Markers of neutrophil activation and neutrophil extracellular traps in diagnosing patients with acute venous thromboembolism: A feasibility study based on two VTE cohorts

Background Venous thromboembolism (VTE) diagnosis would greatly benefit from the identification of novel biomarkers to complement D-dimer, a marker limited by low specificity. Neutrophil extracellular traps (NETs) have been shown to promote thrombosis and could hypothetically be used for diagnosis of acute VTE. Objectives To assess the levels of specific markers of neutrophil activation and NETs and compare their diagnostic accuracy to D-dimer. Methods We measured plasma levels of neutrophil activation marker neutrophil elastase (NE), the NET marker nucleosomal citrullinated histone H3 (H3Cit-DNA) and cell-free DNA in patients (n = 294) with suspected VTE (pulmonary embolism and deep vein thrombosis) as well as healthy controls (n = 30). A total of 112 VTE positive and 182 VTE negative patients from two prospective cohort studies were included. Results Higher levels of H3Cit-DNA and NE, but not cell-free DNA, were associated with VTE. Area under receiver operating curves (AUC) were 0.90 and 0.93 for D-dimer, 0.65 and 0.68 for NE and 0.60 and 0.67 for H3Cit-DNA in the respective cohorts. Adding NE and H3Cit-DNA to a D-dimer based risk model did not improve AUC. Conclusions Our study demonstrates the presence of neutrophil activation and NET formation in VTE using specific markers. However, the addition of NE or H3Cit-DNA to D-dimer did not improve the discrimination compared to D-dimer alone. This study provides information on the feasibility of using markers of NETs as diagnostic tools in acute VTE. Based on our findings, we believe the potential of these markers are limited in this setting

Patients With COVID-19 Have Elevated Levels of Circulating Extracellular Vesicle Tissue Factor Activity That Is Associated With Severity and Mortality

OBJECTIVE: Patients with coronavirus disease 2019 (COVID-19) have a high rate of thrombosis. We hypothesized that severe acute respiratory syndrome coronavirus 2 leads to induction of TF (tissue factor) expression and increased levels of circulating TF-positive extracellular vesicles (EV) that may drive thrombosis. Approach and Results: We measured levels of plasma EV TF activity in 100 patients with COVID-19 with moderate and severe disease and 28 healthy controls. Levels of EV TF activity were significantly higher in patients with COVID-19 compared with controls. In addition, levels of EV TF activity were associated with disease severity and mortality. Finally, levels of EV TF activity correlated with several plasma markers, including D-dimer, which has been shown to be associated with thrombosis in patients with COVID-19. CONCLUSIONS: Our results indicate that severe acute respiratory syndrome coronavirus 2 infection induces the release of TF-positive EVs into the circulation that are likely to contribute to thrombosis in patients with COVID-19. EV TF activity was also associated with severity and mortality

Circulating Markers of Neutrophil Extracellular Traps Are of Prognostic Value in Patients With COVID-19

OBJECTIVE: The full spectrum of coronavirus disease 2019 (COVID-19) infection ranges from asymptomatic to acute respiratory distress syndrome, characterized by hyperinflammation and thrombotic microangiopathy. The pathogenic mechanisms are poorly understood, but emerging evidence suggest that excessive neutrophil extracellular trap (NET) formation plays a key role in COVID-19 disease progression. Here, we evaluate if circulating markers of NETs are associated with COVID-19 disease severity and clinical outcome, as well as to markers of inflammation and in vivo coagulation and fibrinolysis. Approach and Results: One hundred six patients with COVID-19 with moderate to severe disease were enrolled shortly after hospital admission and followed for 4 months. Acute and convalescent plasma samples as well as plasma samples from 30 healthy individuals were assessed for markers of NET formation: citrullinated histone H3, cell-free DNA, NE (neutrophil elastase). We found that plasma levels of NET markers were all elevated in patients with COVID-19 relative to healthy controls, were associated with respiratory support requirement and short-term mortality, and declined to those found in healthy individuals 4 months post-infection. Levels of the NET markers also correlated with white blood cells, neutrophils, inflammatory cytokines, and C-reactive protein, as well as to markers of in vivo coagulation, fibrinolysis, and endothelial damage. CONCLUSIONS: Our findings suggest a role of NETs in COVID-19 disease progression, implicating their contribution to an immunothrombotic state. Further, we observed an association between circulating markers of NET formation and clinical outcome, demonstrating a potential role of NET markers in clinical decision-making, as well as for NETs as targets for novel therapeutic interventions in COVID-19. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04402944, NCT04541979, NCT04445285, NCT04432987, NCT04402970

Consenso de expertos sobre recomendaciones basadas en evidencia para el diagnóstico, tratamiento y seguimiento de enfermedad de Fabry en pediatría

