The -148 C/T fibrinogen gene polymorphism and fibrinogen levels in ischaemic stroke: a case-control study

Effect of the -148C/T, 448G/A, and -854G/A Polymorphisms of the β-Fibrinogen Gene on the Risk of Ischemic Stroke in Chinese Population

BACKGROUND

Several investigations have been performed to examine the influence of the β-fibrinogen (FGβ) gene polymorphisms on the risk of ischemic stroke, but the results of these studies are controversial. Our study aimed at investigating whether the FGβ gene (-148 C/T, 448 G/A, and -854 G/A) polymorphisms were associated with susceptibility to ischemic stroke by conducting meta-analysis.

METHODS

Relevant studies were identified from 4 Chinese databases, PUBMED and EMBASE before May 30, 2014. The strength of association was evaluated by the odds ratio with 95% confidence interval. Inconsistency index and the Cochran's Q statistic were used to check heterogeneity. Publication bias was tested using funnel plots and Egger's regression test.

RESULTS

Thirty-two independent studies with 4311 cases and 4124 controls were included. Significant association between -148 C/T polymorphism and the risk of ischemic stroke was found in overall analysis and middle-age, but not in young adults and elderly people. Similarly, association was also observed for -854 G/A polymorphism, especially in cerebral arterial main trunk infarction (MCI) and cerebral penetrating arterial infarction (PCI). However, no significance was found between 448 G/A polymorphism and ischemic stroke in Chinese people; likewise, no evidence of a significant association was observed when stratified according to the subtype of ischemic stroke (MCI and PCI).

CONCLUSIONS

These results suggest that -148 C/T and -854 G/A polymorphisms probably contribute to susceptibility of ischemic stroke.

Fibrinogen alpha and beta gene polymorphisms in pediatric stroke--case-control and family based study

BACKGROUND/PURPOSE

Data on the role of the -455G > A polymorphism of the gene encoding β fibrinogen subunit (FGB) and the Thr312Ala polymorphism of the gene for the α fibrinogen subunit (FGA) in childhood ischemic stroke are insufficient. Therefore the aim of the study was to evaluate a possible association between these two polymorphisms and arterial ischemic stroke.

METHODS

The study group consisted of 85 children after ischemic stroke, 146 of their parents and 159 controls. Both polymorphisms were genotyped using the restriction fragment length polymorphism method. Two study designs were used: a case-control model and a family-based transmission-disequilibrium test. Statistica 7.1 and EpiInfo 6 softwares were used in all analyses.

RESULTS

In the TDT test, a tendency to a higher transmission of the 312Ala allele of the FGA gene and the -455A allele of the FGB gene was observed, however, it was statistically non-significant. The frequencies of alleles and genotypes of both FGA and FGB genes polymorphisms did not differentiate children from both groups also in the case-control model. Additive or synergistic effects between FGA and FGB genes polymorphisms were not observed.

CONCLUSION

An analysis of the results obtained in this study and a critical review of previously published data indicate that examined gene polymorphisms are not related to ischemic stroke in children.

Anti-inflammatory and anti-thrombogenic effects of atorvastatin in acute ischemic stroke

Atorvastatin decreases inflammation and thrombogenesis in patients with carotid artery plaque. Atorvastatin is administered to lower lipid levels, but its anti-inflammatory and anti-thrombogenic effects remain unclear. Eighty-nine patients from northeastern China with acute ischemic stroke caused by large-artery atherosclerosis were randomly divided into the study and control groups. All patients received routine treatment, including antiplatelet therapy, circulatory support, and symptomatic treatment. The study group (n = 43) also received daily atorvastatin 20 mg/d, and the control group (n = 46) received daily placebo pills containing glucose. After 4 weeks, the levels of C-reactive protein, fibrinogen, and D-dimer were significantly lower in the study group than in the control group. Decreases in the levels of C-reactive protein, fibrinogen, and D-dimer were not associated with decreases in the levels of triacylglycerol and low-density lipoprotein cholesterol. These results suggest that atorvastatin reduces inflammation and thrombogenesis independent of its lipid-lowering effects in patients with acute ischemic stroke caused by large-artery atherosclerosis.

Carpal tunnel syndrome is associated with high fibrinogen and fibrinogen deposits

BACKGROUND

Idiopathic carpal tunnel syndrome (ICTS) is a common entrapment neuropathy. Some cases of ICTS are linked to mutations of the transthyretin gene, whereas others are associated with systemic amyloidosis. The majority of ICTS cases are of unknown etiology.

OBJECTIVE

To study molecular mechanisms of ICTS development.

