GPIIIa Gene Research Articles

Platelet Glycoprotein IIIa PlA1/PlA2 Polymorphism Modulates the Risk of Myocardial Infarction in Non-Diabetics.

Genetic polymorphisms of platelet glycoprotein IIIa (GPIIIa gene) have been investigated intensively in several thrombotic diseases, but their role in cardiovascular diseases remains controversial. This study aimed to investigate the association between platelet glycoprotein IIIa PlA1/PlA2 polymorphism and susceptibility to myocardial infarction in non-diabetics. A total of 200 participants were recruited for the study, 100 non-diabetic patients with myocardial infarction and 100 apparently healthy volunteers as a control group. GPIIIa PlA1/PlA2 polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism. The distribution of GPIIIa PlA1/PlA2 polymorphic genotypes among the study groups was significantly different (P value = 0.00). The PlA1/PlA2 and PlA2/PlA2 genotypes were more frequent in the patients with myocardial infarction while the genotype PlA1/PlA1 was more prevalent in the control group. There was a statistically significant association between the PlA1/PlA1 genotype and reduced risk of both ST-segment elevation myocardial infarction (odds ratio (OR) = 0.19; 95% confidence interval (CI): 0.09 - 0.34, P value = 0.00) and non-ST-segment elevation myocardial infarction (OR = 0.21; 95% CI: 0.09 - 0.45, P value = 0.00). The genotype PlA1/PlA2 was found to be associated with an increased risk of both types of myocardial infarction (OR = 6.0; 95% CI: 2.61 - 13.8, P value = 0.00 for ST-segment elevation myocardial infarction and OR = 6.65; 95% CI: 2.69 - 16.45, P value = 0.00 for non- ST-segment elevation myocardial infarction. In the patients carrying the PlA1/PlA2 genotype, the risk of ST-segment elevation myocardial infarction was increased to about 14 folds in the presence of family history (OR: 13.57, 95% CI: 1.42 - 130.03, P value = 0.02), and the risk of non-ST-segment elevation myocardial infarction increased to about 18 folds in the smokers carrying the genotype PlA2/PlA2 (OR: 17.63, 95% CI: 0.96 - 324.70, P value = 0.05). The GPIII PlA1/PlA1 genotype is associated with a reduced risk of ST-segment elevation and non-ST-segment elevation myocardial infarction, while PlA1/PlA2 is associated with an increased risk of both types of myocardial infarction.

Genetic screening of PLA1/PLA2 polymorphous marker of integrin beta 3 (ITGB3) GP IIIA gene in adolescent girls with puberty menorrhagia.

Puberty menorrhagia is one of the urgent problems of modern reproductive medicine. The study aimed to investigate the relationship between polymorphism of the GP IIIa (PLA1/PLA2) gene and improve the diagnosis of puberty menorrhagia in girls with thyroid gland pathology. Ninety-seven girls at puberty age were divided into three groups: group 1 (main) - girls with puberty menorrhagia and thyroid gland pathology (30 individuals), group 2 (comparison) - 40 girls with puberty menorrhagia, group 3 (control) - 27 practically healthy girls. Polymorphism of the GP IIIa (PLA1/PLA2) gene was studied by isolating genomic DNA from peripheral blood leukocytes, followed by amplification with a polymerase chain reaction. Results showed that mutation in the 17th chromosome of q21.32 of the GP IIIa gene occurred in 8.6% of cases among adolescents with menorrhagia, in contrast to the control group, where it was not observed at all. The A1A1-genotype occurred by 11.7% (X2=4.01, p=0.041) more often in adolescents with menorrhagia than in girls with concomitant thyroid gland pathology and by 15.0% (X2=4.54, p=0.033) more often than in the control group. It was also found that the presence of the A1A2-genotype unreliably reduced the chances of uterine bleeding in adolescent girls by 1.45 times (OR=2.12) and was a protective factor in the puberty menorrhagia occurrence (OR=0.47). It may be concluded that the identification of a hereditary factor of the reproductive system diseases of adolescent girls fundamentally changes the point of view on the tactics of disease management and subsequent therapy.

