Frequency of Thrombocytopenia and Platelet Factor 4/ Heparin Antibodies in Patients with Cerebral Venous Sinus Thrombosis Prior to the COVID-19 Pandemic
Mayte Sánchez van Kammen, MD; Mirjam R. Heldner, MD, MSc; Justine Brodard, MSc; Adrian Scutelnic, MD; Suzanne Silvis, MD, PhD; Verena Schroeder, PhD; Johanna A. Kremer Hovinga, MD; Saskia Middeldorp,MD, PhD; Marcel Levi, MD, PhD; Sini Hiltunen, MD, PhD; Erik Lindgren, MD; MaryamMansour, MD; Antonio Arauz, MD, PhD; Miguel A. Barboza, MD, PhD; Susanna M. Zuurbier,MD, PhD; Diana Aguiar de Sousa, MD, PhD; Jose M. Ferro,MD, PhD; Urs Fischer,MD, MSc; Thalia S. Field, MD, MHSc; Katarina Jood, MD, PhD; Turgut Tatlisumak, MD, PhD; Jukka Putaala, MD, PhD; Marcel Arnold, MD; Jonathan M. Coutinho,MD, PhD
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July 2nd, 2021
IMPORTANCE: Cases of cerebral venous sinus thrombosis in combination with thrombocytopenia have recently been reported multiple times within 4 to 28 days of vaccination with the ChAdOx1 nCov-19 (AstraZeneca/Oxford) and Ad.26.COV2.S (Janssen / Johnson & Johnson) COVID-19 vaccines. An immune-mediated response associated with platelet factor 4/heparin antibodies has been proposed as the underlying pathomechanism.
OBJECTIVE: To determine the frequencies of admission thrombocytopenia, heparin-induced thrombocytopenia, and presence of platelet factor 4/heparin antibodies in patients diagnosed with cerebral venous sinus thrombosis prior to the COVID-19 pandemic.
DESIGN, SETTING, AND PARTICIPANTS: This was a descriptive analysis of a retrospective sample of consecutive patients diagnosed with cerebral venous sinus thrombosis between January 1987 and March 2018 from 7 hospitals participating in the International Cerebral Venous Sinus Thrombosis Consortium from Finland, the Netherlands, Switzerland, Sweden, Mexico, Iran, and Costa Rica.
Of 952 patients, 865 with available baseline platelet count were included. In a subset of 93 patients, frozen plasma samples collected during a previous study between September 2009 and February 2016 were analyzed for the presence of platelet factor 4/heparin antibodies.
EXPOSURES: Diagnosis of cerebral venous sinus thrombosis.
MAIN OUTCOMES AND MEASURES: Frequencies of admission thrombocytopenia (platelet count 0.4, in a subset of patients with previously collected plasma samples).
RESULTS: Of 865 patients (median age,