The Role of Platelet TLRs in Platelet Activation During VTE (ROT-PLAT-VTE)

Venous thromboembolic disease (VTE) is a frequent and potentially serious pathology. Therapeutic management has improved considerably over the last few decades, enabling the application of codified management in line with the recently updated French management recommendations.

One of the main remaining difficulties concerns VTE sequelae, mainly post-thrombotic syndrome after deep vein thrombosis, and post-pulmonary embolism syndrome after pulmonary embolism. The mechanisms leading to the absence of complete repermeabilization of vessels affected by Venous thromboembolic disease (VTE) are still poorly understood.

The concept of immunothrombosis, closely associating immunity, inflammation and thrombosis, could (in part) explain the appearance of these sequelae. Platelets appear to play a key role in the onset of sequelae: Platelets are known to be involved both in the onset of a VTE episode and in the inflammatory response. This involvement is illustrated by the expression of inflammatory receptors such as TLR (toll-like receptor) 2 and TLR4.

Th aim to investigate the role of platelets in the occurrence of sequelae, mainly via their role in the inflammatory response, in Venous thromboembolic disease (VTE) patients.

Study Overview

• Status: Terminated
• Conditions: Venous Thromboembolism
• Intervention / Treatment: Biological: blood sample; Biological: blood sample

• Study Type: Observational
• Enrollment (Actual): 44

Contacts and Locations

Study Locations

• France
  • Saint-Etienne, France, 42055
    • CHU St-Etienne

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Venous ThromboEmbolic (VTE) patients

Description

Inclusion Criteria:

• Patients diagnosed with Venous ThromboEmbolic (VTE) / Proximal Deep vein thrombosis (DVT) of the lower limb and/or pulmonary embolism ≤ 72heures
• Patients are 18 years of age or older at diagnosis.
• Patients received informed written consent
• Patients benefiting from social security coverage

Exclusion Criteria:

• Diagnosis of Venous ThromboEmbolic (VTE) more than 72 hours old
• Isolated sub-segmental pulmonary embolism
• Patients on antiplatelet agents
• Patients on non-steroidal anti-inflammatory drugs (NSAIDs)
• Life expectancy > 3 months

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Venous ThromboEmbolic (VTE) patients; a diagnosis of Venous ThromboEmbolic (VTE) less than 72 hours old at inclusion, with a follow-up of 3 to 6 months	Biological: blood sample; at Day 1 - date of patient inclusion at time of VTE diagnosis; Biological: blood sample; at 6 months (in the patient follow-up)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
expression of TLR2/ TRL4	The characteristic membrane profile of the inflammatory role of platelets is quantified by TLR2/TLR4 receptors expression using flow cytometry. This profile will be compared between patients with VTE sequelae (objectified during follow-up, and defined in accordance with good practice recommendations) 20,21 and patients without VTE sequelae. o A patient with sequelae corresponds to patients who will present during follow-up with a post-thrombotic syndrome (defined by a Villalta score greater than or equal to 5) and/or a post-pulmonary post-pulmonary embolism syndrome (defined by NYHA stage II, III or IV dyspnea, and the presence of perfusion perfusion sequelae on lung scintigraphy).	at day1 and at 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Analysis of characteristic soluble profile of the inflammatory role of platelets	The characteristic soluble profile of the inflammatory role of platelets associated with the existence of sequelae remote from the acute episode of VTE, is quantified by blood assay of platelet immunomodulatory factors (ELISA technique): soluble CD62P, HMGB1, RANTES, PF4, soluble CD40L	at day1 and at 6 months

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Saint Etienne

Study record dates

Study Major Dates

• Study Start (Actual): October 11, 2023
• Primary Completion (Actual): April 9, 2025
• Study Completion (Actual): October 10, 2025

Study Registration Dates

• First Submitted: February 6, 2024
• First Submitted That Met QC Criteria: February 6, 2024
• First Posted (Actual): February 13, 2024

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: platelets; venous thromboembolism; VTE; sequelae; immunothrombosis; inflammatory receptors
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Inflammation; Hematologic Diseases; Embolism and Thrombosis; Blood Coagulation Disorders; Thromboembolism; Thrombosis; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; Thromboinflammation; Venous Thromboembolism; Investigative Techniques; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Blood Specimen Collection
• Other Study ID Numbers: 22CH400; 2023-A00448-37 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No