Генетические механизмы аспиринорезистентности у пациентов с атеротромботическим вариантом ишемического инсульта

The purpose — to study the association of rs2317676 polymorphic variants of the GPIIIa gene with the development of aspirin resistance in patients with atherothrombotic variant of ischemic stroke. Material and methods. The article presents data of 100 patients with acute ischemic stroke and 100 people from the control group. All the patients received aspirin at a dose of 300 mg per day during the first day of the disease and 100 or 125 mg per day thereafter. The control group received aspirin as a primary prophylaxis for cardiovascular diseases. The study measured platelet aggregation on day 5–7 of taking the drug. The rs2317676 polymorphism of the GPIIIa gene was considered as genetic marker. Results. The frequency of A/G polymorphism rs2317676 of the GPIIIa gene was lower among individuals with low platelet aggregation compared to individuals with high platelet aggregation (p = 0.023; OR = 0.33; 95% CI: 0.13–0.89). Conclusion. Carriage of the A/G genotype rs2317676 polymorphism of the GPIIIa gene influences an increase in platelet aggregation and the development of aspirin resistance.

Association of gene polymorphism with menorrhagia combined with thyroid pathology

Purpose of the study: to establish the frequency of alleles and genotypes of GP IIIa gene polymorphism in adolescent girls with uterine bleeding that is concomitant thyroid pathology and conduct a thorough genetic analysis of patients.Materials and methods. 70 teenage girls with puberty menorrhagia were surveyed. Study groups: I (main) – 30 teenage girls with puberty menorrhagia against the background of thyroid gland pathology, II group (comparison) – 40 teenage girls diagnosed with puberty menorrhagia. Control group consist of 25 almost healthy teenage girls. GP IIIa gene polymorphism (PLA1/PLA2) was studied once using PCR polymerase chain reaction.Results. A1/A2 polymorphism of the GP IIIa gene in adolescent girls with menorrhagia against the background of thyroid pathology indicates the likely prevailing frequency of individuals with “favorable” A1 allele over such with A2A2 genotype with and without pathology: in 12.3 and 9 times respectively. In adolescents without concomitant pathology A1A1 genotype was observed 11.7% more frequently than those with thyroid disease and 15.0% more often than in the control group. Distribution of genotypes of the GP IIIa gene polymorphous locus corresponded to the expected Hardy-Weinberg population balance, both in general and separately in the surveyed groups.Conclusions. In adolescents with menorrhagia without thyroid pathology A1A1 genotype occur 11.7% more frequently than in girls with thyroid diseases and 15.0% more often than in the control group. Relative frequency of A1A2- genotype is 9.2% in girls with menorrhagia and thyroid pathology, and A2A2 genotype by 2.5% over such in adolescents of comparison groups. Thus, risk factors for uterine bleeding with existing thyroid pathology in adolescent girls may depend on gene polymorphism.

Evidence of platelet dysfunction in congenital cyanotic heart disease: relevance to palliative systemic-pulmonary shunt and haemostatic parameters

Abstract Introduction Platelets in congenital cyanotic heart disease (CCHD) were occasionally characterized by significantly enhanced expression of P-selectin in resting circulating platelets as well as their augmented activation in response to stimulating agents. P-selectin is present in the alpha granule membrane as well as Weibel-Palade body membrane of endothelial cells. It is translocated to platelet membrane after activation; thus, its expression on platelet surface is an indicator of platelet activation in vivo. The occurrence of the prothrombotic variant of GPIIIa in cyanotic children may be associated with enhanced activation of circulating platelets. Purpose To study the platelet functions in patients with CCHD by determination of Pselectin expression and the GPIIIa polymorphism and to correlate these findings with other clinical, radiological, and laboratory parameters in these patients. Methods This study included 47 patients, with cyanotic congenital heart disease with decreased pulmonary blood flow, attending the Pediatric Cardiology Clinic. They were divided into two groups: Group I: 31 patients with congenital cyanotic heart disease before cardio surgery Group II: 16 patients with congenital cyanotic heart disease 3–6 months after palliative or corrective cardio surgery, Group III: 12 age and sex matched normal children were included in the study as control group. They were subjected to Flow-cytometric evaluation of platelet activation by Pselectin expression: P-selectin expression was estimated using monoclonal antibody.-Typing of GPIIIa gene polymorphism was done. Results Statistically significant higher P-selectin levels were found in patients compared with controls being significantly higher in patients <3 years of age. There was significant negative correlation between P-selectin level and O2 in patients. The incidence of prothrombotic variant A2 was described as phenotype positive. Statistically significant higher levels of P-selectine were found in positive phenotype patients than positive phenotype controls Conclusion Enhanced platelet activation may be an important contributor in the high thrombotic liability in congenital cyanotic heart disease. This may be attributed in part to genetic factors Funding Acknowledgement Type of funding source: None

