Decreased factor XIII levels in factor XIII A subunit Leu34 homozygous patients with coronary artery disease

F13A1 Gene Variant (V34L) and Residual Circulating FXIIIA Levels Predict Short- and Long-Term Mortality in Acute Myocardial Infarction after Coronary Angioplasty

Factor XIIIA (FXIIIA) levels are independent predictors of early prognosis after acute myocardial infarction (AMI) and the Valine-to-Leucine (V34L) single nucleotide polymorphism (SNP) seems associated with lower AMI risk. Since the long-term AMI prognosis merits deeper investigation, we performed an observational study evaluating relationships between FXIIIA residual levels, cardiovascular risk-factors, and inherited genetic predispositions. FXIIIA V34L was genotyped in 333 AMI patients and a five-year follow-up was performed. FXIIIA levels assessed at day-zero (d0) and four days after AMI (d4), and conventional risk factors were analyzed, focusing on the development of major adverse cardiovascular events (MACE). FXIIIA assessed at d0 and d4 was also an independent MACE predictor in the long-term follow-up (FXIIIA_d0, Odds Ratio (OR) = 3.02, 1.79–5.1, p = 0.013; FXIIIA_d4, OR = 4.46, 2.33–8.55, p = 0.0001). FXIIIA_d4 showed the strongest MACE association, suggesting that the FXIIIA protective role is maximized when high levels are maintained for longer time. Conversely, FXIIIA levels stratified by V34L predicted MACE at a lesser extent among L34-carriers (Hazard Risk (HR)_VV34 = 3.89, 2.19–6.87, p = 0.000003; HR_L34-carriers = 2.78, 1.39–5.57, p = 0.0039), and V34L did not predict all MACE, only multiple-MACE occurrence (p = 0.0087). Finally, in survival analysis, heart failure and death differed significantly from stroke and recurrent ischemia (p = 0.0013), with FXIIIA levels appreciably lower in the former (p = 0.05). Overall, genetically-determined FXIIIA levels have a significant long-term prognostic role, suggesting that a pharmacogenetics approach might help to select those AMI patients at risk of poor prognosis in the need of dedicated treatments.

Effect of factor XIII levels and polymorphisms on the risk of myocardial infarction in young patients

Factor XIII (FXIII) stabilizes and protects the fibrin network. Its role in myocardial infarction (MI) is still to be clarified. To evaluate the association of FXIII levels with MI in young patients and to investigate how the FXIII-A p.Val34Leu, FXIII-B p.His95Arg, and IVS11, c.1952 + 144 C>G (Intron K) polymorphisms influence FXIII levels and MI risk. Patients with ST elevation MI below 40 years of age (MI, n = 119), age-matched clinical controls (CC, n = 101) without MI and coronary artery disease, and healthy controls (HC, n = 120) were investigated for FXIII activity, FXIII-A₂B₂, FXIII-B concentrations and for the polymorphisms. FXIII activity and FXIII-A₂B₂ antigen were significantly elevated in MI. FXIII activity and antigen were significantly elevated in Arg95, while decreased in Intron K "G" carriers. Smoking had an independent increasing effect on FXIII activity and FXIII-A₂B₂ antigen. Intron K C>G polymorphism significantly decreased the risk of MI in patients with elevated fibrinogen. Among the investigated factors Intron K C>G polymorphism and smoking have the most powerful effect on FXIII levels and on the risk of MI in the young. The effect of smoking on coronary thrombus formation may partially be attributed to its FXIII increasing effect.

