Monocyte Profiles in Critically Ill Patients With Pseudomonas Aeruginosa Sepsis

Recruiting

• Conditions: Pseudomonas Infections; Pseudomonas; Pneumonia; Pseudomonal Bacteraemia; Sepsis, Severe; Pseudomonas Septicemia; Pseudomonas Urinary Tract Infection; Pseudomonas Gastrointestinal Tract Infection; Sepsis; Critically Ill

• Registration Number: NCT03044223
• Lead Sponsor: University of Ulm

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

Study Timeline

• Study Start: 2014-08
• Study First Submitted: 2017-02-02
• Study First Submitted QC: 2017-02-02
• Study First Posted: 2017-02-06
• Status Verified: 2024-01
• Last Update Submitted: 2024-01-16
• Last Update Posted: 2024-01-17
• Primary Completion: 2025-11
• Study Completion: 2026-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 100

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Monocyte surface marker expression in critically ill patients with Pseudomonas aeruginosa sepsis	two years	Monocyte type 1, type 2 surface marker expression

Secondary Outcome Measures

Name	Time	Method
Cytokine concentrations in serum and production after ex-vivo stimulation of isolated monocytes of critically ill patients with Pseudomonas aeruginosa sepsis with LPS	four years	IL-8 and IFN-gamma

Trial Locations

Locations (1)

Clinic of Anesthesiology; 🇩🇪 Ulm, Germany