Lack of association between the platelet glycoprotein Ia C807T gene polymorphism and coronary artery disease: a meta-analysis

Study the Association of Nucleotide Polymorphisms in Platelet Receptor and Cytochrome P450 Genes with the Development of Resistance to Antiplatelet Drugs in Patients with Coronary Artery Disease

Aim. To study the association of nucleotide polymorphisms in platelet receptor and cytochrome P450 genes with the development of resistance to antiplatelet drugs in CHD patients.

Material and Methods. The study included 243 patients diagnosed with CHD after coronary artery bypass surgery (CABG), including 140 patients in the acetylsalicylic acid (ASA) treatment group and 103 patients in the dual antiplatelet therapy (DAT) group. All patients were tested for platelet aggregation using an optical aggregometer with inducers: 5 mM ADP and 1 mM arachidonic acid (AA). DNA samples were analyzed by allele-specific PCR for the presence of polymorphisms rs2046934, rs1126643, rs5918, rs6065, rs4244285 in the platelet receptor and cytochrome P450 genes.

Results. No statistically significant differences were found during comparison of the prevalence of the studied polymorphisms in the platelet receptor and cytochrome P450 genes between the groups of aspirin-sensitive and aspirin-resistant patients, as well as between the groups of clopidogrelsensitive and clopidogrel-resistant patients. No association between carriage of the minor and major alleles of the polymorphisms studied and the development of antiplatelet drug resistance was found. In the group of patients on ASA therapy, carriers of the C allele of the T1565C (rs5918) ITGB3 polymorphism had a higher rate of AA-induced platelet aggregation compared to carriers of the T allele (18,49±25,92 vs 10,43±17,34, р=0,004).

Conclusion. Polymorphisms of P2RY12 (rs2046934), ITGA2 (rs1126643), ITGB3 (rs5918), GP1BA (rs6065), CYP2C19*2 (rs4244285) genes are not associated with antiplatelet drug resistance in both patients on ASC therapy and on DAT. The presence of minor alleles of the rs2046934, rs1126643, rs6065, rs4244285 polymorphisms are not associated with increased platelet aggregation activity before CABG.However, in the group of patients on ASA therapy C-allele carriers of the rs5918 polymorphism of the ITGB3 gene had a higher rate of AA-induced platelet aggregation compared to T-allele carriers.

Genetic Polymorphism of ITGA2 C807T Collagen Receptor Encoding Gene of Aspirin Therapy among Javanese-Indonesian Healthy Respondents

BACKGROUND: Aspirin is an antiplatelet drug commonly administered as primary and secondary prophylaxis to prevent thromboembolic events. However, there has been a common incidence of aspirin resistance that leads to a recurrent cerebrovascular disease. One of the causes of such event is the genetic polymorphisms of the integrin alpha-2 (ITGA2) gene that encodes the glycoprotein Ia (GPIa) receptor in the pharmacodynamics of aspirin. AIM: This study analyzed the genetic polymorphism of ITGA2 as the GPIa collagen receptor encoding gene of aspirin therapy among healthy Javanese, the largest ethnic group in Indonesia. METHODS: This cross-sectional study involved 100 respondents who met the inclusion criteria with their blood sample taken for DNA isolation. Identification of genetic polymorphism in the target SNPs was done using the PCR-RFLP method with 5’-CCTTAAAGCTACCGGCCCATGT-3’ forward primer and 5’-TTGGCCTATTAGCACCAAAACTTACC-3’ reverse primer as well as Hpy188Irestriction enzyme to fragment the target at position 244 in the C base. RESULTS: This study found that the dominant genotype and allele were CT (51%) and C (66.5%), respectively. CONCLUSION: The allele frequency of ITGA2 gene in this study was similar to that of the populations in other Asian countries. Further research regarding the effects of ITGA2 C807T polymorphism on the pharmacodynamics of aspirin as an antiplatelet is recommended to minimize atherothrombotic events and examine its interactions as a biomarker of the risk and prognosis of some cancer types.

Impact of Platelet Glycoprotein Ia/IIa C807T Gene Polymorphisms on Coronary Artery Aneurysms of KD Patients

Background

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology in children. Coronary artery abnormalities are the most common complications of KD. Recent evidence showed that genetic polymorphisms may lead to susceptibility to KD. Genetic variants in platelet glycoprotein have been reported to be associated with coronary artery disease. The aim of the present study is to investigate the correlation between the role of platelet glycoprotein and coronary artery aneurysms in KD patients.

Methods

We did a case-control study that enrolled 818 KD patients and 1401 healthy children with the same age and sex from January 2013 to December 2016. Analysis of single-nucleotide polymorphism (rs1126643) of the platelet glycoprotein Ia/IIa C807T was performed by multiplex polymerase chain reactions in this study.

