Atherothrombosis Markers in Diabetics (MADI)

Comparison of Atherothrombosis Markers From Aortic Atheroma in Diabetic and Non-diabetic Patients

Intraplaque hemorrhage is the driving force of atherothrombotic plaque vulnerability to rupture and associated clinical complications. Polymorphonuclear neutrophils (PMNs) represent about 70% of leukocytes and may constitute a source of proteases and oxidants that favour plaque rupture. Our objective is to evaluate PMN activation in atherosclerotic plaque of non-diabetic versus type 2 diabetic patients. For this purpose, investigators will quantify the presence of cell-free DNA, that reflect the formation of neutrophil extracellular traps (NETs) in carotid endarterectomy samples.

Study Overview

• Status: Unknown
• Conditions: Cardiovascular Disease; Diabetes; Atherothrombosis
• Intervention / Treatment: Other: diabetics; Other: non-diabetics

Detailed Description

Atherothrombotic plaques of type 2 diabetic patients are characterized by increased neovascularization and associated intraplaque hemorrhage relative to non-diabetic patients that could account for a major incidence of clinical complications. In parallel, Type 2 diabetic patients are characterized by an increased intracellular oxidative stress in circulating PMNs leading to a primed phenotype. PMN priming could be triggered via their receptor for advanced glycation endproducts. In particular, glycated albumin may activate NADPH oxidase and thus promote the production of reactive oxygen species. Under strong activation, PMNs have been described to release NETs that are constituted by externalized nucleosomes associating DNA, histones and enzymes initially present in granules (such as myeloperoxidase, matrix metalloproteinase 9 or elastase). Our hypothesis is that in diabetic conditions, PMNs could be activated within atherothrombotic plaques and thus represent a trigger for plaque rupture. In the present study, we will evaluate PMN activation in carotid plaques of diabetic vs non-diabetic patients as well as in plasma samples of the same patients. For this purpose, all patients that will undergo carotid surgery by endarterectomy will be enrolled in our study and blood samples will be collected the day before the surgery for preparation of plasma and serum. The endarterectomy sample will be collected, dissected into culprit area of the plaque (CP) and the adjacent non-complicated plaque (NCP), incubated separately in culture medium for 24h at 37°C. The resulting conditioned medium will be aliquoted and stored at -80°C for the different assessments. A representative section of the CP will be saved at the moment of dissection for histological evaluation (presence of neovessels/intraplaque hemorrhage, calcifications, lipids, etc). Markers of neutrophil activation, of intraplaque hemorrhage, of glycation and of oxidative stress will be quantified in both conditioned medium and plasma.

• Study Type: Observational
• Enrollment (Anticipated): 100

Contacts and Locations

• Study Contact: Name: CHRISTINE JUHEL, PHD; Phone Number: +262262359949; Email: christine.juhel@chu-reunion.fr

Study Locations

• France
  • Saint Denis de La Réunion, France, 97405
    • Department of endocrinology, University Hospital Reunion Island - Felix Guyon Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Diabetics and non-diabetics with planned endartectomy

Description

Inclusion Criteria:

• Adult patients with planned endarterectomy
• Affiliated to social security rights
• Signed inform consent

Exclusion Criteria:

• pregnancy
• Autoimmune disease, chronic inflammatory disease, neoplasia
• Type 1 diabetes

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
diabetics; Type 2 diabetic patients exhibiting fasting glycemia value over 7 mmol/L or glycated hemoglobin value over 6.5% or type 2 diabetic patients under oral anti-diabetic treatment or type 2 diabetic patient under insulin treatment and in which diabetes has been diagnosed after the age of 45 y	Other: diabetics; additional blood and urine collection during usual medical care endarterectomy samples during usual medical care
non-diabetics; patients without diagnosed diabetes exhibiting fasting glycemia value under 7 mmol/L	Other: non-diabetics; additional blood and urine collection during usual medical care endarterectomy samples during usual medical care

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neutrophile activation assessed by free DNA levels in atherothrombotic plaques	Ability of cfDNA concentration in the conditioned medium to discriminate atherothrombotic plaques from diabetic vs non-diabetic patients	On day 1 (day of the surgery)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neutrophile activation assessed by other makers than free DNA levels in atherothrombotic plaques	Evaluation of PMN activation by assays other than cfDNA (myeloperoxidase, elastase/antielastase complexes, MMP9/neutrophil-gelatinase associated lipocalin NGAL) in the conditioned media and in plasma	On day 1 (day of the surgery)
Intraplaque hemorrhage and oxidative stress assessed in plasma and aortic tissue	Evaluation of markers reflecting the presence of intraplaque hemorrhage and of oxidative stress in conditioned medium and in plasma (CD163, heme, carbonylated proteins, glycated albumin...)	From day 0 (day before the surgery) to day 1 (day of the surgery)
Correlation between plasma and atherothrombotic plaque markers assessement	Correlations between markers released by the plaque and plasma markers (evaluation of the impact of atherothrombosis at a circulating level)	From day 0 (day before the surgery) to day 1 (day of the surgery)
Atherothrombosis characterization assessed by histological analysis	Histological characterization of plaques assessed by quantification of neovessels, calcification, lipids composition	On day 1 (day of the surgery)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Banking of biological samples	Constitution of a biobank available for different assays of markers and for the discovery of new biomarkers of plaques in type 2 diabetic patients (open approaches, such as differential proteomics)	From day 0 (day before the surgery) to day 1 (day of the surgery)

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de la Réunion
• Collaborators: Academic Health Science Centres
• Investigators: Principal Investigator: XAVIER DEBUSSCHE, MD, CHU de la Réunion

Study record dates

Study Major Dates

• Study Start: October 1, 2016
• Primary Completion (Anticipated): November 1, 2018
• Study Completion (Anticipated): June 1, 2019

Study Registration Dates

• First Submitted: September 8, 2016
• First Submitted That Met QC Criteria: September 12, 2016
• First Posted (Estimate): September 13, 2016

Study Record Updates

• Last Update Posted (Estimate): September 13, 2016
• Last Update Submitted That Met QC Criteria: September 12, 2016
• Last Verified: September 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 2013/CHU/06

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO