Lenka Bartosova

Is Gas6 Protein Associated With Sticky Platelet Syndrome

The aim of this study was to detect the prevalence of the polymorphisms of growth arrest—specific gene 6 (Gas6; Gas6 c. 834 + 7G > A) in patients with sticky platelet syndrome (SPS). Sticky platelet syndrome is a hereditary, autosomal dominant thrombophilia characterized by platelet hyperaggregation after low concentrations of platelet inducers—adenosine diphosphate (ADP) and epinephrine (EPI). The cause of SPS still remains unknown, but in recent years it was suggested that Gas6 protein may have a potential role in the pathogenesis of SPS. To assess the Gas6 polymorphisms (Gas6 c. 834 + 7G > A), 128 patients with SPS were included in the study and examined by polymerase chain reaction (PCR) method. GG genotype was detected in 63 (49.2%) patients, GA genotype in 53 (41.4%) patients, and AA genotype in 12 (9.4%) patients. The results in controls did not differ significantly compared to patients with SPS. Our findings did not prove allele A to be less associated with thrombosis and that ‘‘prothrombotic’’ allele G may be associated with higher risk of thrombosis. We cannot support the idea that Gas6 protein and Gas6 polymorphisms may be associated with thrombosis in SPS.

Platelet aggregation abnormalities in patients with fetal losses: the GP6 gene polymorphism.

OBJECTIVE To evaluate the GP6 gene polymorphism in patients with sticky platelet syndrome (SPS) and fetal loss. DESIGN Genetic association study. SETTING Perinatal center. PATIENT(S) Twenty-seven patients with SPS, manifested as fetal loss, and 42 control subjects without SPS and no history of fetal loss and thrombosis. INTERVENTION(S) SPS was diagnosed by platelet aggregometry (PACKS-4 aggregometer; Helena Laboratories). Seven single-nucleotide polymorphisms (SNPs) of the GP6 gene were evaluated. MAIN OUTCOME MEASURE(S) Occurrence of SNPs of the GP6 gene in SPS patients versus control subjects. RESULT(S) We found a higher occurrence of three SNPs of the GP6 gene in SPS patients versus control subjects (rs1671153: 0.204 vs. 0.048, odds ratio [OR] 5.116, 95% confidence interval [CI] 1.536-17.03; rs1654419: 0.204 vs. 0.071, OR 3.326, 95% CI 1.149-9.619; rs1613662: 0.204 vs. 0.071, OR 3.326, 95% CI 1.149-9.619). The haplotype analysis showed a significantly higher occurrence of two haplotypes (CTGAG in haplotype 5: 0.185 vs. 0.059, OR 3.568, 95% CI 1.142-11.14; and CGATAG in haplotype 6: 0.204 vs. 0.048, OR 4.961, 95% CI 1.488-16.53). CONCLUSION(S) Our results, especially the higher occurrence of haplotypes CTGAG and CGATAG in SPS patients, support the idea that GP6 gene polymorphism may be associated with platelet hyperaggregability, a possible cause of fetal loss.

Nine Kindreds of Familial Sticky Platelet Syndrome Phenotype

Introduction: Sticky platelet syndrome (SPS) is most likely a hereditary thrombophilia characterized by platelet hyperaggregation after low concentrations of platelet inducers—adenosine diphosphate and/or epinephrine. We present 9 kindreds with SPS familial occurrence. Material and Methods: Familial trait of SPS was looked up in the database of the National Center of Hemostasis and Thrombosis. Families with at least 3 SPS-positive members were studied, described, and presented. Results: In the group of 1093 symptomatic patients, SPS was confirmed in 240 cases. Familial occurrence with at least 3 SPS-positive relatives was found in 9 cases. Conclusion: The exact pathogenesis of SPS is not sufficiently explained. Our findings seem to support the idea that SPS might have an autosomal dominant hereditary fashion.

Are the platelets activated in sticky platelet syndrome

We read with a great interest in this journal the article written by Sand M. and colleagues “Sticky Platelet Syndrome type II presenting with arterial microemboli in the fingers [1].” In accordancewith the issues of some larger studies and case series [2–6] the authors in this case report stressed that an increased platelet clumping can be clinically associated with otherwise unexplained occlusion of small vessels, arterial thrombosis or less common recurrent venous thrombosis even in the patients under anticoagulant treatment. Sticky platelet syndrome (SPS) is defined as a platelet hyperaggregability after stimulation by very low concentrations of platelet inducers (adenosinediphosphate (ADP) and epinephrine (EPI)), whilst platelet response to other aggregation inducers is normal [1,2]. According to Mammen and Bick the SPS is the second most common hereditary thrombophilia, and even the most common thrombophilia associated with arterial thrombosis with the incidence of 21% approximately [2,3]. SPS seems to be the secondmost common thrombophilia (after antiphospholipid syndrome) that causes recurrent spontaneous abortions [7]. Thromboembolic episodes may occur in any age but patients are usually younger, up to the age of 45-50. Children may be afflicted as well [3]. Recently it was found that SPS is a very frequent condition in patients with AIDS, receiving antiretroviral therapy for at least 6 months and suffering by unexplained cardiovascular events [8]. The etiology of SPS is still uncertain, but it is suggested that glycoprotein (GP) receptors on platelet surface membrane may be involved and their abnormalities can lead to the platelet hyperfunction in SPS patients. This idea inspired us to verify the platelet activation in plasma samples of SPS patients in the basal clinical state. Seventy-five patients with SPS (22 men/53 women; mean age 40,4±15,7 years) were enrolled. The examined SPS patients were without the acute signs of thrombosis and anti-platelet medication although they had a history of arterial and venous thromboembolic episodes (stroke, transitory ischemic attacks, angina pectoris, myocardial infarction, recurrent venous thrombosis and recurrent abortions). The control group included 30 healthy individuals (10 men/20 women; mean age 37,1±9,5 years). All patients and controls agreed with participation in the study and signed an informed consent. SPS was assessed by