Results

A significant difference in the genotype distribution between KD cases and controls was observed for the glycoprotein Ia/IIa C807T (rs1126643) polymorphism (p=0.026). Compared with the healthy children, the rs1126643T allele carriers had odds ratio (OR) of 0.63 for developing KD (TT vs. CC: adjusted OR = 0.62, 95% confidence interval (CI) = 0.43–0.88,p=0.0078; TT vs. CT/CC: adjusted OR = 0.63, 95% CI = 0.44–0.889,p=0.0093). Furthermore, we also found that children less than 60 months of age and female patients with rs1126643 T allele carriers had an adjusted OR of 0.66 (95% CI = 0.46–0.95) for noncoronary artery aneurysm patients (p=0.0242). Single-nucleotide polymorphism rs1126643 TT seems to represent a protective factor against KD in coronary artery aneurysm formation in multivariate analysis.

Conclusions

The platelet glycoprotein Ia/IIa T allele carriers may have a protective effect on the risk of coronary artery aneurysms of KD patients, especially in females and children aged less than 60 months. These results may provide evidence for platelet glycoprotein Ia/IIa gene polymorphisms in the pathogenesis of KD patients.

Association of polymorphisms of platelet receptors GPIa (807C>T), GPVI (13254T>C), and P2Y12 (34C>T and H1/H2 haplotype) with increased risk of periprocedural bleeding in patients undergoing coronary angiography/percutaneous coronary intervention

Introduction

Periprocedural bleeding related to coronary angiography (CAG) or percutaneous coronary intervention (PCI) is associated with worse prognosis. Determining genetic variations associated with increased bleeding risk may help to identify high-risk patients.

Aim

To analyse the association between single nucleotide polymorphisms (SNPs) of crucial haemostatic platelet receptors (GPIa, GPVI, P2Y12) and the risk of periprocedural bleeding complications related to CAG/PCI.

Material and methods

The population consisted of 73 patients with ischaemic heart disease who developed bleeding complications within 30 days after CAG/PCI and 331 patients without bleeding. The frequency of SNPs of GPIa 807C/T, GPVI 13254T/C, P2Y12 32C/T, and P2Y12 H1/H2 haplotype was analysed using polymerase chain reaction (PCR) hybridization methods.

Results

The prevalence of variant alleles GPIa 807T, GPVI 13254C, P2Y12 34T, and P2Y12 H2 haplotype in the total study population was 56.7%, 20.3%, 56.2%, and 24.3%, respectively. The presence of variant alleles was not related to increased risk of periprocedural bleeding: GPIa 807C/T (OR = 1.29, 95% CI: 0.75–2.24, p = 0.334), GPVI 12354T/C (OR = 0.82, 95% CI: 0.40–1.64, p = 0.551), P2Y12 34C/T (OR = 0.71, 95% CI: 0.42–1.22, p = 0.189), P2Y12 H1/H2 haplotype (OR = 0.69, 95% CI: 0.35–1.36, p = 0.258). The frequency of the homozygous form of P2Y12 H2 haplotype was higher in the group of patients who developed bleeding (OR = 2.79, 95% CI: 0.51–13.77, p = 0.161).

Conclusions

No significant association of the SNPs of GPIa 807C/T, GPVI 13254T/C, P2Y12 32C/T, and P2Y12 H1/H2 haplotype with increased risk of periprocedural bleeding was found in patients with ischaemic heart disease undergoing CAG/PCI.

GPla Polymorphisms Are Associated with Outcomes in Patients at High Cardiovascular Risk

BACKGROUND

Platelet membrane glycoprotein receptors mediate thrombus formation. GP Ia/IIa is an essential platelet integrin receptor. Single-nucleotide polymorphisms (SNPs) of the GP Ia/IIa gene alter GP Ia/IIa expression; however, their influence on cardiovascular disease remains unclear. This study aimed to investigate the effect of the GP Ia/IIa SNPs rs1126643 and rs1062535 on clinical outcomes in a large collective including high-risk patients with cardiovascular disease.

METHODS AND RESULTS

GP Ia SNP analysis was performed in 943 patients with symptomatic coronary artery disease. All patients were tracked for all-cause death, myocardial infarction, and ischemic stroke for 360 days. Homozygous carriers of the minor allele showed significantly worse event-free survival when compared with major allele carriers in the complete collective as well as in the subset of high-risk patients (carrying all of the following three risk factors: diabetes type II, hypertension, and hyperlipidemia). There was no significant difference in the subset of low-risk patients (carrying none of the three risk factors).

CONCLUSIONS

GPla SNPs are associated with cardiovascular prognosis especially in high-risk patients. Identification of GPIa SNPs is of importance to tailor therapies in patients at already high cardiovascular risk.

