How common was thrombocytopenia in patients with cerebral venous sinus thrombosis prior to the pandemic?

Takeaway

  • The frequency of thrombocytopenia and heparin-induced thrombocytopenia (HIT) was rare in patients with cerebral venous sinus thrombosis (CVST) before the pandemic, and antibodies against platelet factor 4 (PF4)/heparin were not detected.

Why this matters

  • Vaccine-induced immune thrombotic thrombocytopenia is a rare adverse effect that has been reported in some patients receiving the AstraZeneca/Oxford and Janssen/Johnson & Johnson COVID-19 vaccines.

  • The findings of this study may inform investigations into the association between these vaccines and the occurrence of CVST with thrombocytopenia.