METHODS

A total of 71 ICTS patients and 68 control subjects were included in the study. The fibrinogen level was determined before surgery and its deposition in the transversal carpal ligament (TCL) was detected by immunohistochemistry, Western blot, and mass spectrometry. Fibrinogen interaction with other proteins was studied by immunoprecipitation assay.

RESULTS

Plasma levels of the proinflammatory and hemostatic protein fibrinogen are elevated in ICTS patients. Other measured systemic inflammatory markers were not affected, and local inflammatory responses in TCL were absent. ICTS patients have shorter bleeding times, probably because of the elevated plasma levels of fibrinogen. Polymorphisms of the fibrinogen B promoter region were previously associated with increased plasma fibrinogen, but this association was not observed among patients with ICTS. Interestingly, we detected fibrinogen deposits in the TCL, whereas transcriptional activity of the fibrinogen genes was low. Amyloidogenic proteins, including transthyretin and α-synuclein, were also found in the TCL, whereas their local transcriptional activity was rather high. Finally, we demonstrated that fibrinogen interacts with transthyretin and α-synuclein in TCL lysates.

CONCLUSION

Our data indicate that fibrinogen and other aggregation-prone proteins have potentially important roles in the pathogenesis of ICTS.

The role of genetic risk factors in arterial ischemic stroke in pediatric and adult patients: a critical review

The incidence of arterial ischemic stroke (AIS) in childhood (about 2-13 per 100,000 children a year) is much lower than the incidence in the adult population. Still, adverse outcomes of acute brain ischemia in childhood include death (10% of AIS children), neurological sequel, epileptic seizures (over 50%) and recurrence (over 20%). The knowledge of childhood stroke etiopathogenesis is still insufficient and the diagnostic and therapeutic procedures--controversial. Risk factors for childhood stroke differ from those observed in adults due to differing exposure to external risk factors. The most frequently reported risk factors for pediatric ischemic stroke are cerebral arteriopathies and vascular malformations, cardiac diseases, infections, traumas and metabolic diseases. Because of its multifactorial etiology pediatric AIS probably has a multigenic inheritance pattern. The genetic susceptibility to AIS may be determined by specific polymorphic variants encoding markers of hemostasis regulation and they are some of the most important targets in searching for genetic determinants in pediatric AIS. The authors have reviewed the recent literature on risk factors of childhood ischemic stroke with the focus on genetic factors like polymorphisms of genes encoding coagulation factors II, V, VII and XIII, MTHFR, fibrinogen beta, and compared them with the results performed in adult patients.

A vitronectin M381T polymorphism increases risk of hemangioblastoma in patients with VHL gene defect

Hemangioblastomas, highly vascular tumors, occur sporadically or associated with von Hippel-Lindau (VHL) disease. Diverse mutations in the VHL gene inactivate the VHL protein and constitute the molecular etiology of the disease. Changes in VHL gene were analyzed in patients with multiplex ligation-dependent probe amplification and single-strand conformation polymorphism analyses. We report here that other angiogenesis-related changes in vitronectin were identified with 2D electrophoresis of plasma samples and restriction fragment length polymorphisms. Our findings revealed that most patients (80.0%) with a familial VHL deletion carried the threonine (T) allele at vitronectin codon 381. Adults simultaneously carrying a VHL defect and the T allele were 5.0-fold more likely to be affected by VHL disease than were methionine/methionine (M/M) homozygotes carrying a VHL defect. Patients with sporadic hemangioblastoma, C-terminally truncated VHL protein or a large deletion in the VHL gene, and the T allele were 18.0-fold more likely to develop recurrent disease. Taken together, individuals with mutated VHL are more likely to be affected by familial or recurrent sporadic hemangioblastoma when carrying the M/T or T/T genotype at codon 381 of vitronectin.

Genetic polymorphisms for the study of multifactorial stroke

Single-gene disorders explain only a minority of stroke cases. Stroke represents a complex trait, which is usually assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies, with controversial results. Therefore, it is difficult for the clinician to establish the validity and the level of clinical applicability of the previously reported associations between genetic factors and stroke. This review is an update and an extensive analysis of the more recent association studies conducted in stroke. We evaluated a number of studies on several candidate genes (including F5, F2, FGA/FGB/FGG, F7, F13A1, vWF, F12, SERPINE1, ITGB3/PLA1/PLA2/ITGA2B, ITGA2, GP1BA, ACE, AGT, NOS3, APOE, LPL, PON1, PDE4D, ALOX5AP, MTHFR, MTR, and CBS), providing a final panel of genes and molecular variants. We categorized this panel in relation to the degree of association with stroke, supported by the results of meta-analyses and case-control studies. Our findings could represent a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

Fibrinogen gene variation and ischemic stroke

BACKGROUND

Plasma fibrinogen level and fibrin clot structure are heritable traits that may be of importance in the pathogenesis of ischemic stroke.

