Characterization and Quantification of Platelet/Leukocyte Aggregates in Patients With Suspected Heparin-induced Thrombocytopenia

Not Applicable

Recruiting

• Conditions: Heparin-induced Thrombocytopenia; HIT; Platelet Activation; Platelets; Leukocytes; Platelet/Leukocyte Aggregates; HITSTREAM; Flow Cytometry
• Interventions: Biological: blood sample

• Registration Number: NCT06033300
• Lead Sponsor: Centre Hospitalier Universitaire, Amiens

Brief Summary

The investigators would like to analyze platelet/leukoplak activation, quantify and morphologically characterize these aggregates using in vitro analysis, directly on whole blood from adult patients with suspected HIT. This would enable to better describe the in vivo pathophysiology of the HIT-suspect patient, and eliminate the need for platelet donors to perform the usual confirmatory techniques, whose inter- and intra-individual variability is very high. What's more, the SRA test, evaluated as the reference test, requires the use of radioisotopes and is therefore only carried out in a few biological expertise centers, resulting in a very long delay in the delivery of results. It should also be noted that, in practice, HÉPARINE is immediately stopped in patients with suspected HIT, and they are put on an expensive anticoagulant (DANAPAROIDE SODIQUE or ARGATROBAN) in curative doses until the results of the confirmatory tests are back. In this serious, life-threatening condition, it is essential to have a sensitive, specific test to confirm HIT as quickly as possible. Each patient with suspected HIT (rapid \>30% reduction in platelet count after initiation of heparin therapy) should have 4 tubes of 3.2% citrated whole blood (2.7ml) collected at the time of suspected HIT (D0) and before any therapeutic switch (or 24 h max after switch). A new sample (4 citrated tubes) will be taken at D4, D7 and D14 during hospitalization, in patients who test positive for anti-PF4/H Ac. All patients with suspected HIT will follow the standard diagnostic pathway, i.e. a screening test (immunological test for anti-PF4/heparin antibodies, total Ig, ACL TOP, Werfen) followed by a confirmatory test (platelet aggregation on TA-8V, STAGO and/or SRA). Doppler ultrasonography of the lower limbs will be performed in HIT-suspect patients with a positive anti-PF4/H antibody test, as currently performed as part of routine care.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-04-17
• Study First Submitted: 2023-09-05
• Study First Submitted QC: 2023-09-05
• Study First Posted: 2023-09-13
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-21
• Last Update Posted: 2025-05-25
• Primary Completion: 2026-04
• Study Completion: 2026-04

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

• Age > 18 years
• Any adult patient suspected of having HIT, with a positive anti-PF4/H antibody test
• Patient signed consent to study participation
• Patient with social security coverage

Exclusion Criteria

• All adult patients with suspected HIT and negative anti-PF4/H antibody test.
• Protected adults (guardianship, under curators) or deprived of liberty

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
suspected heparin-induced thrombocytopenia:	blood sample	-

Primary Outcome Measures

Name	Time	Method
percentage of CD41a+/CD45- platelet clusters	day 1	percentage of CD41a+/CD45- platelet clusters relative to platelet count by Flow Imaging ImageStream

Trial Locations

Locations (1)

CHU Amiens; 🇫🇷 Amiens, France