First report of a de novo iTTP episode associated with an mRNA‐based anti‐COVID‐19 vaccination

Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially life‐threatening thrombotic microangiopathy, characterized by disseminated thrombus formation in the microvasculature, causing severe organ failure. Immune‐mediated TTP (iTTP) is occasionally described after vaccination, especially against viral agents. We report a case of a 38‐year‐old woman with a de novo iTTP after exposure to the mRNA‐based anti‐coronavirus disease 2019 (COVID‐19) vaccine produced by Pfizer‐BioNTech. She presented with increased bruising and petechiae starting 2 weeks after receiving the first dose of the anti‐COVID‐19 vaccine. Laboratory data revealed a severe ADAMTS13‐deficiency in combination with a very high autoantibody titer against ADAMTS13. She was successfully treated with plasma exchange, corticosteroids, rituximab, and caplacizumab. To our knowledge, this is the first case report of iTTP after mRNA‐based COVID‐19 vaccination in a previously TTP‐naïve patient.