Genetic predictors of vascular complications in adolescents involved in sports

Introduction. The urgency of the problem is because the carriage of genetic predictors of thrombogenic risk in adolescents can be a significant factor in the formation of arterial and venous thromboses, leading to disability and even death, especially after significant sports overloads. Materials and methods. DNA genotyping was carried out in 259 boys aged 14 to 17 years who were professionally involved in sports for a long time. The reference group consisted of 228 students who were not additionally involved in sports sections at the age of 14-17 years of I-II health groups. Genetic testing was performed using the Real-Time PCR method using competing TagMan probes. 12 genetic allelic DNA polymorphisms were studied. The analysis of laboratory and instrumental methods of research. The results were statistically processed using the STATISTICA 10.0 software package. Results. Among adolescent athletes, a group of children with a high risk of vascular complications was identified on the basis of the studied thrombogenic DNA polymorphisms and folate metabolism genes. The frequency of the minor C1565 allele of the GPIIIa gene was significantly more often determined in adolescent athletes, while the variant of the minor 4G allele (-675) of the PAI-I gene was significantly more often detected in relatively healthy schoolchildren. The heterozygous genotype 1565 TC of the GPIIIa gene, the heterozygous genotype 1298 of the AC MTHFR gene, and the heterozygous genotype 66 AG of the methionine synthase reductase gene (MTRR) were found to be more pronounced in adolescent athletes. The frequency of associations of 4 (17.4%), 5 (28.6%), 6 (25.8%), 7 (10.8%) and 8 (5.4%) genetic polymorphisms was significantly increased in adolescent athletes, which may have pathogenetic significance. Moreover, in athletes, combinations of C677T polymorphisms of the MTHFR gene, 4G (-675) 5G of the PAI-I gene, G (-455) A of the FGB gene were unfavorable for the implementation of vascular lesions. Conclusion. For the first time, criteria have been formulated for the selection of teenage athletes in the high-risk group for vascular complications, taking into account genetic factors. It has been established that the most informative predictors of the risk of vascular complications are the variants of the GPIIIa T1565C, MTRR A66G genes, and gene gene associations of polymorphisms.

Полиморфизм генов тромбоцитарных рецепторов GPIa, GPIb и GPIIIa у женщин с болезнью Виллебранда I типа

