ABSTRACT
Platelets play an important part in arterial thrombosis therefore it is important to consider the role of adhesion molecules of the platelet surface that play a role in increasing arterial risk. Glycoprofein Ia/IIa is the major platelet collagen receptor and is responsible for platelet adherence to exposed vascular subendothelium. A four fold variation of the platelets receptor density of the collagen receptor glycoprotein Ia/IIa correlating with platelet function to adhere to collagen type I and type III. GPIa/IIa surface expression is influenced by two linked single nucleotide polymorphism [807CT, 873GA] in glycoprotein Ia gene. Individuals with low receptor,densities are homozygos for the 807C/873G allele [CC] genotype whereas individuals homozygos for the 807T/873A allele [TT] genotype have high receptor densities with increased risk of thrombosis. The aim of this study was to evaluate the prevalence of platelet glycoprotein Ia allele polymorphism and platelet collagen receptor [CD49/CD29] density in patients with acute coronary syndrome and control subjects to clarify their possible involvement of their genotype and density as risk factors of the disease, and also to study the association between these findings and the other risk factor for myocardial infarction. The study including 41 patients with a mean age 55.23 years [ +/- 10.98] with a male to female ratio of 33:8. They were compared to 22 controls with a mean age of 49.74 years [ +/- 12.05] and a male to female ratio of 11:11.Glycoprotein Ia gene polymorphism analysis was done by PCR technique for patients and control group together with flowcytometric study of platelet collagen receptor [CD49/CD29] density. Plateletes glycoprotein Ia/IIa receptor% among cases showed a mean of 79.22% [ +/- 12.95] in comparison to 70.9% [ +/- 13.68] among controls. The difference was statistically significant. As regards gene rearrangements, the frequencies of homozygotes T807 allele [TT genotype] were significantly higher in patients with ACS than in controls [24.39% vs 13.63% p<0.05]. The prevalence of [CC] genotypes was also higher in control than in patients [31.8% vs 17%, p<0.05]. Platelets glycoprotein receptor Ia/IIa% [R%] among these groups showed a significant difference between TT cases [mean of 90.5% +/- 3.5], CC cases [mean of 66.5% +/- 5.75] and CT cases [mean of 79.8% +/- 4.82]. Studying other risk factors [obesity, hypertension [HTN], diabetes mellitus [DM] and lipid profile including total cholesterol, low density lipoprotein [LDL] and high density lipoprotein [HDL]] among our group of patients comparing to control subjects, showed no marked significant difference but not for triglycerides [TG] where was significantly higher in our patients compared to control. It was concluded that TT genotype was over presented among patients with acute coronary syndrome compared to healthy controls, whether this genotype is associated with more severe type of coronary heart disease or not this deserve larger scale study