| 1. |
- Olsson, Sandra, 1976, et al.
(författare)
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Genetic variation in complement component C3 shows association with ischaemic stroke.
- 2011
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Ingår i: European journal of neurology : the official journal of the European Federation of Neurological Societies. - : Wiley. - 1468-1331. ; 42, s. 214-16
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: The aim of this study was to investigate whether genetic variation at the third complement component (C3) locus is associated with ischaemic stroke (IS). Methods: The Sahlgrenska Academy Study on Ischaemic Stroke comprises 844 patients with IS, and 668 healthy controls. Sixteen SNPs were analyzed. Results: Two SNPs, rs2277984 and rs3745565, showed a significant association with overall IS. The SNP rs2277984 also showed association with the IS subtype cryptogenic stroke. These associations were independent of hypertension, diabetes, and smoking. The independent association between rs3745565 and overall IS withstands correction for multiple testing. Conclusion: In this sample of patients with IS, genetic variation in C3 is associated with IS.
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| 2. |
- Stokowska, Anna, et al.
(författare)
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Cardioembolic and Small Vessel Disease Stroke Show Differences in Associations between Systemic C3 Levels and Outcome
- 2013
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Activation of the complement system has been proposed to play a role in the pathophysiology of stroke. As the specific involvement of the complement proteins may be influenced by stroke etiology, we compared plasma C3 and C3a levels in patients with cardioembolic (CE) and small vessel disease (SVD) subtypes of ischemic stroke and control subjects and evaluated their association to outcome at three months and two years. Methodology/Principal Findings: Plasma C3 and C3a levels in 79 CE and 79 SVD stroke patients, sampled within 10 days and at three months after stroke, and age- and sex-matched control subjects from The Sahlgrenska Academy Study on Ischemic Stroke were measured by ELISA. Functional outcome was assesed with modified Rankin Scale. In the CE group, plasma C3 levels were elevated only in the acute phase, whereas C3a was elevated at both time points. The follow-up phase plasma C3 levels in the upper third were associated with an increased risk of unfavorable outcome at three months (OR 7.12, CI 1.72-29.46, P = 0.007) as well as after two years (OR 8.25, CI 1.61-42.28, P = 0.011) after stroke. These associations withstand adjustment for age and sex. Conversely, three-month follow-up plasma C3a/C3 level ratios in the middle third were associated with favorable outcome after two years both in the univariate analysis (OR 0.19, CI 0.05-0.82, P = 0.026) and after adjustment for age and sex (OR 0.19, CI 0.04-0.88, P = 0.033). In the SVD group, plasma C3 and C3a levels were elevated at both time points but showed no significant associations with outcome. Conclusions: Plasma C3 and C3a levels are elevated after CE and SVD stroke but show associations with outcome only in CE stroke.
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| 3. |
- Stokowska, Anna, et al.
(författare)
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Plasma c3 and c3a levels in cryptogenic and large-vessel disease stroke: associations with outcome.
- 2011
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Ingår i: Cerebrovascular diseases (Basel, Switzerland). - : S. Karger AG. - 1421-9786 .- 1015-9770. ; 32:2, s. 114-22
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Inflammation seems to be a key player in the pathophysiology of stroke. In this study, we compared plasma C3 and C3a levels in cryptogenic and large-vessel disease (LVD) subtypes of ischemic stroke and control subjects and evaluated their association to outcome at 3 months and 2 years. Methods: C3 and C3a levels in plasma of 79 cryptogenic stroke and 73 LVD stroke patients, sampled within 10 days and at 3 months after stroke, and age- and sex-matched control subjects from the Sahlgrenska Academy Study on Ischemic Stroke were measured by ELISA. Functional outcome was assessed with the modified Rankin Scale. Results: Plasma C3 was increased in both stroke groups at both time points. Systemic elevation of C3a was limited to the acute phase in the cryptogenic stroke group, whereas plasma C3a levels in the LVD group were also elevated at the 3-month follow-up. In the LVD group, plasma C3 levels in the upper third at the 3-month follow-up were associated with an unfavorable outcome after 3 months independently of age and sex: odds ratio (OR) 5.56; 95% confidence interval (CI) 1.03-29.93; p = 0.045; as well as after 2 years: OR 4.75; 95% CI 1.11-20.30; p = 0.036. In the cryptogenic stroke group, high plasma C3a levels in the acute phase were associated with an unfavorable outcome after 3 months: OR 3.75; 95% CI 1.01-13.96; p = 0.049 in univariate analysis but not after adjustment for age and sex (p = 0.050). Conclusions: Plasma C3 and C3a levels are elevated in cryptogenic and LVD stroke and the predictive value of these markers may depend on stroke subtype. Further studies on the role of the complement system in ischemic stroke outcome based on larger patient populations and controlling for the effect of infections, are clearly warranted.