Цель исследования: изучить частоту встречаемости полиморфизмов генов тромбоцитарных рецепторов GPIa, GPIb и GPIIIa у женщин с болезнью Виллебранда I типа выполнить клиниколабораторное сопоставление для выявления наличия или отсутствия корреляционной связи между исследуемыми генетическими полиморфизмами и выраженностью дефицита фактора Виллебранда и фактора VIII. Материалы и методы. В исследование включено 136 женщин в возрасте от 18 до 45 лет (в среднем 31,7 0,5 лет) с диагностированной болезнью Виллебранда I типа. Контрольную группу составили 111 здоровых женщин в возрасте от 18 до 45 лет (в среднем 30,0 0,6 лет). Исследование антигена фактора Виллебранда (vWF:Ag), ристоцетинкофакторной активности фактора Виллебранда (vWF:RCo) и активности фактора VIII (FVIII:C) проводили на автоматическом коагулометре Elite PRO (Instrumentation Laboratory, США) с использованием реагентов HemosIL (Instrumentation Laboratory, США). Молекулярногенетическое исследование полиморфизма генов тромбоцитарных рецепторов GPIIIa (1a/1b), GPIa (C807T) и GPIb (A1/A2) выполняли методом аллельспецифической полимеразной цепной реакции с детекцией продуктов амплификации методом электрофореза в полиакриламидном геле. Результаты. Частота встречаемости полиморфизмов генов тромбоцитарных рецепторов GPIIIa (1a/1b), GPIa (C807T) и GPIb (A1/A2) у пациенток с диагностированной болезнью Виллебранда I типа не имела статистически значимых различий с таковой у здоровых женщин. Исключение составил генотип 1a1b гена тромбоцитарного рецептора GPIIIa, частота встречаемости которого у пациенток с болезнью Виллебранда I типа оказалась выше по сравнению с частотой встречаемости данного генотипа в контрольной группе (23,5 и 10,8 , соответственно p 0,05). Заключение. Полиморфизм генов тромбоцитарных рецепторов GPIIIa (1a/1b), GPIa (C807T) и GPIb (A1/A2) одинаково широко встречается как у здоровых лиц, так и у женщин с болезнью Виллебранда. Имеет ли какоелибо клиническое значение выявленная нами несколько бльшая, по сравнению со здоровыми лицами, частота встречаемости генотипа 1a1b гена тромбоцитарного рецептора GPIIIa у пациенток с болезнью Виллебранда, покажут дальнейшие исследования. Aim: to study polymorphisms frequency of GPIa, GPIb and GPIIIa platelet receptors genes in women with von Willebrand disease type I to carry out clinical and laboratory comparison to reveal presence or absence of correlation relationship between the studied genetic polymorphisms and Willebrand factor and factor VIII deficiency expression. Materials and methods. The study included 136 women aged from 18 to 45 years (mean 31.7 0.5 years) with diagnosed von Willebrand disease type I. The control group consisted of 111 healthy women aged from 18 to 45 years (mean 30.0 0.6 years). The study of von Willebrand factor antigen (vWF:Ag), ristocetincofactor activity of von Willebrand factor (vWF:RCo) and factor VIII activity (FVIII:C) was performed on Elite PRO automatic coagulometer (Instrumentation Laboratory, USA) using HemosIL reagents (Instrumentation Laboratory, USA). A moleculargenetic analysis of polymorphism of GPIIIa (1a/1b), GPIa (C807T) and GPIb (A1/A2) platelet receptor genes was performed by allelespecific polymerase chain reaction with detection of amplification products using polyacrylamide gel electrophoresis. Results. Polymorphisms frequency of GPIIIa (1a/1b), GPIa (C807T) and GPIb (A1/A2) platelet receptors genes in patients with diagnosed von Willebrand disease type I was not significantly different from that in healthy women. The exception was the genotype 1a1b of platelet receptor gene GPIIIa, the frequency of which in patients with von Willebrand disease type I was higher compared with the frequency of this genotype in the control group (23.5 and 10.8, respectively p 0.05 ). Conclusion. The polymorphism of GPIIIa (1a/1b), GPIa (C807T) and GPIb (A1/A2) platelet receptors genes is equally widespread both in healthy persons and in women with von Willebrand disease. Further studies will show if higher frequency of 1a1b genotype of GPIIIa platelet receptor gene in patients with von Willebrand disease has any clinical significance.

A Study on the Role of Thrombophilic Genetic Disorders as a Risk Factor for Thrombotic Complications in Patients with Myeloproliferative Disorders

Summary Myeloproliferative neoplasms (MPN) are haematological diseases, characterized by clonal hematopoiesis. Hemostasis abnormalities are among the most critical and frequent complications, affecting the quality of life and a possible reason for death. Thrombotic complications are common and multifactorial. Our aim was to study some genetic thrombophilia factors – Factor V Leiden (FVL), G20210A mutation in prothrombin gene (PR G20210A) and PLA2 allele polymorphism of glycoprotein IIIa gene (GPIIIa gene), and their frequency and association with thrombotic risk in both Philadelphia-positive and Philadelphia-negative MPN – chronic myelogenous leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET), and primary and secondary myelofibrosis (MF). In our patient population, PLA2 allele polymorphism of GPIIIa gene proved to be the most common and significantly associated with thrombotic complications – 26.85% of our patients were carriers, and 24.14% of them reported thrombotic complications.