Antecedentes: La enfermedad de Fabry (EF) es una enfermedad rara ligada a X secundaria al depósito lisosomal de glicoesfingolípidos debido a la deficiencia de la enzima alfa galactosidasa A (α-Gal A). A pesar de su baja frecuencia, es una condición que afecta la calidad de vida de los pacientes y disminuye su esperanza de vida. Objetivo: Generar recomendaciones informadas en evidencia para el diagnóstico y tratamiento de pacientes pediátricos (menores de 8 años) con EF. Métodos: Se realizó una revisión de literatura en bases de datos y literatura gris a partir del 2010, incluyendo guías de práctica clínica, revisiones sistemáticas, estudios primarios. La calidad de evidencia se evalúo de acuerdo con el tipo de evidencia. Las recomendaciones se sometieron a consenso de expertos a través de metodología Delphi modificada. El acuerdo se definió a partir del 80%. Resultados: A partir del análisis de la evidencia recolectada, se formularon un total de 45 recomendaciones para tamización, diagnóstico y tratamiento de paciente pediátrico con enfermedad de Fabry. El panel revisor estuvo conformado por once expertos en el tema. Las recomendaciones fueron aprobadas con puntuaciones entre 82.3% y 100%. Conclusiones: Las recomendaciones resultantes del consenso de expertos permitirán la toma de decisiones clínicas y estandarización de la práctica en la atención de pacientes pediátricos con EF a nivel nacional y regional; el diagnóstico temprano y oportuno garantiza una disminución del impacto en la calidad de vida de los pacientes y sus familiares. Palabras clave: Enfermedad de Fabry, niños, diagnóstico, terapeutica, biomarcadore

Patients With COVID-19 Have Elevated Levels of Circulating Extracellular Vesicle Tissue Factor Activity That Is Associated With Severity and Mortality

OBJECTIVE: Patients with coronavirus disease 2019 (COVID-19) have a high rate of thrombosis. We hypothesized that severe acute respiratory syndrome coronavirus 2 leads to induction of TF (tissue factor) expression and increased levels of circulating TF-positive extracellular vesicles (EV) that may drive thrombosis. Approach and Results: We measured levels of plasma EV TF activity in 100 patients with COVID-19 with moderate and severe disease and 28 healthy controls. Levels of EV TF activity were significantly higher in patients with COVID-19 compared with controls. In addition, levels of EV TF activity were associated with disease severity and mortality. Finally, levels of EV TF activity correlated with several plasma markers, including D-dimer, which has been shown to be associated with thrombosis in patients with COVID-19. CONCLUSIONS: Our results indicate that severe acute respiratory syndrome coronavirus 2 infection induces the release of TF-positive EVs into the circulation that are likely to contribute to thrombosis in patients with COVID-19. EV TF activity was also associated with severity and mortality

Mucosal immune responses following a fourth SARS-CoV-2 vaccine dose

Supplementary appendixThis appendix formed part of the original submission. We post it as supplied by the authors. Supplement to: Bladh O, Marking U, Havervall S, et al. Mucosal immune responses following a fourth SARS-CoV-2 vaccine dose. Lancet Microbe 2023; published online April 19. https://doi.org/10.1016/S2666-5247(23)00102-7</p

Comparison of SARS-CoV-2 spike-specific IgA and IgG in nasal secretions, saliva and serum

IntroductionSeveral novel vaccine platforms aim at mucosal immunity in the respiratory tract to block SARS-CoV-2 transmission. Standardized methods for mucosal sample collection and quantification of mucosal antibodies are therefore urgently needed for harmonized comparisons and interpretations across mucosal vaccine trials and real-world data.MethodsUsing commercial electrochemiluminescence antibody panels, we compared SARS-CoV-2 spike-specific IgA and IgG in paired saliva, nasal secretions, and serum from 1048 healthcare workers with and without prior infection.ResultsSpike-specific IgA correlated well in nasal secretions and saliva (r&gt;0.65, p&lt;0.0001), but the levels were more than three-fold higher in nasal secretions as compared to in saliva (p&lt;0.01). Correlations between the total population of spike-specific IgA and spike-specific secretory IgA (SIgA) were significantly stronger (p&lt;0.0001) in nasal secretions (r=0.96, p&lt;0.0001) as opposed to in saliva (r=0.77, p&lt;0.0001), and spike-specific IgA correlated stronger (p&lt;0.0001) between serum and saliva (r=0.73, p&lt;0.001) as opposed to between serum and nasal secretions (r=0.54, p&lt;0.001), suggesting transudation of monomeric spike specific IgA from the circulation to saliva. Notably, spike-specific SIgA had a markedly higher SARS-CoV-2 variant cross-binding capacity as compared to the total population of spike specific IgA and IgG in both nasal secretions, saliva and serum, (all p&lt;0.0001), which emphasizes the importance of taking potential serum derived monomeric IgA into consideration when investigating mucosal immune responses.DiscussionTaken together, although spike-specific IgA can be reliably measured in both nasal secretions and saliva, our findings imply an advantage of higher levels and likely also a larger proportion of SIgA in nasal secretions as compared to in saliva. We further corroborate the superior variant cross-binding capacity of SIgA in mucosal secretions, highlighting the potential protective benefits of a vaccine targeting the upper respiratory tract