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- Lundström, Annika, et al.
(författare)
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High Thrombin Generation after Acute Ischemic Stroke or Transient Ischemic Attack Is Associated with a Reduced Risk of Recurrence : An Observational Cohort Study
- 2021
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Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 121:05, s. 584-593
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Tidskriftsartikel (refereegranskat)abstract
- Thrombin is increasingly recognized to be of importance for cardiovascular disease. The aim of this study was to investigate the prognostic value of thrombin generation variables in a cohort of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA). Thrombin generation potential measured by calibrated automated thrombogram (CAT) and prothrombin fragment F1+2 was determined in the acute and convalescent phases for a cohort of 190 patients with AIS/TIA. Microvesicle (MV)-induced thrombin generation potential was determined for a subset of patients using modified CAT. Primary outcome was a composite of fatal and nonfatal AIS or myocardial infarction as documented in Swedish registers during a total follow-up of 986 patient-years. Hazard ratios (HRs) were calculated using Cox regression based on variable median split. Peak thrombin and endogenous thrombin potential (ETP) above median in the acute phase were associated with a reduced risk of primary outcome after adjustment for cardiovascular risk factors, HR: 0.50 (0.27-0.92), p =0.026 and HR: 0.53 (0.28-0.99), p =0.048, respectively. F1+2 was lower in patients than in healthy controls but not associated with outcome. MV-induced peak thrombin above median in the acute phase was associated with recurrent AIS, unadjusted HR: 2.65 (1.03-6.44), p =0.044. Contrary to expectation, high thrombin generation potential is associated with a reduced risk of recurrent ischemic event in patients with AIS/TIA. Low ETP/peak thrombin combined with high MV-induced peak thrombin can potentially identify patients at high risk of recurrence.
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| 2. |
- Thålin, Charlotte, et al.
(författare)
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Elevated Troponin Levels in Acute Stroke Patients Predict Long-term Mortality
- 2015
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Ingår i: Journal of Stroke & Cerebrovascular Diseases. - : Elsevier BV. - 1052-3057 .- 1532-8511. ; 10, s. 285-286
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Forskningsöversikt (refereegranskat)abstract
- Background: Elevated plasma levels of troponin in acute stroke patients are common and have in several studies been shown to predict in-hospital and short-term mortality. Little is, however, known about the long-term prognosis of these patients. The aim of this study was to determine patient characteristics and 5-year mortality in patients with acute stroke and troponin elevation on admission. Methods: A retrospective cohort study of all consecutive patients with acute stroke and a plasma troponin I (TnI) analyzed on admission to Danderyd Hospital between January 1, 2005, and January 1, 2006 (n = 247). Patient characteristics were obtained from the Swedish National Stroke Register, Riksstroke, as well as hospital records. Mortality data were obtained from the Swedish Cause of Death Register. Results: There were 133 patients (54%) with TnI less than .03 mu g/L (normal), 74 patients (30%) with TnI .03-.11 mu g/L (low elevation), and 40 patients (16%) with TnI greater than .11 mu g/L (high elevation). TnI elevations were associated with a higher age, prior ischemic stroke, chronic heart failure, renal insufficiency, stroke severity, and ST segment elevation or depression on admission. The rate of hyperlipidemia decreased with increasing TnI. Adjusted for age and comorbidity, elevated TnI values on admission had a significantly and sustained increased mortality over the 5-year follow-up, with a hazard ratio of 1.90 (95% confidence interval, 1.33-2.70). Conclusions: Troponin elevation in patients with acute stroke, even when adjusted for several possible confounders, is associated with an almost 2-fold increased risk of 5-year mortality.
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| 3. |
- Thålin, Charlotte, et al.
(författare)
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Validation of an enzyme-linked immunosorbent assay for the quantification of citrullinated histone H3 as a marker for neutrophil extracellular traps in human plasma
- 2017
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Ingår i: Immunologic research. - : Springer Science and Business Media LLC. - 0257-277X .- 1559-0755. ; 65:3, s. 706-712
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Tidskriftsartikel (refereegranskat)abstract
- There is an emerging interest in the diverse functions of neutrophil extracellular traps (NETs) in a variety of disease settings. However, data on circulating NETs rely largely upon surrogate NET markers such as cell-free DNA, nucleosomes, and NET-associated enzymes. Citrullination of histone H3 by peptidyl arginine deiminase 4 (PAD4) is central for NET formation, and citrullinated histone H3 (H3Cit) is considered a NET-specific biomarker. We therefore aimed to optimize and validate a new enzyme-linked immunosorbent assay (ELISA) to quantify the levels of H3Cit in human plasma. A standard curve made of in vitro PAD4-citrullinated histones H3 allows for the quantification of H3Cit in plasma using an anti-histone antibody as capture antibody and an anti-histone H3 citrulline antibody for detection. The assay was evaluated for linearity, stability, specificity, and precision on plasma samples obtained from a human model of inflammation before and after lipopolysaccharide injection. The results revealed linearity and high specificity demonstrated by the inability of detecting non-citrullinated histone H3. Coefficients of variation for intra- and inter-assay variability ranged from 2.1 to 5.1% and from 5.8 to 13.5%, respectively, allowing for a high precision. Furthermore, our results support an inflammatory induction of a systemic NET burden by showing, for the first time, clear intra-individual elevations of plasma H3Cit in a human model of lipopolysaccharide-induced inflammation. Taken together, our work demonstrates the development of a new method for the quantification of H3Cit by ELISA that can reliably be used for the detection of NETs in human plasma.