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| 4. |
- Ay, Hakan, et al.
(författare)
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Pathogenic Ischemic Stroke Phenotypes in the NINDS-Stroke Genetics Network
- 2014
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Ingår i: Stroke. - 0039-2499. ; 45:12, s. 3589-3596
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: NINDS (National Institute of Neurological Disorders and Stroke)-SiGN (Stroke Genetics Network) is an international consortium of ischemic stroke studies that aims to generate high-quality phenotype data to identify the genetic basis of pathogenic stroke subtypes. This analysis characterizes the etiopathogenetic basis of ischemic stroke and reliability of stroke classification in the consortium. METHODS: Fifty-two trained and certified adjudicators determined both phenotypic (abnormal test findings categorized in major pathogenic groups without weighting toward the most likely cause) and causative ischemic stroke subtypes in 16 954 subjects with imaging-confirmed ischemic stroke from 12 US studies and 11 studies from 8 European countries using the web-based Causative Classification of Stroke System. Classification reliability was assessed with blinded readjudication of 1509 randomly selected cases. RESULTS: The distribution of pathogenic categories varied by study, age, sex, and race (P<0.001 for each). Overall, only 40% to 54% of cases with a given major ischemic stroke pathogenesis (phenotypic subtype) were classified into the same final causative category with high confidence. There was good agreement for both causative (κ 0.72; 95% confidence interval, 0.69-0.75) and phenotypic classifications (κ 0.73; 95% confidence interval, 0.70-0.75). CONCLUSIONS: This study demonstrates that pathogenic subtypes can be determined with good reliability in studies that include investigators with different expertise and background, institutions with different stroke evaluation protocols and geographic location, and patient populations with different epidemiological characteristics. The discordance between phenotypic and causative stroke subtypes highlights the fact that the presence of an abnormality in a patient with stroke does not necessarily mean that it is the cause of stroke.
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| 5. |
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| 6. |
- Gidlöf, Olof, et al.
(författare)
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A Common Missense Variant in the ATP Receptor P2X7 Is Associated with Reduced Risk of Cardiovascular Events
- 2012
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Extracellular adenosine triphosphate (ATP) regulates inflammatory cells by activation of the P2X(7) receptor. We hypothesized that polymorphisms in P2RX7 influence the risk of ischemic heart disease (IHD), ischemic stroke (IS) and cardiovascular risk factors and tested this hypothesis using genetic association studies. Methods: Two loss-of-function SNPs in P2RX7 were genotyped in 1244 IHD cases and 2488 controls as well as 5969 individuals with cardiovascular risk factors. Eleven SNPs in a 250 kb region on chromosome 12 spanning P2RX7 as well as neighboring genes OASL, P2RX4 and CAMKK2 were genotyped in 4138 individuals with IS and 2528 controls. Association was examined using linear and logistic regression models with an additive genetic model. Results: The common loss-of-function variant rs3751143 was significantly associated with a decreased risk of IHD in smokers (P = 0.03) as well as decreased risk of IS (OR 0.89; 95% CI = 0.81-0.97; P = 0.012). In addition, an intronic SNP in CAMKK2, rs2686342, were associated with a decreased risk of IS (OR 0.89; 95% CI = 0.82-0.97; P = 0.011). In subgroup analyses, both SNPs were associated with decreased risk of IS in individuals with hypertension (P = 0.045 and 0.015, respectively). Conclusions: A common loss-of-function missense variant in the gene encoding the P2X7 receptor is associated with reduced risk of IS and with IHD in smokers. These findings might implicate a role of purinergic signaling in atherogenesis or atherothrombosis.
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| 7. |
- Hanson, Ellen, et al.
