ORIGINAL ARTICLESApoptosis in platelets from adult patients with chronic idiopathic thrombocytopenic purpuraXie, Longa,∗; Xu, Da-Mingb,∗; Cai, Xin-Jiana,∗; Zhang, Ze-Wenc; Yu, Wen-Junc; Qiu, Jin-Fengd; Xu, Cheng-Weie; He, Chun-Lingf; Xu, Xian-Rug; Yin, Juna,c Author Information aDepartment of Clinical Laboratory Medicine bDivision of Urological Surgery cDivision of Hematology dDivision of Respirology eDepartment of Blood Purification fDepartment of Pathology gDivision of Inventional Ultrasonic Therapeutics, the Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong Province, China Correspondence to Jun Yin, MD, PhD, Department of Clinical Laboratory Medicine and Division of Hematology, Second Affiliated Hospital of Shantou University Medical College, Dongxia Road North, Shantou, Guangdong Province 515041, China Tel: +86 754 8891 5950; e-mail: [email protected] Received 10 February, 2021 Revised 13 April, 2021 Accepted 25 May, 2021 Blood Coagulation & Fibrinolysis: October 2021 - Volume 32 - Issue 7 - p 434-442 doi: 10.1097/MBC.0000000000001054 Buy Metrics Abstract Adult chronic idiopathic thrombocytopenic purpura (cITP) is a chronic and usually life-long haemorrhagic disorder in which enhanced platelet destruction and weakened platelet production lead to thrombocytopenia. Platelets were isolated from blood samples collected from 40 adult patients with cITP and 40 healthy volunteers. Mitochondrial membrane potential (ΔΨm) and plasma membrane phosphatidylserine externalization were determined by flow cytometry, and activation of caspase-3 and expressions of Bax, Bak and Bcl-xL were analysed by western blotting. Flow cytometry showed increased mitochondrial depolarization and lower ΔΨm in platelets from adult patients with cITP. In addition, plasma membrane phosphatidylserine externalization was observed on platelets from adult patients with cITP, but rarely from healthy volunteers. Western blot analysis of platelet proteins revealed that, in adult cITP patients, caspase-3 was activated, which cleaved gelsolin and to release a 47-kDa fragment. Moreover, the expressions of Bax and Bak were elevated, and Bcl-xL was decreased markedly in platelets from adult patients with cITP. Our findings reveal, based on loss of mitochondrial membrane potential (Δψm), phosphatidylserine exposure, caspase-3 activation, enhanced expression of Bax and Bak, and attenuated expression of Bcl-xL, that platelet death in the pathogenesis of thrombocytopenia in chronic ITP in adults is apoptotic. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.