COVID-19 Vaccination-Associated Spontaneous Heparin-Induced Thrombocytopenia Syndrome

Abstract

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has emerged as the deadliest outbreak in recent American history, surpassing the estimated U.S. fatalities from the 1918 influenza pandemic. Since its identification in December 2019 in Wuhan, China, COVID-19 has contributed to the death of nearly six million people worldwide. The United States (U.S.) Food and Drug Administration (FDA) initially issued emergency use authorization for three vaccines for prevention of COVID-19, and currently two have received full FDA approval. Herein, we report a case of severe thrombocytopenia in a man following heterologous booster vaccination with the Pfizer-BioNTech COVID-19 vaccine with concomitant presence of a heparin-P4 antibody but without proximate heparin exposure. The degree of thrombocytopenia was severe, but the patient had a natural recovery of platelet count over the next 2 weeks without need for any immunomodulatory therapies. This is the first case report of COVID vaccine-associated heparin-induced thrombocytopenia (HIT)-like platelet disorder without proximate heparin exposure, also called spontaneous HIT syndrome. Keywords: Thrombocytopenia, Cor