Platelet-neutrophil aggregate formation induces NLRP3 inflammasome activation in vaccine-induced thrombotic thrombocytopenia.

Background: Although rare, vaccine-induced thrombotic thrombocytopenia (VITT) following adenoviral vector COVID-19 vaccination is a concerning and often severe adverse effect of vaccination. The generation of high antiplatelet factor 4 antibody titers promotes the formation of immune complexes capable of activating platelets and neutrophils through FcγRIIa.

Objectives: Given that platelet-leukocyte aggregate formation and inflammasome activation are common features of thromboinflammatory diseases, we aimed to evaluate if these are also features of VITT.

Anti-PF4 positivity and platelet activation after Ad26.COV2·S vaccination in Brazil.

Introduction: The Ad26.COV2·S (Janssen/Johnson & Johnson) COVID-19 vaccine, has been rarely associated with vaccine-induced immune thrombocytopenia and thrombosis (VITT). We investigated the prevalence of anti-PF4 antibody positivity, thrombocytopenia, D-dimer elevation, plasmatic thromboinflammatory markers, and platelet functional assays following Ad26.

A case report of vaccine-induced immune thrombotic thrombocytopenia (VITT) with genetic analysis.

The emergence of the rare syndrome called vaccine-induced immune thrombocytopenia and thrombosis (VITT) after adenoviral vector vaccines, including ChAdOx1 nCov-19, raises concern about one's predisposing risk factors. Here we report the case of a 56-year-old white man who developed VITT leading to death within 9 days of symptom onset. He presented with superior sagittal sinus thrombosis, right frontal intraparenchymal hematoma, frontoparietal subarachnoid and massive ventricular hemorrhage, and right lower extremity arterial and venous thrombosis.

Clinical Presentation of Parvovirus B19 Infection in Adults Living with HIV/AIDS: A Case Series.

Parvovirus B19 (B19V) infection varies clinically depending on the host's immune status. Due to red blood cell precursors tropism, B19V can cause chronic anemia and transient aplastic crisis in patients with immunosuppression or chronic hemolysis. We report three rare cases of Brazilian adults living with human immunodeficiency virus (HIV) with B19V infection.

Acute promyelocytic leukemia in a long-standing HIV-positive patient: Case report and literature review.

The use of antiretroviral therapy has drastically improved the life quality and prognosis of people living with the human immunodeficiency virus (HIV). The risk of acute myeloid leukemia (AML) currently does not appear to be significantly increased compared to the general population. Acute promyelocytic leukemia (APL), infrequent in people with HIV, is a distinct subtype of AML with unique molecular pathogenesis, clinical manifestations, and treatment.

Generalized Edema and Pseudothrombocytopenia After ChAdOx1 nCoV-19 COVID-19 Vaccination: A Case Report.

Reports of side effects of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasing worldwide. Capillary leak syndrome and vaccine-induced immune thrombotic thrombocytopenia are very rare but life-threatening adverse events that should be identified early and treated. However, isolated thrombocytopenia can indicate pseudothrombocytopenia.