Factor XIIIA-V34L and factor XIIIB-H95R in venous thromboembolism in central Iran: protective and neutral

Polymorphisms of coagulation factor XIII, an A2B2 tetramer, have been reported in correlation with venous and arterial thrombotic events. As there were limited data on these polymorphisms from Iranian population, we studied the correlation of factor XIIIA-Val34Leu and factor XIIIB-His95Arg with venous thromboembolism (VTE) in central Iran. Venous blood was collected from 102 unrelated VTE patients, diagnosed as pulmonary embolism, deep vein thrombosis (DVT), and pulmonary embolism/DVT and 165 healthy persons as control group. Genotyping was performed from DNA for FXIIIA-V34L and FXIIIB-H95R by polymerase chain reaction-restriction fragment length polymorphism and data were analyzed using Statistical Package for the Social Services software. There was no difference in age among the three groups of patients and between male and female participants. 41.02% of patients versus 42.04% of controls were carriers of FXIIIA-V34L as homozygous or heterozygous. Homozygosity of 34LL was significantly lower in patients compared with control participants (OR: 0.107, 95% CI: 0.14-0.83, P = 0.01) with only one homozygous in patients compared with 14 in the control group. Factor XIIIB-H95R was observed in 26.5% of patients versus 17.6% of control participants with no significant difference. There was no significant difference between patients and control group in homozygosity. Our findings on the frequency of FXIIIA-V34L is compatible with Caucasians. The significantly higher existence of homozygous 34LL in control participants is comparable with those who found it as protective against VTE. It may help to recognize risk factors or may contribute to prophylaxis in family members. We found FXIIIB-H95R polymorphism neutral. As there are different ethnicities in Iran, it may be beneficial to study other populations.

Factor XIII-A dynamics in acute myocardial infarction: a novel prognostic biomarker?

After acute myocardial infarction (MI) the damaged heart has to be repaired. Factor XIII (FXIII) is considered a key molecule in promoting heart healing. FXIII deficiency was associated to cardiac rupture and anomalous remodelling in MI. During MI, FXIII contributes firstly to the intracoronary thrombus formation and shortly after to heal the myocardial lesion. To quantify the real contribution of FXIII in this process, and to explore its possible prognostic role, we monitored the FXIII-A subunit levels in 350 acute MI patients during the first six days (d0-d5) plus a control at 30-60 days (d30). A one-year follow-up was performed for all the patients. A transient drop in the FXIII-A mean level was noted in the whole cohort of patients (FXIII-Ad0 99.48 ± 30.5 vs FXIII-Ad5 76.51 ± 27.02; p< 0.0001). Interestingly, those who developed post-MI heart failure showed the highest drop (FXIII-Ad5 52.1 ± 25.2) and they already presented with low levels at recruitment. Similarly, those who died showed the same FXIII-A dynamic (FXIII-Ad5 54.0 ± 22.5). Conversely, patients who remained free of major adverse cardiac events, had lower consuming (FXIII-Ad0 103.6 ± 29.1 vs FXIII-Ad5 84.4 ± 24.5; p< 0.0001). Interestingly, the FXIII-A drop was independent from the amount of injury assessed by TnT and CKMB levels. The survival analysis ascribed an increased probability of early death or heart failure inversely related to FXIII-A quartiles (FXIII-A25th< 59.5 %; hazard ratio 4.25; 2.2-5.1; p< 0.0001). Different FXIII-A dynamics and levels could be utilised as early prognostic indicators during acute MI, revealing the individual potential to heal and suggesting tailored treatments to avoid heart failure or its extreme consequence.

Factor XIII B subunit polymorphisms and the risk of coronary artery disease

The aim of the case-control study was to explore the effect of coagulation factor XIII (FXIII) B subunit (FXIII-B) polymorphisms on the risk of coronary artery disease, and on FXIII levels. In the study, 687 patients admitted for coronary angiography to investigate suspected coronary artery disease and 994 individuals representing the Hungarian population were enrolled. The patients were classified according to the presence of significant coronary atherosclerosis (CAS) and history of myocardial infarction (MI). The F13B gene was genotyped for p.His95Arg and for intron K nt29756 C>G polymorphisms; the latter results in the replacement of 10 C-terminal amino acids by 25 novel amino acids. The p.His95Arg polymorphism did not influence the risk of CAS or MI. The FXIII-B intron K nt29756 G allele provided significant protection against CAS and MI in patients with a fibrinogen level in the upper tertile. However, this effect prevailed only in the presence of the FXIII-A Leu34 allele, and a synergism between the two polymorphisms was revealed. Carriers of the intron K nt29756 G allele had significantly lower FXIII levels, and FXIII levels in the lower tertile provided significant protection against MI. It is suggested that the protective effect of the combined polymorphisms is related to decreased FXIII levels.

