Exacerbation of immune thrombocytopenia following initial and booster vaccination with Pfizer-BioNTech COVID-19 vaccine.

As the immune thrombocytopenia exacerbation rate after booster COVID-19 vaccines is unknown, we explore the rates after first, second and booster Pfizer-BioNTech COVID-19 vaccines. A retrospective study of adult ITP patients, receiving 1-3 vaccines was performed. The primary outcome was clinical ITP exacerbation defined as platelet count decrease requiring initiation/escalation of ITP treatment and/or new medical attention due to bleeding, within 3 months. Secondary outcome was any clinically relevant platelet decrease during the 3 months post-vaccination. The study included 93 ITP patients receiving 1 (n = 2), 2 (n = 22) or 3 (n = 69) vaccines. ITP exacerbation occurred in 2/93 (2.2%) patients following initial vaccination and in 3/69 (4.3%) following booster dose. Clinically relevant platelet decreases after initial doses occurred in 8/72 (11.1%) patients and in 8/39 (20.5%) after the booster. Clinical ITP exacerbation after booster doses did not follow clinical exacerbation after initial doses. Half of patients with clinically relevant platelet decreases after booster dose also had clinically relevant decreases following initial vaccination. We concluded that clinical ITP exacerbation is infrequent following Pfizer-BioNTech COVID-19 vaccine. Clinical exacerbation after booster doses was not preceded by clinical exacerbation after initial doses. Clinically relevant platelet decreases after booster doses occur frequently in patients with clinically relevant decreases after initial doses.

An Early Unexpected Immune Thrombotic Thrombocytopenic Purpura Relapse Associated with SARS-CoV-2 Infection: A Case Report and Literature Review.

SARS-CoV-2 has been reported as a possible triggering factor for the development of several autoimmune diseases and inflammatory dysregulation. Here, we present a case report of a woman with a history of systemic lupus erythematosus and antiphospholipid syndrome, presenting with concurrent COVID-19 infection and immune thrombotic thrombocytopenic purpura (TTP). The patient was treated with plasma exchange, steroids, and caplacizumab with initial good response to therapy. The course of both TTP and COVID-19 disease was mild. However, after ADAMTS-13 activity was normalized, the patient experienced an early unexpected TTP relapse manifested by intravascular hemolysis with stable platelet counts requiring further treatment. Only 3 cases of COVID-19 associated TTP were reported in the literature thus far. We summarize the literature and suggest that COVID-19 could act as a trigger for TTP, with good outcomes if recognized and treated early.

Venous Thromboembolism Complicated with COVID-19: What Do We Know So Far?

Coronavirus disease (COVID-19) is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is responsible for the ongoing 2019-2020 pandemic. Venous thromboembolism (VTE), a frequent cardiovascular and/or respiratory complication among hospitalized patients, is one of the known sequelae of the illness. Hospitalized COVID-19 patients are often elderly, immobile, and show signs of coagulopathy. Therefore, it is reasonable to assume a high incidence of VTE among these patients. Presently, the incidence of VTE is estimated at around 25% of patients hospitalized in the intensive care unit for COVID-19 even under anticoagulant treatment at prophylactic doses. In this review, we discuss present knowledge of the topic, the unique challenges of diagnosis and treatment of VTE, as well as some of the potential mechanisms of increased risk for VTE during the illness. Understanding the true impact of VTE on patients with COVID-19 will potentially improve our ability to reach a timely diagnosis and initiate proper treatment, mitigating the risk for this susceptible population during a complicated disease.