key: cord-0937849-vme0np71
authors: van Dijk, Wobke E. M.; Schutgens, Roger E. G.
title: Relapse of immune thrombocytopenia after COVID‐19 vaccination
date: 2021-10-17
journal: Eur J Haematol
DOI: 10.1111/ejh.13713
sha: 985d41489d924acc683f9fbe7a071f3ead60381f
doc_id: 937849
cord_uid: vme0np71

Patients with immune thrombocytopenia (ITP) are worldwide offered vaccination against COVID-19, but these have been associated with thrombocytopenia.1-6 We conducted this pragmatic single-centre retrospective cohort study to assess whether COVID-19 vaccination induces relapses in patients with pre-existing ITP.

To the Editor:

Patients with immune thrombocytopenia (ITP) are worldwide offered vaccination against COVID-19, but these vaccines have been associated with thrombocytopenia. [1] [2] [3] [4] [5] [6] We have conducted this pragmatic single-centre retrospective cohort study to assess whether COVID-19 vaccination induces relapses in patients with pre-existing ITP. Eighty five ITP patients were included (mean age 48 ± 17 years, 53% female, 82% primary ITP, median ITP duration 7 (interquartile range (IQR): 3-16) years). The median time between the last available platelet count and the first injection was 29 (IQR:

After the first injection (n = 85), 8% had a relapse (2 observed, 5 possible). In one of the observed relapses, the ITP treatment was intensified. Within the patients who experienced increased bleeding (n = 10), 20% had a fall in platelet count of ≥50% ( Figure 1A ; two out of five (40%) patients who obtained platelets counts). This 20% was significantly more often than the 1% in patients without bleeding (n = 75; P = .04). After the second injection (n = 81), 4% had a relapse (1 observed, 2 possible). A fall in platelet count of ≥50% occurred as frequently in patients with (n = 3) and without (n = 78) increased bleeding (0% versus 4%; P = 1.00) ( Figure 1B ).

In our study, 8% of the ITP patients clinically relapsed after the first COVID-19 injection and 4% after the second. A fall in platelet count was more likely in the presence of bleeding symptoms, but only after the first injection.

A recent prospective study found a relapse incidence of 12%. 7

As reported by the author, this may be an overestimation due to an intensified focus on bleeding complaints resulting from media attention for vaccine-induced thrombotic thrombocytopenia.

In general, ITP relapses after COVID-19 vaccination may occur, particularly after the first injection, and bleeding complaints should prompt checking platelet counts.

The authors declare to have no potential conflict of interest.

Immune thrombocytopenic purpura after SARS-CoV-2 vaccine

Immune thrombocytopenia in a 22-year-old post Covid-19 vaccine

Secondary immune thrombocytopenia supposedly attributable to COVID-19 vaccination

Severe, refractory immune thrombocytopenia occurring after SARS-CoV-2 vaccine

Immune thrombocytopenia and COVID-19: Case report and review of literature

Outcomes and management of immune thrombocytopenia secondary to COVID-19: cleveland clinic experience

Exacerbation of immune thrombocytopenia following COVID-19 vaccination