ABSTRACT
Vaccine-induced thrombotic thrombocytopenia (VITT) is a newly-described hematologic disorder which presents as acute thrombocytopenia and thrombosis after administration of adenovirus-based vaccines against COVID-19. Due to positive assays for antibodies against platelet factor 4 (PF4), VITT is managed similarly to autoimmune heparin-induced thrombocytopenia (HIT) with intravenous immunoglobulin (IVIG) and non-heparinoid anticoagulation. We describe a case of VITT in a 50-year-old man with antecedent alcoholic cirrhosis who presented with platelets of 7 × 10 3 /µL and portal vein thrombosis 21 days following administration of the Ad26.COV2.S COVID-19 vaccine. The patient developed progressive thrombosis and persistent severe thrombocytopenia despite IVIG, rituximab and high-dose steroids and had persistent anti-PF4 antibodies over 30 days after his initial presentation. As such, delayed therapeutic plasma exchange (TPE) was pursued as salvage therapy, with a rapid and sustained improvement in his platelet count. Our case serves as proof-of-concept of the efficacy of TPE in VITT.