Abstract

Background: Coronavirus disease 2019 (COVID-19) vaccination has been associated with immune thrombocytopenic purpura (ITP) exacerbation, with worsening thrombocytopenia and bleeding manifestations seen in reported cases. We conducted a systematic review and meta-analysis to explore factors associated with ITP exacerbation post-COVID-19 vaccination. Method(s): A search was conducted across multiple databases (PubMed, Google Scholar, Cochrane, VHL, WOS, Embase, Scopus) as well as handsearch. We included studies published from 2020 to April 2023 with patients with prior or current ITP who received at least 1 COVID-19 vaccination, and compared ITP patients who developed ITP exacerbations post-COVID-19 vaccination to those who did not. Isolated case reports were excluded. The risk of bias was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) checklists. Extracted data was analysed using restricted maximum likelihood (REML) random effects models. Result(s): A total of 811 articles were screened and 6 studies were included for analysis from multiple countries, including 4 retrospective cohort studies, 1 prospective cohort study and 1 prospective case-control study. Data was pooled with a pre-existing database from a local tertiary paediatric hospital. Across 569 patients, we found factors associated with ITP exacerbation included: ongoing active treatment (of any kind, excluding platelet transfusions) at the time of the first vaccination dose [pooled odds ratio (OR) 3.43, 95% confidence interval (CI): 1.87-6.29, P<0.001], treatment with rituximab at the time of vaccination or at any time during the disease course prior to vaccination (pooled OR 3.06, 95% CI: 1.68-5.58, P<0.001) and treatment with thrombopoietin agonists at the time of vaccination or at any time during the disease course prior to vaccination (pooled OR 4.32, 95% CI: 2.20 to 8.49, P<0.001). Sensitivity analysis for the above factors yielded similar significance. The meta-analysis was limited by the number of available studies. Conclusion(s): COVID-19 vaccination may increase the risk of ITP exacerbations in certain patients as highlighted above. Further large-scale studies can be conducted with subgroup analysis to confirm these factors in patients at risk who might benefit from closer monitoring and who may benefit from a judicious approach to vaccination. Copyright © AME Publishing Company.

All age groups COVID-19 Safety