Study On The Relationship Between Platelet Membrane Glycoprotein Ⅱb Gene Polymorphism And Ischemic Stroke

Objective:Cerebrovascular disease (CVD) is threatening human life as one of the leading causes of mortality and morbidity. The ischemic stroke (IS) accounts for about 70% patients with CVD. The main underlying pathogenesis for IS include atherosclerotic lesions in large artery, such as carotid, vertebrobasilar, and cerebral arteries, typically proximal to major branches and cardiogenic emboli; Small-vessel diseases are main causes of lacunar infarction. Platelets play an important role in the process of arteral thrombosis. The gene polymorphism of platelet membrane glycoprotein(GP), which affects platelet function, may lead to arterial thombolic diseases such as acute myocardial infarction, cerebral infarction as one of the risk factors. Along with the rapid development of molecular biology techniques, gene polymorphism is concerned widespreadly in its role of the pathogenesis of cerebral infarction. Genetic susceptibility can increase the risk of cerebral vascular thrombotic diseases. Studying on the correlation between gene polymorphism of platelet membrane glycoprotein and IS would be able to provide evidence of molecular biology and genetics for early detection and prevention for IS. The GPIIb/IIIa complex was found to play an important role in thrombosis caused by platelet as a media, in recent years, some reports indicated there is the correlation between platelet membrane GPⅡbSer843 homozygous and young women with ischemic stroke and platelet membrane GPIIbSer843 increased the risk of mortality in elderly pationts with ischemic stroke. Chinese studies also showed, GPIIbHPA-3 gene polymorphism in Han population associated with coronary heart disease. But there are conflicting conclusions among studies regarding the relationship between GPⅡbHPA-3 polymorphism and IS. In view of genetic factors in different regions have different roles, it is necessary to expand more detailed study on the Chinese population. This study aims to find out the GPⅡb HPA-3 polymorphism distribution of Han population in Tianjin area, in hope to clarify the role of GPⅡb HPA-3 polymorphism in ischemic stroke, which might provide a new ideas for anti-platelet therapy and molecular genetic basis to help us to guide prevention and treatmemt.Methods:150 cases of IS diagnosed by clinical features and CT and/or MRI according to the WHO criteria for acute ischemic stroke were recruited into patients group.135 cases healthy control group.150 cases of IS were recorded vascular risk factors sush as smoking (>10 cigarettes/day, at least 5 years), old cerebral infarction, hypertention, history of coronary heart disease and diabetes. All the patients were measured with National Institutes of Health Stroke Scale (NIHSS). Case and control groups were normal fasting morning venous blood 2 ml, all blood test indicators were measured using automatic biochemical analysis of total cholesterol (TC), triglyceride (TG), high-density lipoproteins (HDL-C), low-density lipoprotein (LDL-C)and fasting plasma glucose(FPG), measurement of blood pressure and waist circumference. Using specific PCR(PCR-RFLP) amplification and BseGI restriction enzyome analysis,2.5% agarose gel electrophoresis to determine genotype, and measuring gene sequencing to detect alleles, analysis and compare the distribution of genotype and allele frequencies. Statistical method t-test measurement data, count data withχ2 test, using Logistic regression analysis to control other confounding variables. P<0.05 is considered significant difference.Resulst:1. Using the methods of independent samples t test considered:the average age of the two groups were 67.50±19.76 years old and 63.23±12.23 years old, t=3.040,P=0.742, match, no difference. Gender composition between the two groups usingχ2 test, the result showed no difference,χ2=1.11,P=0.292, on smoking history, 61.35% in the IS group and control group is 36.75%, the difference was statistically significant; hypertention,diabetes, high cholesterol, etc. risk factors was significantly higher in the IS group than control group, P<0.05.2. IS group, starting group, relapse group and control group GPIIb HPA-3 genotype and allele frequency distribution:the case group ab 35.1%, aa 32%, bb 33%, a allele 49.5%,b allele 50.5%; the control group ab 23.7%, aa 51.1%, bb 25.2%, a allele 63%, b allele 37%.3. Genetic survey:GPⅡb HPA-3 polymorphism are consistent with Hardy-Weinberg distribution of equilibrium between groups.4. Bb genotype and b allele frequency of IS group compared with healthy control group, the result showed significant difference,P<0.05. Starting group compared with healthy control group, the result showed significant difference, P<0.05. Relapse group compared with healthy control group, the result showed significant difference, P=0.005. the incidence and recurrence of IS is likely related to b allele, bb genotype may be a risk factor for morbidity and recurrence of IS.5. Genotype and allele frequency of starting group compared with relapse group, starting group and relapse group no significant difference,χ2=5.739,P=0.057. Starting group compared with relapse group showed significant difference, in which b allele frequency were 50.5%,χ2=5.157, P=0.023. B allele may be a risk factor for morbidity and recurrence of IS.6. Genotype and allele frequency comparison of different gender in case group, the result showed no significant difference.7. Genotype and allele frequency comparison of different age groups in case group, the result showed no significant difference.8.Genotype and allele frequency comparison of different NIHSS groups in case group, the genotype frequency distribution in different NIHSS groups were statistically significant,χ2=29.217,P=0.000. The allele frequency distribution in different NIHSS groups were statistically significant,χ2=25.162, P=0.000. Severe group, and b allele frequency were 43.8% and 73.2%, compared to mild and moderate, it was higher, so bb genotype and b allele may affect the severity of IS.9. TOAST classification of the case group, the genotype frequency was no statistically significant,χ2=7.027, P=0.134. allele frequency was statistically significant. LAA group b allele frequency 61.8% higher than the other group,χ2=6.573,P=0.037.10. Logistic regression analysis of risk factor of IS incidence showed that hypertention and b allele was statistically significant, after b allele into equation, P=0.018, may be an independent risk factor for IS, OR:3.678,95%Confidence Intervals:1.246-10.863.Conclusoins:GPⅡb HPA-3 polymorphism associated with morbidity and recurrence in patient with IS. HPA-3 bb genotype is possibly risk factor of morbidity and recurrence in patient with IS. B allele may be an independent risk factor for onset of IS. Bb genotype and b allele may affect the severity of IS.