Prospective investigation of the incidence of anti-platelet factor 4 antibodies in suspected immune-associated arterial and/or venous thrombosis

Patients with venous and/or arterial thrombosis aged 18 to 60 years are included.Thromboses should have occurred spontaneously or within 30 days after an infection or vaccination. In addition, patients with recurrent thrombosis, despite anticoagulation, are also included in the study. The primary aim of the study is to determine the incidence of anti-platelet factor 4 antibodies in relation to venous and/or arterial thrombosis. For this purpose, we will take a blood sample from the patients within 120 days of the occurrence of the thrombosis.

As a secondary objective, platelet count, D-dimer and results of a thrombophilia screening as well as thrombosis localization are recorded.

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

Patients with venous and/or arterial thromboses that occur spontaneously, in association with infections or vaccinations or recurrently and are not associated with the presence of typical risk factors.