has become apparent that increasing or lowering the degree of oxygen in the blood, the inflammatory response can be altered. We will investigate of this is also true in humans by increasing, lowering or keeping oxygen levels normal while giving healthy subjects a short inflammatory stimulus.

Detailed Description

The primary objective of the study is to determine the effects of hyperoxia and hypoxia compared to normoxia in the human endotoxemia model on the innate immune reponse in healthy volunteers.

A parallel, randomized study in healthy male volunteers. The subjects will be randomized to hypoxia, hyperoxia, or normoxia, and will all undergo experimental human endotoxemia (administration of 2 ng/kg LPS iv).

In the hypoxia group: the subjects will breathe an individualized mix of nitrogen and room air for 3.5 hours using an air-tight respiratory helmet. The gas mixture will be adjusted to achieve a saturation of 80-85%. In the hyperoxia group, subjects will breathe 100% oxygen for 3.5 hours using the same respiratory helmet. In the normoxia group, subjects will breathe room air (21% oxygen, 79% nitrogen) also wearing the respiratory helmet. 1 hour after oxygen status adjustment (t=0), all subject will be administered an intravenous bolus (2ng/kg) of LPS derived from E coli O:113. 2.5 hours after LPS administration, the helmets will be removed and all subjects will breathe ambient room air.

The primary study endpoint is the difference in plasma cytokines between the hypoxia and normoxia group, and between the hyperoxia and normoxia group. Secondary objectives include HIF-1α protein and mRNA, aHIF mRNA expression in circulating leukocytes, measures of ROS, leukocyte phagocytosis, and cytokine production by leukocytes stimulated ex vivo with various inflammatory stimuli, and measurement of basic hemodynamic and ventilatory parameters and temperature.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
30
Inclusion Criteria
  • Written informed consent to participate in this trial
  • Male subjects aged 18 to 35 years inclusive
  • Healthy as determined by medical history, physical examination, vital signs, 12-lead electrocardiogram, and clinical laboratory parameters
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Exclusion Criteria
  • Use of any medication(including herbal remedies and vitamin/mineral supplements) or recreational drugs within 7 days prior to profiling day
  • Smoking
  • Use of caffeine, or alcohol or within 1 day prior to profiling day
  • Previous participation in a trial where LPS was administered
  • Surgery or trauma with significant blood loss or blood donation within 3 months prior to profiling day
  • Participation in another clinical trial within 3 months prior to profiling day.
  • History, signs or symptoms of cardiovascular disease
  • An implant that in the opinion of the investigator may make invasive procedures risky for the subject due to the increased risks associated with a possible infection.
  • Subject has an implanted active cardiac device (ICD, IPG and/or CRT) Implanted active neurostimulation device
  • Subject has internal jugular vein that cannot be accessed
  • History of vaso-vagal collapse or of orthostatic hypotension
  • History of atrial or ventricular arrhythmia
  • Resting pulse rate ≤45 or ≥100 beats / min
  • Hypertension (RR systolic >160 or RR diastolic >90)
  • Hypotension (RR systolic <100 or RR diastolic <50)
  • Conduction abnormalities on the ECG consisting of a 1st degree atrioventricular block or a complex bundle branch block
  • Subject is diagnosed with epilepsy or history of seizures
  • Renal impairment: plasma creatinine >120 μmol/L
  • Liver function abnormality: alkaline phosphatase>230 U/L and/or ALT>90 U/L
  • Coagulation abnormalities: APTT or PT > 1.5 times the reference range
  • History of asthma
  • Immuno-deficiency CRP > 20 mg/L, WBC > 12x109/L, or clinically significant acute illness, including infections, within 2 weeks before profiling day
  • Known or suspected of not being able to comply with the trial protocol - Inability to personally provide written informed consent (e.g. for linguistic or mental reasons) and/or take part in the study.
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
HyperoxiaLipopolysaccharideSubjects will be breathing 100% of oxygen
HypoxiaLipopolysaccharideSubjects will be breathing an individualized mix of nitrogen and room air titrated to an oxygen saturation of 80-85%.
NormoxiaLipopolysaccharideSubjects wil be breathing room air (21%)
Primary Outcome Measures
NameTimeMethod
Plasma TNF-alpha concentration following LPS administration1 day

Plasma TNF-α concentration after LPS administration (Area Under Curve); comparison of subjects treated with hypoxia compared to normoxia and hyperoxia compared to hypoxia

Secondary Outcome Measures
NameTimeMethod
heart rate variability1 day
Hypoxia Inducible Factor 1 alpha in circulating leukocytes1 day

Hypoxia Inducible Factor 1 alpha in circulating neutrophils, lymfocytes and monocytes as measured with flow cytometry

Hypoxia Inducible Factor mRNA and anti Hypoxia Inducible Factor mRNA in circulating leukocytes24 hours
Reactive Oxygen Species in circulating leukocytes1 day
Phagocytic function of circulating leukocytes1 day
cytokine production after ex vivo stimulation of leukocytes1 day
circulating cytokines (including but not limited to IL-6, IL-10, IL-1RA)1 day
Hemodynamic parameters1 day

Blood pressure, heart frequency, cardiac output measurement

ventilatory response1 day

Measures of ventilation: respiratory rate, blood gas changes

oxygen saturation and arterial blood gas1
subjective symptom scores1 day
high sensitive troponine1 day
iFABP1 day
brain specific proteins1 day
endocan1 day
downstream targets of HIF1 day

adrenomedullin, VEGF, EPO

adenosine metabolism1 day

urine and plasma adenosine,adenosine receptor mRNA, purines

alkaline phosphatase1 day
cognitive function1 day

neuropsychologic assessment of cognitive function

Hepcidin and iron parameters1 day
catecholamines and cortisol1 day

adrenaline, noradrenaline, dopamine and cortisol

Neutrophilic function1 day
body temperature1 day
kidney injury markers in plasma and urine2 days
microbiome in feces-1 day untill 1 week
markers of immunoparalysis1 day

monocytic histone 3 lysine 4 trimethylation of the promotor region of pro-inflammatory genes, ex viv production of proinflammatory cytokines, HLA-DR expression on moncytes.

measures of coagulation and plateletfunction1 day

platelet activation and platelet function, thrombin generation and other coagulation parameters, hematolocial infection profile using hematology analyser

meausures of coagulation and fibrinolysis1 day

thrombin generation, thrombocyte function, ROTEM, plasmatic coagulation, fibrinolysis parameters

Trial Locations

Locations (1)

Intensive Care Medicine

🇳🇱

Nijmegen, Gelderland, Netherlands

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