Linda Schönborn

Universitätsmedizin Greifswald · Transfusion Medicine

Introduction: Fcγ-receptors (FcγR) are membrane receptors expressed on a variety of immune cells, specialized in recognition of the Fc part of immunoglobulin G (IgG) antibodies. FcγRIIA-dependent platelet activation in platelet factor 4 (PF4) antibody-related disorders have gained major attention, when these antibodies were identified as the cause...

Platelet-activating anti-platelet factor 4 (PF4)/heparin antibodies and anti-PF4 antibodies cause heparin-induced thrombocytopenia (HIT) and vaccine-induced immune thrombocytopenia and thrombosis (VITT), respectively. Diagnostic and treatment considerations differ somewhat between HIT and VITT. We identified patients with thrombocytopenia and throm...

An effective worldwide vaccination campaign started and is still being carried out in the face of the coronavirus disease 2019 (COVID-19) pandemic. While vaccines are great tools to confront the pandemic, predominantly adenoviral vector-based vaccines can cause a rare severe adverse effect, termed vaccine-induced immune thrombocytopenia and thrombo...

Background: Rapid diagnosis and treatment has improved outcome of patients with vaccine-induced immune thrombocytopenia and thrombosis (VITT). However, after the acute episode, many questions on long-term management of VITT remained unanswered. Objectives: To analyze in VITT patients the long-term course of anti-PF4 antibodies, clinical outcomes...

Vaccine‐induced immune thrombotic thrombocytopenia (VITT) is a rare clinical condition that has emerged during the mass immunization against SARS‐CoV‐2. Reports indicate that VITT may also be induced by other vaccines, such as the human papillomavirus vaccine, or occur independently of vaccination. Its recognition requires a high index of suspicion...

Zusammenfassung In diesem Übersichtsartikel beschreiben wir die klinischen und paraklinischen Charakteristika der Vakzin-induzierten immunthrombotischen Thrombozytopenie (VITT) und fassen den gegenwärtigen Kenntnisstand zur Pathogenese zusammen. Bei der VITT bilden sich 5–20 Tage nach einer Impfung mit einem Adenovirus-vektorbasiertem SARS-CoV-2-Va...

Background: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a prothrombotic, heparin-induced thrombocytopenia(HIsT)-mimicking, adverse reaction caused by platelet-activating anti-platelet factor 4 (PF4) antibodies that occurs rarely after adenovirus vector-based Covid-19 vaccination. Strength of PF4-dependent enzyme-immunoassay (EIA)...

Aims Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but highly morbid complication after adenoviral vector-based SARS-CoV-2 vaccination. The pre-VITT syndrome is defined as vaccine-induced immune thrombocytopenia without thrombosis typically presenting with new-onset headache. This review aims to identify at-risk patients befor...

In hundreds of patients worldwide, vaccination against COVID-19 with adenovirus vector vaccines (ChAdOx1 nCoV-19; Ad26.COV2.S) triggered platelet-activating anti-platelet factor 4 (PF4) antibodies inducing vaccine-induced immune thrombotic thrombocytopenia (VITT). In most VITT patients, platelet-activating anti-PF4-antibodies are transient and the...

Vaccine-induced Thrombotic Thrombocytopenia (VITT) is triggered by vaccination against COVID-19 with adenovirus vector vaccines (ChAdOx1 nCoV-19; Ad26.COV2-S). In this observational study, we followed VITT patients for changes in their reactivity of platelet-activating anti-platelet factor 4 (PF4) IgG antibodies by an anti-PF4/heparin IgG enzyme im...

Vaccine-induced immune thrombotic thrombocytopenia (VITT; synonym, thrombosis with thrombocytopenia syndrome, TTS), is associated with high-titer immunoglobulin G (IgG) antibodies directed against platelet factor 4 (PF4). These antibodies activate platelets via platelet FcγIIa receptors, with platelet activation greatly enhanced by PF4. Here we sum...

Background Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe adverse event of SARS-CoV-2 vaccination. We describe the characteristics of patients reported in Germany based on the Brighton Collaboration (BC) case definition criteria for Thrombosis and Thrombocytopenia Syndrome (TTS) and focus on patients with complete anti-platel...

necessary because our manuscript is a letter to the editor.

Background and objectives: Vaccine induced thrombotic thrombocytopenia (VITT) may occur after COVID-19 vaccination with recombinant adenoviral vector-based vaccines. VITT can present as cerebral sinus and venous thrombosis (CSVT), often complicated by intracranial hemorrhage. Today it is unclear, how long symptomatic VITT can persist. Here, we rep...

SARS-CoV-2 vaccine ChAdOx1 nCov-19 (AstraZeneca) causes a thromboembolic complication termed vaccine-induced immune thrombotic thrombocytopenia (VITT). Using biophysical techniques, mouse models and analysis of VITT patient samples we identified determinants of this vaccine-induced adverse reaction. Super-resolution microscopy visualized vaccine co...

Vaccination using the adenoviral vector COVID-19 vaccine ChAdOx1 nCoV-19 (AstraZeneca) has been associated with rare vaccine-induced immune thrombotic thrombocytopenia (VITT). Affected patients test strongly positive in PF4/polyanion enzyme immunoassays (EIAs) and serum-induced platelet activation is maximal in the presence of PF4. We determined th...

Vaccination is crucial in combatting the SARS-CoV-2 pandemic. The rare complication of thrombocytopenia and thrombotic complications at unusual sites after ChAdOx1 nCov-19 vaccination is caused by platelet-activating antibodies directed against platelet factor 4. We present a widely applicable whole blood standard flow cytometric assay to identify...

Background SARS-CoV-2 vaccine ChAdOx1 nCov-19 rarely causes vaccine-induced immune thrombotic thrombocytopenia (VITT) that—like autoimmune heparin-induced thrombocytopenia—is mediated by platelet-activating anti-platelet factor 4 (PF4) antibodies. Methods We investigated vaccine, PF4, and VITT patient-derived anti-PF4 antibody interactions using dy...

It is crucial to provide updated knowledge about blood (non-)donors, as it is necessary to design targeted interventions with the aim of retaining blood donors and thus contributing to a functioning health system. This study investigates the prevalence and socio-demographic patterning of lifetime blood donation, assessing blood donation intention w...

Background: The federal state of Saarland (SL) is experiencing the fastest demographic change in the western part of Germany. In this study, we analyzed retrospective data on the current and future supply of red blood cell concentrates (RBC) in this region and compared it to the current and future RBC demand in SL hospitals. Methods: The project...

Background: Annual transfusion rates in many European countries range between 25 and 35 red blood cell concentrates (RBCs)/1,000 population. It is unclear why transfusion rates in Germany are considerably higher (approx. 50-55 RBCs/1,000 population). Methods: We assessed the characteristics of transfusion recipients at all hospitals of the Germa...

Background: Securing future blood supply is a major issue of transfusion safety. In this prospective 10-year longitudinal study we enrolled all blood donation services and hospitals of the federal state Mecklenburg-Western Pomerania. Methods and results: From 2005 to 2015 (time period with major demographic effects), whole blood donation numbers...

Key Points Demographic changes have a direct impact on the blood supply, and demography can be used to predict blood donation rates in the future. The transfusion demand cannot be predicted from demography.