OBJECTIVES

To investigate associations between variation in the fibrinogen gamma (FGG), alpha (FGA) and beta (FGB) genes, fibrinogen level, and ischemic stroke.

METHODS

The Sahlgrenska Academy Study on Ischemic Stroke comprises 600 cases and 600 matched population controls. Stroke subtypes were defined according to TOAST criteria. Plasma fibrinogen level was measured by an automated clot-rate assay. Eight tagging single nucleotide polymorphisms (SNPs) were selected to capture genetic variation in the FGA, FGG, and FGB genes.

RESULTS

Plasma fibrinogen was independently associated with overall ischemic stroke and all subtypes, both in the acute stage (P < 0.001) and at three-month follow-up (P < 0.05). SNPs belonged to two haplotype blocks, one containing the FGB gene and the other the FGG and FGA genes. FGB haplotypes were associated with fibrinogen level (P < 0.01), but not with ischemic stroke. In contrast, FGG/FGA haplotypes showed independent association to ischemic stroke but not to fibrinogen level. In an additive model with the most common FGG/FGA haplotype (A1) as reference, the adjusted odds ratios of ischemic stroke were 1.4 [95% confidence interval (95% CI) 1.1-1.8], P < 0.01, 1.4 (95% CI 1.0-1.8), P < 0.05, and 1.5 (95% CI 1.0-2.1), P < 0.05 for the A2, A3, and A4 FGG/FGA haplotypes, respectively.

CONCLUSION

FGG/FGA haplotypes show association to ischemic stroke. This association is independent of fibrinogen level, thus suggesting that the association between ischemic stroke and variation at the FGG/FGA genes is mediated by qualitative rather than quantitative effects on fibrin(ogen).

Fibrinogen gamma' in ischemic stroke: a case-control study

BACKGROUND AND PURPOSE

To determine the contribution of fibrinogen gamma' levels and FGG haplotypes to ischemic stroke.

METHODS

Associations between fibrinogen gamma' levels, fibrinogen gamma'/total fibrinogen ratio, and FGG haplotypes with the risk of ischemic stroke were determined in 124 cases and 125 controls.

RESULTS

Fibrinogen gamma'/total fibrinogen ratio was higher in patients than in controls during the acute phase of the stroke and lower in the convalescent phase 3 months after the stroke. FGG haplotype 3 (H3) was associated with a reduced risk of ischemic stroke (odds ratio 0.60; 95% CI, 0.38 to 0.94), but not with the fibrinogen gamma'/total fibrinogen ratio. In contrast, FGG-H2 was associated with a decreased fibrinogen gamma'/total fibrinogen ratio, but not with risk of stroke.

CONCLUSIONS

Fibrinogen gamma'/total fibrinogen ratio is associated with ischemic stroke, especially in the acute phase of the disease. In addition, FGG-H3 haplotype appears to be protective against ischemic stroke.

Association studies of genetic polymorphism, environmental factors and their interaction in ischemic stroke

Genetic background plays an important role in susceptibility to ischemic stroke. Our aim was to investigate the association of genetic polymorphisms and ischemic stroke and to evaluate their interaction with environmental risk factors in the Chinese population. Angiotensin-converting enzyme (ACE) gene I/D polymorphism, apolipoprotein E (ApoE) gene polymorphism, methylenetetrahydrofolate reductase (MTHFR) gene 677C/T polymorphism, and beta fibrinogen (Fgbeta) gene 148C/T polymorphism were analyzed in 100 patients and 100 matched controls. The subjects were genotyped by polymerase chain reaction (PCR) amplification and denaturing high-performance liquid chromatography (DHPLC) analysis. Persons with the Fgbeta CT/TT, MTHFR CT/TT, and ACE ID/DD genotypes had an elevated incidence of ischemic stroke (OR 3.907, 95% CI, 1.160-13.162, P=0.028). Smokers with the Fgbeta CT/TT or APOEepsilon4epsilon3 genotype, as well as individuals with the Fgbeta CT/TT genotype who consumed alcohol were more likely to develop a stroke. The data indicate that certain unfavorable genotypic combinations act synergistically in the development of ischemic stroke in the Chinese population. Synergism was also observed between genotype and environmental risk factors. This study may facilitate the development of a strategy to effectively prevent ischemic strokes.