Lipidomics and Functional Analyses of Platelets in Fabry Disease

Study Overview
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Brief Summary
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This study aims to evaluate whether platelets are biochemically and functionally altered in Fabry disease (FD) and therefore possibly implicated in FD manifestations such as cerebrovascular events. To test this hypothesis the investigators aim to compare platelet and plasma lipid profiles, as well as platelet function and coagulation parameters of FD patients and healthy controls.

Detailed Description
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Fabry disease (FD) is a severe X-linked inborn error of the lysosomal glycosphingolipid metabolism. FD patients have significantly increased risks for cardiac and cerebrovascular events, which can also occur early and in absence of the typical FD symptoms. However, the pathophysiological mechanisms leading to vascular occlusion and ischemia in FD are largely unclear. Prevention of recurrent cerebrovascular events is usually based on empirical anti-platelet therapy. Prothrombotic states and partially activated platelets have been reported for FD patients. Platelets contain glycosphingolipids, including globotriaosylceramide (Gb3), and have lysosomal α-galactosidase activity. To investigate whether the lack of or the reduced α-galactosidase enzyme activity present in Fabry disease affects platelet lipid metabolism the investigators plan to perform LC-MS-based lipidomics analyses of platelets and plasma in FD patients and healthy controls. To assess whether platelets are functionally altered in FD, the investigators aim to determine the activation status, activability, aggregability and other parameters along with plasma markers of coagulation using flow cytometry, aggregometry and immunoassays.

Official Title
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Lipidomics and Functional Analyses of Platelets in Fabry Disease

Conditions
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Fabry Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy Volunteers: without any known cardiovascular, cerebrovascular and renal diseases and without any known conditions affecting platelet function, blood coagulation and lipid metabolism. Patients: Genetically confirmed Fabry Disease Adult persons (18-65 years old), both female and male Informed written consent Exclusion Criteria: Failure to meet inclusion criteria Pregnancy (as declared by the study participant, no pregnancy test will be performed)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in sphingolipid profiles of platelets and plasma between Fabry disease patients and healthy subjects | Determination of sphingolipid concentrations in isolated platelets and plasma by targeted LC-MS (liquid chromatography mass spectrometry)-based lipidomics analysis of globotriaosylceramides (Gb3), globotriaosylspingosines (Lyso-Gb3), globotetraosylceramides (Gb4), lactosylceramides (LacCer), glucosylceramides, ceramides, sphingomyelins, sphingosines and sphingosine-1-phosphates. | Baseline | 
| Differences in platelet function assessed by aggregometry | Determination of platelet aggregation after agonist stimulation with TRAP (thrombin receptor activator peptide), ADP (adenosine disphosphate) and arachidonic acid by light transmission aggregometry. | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in expression of the platelet activation marker P-selectin (CD62P) between Fabry disease patients and healthy subjects at baseline and after agonist stimulation | Flow cytometric analysis of platelet surface expression of CD62P in whole blood determined at baseline and after platelet activation with the agonists TRAP (thrombin receptor activator peptide), ADP, and arachidonic acid. | Baseline | 
| Differences in expression of the platelet activation marker CD63 between Fabry disease patients and healthy subjects at baseline and after agonist stimulation | Flow cytometric analysis of platelet surface expression of CD63 in whole blood determined at baseline and after platelet activation with the agonists TRAP (thrombin receptor activator peptide), ADP, and arachidonic acid. | Baseline | 
| Differences in plasma levels of the platelet activation marker soluble P-selectin between Fabry disease patients and healthy subjects | Plasma concentrations of soluble P-selectin (soluble CD62P) are determined by ELISA (enzyme-linked immunosorbent assay) | Baseline | 
| Differences in plasma levels of the platelet activation marker sCD40L between Fabry disease patients and healthy subjects | Plasma concentrations of sCD40L (soluble CD40 ligand) are determined by ELISA (enzyme-linked immunosorbent assay) | Baseline | 
| Differences in presence of platelet aggregates between Fabry disease patients and healthy subjects | Flow cytometric assessment of platelet-platelet and platelet-leukocyte aggregates | Baseline | 
| Differences of alpha-galactosidase A enzyme activity in plasma and isolated platelets between Fabry disease patients and healthy subjects | Analysis of the alpha-galactosidase A enzyme activity using a fluorometric enzyme assay with 4-methylumbelliferyl-α-D-galactopyranoside as substrate. | Baseline | 
| Differences in phospholipid profiles in platelets and plasma between Fabry disease patients and healthy subjects | Determination of phospholipid concentrations in isolated platelets and plasma by targeted LC-MS-based lipidomics analysis of phosphatidylcholines, phosphatidylserines, phosphatidylinositols, and phosphatidylethanolamines. | Baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fabry Disease, Platelets, Lipidomics, Sphingolipids, α-Galactosidase A, Globotriaosylceramide, Gb3, GL-3, CD77, Alpha-galactosidase, Platelet activation, Lysosomal storage disease, LysoGb3, Spingosine-1-Phosphate, Platelet function, CD62P, P-selectin