Treatment, outcome and re-vaccination of patients with SARS-CoV-2 vaccine-associated immune thrombocytopenia

Abstract

Purpose: Following the emergency use authorization of BNT162b2 by the Food and Drug administration (FDA) in early December 2020, mRNA- and vector-based vaccines became an important means of reducing the spread and mortality of the COVID-19 pandemic. The European Medicines Agency labelled immune thrombocytopenia (ITP) as a rare adverse reaction of unknown frequency after vector-, but not mRNA-vaccination. Here, we report on the long-term outcome of 6 patients who were diagnosed with de-novo, vaccine-associated ITP (VA-ITP), and on the outcome of subsequent SARS-CoV-2 re-vaccinations.

Methods: Patients were included after presenting to our emergency department. Therapy was applied according to ITP guidelines. Follow-up data were obtained from outpatient departments. Both mRNA- or vector-based vaccines were each used in 3 cases, respectively.

Results: In all patients, the onset of symptoms occurred after the 1st dose of vaccine was applied. 5 patients required treatment, 3 of them 2nd line therapy. All patients showed a complete response eventually. After up to 359 days of follow-up, 2 patients were still under 2nd line therapy with thrombopoietin receptor agonists. 5 patients have been re-vaccinated with up to 3 consecutive doses of SARS-CoV-2 vaccines, 4 of them showing stable platelet counts hereafter.

Conclusion: Thrombocytopenia after COVID-19 vaccination should trigger a diagnostic workup to exclude vaccine-induced immune thrombotic thrombocytopenia (VITT) and, if confirmed, VA-ITP should be treated according to current ITP guidelines. Re-vaccination of patients seems feasible under close monitoring of blood counts and using a vaccine that differs from the one triggering the initial episode of VA-ITP.

Keywords: COVID-19; COVID-19 vaccine; Immune thrombocytopenia; Post-vaccinal ITP; SARS-CoV-2; Vaccine-associated ITP.

Fig. 1

Response to therapy in patient 1. Day 0 is the time point of the first SARS-CoV-2 vaccination, simultaneously with which a SARS-CoV-2 infection was diagnosed by PCR test for the first time. The platelet count, laboratory parameters and treatment with IVIGs are depicted starting at the day of admission (day 7). Steroids (prednisolone 100 mg/day) were applied from day 6 to 19

Fig. 2

Treatment and course of disease including SARS-CoV-2 re-vaccinations after VA-ITP. Treatment of VA-ITP is depicted by colored bars. Partial and complete responses are indicated by circles. Relapse and persistent thrombocytopenia are reflected by the respective red symbols. Follow-up time, starting at admission, is visualized by the horizontal lines. SARS-CoV-2 re-vaccinations and their respective count are indicated by the serrated arrows