Sequence variations in the FII, FV, F13A1, FGB and PAI-1 genes are associated with differences in myocardial perfusion

AIMS

Coronary artery disease (CAD) is a significant cause of morbidity and mortality in modern societies. The association between genetic markers and CAD is still poorly understood. In this study, we evaluated the effect of five genetic variants: Factor V Leiden (FV:c.1691G>A) (rs6025), Factor II prothrombin (FII:c.20210G>A; rs1799963), plasminogen activator inhibitor 1 (PAI-1) -675(4G/5G; SERPINE1:g.4329_4330insG; rs34857375), β-fibrinogen -455G>A (FGB:c.4577G>A; rs1800790) and Factor XIII (F13A1:c.103G>T; rs5985) on myocardial perfusion.

MATERIALS & METHODS

We examined 523 patients using exercise-rest myocardial perfusion single photon emission computed tomography, where the summed stress score (SSS), summed rest score and summed difference score (SDS) indexes, were calculated. In order to examine the independent prognostic ability of genotype on SSS and SDS, multiple linear regression models were used.

RESULTS

It was found that Factor V Leiden, Factor XIII, β-fibrinogen and PAI-1 genotypes were independent prognostic predictors of SSS and SDS with Factor XIII exhibiting the strongest association. Moreover, Factor II prothrombin proved an independent prognostic predictor of SSS.

CONCLUSION

Our study provides the first evidence of an association between these polymorphisms and myocardial perfusion, suggesting that the process of coronary artery disease and also patients' prognosis, may be modified by the FV:c.1691G>A, FII:c.20210G>A, PAI-1 -675 (4G/5G), β-fibrinogen FGB:c.4577G>A and F13A1:c.103G>T genotypes.

Gene-gene and gene-environment interactions: new insights into the prevention, detection and management of coronary artery disease

Despite the recent success of genome-wide association studies (GWASs) in identifying loci consistently associated with coronary artery disease (CAD), a large proportion of the genetic components of CAD and its metabolic risk factors, including plasma lipids, type 2 diabetes and body mass index, remain unattributed. Gene-gene and gene-environment interactions might produce a meaningful improvement in quantification of the genetic determinants of CAD. Testing for gene-gene and gene-environment interactions is thus a new frontier for large-scale GWASs of CAD. There are several anecdotal examples of monogenic susceptibility to CAD in which the phenotype was worsened by an adverse environment. In addition, small-scale candidate gene association studies with functional hypotheses have identified gene-environment interactions. For future evaluation of gene-gene and gene-environment interactions to achieve the same success as the single gene associations reported in recent GWASs, it will be important to pre-specify agreed standards of study design and statistical power, environmental exposure measurement, phenomic characterization and analytical strategies. Here we discuss these issues, particularly in relation to the investigation and potential clinical utility of gene-gene and gene-environment interactions in CAD.

Cardiovascular disease and heritability of the prothrombotic state

Atherothrombotic disease remains a major cause of mortality worldwide, and family clustering suggests an important contribution of genetic factors to disease pathogenesis. Thrombus formation represents the final step in atherothrombosis, a process influenced by genetic and environmental factors. A major difficulty of investigating the genetic regulation of thrombotic conditions is the complexity of the phenotype and the relatively modest effects of individual genetic variations. We address in this review genetic aspects involved in regulating thrombosis potential and their impact on the development of atherothrombotic disease. The effects of common genetic polymorphisms in clotting factors are discussed and examples of complex gene-gene and gene-environment interactions are highlighted. Understanding the effects of genetic factors on predisposition to thrombotic disease and unravelling the complex gene-environment interactions will help to better understand the pathophysiology of this complex condition, which will enable the development of new preventative and treatment strategies.