A brief review on the mechanisms of aspirin resistance

Aspirin is the most widely prescribed drug for the primary and secondary prevention of cardiovascular and cerebrovascular diseases. However, a large number of patients continue to experience thromboembolic events despite aspirin therapy, a phenomenon referred to as aspirin resistance or treatment failure. Aspirin resistance is often observed along with a high incidence of unstable plaque, cardiovascular events and cerebrovascular accident. Studies have shown that aspirin reduces the production of TXA2, but not totally inhibits the activation of platelets. In this review, we analyze current and past research on aspirin resistance, presenting important summaries of results regarding the potential contributive roles of single nucleotide polymorphisms, inflammation, metabolic syndrome and miRNAs. The aim of this article is to provide a brief review on aspirin resistance and platelet function, which will provide important insights into the research of aspirin resistance.

Genetic susceptibility to deep venous thromboembolism: the roles of inherited thrombophilia polymorphisms

Recently much attention has been paid to the possibly considerable role of the thrombophilic gene polymorphisms in the pathogenesis of deep venous thromboembolism (DVT). However, the reported results are controversial. Hence, this study aimed to disclose the association between factor VII (FVII) 10976G/A, angiotensin-converting enzyme (ACE; intron 16 I/D), glycoprotein Ia (GPIa) 807C/T, tissue-type plasminogen activator (t-PA; intron 8 D/I) and tissue-factor pathway inhibitor 536C/T polymorphisms and DVT. We investigated these gene polymorphisms in 693 study participants including 193 patients who showed clinical symptoms of DVT and 500 healthy individuals without both personal and family histories of thromboembolic disorders. Genotyping was performed using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. Comparison of genotypes distribution revealed that the FVII 10976G/A polymorphism was significantly related with DVT (P < 0.05), whereas there was no association between the ACE (intron 16 I/D), GPIa807C/T, t-PA (intron 8 D/I) and tissue-factor pathway inhibitor 536C/T gene polymorphisms and DVT (P > 0.05). In addition, the prevalence of homozygote genotype and mutant allele for FVII 10976G/A polymorphism was significantly higher in cases compared with controls (P < 0.05). Taken together, our data provide evidence to support the hypothesis that FVII 10976G/A polymorphism may be associated with a predisposition to DVT.

Endobiogeny: a global approach to systems biology (part 1 of 2)

Endobiogeny is a global systems approach to human biology that may offer an advancement in clinical medicine based in scientific principles of rigor and experimentation and the humanistic principles of individualization of care and alleviation of suffering with minimization of harm. Endobiogeny is neither a movement away from modern science nor an uncritical embracing of pre-rational methods of inquiry but a synthesis of quantitative and qualitative relationships reflected in a systems-approach to life and based on new mathematical paradigms of pattern recognition.

Association between tumor necrosis factor alpha-238G/a polymorphism and tuberculosis susceptibility: a meta-analysis study

Background

Tumor necrosis factor alpha (TNF-α) plays a key role in the containment of tuberculosis. The relationship between the TNF -238G/A polymorphism and tuberculosis susceptibility remains inconclusive. A comprehensive meta-analysis was made to provide a more precise estimate of the relationship between them.

Methods

Multiple search strategies were used. A fixed effect model was takentook to estimate pooled OR with 95% confidence interval (CI) for the association between the TNF -238G/A polymorphism and tuberculosis susceptibility. The Chi-squared-based Q-test and I-squaredI² statistic were calculated to examine heterogeneity. Begg’s funnel plot and Egger’s test were used to assess publication bias.

Results

9 case-control studies were included in this meta-analysis. No significant heterogeneity was demonstrated, and no obvious publication bias was detected among the included studies. The meta-analysis indicated that there was no significant association between the TNF -238G/A polymorphism and tuberculosis susceptibility (GA+AA versus GG model: OR=1.005, 95% CI: 0.765-1.319; A versus G model: OR=1.000, 95% CI: 0.769-1.300). In the subgroup analyses by ethnicity, types of TB and human immunodeficiency virus (HIV) status, no significant association were identified.

Conclusions

The meta-analysis involving 2723 subjects did not detect any association between the TNF -238G/A polymorphism and tuberculosis susceptibility.

Association of platelet collagen receptor polymorphisms with premature acute myocardial infarction

The impact of platelet collagen receptor polymorphisms in the pathogenesis of myocardial infarction at young age remains unknown. To determine whether either of the two platelet collagen receptor polymorphisms (GP VI T13254C and GP Ia C807T) was associated with premature acute myocardial infarction. One hundred patients with premature acute myocardial infarction and 100 age-matched controls with normal coronary angiograms were studied. Genotyping was done using PCR followed by restriction fragment length polymorphism (RFLP). GP Ia C807T polymorphism was more frequent in the patient group (65%) than in the control group (53%). However, there was no association between this polymorphism and premature acute myocardial infarction (P = 0.08). The prevalence of T13254C polymorphism did not differ between patients (38%) and controls (33%), and this polymorphism was not associated with premature acute myocardial infarction (P = 0.46). Logistic regression analysis also indicated no association between these polymorphisms and premature acute myocardial infarction (C807T with P = 0.51 and T13254C with P = 0.20). There is no association between GP VI T13254C or GP Ia C807T polymorphisms and premature acute myocardial infarction.

