Background
An association between vaccines and the rare development of immune thrombocytopenic purpura (ITP) has been reported in the literature. More recently, there have been a few case reports published describing patients developing ITP shortly after COVID- 19 vaccination, but this has not been reported specifically in the Veteran population. The SVAHCS has three cases of Veterans diagnosed with new or relapsed ITP within two months of receiving the second COVID-19 vaccine (all Pfizer brand). The treatment(s) and current outcome for each patient is summarized below.
Case Reports
Case 1 is a 78-year-old male Veteran who received his second COVID-19 vaccine on 2/10/21. Patient was diagnosed with ITP 4/27/21, hospitalized multiple times and treated with pulse dexamethasone, prednisone taper, rituximab IV weekly and romiplostim injections. Currently, patient has a thrombocytosis and romiplostim injections are on hold. Case 2 is a 90-yearold male Veteran who received his second COVID-19 vaccine on 3/16/21. Patient was diagnosed on 5/3/21 and treated with pulse dexamethasone, prednisone taper and rituximab IV weekly. Platelet count is currently normal. Case 3 is a 75-year-old male Veteran who received his second COVID-19 vaccine on 2/1/21. He has a history of ITP diagnosed 12/12/14 that has been well controlled with weekly romiplostim injections until 4/9/21. Patient was hospitalized and treated with pulse dexamethasone and prednisone taper. Upon discharge, therapy was changed from romiplostim to fostamatinib. Currently, platelet count recovered and is stable.
Conclusions
The two Veterans with de novo ITP exhibited resistant disease and had prolonged treatment courses, taking approximately a month to recover their platelet counts. In contrast, the Veteran with relapsed ITP exhibited a faster recovery period of approximately two weeks. In the safety trials conducted for the Pfizer COVID-19 vaccine, participants received vaccination or placebo and had a follow-up for an average of two months which may explain why ITP was not reported as a possible association until after marketing. After treating the above cases, the SVAHCS plans to use thrombopoietin receptor agonists (TPO-RAs) earlier in the treatment of ITP that may be associated with the COVID-19 vaccine as this has recently been recommended in case reports from the general population.
