key: cord-0965310-h14au6l6 authors: Hamada, Eriko; Sakai, Kazuya; Yamada, Shinya; Kubo, Masayuki; Hayakawa, Masaki; Matsumoto, Masanori title: No aggravation of congenital thrombotic thrombocytopenic purpura by mRNA-based vaccines against COVID-19: a Japanese registry survey date: 2022-02-04 journal: Ann Hematol DOI: 10.1007/s00277-022-04774-2 sha: 54b9a62754c80b4e5449b7276c86876465a8b43f doc_id: 965310 cord_uid: h14au6l6 nan yet received them. Table 1 presents the results for these 38 patients. Of these, 24 patients were administered prophylactic fresh frozen plasma (FFP) infusions at 2-3 weeks interval to prevent TTP episodes, and three were involved in clinical trials of recombinant ADAMTS13. Regarding the type of COVID-19 vaccination, 35 patients received BNT162b2, one received mRNA-1273, and the data for two patients were unknown. No severe adverse effects of vaccination, especially exacerbation of cTTP, were observed, and platelet counts after vaccinations were unchanged compared with the pre-vaccination levels. All patients receiving FFP infusion were vaccinated within 2 weeks of FFP infusion. In contrast, the patient reported by Dykes et al. underwent vaccination 6 weeks after OctaPlas™ (solvent/detergent treated, pooled human plasma) infusion and developed ischemic stroke 1 week after vaccination [6] . We hypothesize that a long interval between plasma infusion and vaccination could be a risk factor for cTTP exacerbation. We believe that all patients with cTTP should receive COVID-19 vaccination based on the following considerations: 1) It is desirable to maintain a platelet count of 50,000/μL or higher at the time of vaccination. This is due to the possibility of intramuscular hematoma in cases of severe thrombocytopenia. should be vaccinated as soon as possible (preferable within 7 days) after the infusion. Physicians should pay attention to any changes in the physical condition of patients after vaccination. Hereditary thrombotic thrombocytopenic purpura Morbidities and mortality in patients with hereditary thrombotic thrombocytopenic purpura Natural history of Upshaw-Schulman syndrome based on ADAMTS13 gene analysis in Japan Current prophylactic plasma infusion protocols do not adequately prevent long-term cumulative organ damage in the Japanese congenital thrombotic thrombocytopenic purpura cohort Peyvandi F (2021) The ADAMTS13-von Willebrand factor axis in COVID-19 patients First report of COVID-19 vaccine induced flare of compensated congenital thrombotic thrombocytopenic purpura First report of a de novo iTTP episode associated with an mRNA-based anti-COVID-19 vaccination Acquired thrombotic thrombocytopenic purpura following BNT162b2 mRNA coronavirus disease vaccination in a Japanese patient The authors thank the physicians for sharing the