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| 7. |
- Göranson, Sofie Paues, et al.
(författare)
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Circulating H3Cit is elevated in a human model of endotoxemia and can be detected bound to microvesicles
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Early diagnosis of sepsis is crucial since prompt interventions decrease mortality. Citrullinated histone H3 (H3Cit), released from neutrophil extracellular traps (NETs) upon binding of platelets to neutrophils following endotoxin stimulation, has recently been proposed a promising blood biomarker in sepsis. Moreover, microvesicles (MVs), which are released during cell activation and apoptosis and carry a variety of proteins from their parental cells, have also been shown to be elevated in sepsis. In a randomized and placebo-controlled human model of endotoxemia (lipopolysaccharide injection; LPS), we now report significant LPS-induced elevations of circulating H3Cit in 22 healthy individuals. We detected elevations of circulating H3Cit by enzyme-linked immunosorbent assay (ELISA), as well as bound to MVs quantified by flow cytometry. H3Cit-bearing MVs expressed neutrophil and/or platelet surface markers, indicating platelet-neutrophil interactions. In addition, in vitro experiments revealed that H3Cit can bind to phosphatidylserine exposed on platelet derived MVs. Taken together; our results demonstrate that NETs can be detected in peripheral blood during endotoxemia by two distinct H3Cit-specific methods. Furthermore, we propose a previously unrecognized mechanism by which H3Cit may be disseminated throughout the vasculature by the binding to MVs.
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| 8. |
- Havervall, Sebastian, et al.
(författare)
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Robust humoral and cellular immune responses and low risk for reinfection at least 8 months following asymptomatic to mild COVID-19
- 2022
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Ingår i: Journal of Internal Medicine. - : John Wiley & Sons. - 0954-6820 .- 1365-2796. ; 291:1, s. 72-80
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Tidskriftsartikel (refereegranskat)abstract
- Background: Emerging data support detectable immune responses for months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination, but it is not yet established to what degree and for how long protection against reinfection lasts.Methods: We investigated SARS-CoV-2-specific humoral and cellular immune responses more than 8 months post-asymptomatic, mild and severe infection in a cohort of 1884 healthcare workers (HCW) and 51 hospitalized COVID-19 patients. Possible protection against SARS-CoV-2 reinfection was analyzed by a weekly 3-month polymerase chain reaction (PCR) screening of 252 HCW that had seroconverted 7 months prior to start of screening and 48 HCW that had remained seronegative at multiple time points.Results: All COVID-19 patients and 96% (355/370) of HCW who were anti-spike IgG positive at inclusion remained anti-spike IgG positive at the 8-month follow-up. Circulating SARS-CoV-2-specific memory T cell responses were detected in 88% (45/51) of COVID-19 patients and in 63% (233/370) of seropositive HCW. The cumulative incidence of PCR-confirmed SARS-CoV-2 infection was 1% (3/252) among anti-spike IgG positive HCW (0.13 cases per 100 weeks at risk) compared to 23% (11/48) among anti-spike IgG negative HCW (2.78 cases per 100 weeks at risk), resulting in a protective effect of 95.2% (95% CI 81.9%-99.1%).Conclusions: The vast majority of anti-spike IgG positive individuals remain anti-spike IgG positive for at least 8 months regardless of initial COVID-19 disease severity. The presence of anti-spike IgG antibodies is associated with a substantially reduced risk of reinfection up to 9 months following asymptomatic to mild COVID-19.
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| 9. |
- Havervall, Sebastian, et al.
(författare)
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SARS-CoV-2 induces a durable and antigen specific humoral immunity after asymptomatic to mild COVID-19 infection
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:1, s. e0262169-e0262169
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Tidskriftsartikel (refereegranskat)abstract
- Current SARS-CoV-2 serological assays generate discrepant results, and the longitudinal characteristics of antibodies targeting various antigens after asymptomatic to mild COVID-19 are yet to be established. This longitudinal cohort study including 1965 healthcare workers, of which 381 participants exhibited antibodies against the SARS-CoV-2 spike antigen at study inclusion, reveal that these antibodies remain detectable in most participants, 96%, at least four months post infection, despite having had no or mild symptoms. Virus neutralization capacity was confirmed by microneutralization assay in 91% of study participants at least four months post infection. Contrary to antibodies targeting the spike protein, antibodies against the nucleocapsid protein were only detected in 80% of previously anti-nucleocapsid IgG positive healthcare workers. Both anti-spike and anti-nucleocapsid IgG levels were significantly higher in previously hospitalized COVID-19 patients four months post infection than in healthcare workers four months post infection (p = 2*10−23 and 2*10−13 respectively). Although the magnitude of humoral response was associated with disease severity, our findings support a durable and functional humoral response after SARS-CoV-2 infection even after no or mild symptoms. We further demonstrate differences in antibody kinetics depending on the antigen, arguing against the use of the nucleocapsid protein as target antigen in population-based SARS-CoV-2 serological surveys
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