Variants in exon 11 of MEF2A gene and coronary artery disease: evidence from a case-control study, systematic review, and meta-analysis

Background

Coronary artery disease (CAD) is the most common heart disease worldwide. Association of CAD with variants in the myocyte enhancer factor 2A (MEF2A) gene, the first identified CAD-causing gene, has attracted special attention but the results are controversial. We aimed to evaluate this genetic association via a case-control study and meta-analysis.

Methodology/Principal Findings

We performed a case-control association study to investigate the relationship between variations in exon 11 of MEF2A gene and CAD in 1045 sporadic patients and 1008 controls enrolled angiographically among southern Chinese population, and then the data from this study were compared and discussed in a systematic review and meta-analysis with all available published studies on MEF2A gene and CAD. In total, eight variants were identified (21-bp deletion, CAG repeats, CCG repeats, a CCA deletion and four SNPs). No significant link was observed between the common (CAG)_n polymorphism and CAD, whereas the rare 21-bp deletion was detected only in five affected individuals. The meta-analysis of (CAG)_n polymorphism and CAD risk, including nine studies with 3801 CAD patients and 4020 controls, also provided no convincing evidence for the genetic association, even upon stratification by race (mainly Whites and Chinese). However, the 21-bp deletion was regarded as a potentially logical, albeit undetermined, candidate for CAD in the following systematic review.

Conclusions/Significance

Our findings failed to demonstrate a correlation between (CAG)_n polymorphism with CAD, however, we concluded that the rare 21-bp deletion might have a more compelling effect on CAD than the common (CAG)_n polymorphism, and MEF2A genetic variant might be a rare but specific cause of CAD/MI.

Genetic regulation of platelet receptor expression and function: application in clinical practice and drug development

Understanding genetic contributions to platelet function could have profound clinical ramifications for personalizing platelet-directed pharmacotherapy, by providing insight into the risks and possible benefits associated with specific genotypes. This article represents an integrated summary of presentations related to genetic regulation of platelet receptor expression and function given at the Fifth Annual Platelet Colloquium in January 2010. It is supplemented with additional highlights from the literature covering (1) approaches to determining and evidence for the associations of genetic variants with platelet hypo- and hyperresponsive phenotypes, (2) the ramifications of these polymorphisms with regard to clinical responses to antiplatelet therapies, and (3) the role of platelet function/genetic testing in guiding antiplatelet therapy.

The new platelet alloantigen Cab a: a single point mutation Gln 716 His on the alpha 2 integrin

BACKGROUND

Fetal/neonatal alloimmune thrombocytopenia (FNAIT) is caused by maternal alloimmunization against fetal platelet (PLT) antigens, inherited from the father and absent from maternal PLTs.

STUDY DESIGN AND METHODS

A 29-year-old mother gave birth to a severely thrombocytopenic newborn (16 x 10(9) PLTs/L) leading to PLT transfusion therapy associated with intravenous immunoglobulins. The outcome was uneventful. Maternal serum showed a specific positive reaction with the antigen-capture assay (monoclonal antibody [MoAb]-specific immobilization of PLT antigens) only when it was tested with the paternal PLTs and a panel of MoAbs against glycoprotein (GP)Ia-IIa (alpha(2)beta(1) integrin) suggesting the implication of a new PLT antigen.

RESULTS

Nucleotide sequence analysis of GPIa cDNA of the father and newborn showed a nucleotide substitution at position 2235 (2235G > T according to the international nomenclature). This substitution induces a Q716H amino acid change in the GPIa mature protein, located outside the I domain involved in cell adhesion for collagen. In vitro analysis of recombinant Chinese hamster ovary (CHO) cells expressing wild-type or mutant (Q716H) human GPIa allowed us to demonstrate that this single amino acid substitution is responsible and sufficient for inducing Cab(a) antigen expression. Adhesion of CHO cells to collagen was not modified by the Cab polymorphism, nor by the maternal anti-Cab(a) alloantibodies, indicating that the mutation does not affect the function of integrin alpha(2)beta(1). In a Caucasian population study, none of the 104 unrelated blood donors was found to be Cab(a)(+).

CONCLUSION

We describe here a new PLT alloantigen Cab(a) involved in a severe case of FNAIT. Laboratory investigation for the "common" PLT alloantigens is no longer sufficient to evaluate neonatal alloimmune thrombocytopenia in suspected cases.