Publications by authors named "Jason Knight"

Nontyphoidal strains of are a major cause of foodborne illnesses, and infection with these bacteria results in inflammatory gastroenteritis. Polymorphonuclear leukocytes (PMNs), also known as neutrophils, are a dominant immune cell type found at the site of infection in infected individuals, but how they regulate infection outcome is not well understood. Here, we used a co-culture model of primary human PMNs and human intestinal organoids to probe the role of PMNs during infection with two of the most prevalent serovars: serovar Enteritidis and Typhimurium.

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  • The study investigates the link between antiphospholipid antibodies (aPL) and diffuse alveolar hemorrhage (DAH) in patients with systemic lupus erythematosus (SLE) through a systematic review and meta-analysis.
  • Out of 454 studies reviewed, 9 were included, showing that SLE patients with positive aPL, especially lupus anticoagulant and anticardiolipin IgG, are more likely to experience DAH.
  • Additionally, having antiphospholipid syndrome (APS) increases the risk of DAH significantly compared to patients without APS.
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  • - This study examined the occurrence and effects of antinuclear antibodies (ANA) in patients with antiphospholipid antibodies (aPL) but without other systemic autoimmune diseases, using data from the APS ACTION Registry.
  • - Among the 430 analyzed patients, 56% tested positive for ANA, revealing significant links between ANA positivity and various autoimmune features like hematologic issues and joint involvement.
  • - Despite the presence of these autoimmune characteristics in ANA-positive patients, the study found no connection between ANA status and complications related to thrombosis or pregnancy; interestingly, ANA-negative patients had more pregnancies and live births.
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Objectives: Neutrophils and neutrophil extracellular traps (NETs) contribute to the vascular complications of multiple diseases, but their role in systemic sclerosis (SSc) is understudied. We sought to test the hypothesis that NETs are implicated in SSc vasculopathy and that treatment with prostacyclin analogs may ameliorate SSc vasculopathy not only through vasodilation but also by inhibiting NET release.

Methods: Blood from 125 patients with SSc (87 diffuse cutaneous SSc and 38 limited cutaneous SSc) was collected at a single academic medical center.

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Objective: Primary antiphospholipid syndrome (PAPS) is a rare autoimmune disease characterized by the presence of antiphospholipid antibodies and the occurrence of thrombotic events and pregnancy complications. Our study aimed to identify novel genetic susceptibility loci associated with PAPS.

Methods: We performed a genome-wide association study comprising 5,485 individuals (482 affected individuals) of European ancestry.

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  • Neutrophil hyperactivity and NET release are key factors in the autoimmune disease antiphospholipid syndrome (APS).
  • Research shows that neutrophils from APS patients have a higher reliance on glycolysis compared to those from healthy individuals, particularly in cases linked to microvascular disease.
  • Inhibiting glycolysis or the pentose phosphate pathway (PPP) not only reduces NET release and reactive oxygen species production in neutrophils but also significantly decreases thrombosis in mice models of APS.
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Antiphospholipid syndrome (APS) consists of thrombotic, non-thrombotic and obstetric clinical manifestations developing in individuals with persistent antiphospholipid antibodies (aPL). Although researchers have made progress in characterizing different clinical phenotypes of aPL-positive people, the current approach to clinical management is still mostly based on a 'one size fits all' strategy, which is derived from the results of a limited number of prospective, controlled studies. With the 2023 publication of the ACR-EULAR APS classification criteria, it is now possible to rethink APS, to lay the groundwork for subphenotyping through novel pathophysiology-informed approaches, and to set a future APS research agenda guided by unmet needs in clinical management.

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Objectives: Primary antiphospholipid syndrome (PAPS) is a rare autoimmune disease characterized by the presence of antiphospholipid antibodies and the occurrence of thrombotic events and pregnancy complications. Our study aimed to identify novel genetic susceptibility loci associated with PAPS.

Methods: We performed a genome-wide association study comprising 5,485 individuals (482 affected individuals) of European ancestry.

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Our study aimed to evaluate the presence, clinical associations, and potential mechanistic roles of non-criteria antiphospholipid antibodies (aPL) and circulating calprotectin, a highly stable marker of neutrophil extracellular trap release (NETosis), in pediatric APS patients. We found that 79% of pediatric APS patients had at least one non-criteria aPL at moderate-to-high titer. Univariate logistic regression demonstrated that positive anti-beta-2 glycoprotein I domain 1 (anti-D1) IgG (p = 0.

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Many patients with antiphospholipid syndrome had decreased ectonucleotidase activity on neutrophils and platelets, which enabled extracellular nucleotides to trigger neutrophil-platelet aggregates. This phenotype was replicated by treating healthy neutrophils and platelets with patient-derived antiphospholipid antibodies or ectonucleotidase inhibitors.

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  • - Levels of circulating calprotectin are higher in primary antiphospholipid syndrome (APS) patients compared to healthy controls, indicating its potential role in the condition.
  • - The study revealed calprotectin's association with increased neutrophil counts and C-reactive protein levels, while showing a negative correlation with platelet counts, suggesting its involvement in thrombocytopenia.
  • - Mechanistic insights suggested that calprotectin may trigger aPL-mediated thrombocytopenia by activating platelet surface receptors and the NLRP3-inflammasome, leading to reduced platelet viability.
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Objective: The objective of this study was to explore what non-pharmacological interventions have been examined for individuals with antiphospholipid syndrome (APS).

