title: Microparticles from splenectomized β-thalassemia/HbE patients play roles on procoagulant activities with thrombotic potential.
abstract: Thromboembolic events including cerebral thrombosis, deep vein thrombosis, and pulmonary embolism are major complications in β-thalassemia. Damaged red blood cells and chronic platelet activation in splenectomized β-thalassemia/HbE patients were associated with increased microparticles (MPs) releases into blood circulation. MPs are small membrane vesicles, which play important roles on coagulation. However, the role of MP in thalassemia is poorly understood. In this study, the effects of splenectomized-MPs on platelet activation and aggregation were investigated. The results showed that isolated MPs from fresh platelet-free plasma of patients and normal subjects directly induce platelet activation, platelet aggregation, and platelet-neutrophil aggregation in a dose-dependent manner. Interestingly, MPs obtained from splenectomized patients are more efficient in induction of platelet activation (P-selectin+) when compared to MPs from normal subjects (P < 0.05), tenfold lower than pathophysiological level, at 1:0.1 platelet MP ratio. Co-incubation of splenectomized-MPs with either normal-, non-splenectomized- or splenectomized-platelets at 1:10 platelet MP ratio increased platelet activation up to 5.1 ± 2.2, 5.6 ± 3.7, and 9.5 ± 3.0%, respectively, when normalized with individual baseline. These findings suggest that splenectomized patients were proned to be activated by MPs, and splenectomized-MPs could play an important role on chronic platelet activation and aggregation, leading to thrombus formation in β-thalassemia/HbE patients.
authors.affiliation: Department of Immunology and Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Pran-Nok, Bangkok-Noi, Bangkok, 10170, Thailand.
authors.forename: Phatchanat
authors.initials: P
authors.lastname: Klaihmon
authors.affiliation: Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.|Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Kunwadee
authors.initials: K
authors.lastname: Phongpao
authors.affiliation: Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.|Molecular Medicine Graduate Program, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Wasinee
authors.initials: W
authors.lastname: Kheansaard
authors.affiliation: Department of Immunology and Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Pran-Nok, Bangkok-Noi, Bangkok, 10170, Thailand.
authors.forename: Egarit
authors.initials: E
authors.lastname: Noulsri
authors.affiliation: Division of Hematology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Archrob
authors.initials: A
authors.lastname: Khuhapinant
authors.affiliation: Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.
authors.forename: Suthat
authors.initials: S
authors.lastname: Fucharoen
authors.affiliation: Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Noppawan Phumala
authors.initials: NP
authors.lastname: Morales
authors.affiliation: Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.|Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.|Molecular Medicine Graduate Program, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Saovaros
authors.initials: S
authors.lastname: Svasti
authors.affiliation: Department of Immunology and Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Pran-Nok, Bangkok-Noi, Bangkok, 10170, Thailand. kovit.pat@mahidol.ac.th.
authors.forename: Kovit
authors.initials: K
authors.lastname: Pattanapanyasat
authors.affiliation: Department of Pathobiology, Faculty of Science, Mahidol University, 272 RamaVI Rd., Ratchathewi, Bangkok, 10400, Thailand. pornthip.chh@mahidol.ac.th.
authors.forename: Pornthip
authors.initials: P
authors.lastname: Chaichompoo
mesh_terms: D000328:Adult; D001777:Blood Coagulation / Q000502:physiology*; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D005260:Female; D006446:Hemoglobin E / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology; D013156:Splenectomy / Q000639:trends; D013927:Thrombosis / Q000097:blood* / Q000601:surgery; D055815:Young Adult; D017086:beta-Thalassemia / Q000097:blood* / Q000601:surgery
chemical_list: D006446:Hemoglobin E
keywords: Coagulation; Microparticles; Platelet-leukocyte aggregation; Thalassemia; Thrombosis