GPIIB ALLELIC POLYMORPHISM AS A FACTOR ASSOCIATED WITH THE PROBABILITY OF IMMUNE THROMBOCYTOPENIA AND THE SEVERITY OF HEMORRHAGIC SYNDROME

Russian Scientific Research Institute of Hematology and Transfusiology under the Federal Medico-Biological Agency; 16 Vtoraya Sovetskaya St., 191024 Saint Petersburg, RussiaPolymorphism of platelet glycoproteins GPIIIa (T1565C), GPIba (T434C), GPIIb (T2622G) and GPIa (A1648G) genes, responsible for the formation of alloantigenic platelet systems HPA-1, -2, -3 and -5, in patients with chronic immune thrombocytopenia (ITP) and in control group (CG) was investigated. Among ITP patients, the proportion of homozygotes of the GPIIb 2622 GG (HPA-3b/3b) gene was more than 2 times higher than in CG: 23.9 % versus 11.4 % (odds ratio (OR) = 2.4, 95 % confidence interval (CI): 1.0–5.8, p = 0.05). The frequency of HPA-3a/3a (GPIIb 2622TT,843Ile/Ile) genotype was higher in ITP patients with 2–3rd degrees of hemorrhagic syndrome (HS): 55.6% versus 25.0% in the group with 0–1st degree of HS (OR = 3.8, 95 % CI: 1.3–10.7, p = 0.02). The obtained data suggest the effect of T2622G polymorphism GPIIb gene both on development of disease (2622 GG genotype), and on serious manifestations of HS (2622 TT genotype), which allows considering this polymorphism as unfavorable prognostic criterion in ITP patients.

Role of and genes polymorphisms in the pathogenesis of stroke of the Erzya population in the Republic of Mordovia

To determine the frequency of GPIIIa and eNOS genes polymorphisms in patients with ischemic stroke in the Erzya population in the Republic of Mordovia. An open, prospective, randomized study included 4 groups: 1) Erzya with ischemic stroke (main group, n=65), 2) Russians with ischemic stroke (comparison group, n=60), 3) Erzya healthy volunteers (control-1, n=63), 4) Russian healthy volunteers (control-2, n=61). T1565C polymorphism of GPIIIa gene (rs5918) and G894T polymorphism of eNOS gene (rs1799983) were determined by real-time PCR. In the population of healthy Erzya, the accumulation of mutant alleles of the GPIIIa gene was observed with less frequency than in healthy Russians, however, in the absence of differences in the frequency of homozygous carriage of both mutant and normal alleles, in the Erzya, the accumulation of the mutant allele in heterozygous genotypes prevailed. In patients with stroke, the probability of detecting the allele C of the GPIIIa gene in the Erzya was significantly higher than in the Russians, as was the likelihood of heterozygous carriage of the C/T genotype. No differences between eNOS allele frequencies were found between the groups of healthy Erzya and Russian volunteers. The higher frequency of the mutant allele T was found in Russian patients with stroke while the heterozygous carriage of the G/T genotype, which had an unfavorable prognostic value, predominated in the Erzya.

Association of FGB, LPL, GPIIIA and TGFB gene polymorphisms with variants of atherosclerosis severity

Aim. To estimate the effect of transforming growth factor в, lipoprotein lipase, fibrinogen в and glycoprotein 3б gene polymorphisms on different variants of atherosclerosis severity. 
 Methods. The study included 319 patients with angiografically verified atherosclerosis. In all patients FGB (rs1800788), LPL (rs328), GpIIIa (rs5918) and TGFВ (rs1800469) polymorphism genotyping was performed. In all patients we evaluated the influence of the studied gene polymorphisms on parameters of atherosclerosis severity such as occlusion and presence and severity of stenosis. Presence of occlusion, occlusion and/or two and more stenoses over 70%, occlusion and multiple critical stenoses were considered the severity criteria. 
 Results. The studied gene polymorphisms were shown to be associated with severe course of atherosclerosis. GPIIIa polymorphism was commonly determined in patients with more severe course regardless of occlusion and number and severity of stenoses. FGB gene influenced the rate of occlusion development, TGF gene was expressed only in the group with occlusion and/or two and more stenoses over 70%, and LPL gene proved to be significant for the development of occlusion associated with critical stenosis. 
 Conclusion. The frequency of rare alleles of polymorphic regions is significantly associated with different variants of severe atherosclerosis course; this could suggest unequal influence of gene polymorphisms as well as their proteins on different stages of atherogenesis and requires further investigation.

