SARS-CoV-2 vaccination and ITP in patients with de novo or preexisting ITP.

Cases of de novo immune thrombocytopenia (ITP), including a fatality, following SARS-CoV-2 vaccination in previously healthy recipients led to studying its impact in preexisting ITP. In this study, 4 data sources were analyzed: the Vaccine Adverse Events Reporting System (VAERS) for cases of de novo ITP; a 10-center retrospective study of adults with preexisting ITP receiving SARS-CoV-2 vaccination; and surveys distributed by the Platelet Disorder Support Association (PDSA) and the United Kingdom (UK) ITP Support Association. Seventy-seven de novo ITP cases were identified in VAERS, presenting with median platelet count of 3 [1-9] ×109/L approximately 1 week postvaccination. Of 28 patients with available data, 26 responded to treatment with corticosteroids and/or intravenous immunoglobulin (IVIG), and/or platelet transfusions. Among 117 patients with preexisting ITP who received a SARS-CoV-2 vaccine, 19 experienced an ITP exacerbation (any of: ≥50% decline in platelet count, nadir platelet count <30 × 109/L with >20% decrease from baseline, and/or use of rescue therapy) following the first dose and 14 of 70 after a second dose. Splenectomized persons and those who received 5 or more prior lines of therapy were at highest risk of ITP exacerbation. Fifteen patients received and responded to rescue treatment. In surveys of both 57 PDSA and 43 UK patients with ITP, prior splenectomy was associated with worsened thrombocytopenia. ITP may worsen in preexisting ITP or be identified de novo post-SARS-CoV2 vaccination; both situations responded well to treatment. Proactive monitoring of patients with known ITP, especially those postsplenectomy and with more refractory disease, is indicated.

VITT following Ad26.COV2.S vaccination presenting without radiographically demonstrable thrombosis.

We report a case of vaccine-induced immune thrombotic thrombocytopenia (VITT) in a young man diagnosed 13 days after Ad26.COV2.S COVID-19 (Johnson & Johnson/Janssen) vaccination. He presented to us with 5 days of progressive left leg pain, thrombocytopenia, hypofibrinogenemia, and markedly elevated d-dimers, but without radiographically demonstrable thrombosis. Despite negative imaging, we initiated treatment of presumptive VITT given the striking clinical picture that included the timing of his recent adenovirus-based COVID-19 vaccine, leg symptoms, marked thrombocytopenia, and consumptive coagulopathy. He received intravenous immune globulin, prednisone, and argatroban and was discharged 7 days later much improved. His positive platelet factor 4 enzyme-linked immunosorbent assay antibody test returned after treatment was initiated. To our knowledge, this is the first reported case of VITT following Ad26.COV2.S vaccination presenting without radiographically demonstrable thrombosis. Our patient highlights the importance of knowing vaccine status and initiating treatment as soon as possible in the right clinical setting, even in the absence of radiographic evidence of thrombus. Early VITT recognition and treatment provide an opportunity to prevent serious thrombotic complications.