Clinical trial NCT03044223: Monocyte Profiles in Critically Ill Patients With Pseudomonas Aeruginosa Sepsis
Official title: Phenotypical Und Functional Characterization of Macrophages in Critically Ill Patients With Pseudomonas Aeruginosa Induced Sepsis
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Pseudomonas Infections
Pseudomonas Septicemia
Pseudomonas; Pneumonia
Pseudomonal Bacteraemia
Pseudomonas Urinary Tract Infection
Pseudomonas Gastrointestinal Tract Infection
Sepsis
Sepsis, Severe
Critically Ill
Keywords: pseudomonas aeruginosa
critically ill patient
sepsis
monocyte
macrophage
cytokine
severity of disease
Lead sponsor: University of Ulm
Sponsor class: OTHER
First posted: 2017-02-06
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Critically ill patients with sepsis with microbiologically proven infection with Pseudomonas aeruginosa

Brief summary: The present study focuses on patients with Pseudomonas aeruginosa (PSA) sepsis. The aim of the present study is to find out whether the M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotype predominates in blood monocytes in critically ill patients with PSA-sepsis, and whether the severity of sepsis and outcome is associated with distinct monocyte phenotype and function.

Detailed description: During bacterial related sepsis, one of the key playing cells are macrophages, monocytes and T-lymphocytes (Hotchkiss et al., 2003). Macrophages and monocytes are supposed to be essential for the septic reaction to Gram-negative bacteria (Hotchkiss et al. 2003). Generally, there are two dominant types of macrophages: the pro-inflammatory M1 macrophage and the anti-inflammatory M2 macrophage (Mantovani et al., 2006). Similar to this macrophage characteristics, monocytes can also be categorized into pro-or anti-inflammatory. These macrophage/monocyte phenotypes can be differentiated in vitro from freshly isolated human blood monocytes using either GM-CSF giving raise to M1 macrophage/monocyte or M-CSF resulting in M2 macrophage/monocyte (Mantovani et al., 2006; Neu et al., 2013). Brunialti et al. (2012) have already demonstrated that the population of antiinflammatory M2 monocytes in septic patients is bigger than the pro-inflammatory M1 population. However, the authors did not further analyze the underlying mechanisms of M2 polarization nor did they identify the sepsis-causing pathogens.

In the present study, monocytes and macrophages of patients with Pseudomonas aeruginosa (PSA) sepsis are characterized by their surface marker expression profile via flow cytometry and cytokine pattern by ELISA in vivo and after ex-vivo LPS stimulation. In addition, an ex-vivo model system for PSA induced sepsis is validated. Blood of critically ill patients in the ICU infected with PSA is sampled to isolate peripheral blood mononuclear cells (PBMCs). Blood monocytes are analyzed for surface marker expression to determine the relative proportions of M1 and M2 monocytes in these patients and in healthy controls by flow cytometry

Eligibility criteria: Inclusion Criteria:

* age \> 18 years
* critically ill patients with sepsis
* microbiologically proven infection with Pseudomonas aeruginosa

Exclusion Criteria:

* life expectancy \< 24 hours
* participation in other studies

Primary outcomes:
measure: Monocyte surface marker expression in critically ill patients with Pseudomonas aeruginosa sepsis
timeFrame: two years
Secondary outcomes:
measure: Cytokine concentrations in serum and production after ex-vivo stimulation of isolated monocytes of critically ill patients with Pseudomonas aeruginosa sepsis with LPS
timeFrame: four years
Other outcomes:
Locations:
city: Ulm
country: Germany
facility: Clinic of Anesthesiology
Study officials:
affiliation: University Ulm, University Hospital Ulm
name: Manfred Weiss, MD, MBA
role: PRINCIPAL_INVESTIGATOR
affiliation: University Ulm, Institute of Microbiology and Biotechnology
name: Anne Sedlag, Biochemist
role: PRINCIPAL_INVESTIGATOR
References:
citation: Brunialti MK, Santos MC, Rigato O, Machado FR, Silva E, Salomao R. Increased percentages of T helper cells producing IL-17 and monocytes expressing markers of alternative activation in patients with sepsis. PLoS One. 2012;7(5):e37393. doi: 10.1371/journal.pone.0037393. Epub 2012 May 31.
citation: Hotchkiss RS, Karl IE. The pathophysiology and treatment of sepsis. N Engl J Med. 2003 Jan 9;348(2):138-50. doi: 10.1056/NEJMra021333. No abstract available.
citation: Mantovani A, Sica A, Locati M. New vistas on macrophage differentiation and activation. Eur J Immunol. 2007 Jan;37(1):14-6. doi: 10.1002/eji.200636910.
citation: Neu C, Sedlag A, Bayer C, Forster S, Crauwels P, Niess JH, van Zandbergen G, Frascaroli G, Riedel CU. CD14-dependent monocyte isolation enhances phagocytosis of listeria monocytogenes by proinflammatory, GM-CSF-derived macrophages. PLoS One. 2013 Jun 11;8(6):e66898. doi: 10.1371/journal.pone.0066898. Print 2013.