Interaction among CYP2C8, GPIIIa and P2Y12 variants increase susceptibility to ischemic stroke in Chinese population.

PurposeGenetic variants in cytochrome P450 (CYP), platelet membrane receptor (P2Y12, P2Y1), and glycoprotein IIIa (GPIIIa) genes are associated with the efficacy of clopidogrel and adverse clinical events on ischemic stroke (IS) patients. However, few studies have assessed whether gene-gene interactions among these genes influence the risk of IS. The aim of the present study was to investigate the association of fifteen variants with IS and to determine whether these gene-gene interactions increase the risk of IS.MethodsFifteen variants in CYP3A4, CYP3A5, CYP2C8, CYP2C9, CYP2C19, P2Y12, P2Y1 and GPIIIa genes were examined using mass spectrometry methods in 396 patients with IS and 378 controls. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods.ResultsSingle-gene variant analysis showed no significant differences in the genotype distributions of the fifteen variants between IS patients and controls using the single-locus analytical approach. However, GMDR analysis showed a significant gene-gene interaction among rs17110453A>C, rs2317676A>G, and rs16863323C>T, which scored 10 for cross-validation consistency and 9 for the sign test (P = 0.016). Logistic regression analysis showed that high-risk interactions among rs17110453A>C, rs2317676A>G, and rs16863323C>T were independent risk factor for IS after adjusting for age, hypertension, diabetes mellitus, and hemoglobin A1C (OR=2.24, 95% CI: 1.17–5.62, P=0.005).ConclusionsThe rs17110453A>C, rs2317676A>G, and rs16863323C>T three-loci interaction may confer a higher risk for IS. The combinatorial analysis used in this study may be helpful to elucidate complex genetic risk factors for IS.

Platelet receptor Gene (P2Y12, P2Y1) and platelet glycoprotein Gene (GPIIIa) polymorphisms are associated with antiplatelet drug responsiveness and clinical outcomes after acute minor ischemic stroke.

Patients with minor ischemic stroke (MIS) are at high risk of recurrent ischemic stroke (RIS). The aim of this study was to evaluate the effects of platelet receptor gene (P2Y12, P2Y1) and glycoprotein gene (GPIIIa) polymorphisms, as well as their interactions, on antiplatelet drug responsiveness and clinical outcomes in patients with acute MIS. We prospectively enrolled 426 patients with acute MIS who had been receiving combined aspirin and clopidogrel treatment for at least 3months. Prevalence of seven variants in P2Y12, P2Y1, and GPIIIa genes were examined using mass spectrometry. Gene-gene interactions were evaluated using generalized multifactor dimensionality reduction (GMDR) analysis. Antiplatelet drug responsiveness was assessed by platelet aggregation assay. All patients were followed for 90days. Primary outcomes were defined as a composite of RIS, myocardial infarction (MI), and death. The incidence of primary outcomes was 10.8% (46/426; 40 had RIS, 2 died, and 4 had MI) during the first 90days after stroke. No significant differences were found regarding genotype frequencies of the seven variants between those with and without incidence of primary outcomes. However, we observed significant gene-gene interaction between rs16863323 and rs2317676 polymorphisms. The high-risk interactive genotypes were independently associated with poor antiplatelet drug responsiveness and increased risk of primary outcomes. Responsiveness to antiplatelet drugs and the risks for adverse clinical events in this MIS cohort appear to be multifactorial since the outcomes were not mediated by single gene polymorphisms.

Interaction among COX-2, P2Y1 and GPIIIa gene variants is associated with aspirin resistance and early neurological deterioration in Chinese stroke patients

