RESUMO
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.COV2·S vaccination in Rio de Janeiro, Brazil. METHODS: From July to September 2021, participants were assessed prior, 1, and 3 weeks post-vaccination. Platelet count and D-dimer were measured at each visit and anti-PF4 at week 3. A positive anti-PF4 prompted retrospective testing of the sample from week 0. Individuals with new thrombocytopenia or elevated D-dimer, positive anti-PF4, and 38 matched controls without laboratory abnormalities were evaluated for plasmatic p-selectin, tissue factor, and functional platelet activation assays. RESULTS: 630 individuals were included; 306 (48.57%) females, median age 28 years. Forty-two (6.67%) presented ≥1 laboratory abnormality in week 1 or 3. Five (0.79%) had thrombocytopenia, 31 (4.91%) elevated D-dimer, and 9 (1.57%) had positive anti-PF4 at week 3. Individuals with laboratory abnormalities and controls showed a slight increase in plasmatic p-selectin and tissue factor. Ten individuals with laboratory abnormalities yielded increased surface expression of p-selectin, and their ability to activate platelets in a FcγRIIa dependent manner was further evaluated. Two were partially inhibited by high concentrations of heparin and blockage of FcγRII with IV.3 antibody. Plasma obtained before vaccination produced similar results, suggesting a lack of association with vaccination. CONCLUSIONS: Vaccination with Ad26.COV2·S vaccine led to a very low frequency of low-titer positive anti-PF4 antibodies, elevation of D-dimer, and mild thrombocytopenia, with no associated clinically relevant increase in thromboinflammatory markers and platelet activation.
Assuntos
COVID-19 , Produtos de Degradação da Fibrina e do Fibrinogênio , Ativação Plaquetária , Fator Plaquetário 4 , Humanos , Feminino , Masculino , Brasil/epidemiologia , Adulto , Fator Plaquetário 4/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Pessoa de Meia-Idade , Trombocitopenia/induzido quimicamente , SARS-CoV-2/imunologia , Adulto Jovem , Ad26COVS1 , Contagem de Plaquetas , Vacinação , Estudos Retrospectivos , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/efeitos adversos , Adolescente , Trombose/imunologia , Trombose/prevenção & controleRESUMO
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. His laboratory results showed elevated D-dimer, C-reactive protein, tissue factor, P-selectin (CD62p), and positive anti-platelet factor 4. The patient's plasma promoted higher CD62p expression in healthy donors' platelets than the controls. Genetic investigation on coagulation, thrombophilia, inflammation, and type I interferon-related genes was performed. From rare variants in European or African genomic databases, 68 single-nucleotide polymorphisms (SNPs) in one allele and 11 in two alleles from common SNPs were found in the patient genome. This report highlights the possible relationship between VITT and genetic variants. Additional investigations regarding the genetic predisposition of VITT are needed.
RESUMO
Heparin induced thrombocytopenia (HIT) is an immune-mediated adverse reaction characterized by thrombocytopenia and paradoxical arterial or venous thrombosis, due to the formation IgG antibodies directed to a multimolecular complex of heparin-platelet factor 4 (PF4). Fondaparinux is a selective factor Xa inhibitor with little affinity for PF4 and thus less likely to induce an immune response, making fondaparinux a potentially useful drug for the treatment of HIT. Herein we report the case of a 73 years old woman with HIT associated with arterial and venous thrombosis that was successfully treated with fondaparinux, with normalization of the platelet countand without progression of thrombosis.
Assuntos
Anticoagulantes/uso terapêutico , Heparina/efeitos adversos , Polissacarídeos/uso terapêutico , Trombocitopenia/tratamento farmacológico , Trombose Venosa/tratamento farmacológico , Idoso , Anticoagulantes/efeitos adversos , Feminino , Fondaparinux , Humanos , Necrose , Contagem de Plaquetas , Fator Plaquetário 4/imunologia , Trombocitopenia/induzido quimicamente , Resultado do Tratamento , Trombose Venosa/induzido quimicamenteRESUMO
La trombocitopenia inducida por heparina (TIH) es una reacción adversa inmunológica caracterizada por trombocitopenia y la asociación paradojal de trombosis arterial o venosa. Es causada por la formación de anticuerpos IgG contra el complejo multimolecular de heparina-factor plaquetario 4 (FP4). Fondaparinux es un inhibidor selectivo del factor Xa que tiene escasa afinidad por el FP4 y posee un menor potencial para inducir una respuesta inmunológica, haciendo del mismo un agente potencialmente útil en el tratamiento de la TIH. Se presenta el caso de una mujer de 73 años con TIH asociada a fenómenos trombóticos arteriales y venosos, que recibió exitosamente fondaparinux, con normalización del recuento plaquetario y sin progresión trombótica.
Heparin induced thrombocytopenia (HIT) is an immune-mediated adverse reaction characterized by thrombocytopenia and paradoxical arterial or venous thrombosis, due to the formation IgG antibodies directed to a multimolecular complex of heparin-platelet factor 4 (PF4). Fondaparinux is a selective factor Xa inhibitor with little affinity for PF4 and thus less likely to induce an immune response, making fondaparinux a potentially useful drug for the treatment of HIT. Herein we report the case of a 73 years old woman with HIT associated with arterial and venous thrombosis that was successfully treated with fondaparinux, with normalization of the platelet countand without progression of thrombosis.