key: cord-1009976-bnhewrp6
authors: Bakchoul, Tamam; Singh, Anurag
title: Vaccinations and ITP: keep on track(ing)
date: 2022-03-10
journal: Blood
DOI: 10.1182/blood.2021014193
sha: a5ee95f8c714a916bc297371e5d8733665d31df6
doc_id: 1009976
cord_uid: bnhewrp6

nan

In this issue of Blood, Lee et al report a retrospective analysis of the effects of SARS-CoV-2 vaccination on thrombocytopenia in patients with immune thrombocytopenia (ITP). 1 This study shows that SARS-CoV-2 vaccines are safe in general for patients with preexisting ITP. Although the data presented should encourage the administration of both the doses of 2-dose vaccines to counter the virus, the authors also observed that thrombocytopenia exacerbations may occur, and, hence, careful monitoring is required. The authors emphasize the need for more careful postvaccination tracking of vulnerable patient groups, such as those who have had splenectomy and those who have received 5 or more therapies for ITP because they have a higher risk for worsening thrombocytopenia.

A major breakthrough was achieved in the ongoing COVID-19 pandemic by the rapid development, emergency rollout, and administration of several vaccines against SARSCoV-2 coronavirus. 2 There has also been a global push to understand potential side effects, especially in patients with comorbidities. Although SARS-CoV-2 vaccines are largely effective and safe, with the increasing number of vaccinated individuals across the world, there have been reports of thrombocytopenia after vaccinations with SARS-CoV-2 vaccines. 3 The goal of the study by Lee et ) .

In 109 patients identified with preexisting ITP who received a SARS-CoV-2 vaccine, approximately 20% experienced an ITP exacerbation following the first dose with 14 of 70 patients having an exacerbation after the second dose. Data from the Platelet Disorder Support Association (57 patients) and UK surveys (43 patients) confirmed the absence of severe bleeding but identified splenectomy as a risk factor for an ITP exacerbation. Along with splenectomy, 5 or more prior lines of therapy for ITP was also shown to increase risk of exacerbation. Response to treatment and outcomes were also favorable in the patients with preexisting ITP, and no major bleeds were reported after vaccination. Therefore, the authors concluded that ITP might worsen in some patients with preexisting ITP, or may occur de novo post-SARS-CoV-2 vaccination. However, under both circumstances, patients respond well to treatment regimes. Most importantly, although vaccinations were applied intramuscularly, no local vaccination-related hematomas were reported in this study. Authors recommend, however, a proactive monitoring of platelet counts for patients with known ITP, and especially those in high-risk groups including postsplenectomy and more refractory disease. Cases of de novo ITP were reported previously in healthy recipients following SARS-CoV-2 vaccination followed with a broad global attention. 4, 5 Although rare but serious adverse events have also been reported with a higher fatality rate after ChAdOx1 nCoV-19 (AstraZeneca) vaccination. 6, 7 These thrombotic events associated with thrombocytopenia after vaccination against SARS-CoV-2 are collectively referred as vaccine-induced immune thrombotic thrombocytopenia or thrombosis with thrombocytopenia syndrome. 8 Cases of thrombosis, including cerebral venous sinus thrombosis, associated with severe thrombocytopenia have also been reported after administration of Ad26.COV2.S vaccine (Johnson & Johnson/Janssen). 9 This important study comes in a timely manner because of considerably growing vaccine hesitancy and uncertainty among high-risk patient groups, general population, and physicians caring for high-risk patient groups. Therefore, reassuring data regarding successful treatment of de novo as well as preexisting ITP will have significant impact on patient management and care for ITP patients after vaccination. Pharma GmbH, and Novo Nordisk Pharma GmbH; has provided consulting services to Terumo; and has provided expert witness testimony relating to heparin-induced thrombocytopenia and non-heparin-induced thrombocytopenia thrombocytopenic and coagulopathic disorders. All of these are outside the current work. A.S. declares no competing financial interests. n R E F E R E N C E S

SARS-CoV-2 vaccination and ITP in de novo or pre-existing ITP patients

COVID research: a year of scientific milestones

COVID-19 vaccination and immune thrombocytopenia

Thrombocytopenia following Pfizer and Moderna SARS-CoV-2 vaccination

Thrombotic thrombocytopenia after ChAdOx1 nCov-19 vaccination

Antibody-mediated procoagulant platelets in SARS-CoV-2-vaccination associated immune thrombotic thrombocytopenia

Pathologic antibodies to platelet factor 4 after ChAdOx1 nCoV-19 vaccination

Summary of thrombocytopenia events after SARS-CoV-2 vaccination. Individuals without a previously reported platelet disorders and suspected de novo ITP were identified in the Vaccine Adverse Events Reporting System. In patients with preexisting ITP, splenectomy and/or 5 more prior therapies led to a greater risk of exacerbation. Both groups of patients responded well to therapy.