BackgroundThe effect of genetic variants on aspirin resistance (AR) remains controversial. We sought to assess the association of genetic variants with AR and early clinical outcomes in patients with acute ischemic stroke (IS).MethodsA total of 850 acute IS patients were consecutively enrolled. Platelet aggregation was measured before and after a 7–10 day aspirin treatment. The sequences of 14 variants of COX-1, COX-2, GPIb, GPIIIa, P2Y1 and P2Y12 were determined using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR). The primary outcome was early neurological deterioration (END) within 10 days of admission. The secondary outcome was a composite of early recurrent ischemic stroke (ERIS), myocardial infarction (MI) and death within 10 days of admission.Results175 (20.6%) patients were AR, 45 (5.3%) were aspirin semi-resistant, 121 (14.2%) developed END, 17 (0.2%) had ERIS, 2 (0.2%) died, and 6 (0.7%) had MI. Single locus analysis indicated that only rs1371097 was associated with AR. However, GMDR analysis indicated that the following three sets of gene-gene interactions were significantly associated with AR: rs20417CC/rs1371097TT/rs2317676GG; rs20417CC/rs1371097TT/rs2317676GG; rs20417CC/rs1371097CT/rs2317676AG. END occurred significantly more frequently in patients with AR or high-risk interactive genotypes. Moreover, AR and high-risk interactive genotypes were independently associated with END.ConclusionSensitivity of IS patients to aspirin and END may be multifactorial and is not significantly associated with a single gene polymorphism. Combinational analysis may useful for further insight into the genetic risks for AR.

Platelet Glycoprotein IIIa Gene Polymorphism (Leu33Pro) and Aspirin Resistance in a Very Elderly Chinese Population

To study the relationship between platelet glycoprotein IIIa gene (GP IIIa) polymorphism (Leu33Pro) and aspirin resistance in a very elderly Chinese population. Four hundred fifty very elderly Chinese people receiving aspirin therapy were enrolled in the study. Patients who underwent arachnoid acid-induced platelet aggregation were then divided into two groups based on their resistance to aspirin: aspirin-resistant (AR) group (n=236) and aspirin-sensitive (AS) group (n=214). The Leu33Pro polymorphism of the GP IIIa gene was scanned by polymerase chain reaction-restriction fragment-length polymorphism. In the AR group, 224 participants had the A1/A1 genotype and 12 had the A1/A2 genotype. All patients in the AS group had the A1/A1 genotype. Thus, there was significant difference between these two groups in the genotype distribution (p<0.05). The genetic polymorphism of the GP IIIa gene was associated with AR in a very elderly Chinese population.

Different biochemical expression pattern of platelet surface glycoproteins suggests molecular diversity of Glanzmann's thrombasthenia in Iran

Glanzmann's thrombasthenia is a rare congenital bleeding disorder characterized by lack of platelet aggregation induced by most agonists. The disease is caused by different mutations in either GPIIb or GPIIIa genes that lead to a lack or dysfunction of the αIIbβ3. Western blot analysis was performed on the platelet lysates of 95 patients with Glanzmann's thrombasthenia who were referred to the Iranian Blood Transfusion and Hemophilia Clinic. Glanzmann's thrombasthenia was diagnosed based on clinical findings and were classified according to Glanzmann's Thrombasthenia Italian Team (GLATIT) protocol. The platelet glycoprotein expression pattern in Iranian patients with Glanzmann's thrombasthenia was studied and the relationship between the platelet glycoprotein expression levels and clinical symptoms were investigated. Loss or severe reduction of platelet GpIIb and GpIIIa were observed in majority of patients (78%). The remaining patients (22%) showed a relatively sharp decline to the normal amounts of the glycoproteins. None of the patients showed expression of CD41 without CD61. Statistical analysis showed no significant relationship between clinical symptoms and expression of platelet glycoproteins. Different patterns of platelet glycoproteins expression suggest that there is variety of mutations in the patients. Unlike the universal Glanzmann's thrombasthenia database, the majority of Iranian patients may suffer from a GpIIIa gene mutation. This study also confirmed a lack of correlation between clinical manifestation and GPIIb/IIIa expression in the patients.

