Investigating anti-platelet factor 4 antibodies in patients with thrombosis

The APIT Study: Prospective Observational Study of the Incidence of Anti-platelet Factor 4 Antibodies in Suspected Immune-associated Arterial and/or Venous Thrombosis

Observational Cardioangiologisches Centrum Bethanien · NCT06650826

This study is trying to see if certain antibodies are present in adults aged 18 to 60 who have had blood clots, even after being treated with blood thinners.

Quick facts

Study typeObservational
Enrollment200 (estimated)
Ages18 Years to 60 Years
SexAll
SponsorCardioangiologisches Centrum Bethanien Academic / other
Locations2 sites (Berlin and 1 other locations)
Trial IDNCT06650826 on ClinicalTrials.gov

What this trial studies

This observational study aims to investigate the incidence of anti-platelet factor 4 antibodies in patients aged 18 to 60 years who have experienced spontaneous or infection- or vaccine-associated arterial and/or venous thrombosis. Participants will have blood samples taken within 120 days of their thrombosis event to assess the presence of these antibodies. Additionally, the study will collect data on platelet counts, D-dimer levels, and results from thrombophilia screenings to better understand the relationship between these factors and thrombosis. The study includes patients with recurrent thrombosis despite anticoagulation treatment.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 18 to 60 years with spontaneous or infection- or vaccine-associated arterial and/or venous thrombosis.

Not a fit: Patients with thrombosis related to known risk factors such as surgery or chronic vascular conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved understanding and management of thrombosis in patients with anti-platelet factor 4 antibodies.

How similar studies have performed: While the investigation of anti-platelet factor 4 antibodies is a recognized area of interest, this specific observational approach is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age between 18-60 years
* Written informed consent of the patient
* Spontaneous arterial and/or venous thrombosis
* infection-associated arterial and/or venous thrombosis within 30 days of infection
* Vaccine-associated arterial and/or venous thrombosis within 30 days of vaccination
* Recurrent arterial or venous thrombosis despite anticoagulant therapy

Exclusion Criteria:

* Lack of consent of the patient
* Risk-associated venous thromboses (e.g. following surgery, immobilization, plaster cast, fractures or sprains)
* Risk-associated arterial thromboses (in the presence of vascular risk factors such e.g. diabetes mellitus, hypercholesterolemia, hypertension, nicotine abuse)
* Thromboses more than 120 days old at the time of blood sampling

Where this trial is running

Berlin and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Arterial or Venous ThrombosisAnti-PF4 antibodiesinfectionsvaccination
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.