MedPath

Mediastinitis and Staphylococcus Aureus

Completed
Conditions
Infection
Surgery, Cardiac
Interventions
Other: No intervention
Registration Number
NCT03262558
Lead Sponsor
Rennes University Hospital
Brief Summary

Cardiac surgery with extracorporeal circulation (ECC) yields a deep immune system dysfunction that exposes patients to postoperative infectious complications. Among these, post-operative mediastinitis with Staphylococcus aureus (SA) generates significant morbidity and mortality. Two radically different approaches have been proposed in recent years to reduce the incidence of this complication. A first approach has attempted, without real success, to decrease postoperative immunosuppression. The second, more efficient, consisted of screening and preoperatively treating patients colonized with SA. However, although its incidence has decreased, postoperative mediastinitis remains a terrible nosocomial infection. The authors believe that a thorough analysis of the immunological changes induced by cardiac surgery will initiate active therapeutics to reduce the post-operative immunosuppression phase, thereby decreasing the risk of nosocomial infections. In addition, a study of the interactions between the operated (host) and staphylococcus aureus (pathogenic) immune systems will provide a better understanding of the mechanisms that expose patients to this bacterium.

Detailed Description

In particular, changes induced by the ECC will be evaluated on:

* Indoleamine 2,3-dioxygenase activity (IDO)

* Apoptosis of lymphocytes and dendritic cells

* Polymorphonuclear neutrophils (PMNs)

* Myeloid Derived Suppressor Cells (MDSC )

After general anesthesia and arterial catheterization and prior to the start of ECC, blood samples will be taken for flow cytometry studies, for the purification of PMNs and monocytes. The purified PMNs and monocytes will then be used for the measurement of cytokine, phagocytosis and bactericidal production capacities.

The morning following surgery, blood samples will be taken and follow the same process.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
27
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Patients with ECCNo interventionNo intervention
Primary Outcome Measures
NameTimeMethod
Variation of plasma IDO activityBaseline and the morning following surgery

IDO activity is evaluated by the Kynurenin / Tryptophan ratio before and after ECC.

Enzymatic activities will be measured by high performance liquid chromatography (HPLC) on pre- and post-operative blood tests

Secondary Outcome Measures
NameTimeMethod
Quantification of lymphocytic apoptosis before and after the ECCBaseline and the morning following surgery

Quantification of apoptosis by flow cytometry

Variation of bactericidal capacity of PMNsBaseline and the morning following surgery

Comparison before and after ECC

Effect of an inhibitor of IDO on phagocytosis capacities of PMNsThe day following surgery
Variation of phagocytosis capacity of PMNsBaseline and the morning following surgery

Comparison before and after ECC

Variation of bactericidal capacity of macrophagesBaseline and the morning following surgery

Comparison before and after ECC

Effect of an inhibitor of IDO on phagocytosis capacities of macrophagesThe day following surgery
Effect of an inhibitor of IDO on bactericidal capacities of macrophagesThe day following surgery
Quantification of lymphocytic apoptosis in the presence of an inhibitor of IDOThe day following surgery

Quantification of apoptosis by flow cytometry

Variation of phagocytosis capacity of macrophagesBaseline and the morning following surgery

Comparison before and after ECC

Effect of an inhibitor of IDO on bactericidal capacities of PMNsThe day following surgery

Trial Locations

Locations (1)

Rennes Hospital University

🇫🇷

Rennes, France

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