The first two cases of neonatal alloimmune thrombocytopenia associated with the low‐frequency platelet antigen HPA‐21bw (Nos) in Japan

Neonatal alloimmune thrombocytopenia (NAIT) is a disorder characterized by maternal alloimmunization against paternal fetal platelet antigens. Two healthy, unrelated Japanese women each gave birth to a child with severe NAIT. To elucidate the maternal causes of NAIT, we conducted serologic and genetic studies in these two NAIT infants. The serologic experiments localized the antigens to the glycoprotein (GP) IIIa subunit of the GPIIb/IIIa complex. Sequence-based typing studies subsequently identified a G>A mutation at Nucleotide 1960 (a glutamic acid > lysine substitution at Position 628) in the 11th exon of the GPIIIa gene. This mutation was recently identified in a report as HPA-21bw. Next, it was determined that the cause of NAIT in both cases was the HPA-21bw antigen, as shown by the mothers' antibodies reacting with the mutated GPIIIa-transfected cells, but not with transfectants expressing wild-type GPIIIa. A molecular genetic screening for the HPA-21bw allele among Japanese donors showed that its genetic frequency in the population was 0.53% (10/1888), indicating that HPA-21bw occurs at a low but appreciable frequency in the population. Furthermore, in a retrospective study of 50 previous NAIT cases of unknown causes, we found one NAIT case associated with the HPA-21bw antibody. The two NAIT cases in this study represent the first ones to be associated with HPA-21bw in Japan. We identified the HPA-21bw allele from two unrelated Japanese infants with severe NAIT. We identified 10 individuals (1.06%) positive for the HPA-21bw allele from a genetic screening of 944 Japanese blood donors.

Neonatal alloimmune thrombocytopenia caused by an antibody specific for a newly identified allele of human platelet antigen‐7

Neonatal alloimmune thrombocytopenia (NAIT) is a neonatal disorder characterized by maternal alloimmunization against fetal platelet (PLT) antigens inherited from the father. A healthy 30-year-old Japanese woman (Hit) gave birth to her second child after an uneventful pregnancy. Nine hours after birth, the infant presented with severe petechiae and a PLT count of 6 x 10(9)/L. To elucidate the maternal cause of NAIT in the infant, serologic and genetic studies, including PLT genotyping and sequence-based analysis, were conducted. Additionally, serologic screening for the new PLT antigen was performed. Serum from the NAIT infant's mother contained antibodies directed against a human PLT antigen (HPA) of the newborn. Using five-cell-lineage flow cytometry, we localized the antigen to a PLT glycoprotein (GP). Subsequent monoclonal antibody immobilization of PLT antigen assay and PLT immunofluorescence inhibition experiments localized the antigen to the GPIIIa subunit of the GPIIb/IIIa complex. GPIIIa localization was confirmed by sequence-based typing studies, which identified a 1297C>T (407proline>serine substitution) mutation on the ninth exon of the GPIIIa gene. This mutation identified the third allele of HPA-7. Anti-Hit(a) reacted with mutated GPIIIa-transfected cells but not with stable transfectants expressing wild-type GPIIIa. Serologic screening for Hit(a) in the Japanese population revealed a phenotypic frequency of approximately 0.0015. We identified a new third allele of HPA-7, which is characterized by a 1297C>T mutation in the GPIIIa gene. This 1297C>T allele was found in 0.15% of the Japanese population. An antibody against this antigen could be the cause of severe NAIT.

Anterior ischemic optic neuropathy in a patient with Crohn's disease and aberrant MTHFR and GPIIIa gene variants

Large spectrums of ophthalmic manifestations from the anterior to the posterior segment have been so far reported in patients with inflammatory bowel disease. Anterior ischemic optic neuropathy is caused by acute ischemic infarction of the optic nerve head and is distinguished in two different types, non-arteritic anterior ischemic optic neuroparhy (NAION) which is the most frequent type and arteritic anterior ischemic optic neuropathy. Non-arteritic anterior ischemic optic neuroparhy may result in severe visual field loss. We present the case of a 69 year-old man with known history of Crohn's disease that was referred to the Department of Ophthalmology after noticing sudden blurred vision of his left eye. Ophthalmologic examination revealed a corrected visual acuity of 8/10 OS and 10/10 OD. Pupil examination showed a relative afferent pupillary defect of the left pupil and fluoroangiography revealed hyperfluorescence of the left optic disc, indicating edema and NAION attack on his left eye. Genetic analysis showed that the patient was homozygous for MTHFR C677T genetic polymorphism and A1/A2 heterozygous for GPIIIa polymorphism.

血小板無力症患者のglycoprotein (GP) IIbとGP IIIaの遺伝子解析

血小板無力症患者のglycoprotein (GP) IIbとGP IIIaの遺伝子解析