(författare)
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Genetic Variants of Coagulation Factor XI Show Association with Ischemic Stroke Up to 70 Years of Age
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Coagulation factor XI (FXI) has an important role in the propagation and stabilization of a thrombus upon vessel injury. High FXI levels have been implicated in thrombotic diseases including ischemic stroke. The aim of our study was to investigate whether FXI gene (F11) variants are associated with ischemic stroke. The discovery sample, the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), included 844 patients with ischemic stroke and 668 controls, all aged 18-70 years. Replication was performed in the Lund Stroke Register (LSR) and Malmö Diet and Cancer study (MDC), together including 1213 patients and 788 controls up to 70 years of age, and in total 3145 patients and 1793 controls (18-102 years). Seven F11 single-nucleotide polymorphisms (SNPs) were selected using a tagging approach. The SNPs rs3733403, rs925451, and rs1593 showed independent associations with overall ischemic stroke in SAHLSIS, ORs of 0.74 (95% CI 0.59-0.94), 1.24 (95% CI 1.06-1.46), and 0.70 (95% CI 0.55-0.90), respectively. The association for rs925451 was replicated in the LSR and MDC sample in a pre-specified analysis of subjects aged 70 years or younger, OR of 1.16 (95% CI 1.00-1.34), whereas no SNP was replicated when all ages were included. In line with this, one F11 haplotype was associated with overall ischemic stroke in the discovery sample and in the replication sample ≤70 years. We found significant associations between F11 variation and overall ischemic stroke up to 70 years of age. These findings motivate further studies on the role of F11 in ischemic stroke, especially in younger individuals.
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| 8. |
- Hanson, Ellen, et al.
(författare)
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No evidence for an association between ABO blood group and overall ischemic stroke or any of the major etiologic subtypes
- 2012
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Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 130:3, s. 339-342
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The ABO blood group system is encoded by one gene, ABO. Previous studies have reported an association between blood group non-O (i.e. phenotype A, B or AB) and myocardial infarction. Studies on stroke and ABO are, however, more scarce. Therefore, we aimed to investigate whether ABO phenotype or genotype is associated with ischemic stroke and/or etiologic subtypes of ischemic stroke. Materials and methods: The study was performed in the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), which comprises 600 patients with ischemic stroke before the age of 70 years, and 600 matched controls. Patients were classified according to the TOAST criteria. Results: There was no significant association between ABO phenotype (blood group O vs. non-O) and overall ischemic stroke (multivariable odds ratio of 0.9, 95% confidence interval 0.7-1.2). This was also true for blood group O vs. A and O vs. B. Furthermore, no association between ABO genotypes and ischemic stroke was detected. The ischemic stroke subtype analysis was confined to large-vessel disease, small-vessel disease, cardioembolic stroke and cryptogenic stroke. In this analysis, there was no significant association between any ischemic stroke subtype and ABO phenotype or genotype. Conclusions: The findings in this study suggest that ABO phenotype or genotype does not have a major impact in the pathophysiology of ischemic stroke or any of the ischemic stroke subtypes.
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| 9. |
- Hanson, Ellen, et al.
(författare)
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Plasma factor VII-activating protease antigen levels and activity are increased in ischemic stroke.
- 2012
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Ingår i: Journal of thrombosis and haemostasis : JTH. - : Elsevier BV. - 1538-7836 .- 1538-7933. ; 10:5, s. 848-56
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Tidskriftsartikel (refereegranskat)abstract
- Factor VII-activating protease (FSAP) is a recently discovered plasma protease with a role in the regulation of hemostasis and vascular remodeling processes. Higher levels and activity of FSAP have been reported in patients with deep vein thrombosis, but there are no data on plasma FSAP in ischemic stroke (IS).
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| 10. |
- Hanson, Ellen, et al.
(författare)
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Plasma levels of von Willebrand factor in the etiologic subtypes of ischemic stroke
- 2011
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 9:2, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Background: Compared with coronary artery disease, there are few studies on von Willebrand factor (VWF) in ischemic stroke (IS). Moreover, there is little information on VWF in the etiologic subtypes of IS. Objectives: The aim of the present study was to investigate VWF in IS and in the etiologic subtypes of IS. Patients/methods: The Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS) is a case-control study comprising 600 patients and 600 matched controls. Etiologic IS subtype was defined according to the TOAST criteria. Blood sampling was performed in the acute phase and after 3 months. Results: The levels of VWF were increased in overall IS, at both time-points. The 3-month VWF levels were increased in the subtypes of large-vessel disease (LVD), cardioembolic (CE) stroke and cryptogenic stroke, but not in the subtype of small-vessel disease (SVD), as compared with the controls. The acute phase VWF levels were significantly increased in all four subtypes. In the multivariate regression analysis, with vascular risk factors as covariates, the 3-month VWF levels were associated with CE stroke and cryptogenic stroke, and the acute phase VWF levels with all subtypes. There were significant subtype-specific differences in VWF, with the highest levels in LVD and CE stroke. Conclusions: The present results show that VWF levels are increased in patients with IS. Furthermore, the VWF levels differ between etiologic IS subtypes and thus, it is important to consider etiologic subtypes in future studies of VWF in patients with IS.
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