SARS-CoV-2 Vaccination: Long-Term Follow-Up of Pre-existing and De Novo Immune Thrombocytopenia

In this single-center retrospective study, 17% (16/95) of patients with pre-existing ITP experienced an ITP exacerbation after SARS-CoV-2 vaccination(s): 10/84 post-dose#1, 9/73 post-dose#2, and 5/24 post-booster. Several of these patients tolerated previous vaccinations or received subsequent doses without ITP exacerbation. Among 11 patients who received rescue treatment, 7 had pre-existing, difficult-to-control ITP; exacerbations in these 7 may not have been caused by the vaccine. Six separate patients with de novo ITP post-SARS-CoV-2 vaccine who were followed for a median of 11 months (range 3-15) responded well to standard treatments for ITP and had favorable longer-term outcomes.