Methods: We conducted a systematic literature search of the databases PubMed, Embase, Scopus, Web of Science, CINAHL, and ClinicalTrials.gov from 1983-Feb.

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Introduction: Neutrophil extracellular traps (NETs) contribute to trauma-induced coagulopathy. We aimed to develop a murine multiple-injury model that induces thrombo-inflammatory response, that is, NETosis and accelerated thrombin generation.

Methods: Wild-type male mice (n = 10, aged 8-12 weeks) underwent multiple injuries (gastrocnemius crush, femur fracture, and laparotomy) and were compared with an uninjured control group (n = 10).

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While neutrophil extracellular traps (NETs) have previously been linked to some diabetes-associated complications, such as dysfunctional wound healing, their potential role in diabetic vascular dysfunction has not been studied. Diabetic Akita mice were crossed with either or mice to generate NET-deficient diabetic mice. By 24 weeks of age, Akita aortae showed markedly impaired relaxation in response to acetylcholine, indicative of vascular dysfunction.

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Objectives: Taxifolin (dihydroquercetin) is a bioactive plant flavonoid that exhibits anti-inflammatory and anti-oxidative properties. We hypothesized that taxifolin might be an effective dietary supplement to ameliorate symptoms arising from thrombo-inflammatory diseases such as lupus and APS.

Methods: We used in vitro assays and a mouse model to determine mechanisms by which taxifolin inhibits neutrophil extracellular trap (NET) formation (i.

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We previously reported that treatment of mice with 6-gingerol, the most abundant phytochemical in ginger root, leads to phosphodiesterase inhibition that counteracts neutrophil hyperactivity in models of antiphospholipid syndrome (APS) and lupus. Here, we explored the extent to which oral intake of a whole-ginger extract would similarly impact neutrophils in both autoimmune mice and healthy humans. In vitro, a solubilized ginger extract was able to attenuate neutrophil extracellular trap formation (NETosis) by human neutrophils through a mechanism that was dependent upon the cyclic AMP-dependent kinase, protein kinase A.

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Objective: To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR.

Methods: This international multidisciplinary initiative included four phases: (1) Phase I, criteria generation by surveys and literature review; (2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; (3) Phase III, criteria definition, further reduction with the guidance of real-world patient scenarios, and weighting via consensus-based multicriteria decision analysis, and threshold identification; and (4) Phase IV, validation using independent adjudicators' consensus as the gold standard.

Results: The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL-associated clinical criterion, followed by additive weighted criteria (score range 1-7 points each) clustered into six clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and two laboratory domains (lupus anticoagulant functional coagulation assays, and solid-phase enzyme-linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti-β-glycoprotein I antibodies).

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Article Synopsis
  • - The study aimed to create new and more specific classification criteria for antiphospholipid syndrome (APS) in collaboration with the American College of Rheumatology (ACR) and EULAR, using a detailed four-phase methodology.
  • - The new criteria require at least one positive antiphospholipid antibody test and assign points across six clinical and two laboratory domains, classifying patients with a minimum of 3 points in both areas as having APS.
  • - Compared to the older Sapporo criteria, the 2023 ACR/EULAR criteria showed a significant increase in specificity (99% vs. 86%) but slightly lower sensitivity (84% vs. 99%), demonstrating a more refined approach to diagnosing APS.
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Risk of severe disease and death due to COVID-19 is increased in certain patient demographic groups, including those of advanced age, male sex, and obese body mass index. Investigations of the biological variations that contribute to this risk have been hampered by heterogeneous severity, with immunologic features of critical disease potentially obscuring differences between risk groups. To examine immune heterogeneity related to demographic risk factors, we enrolled 38 patients hospitalized with clinically homogeneous COVID-19 pneumonia - defined as oxygen saturation less than 94% on room air without respiratory failure, septic shock, or multiple organ dysfunction - and performed single-cell RNA-Seq of leukocytes collected at admission.

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Beta-2 glycoprotein I (βGPI) is a phospholipid-binding plasma protein and prominent autoantigen in antiphospholipid syndrome (APS). Here, we tested the hypothesis that βGPI might bind to not only phospholipids, but also cell-free DNA and neutrophil extracellular traps (NETs). We report that βGPI interacts with cell-free DNA from different species, as well as NETs, in a dose-dependent manner, retarding their migration in an agarose-gel electrophoretic mobility shift assay.

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While immunologic correlates of COVID-19 have been widely reported, their associations with post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, understanding if specific disease features associate with discrete immune processes and therapeutic opportunities is important. Here we profile patients in the recovery phase of COVID-19 via proteomics screening and machine learning to find signatures of ongoing antiviral B cell development, immune-mediated fibrosis, and markers of cell death in PASC patients but not in controls with uncomplicated recovery.

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Objectives: Our primary objective was to quantify damage burden measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in aPL-positive patients with or without a history of thrombosis in an international cohort (the APS ACTION cohort). Secondly, we aimed to identify clinical and laboratory characteristics associated with damage in aPL-positive patients.

Methods: In this cross-sectional study, we analysed the baseline damage in aPL-positive patients with or without APS classification.

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