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Delshad M, Davoodi-Moghaddam Z, Pourbagheri-Sigaroodi A, Faranoush M, Abolghasemi H, Bashash D. Translating mechanisms into therapeutic strategies for immune thrombocytopenia (ITP): Lessons from clinical trials. Thromb Res 2024; 235:125-147. [PMID: 38335568 DOI: 10.1016/j.thromres.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disorder that causes a significant reduction in peripheral blood platelet count. Fortunately, due to an increased understanding of ITP, there have been significant improvements in the diagnosis and treatment of these patients. Over the past decade, there have been a variety of proven therapeutic options available for ITP patients, including intravenous immunoglobulins (IVIG), Rituximab, corticosteroids, and thrombopoietin receptor agonists (TPO-RAs). Although the effectiveness of current therapies in treating more than two-thirds of patients, still some patients do not respond well to conventional therapies or fail to achieve long-term remission. Recently, a significant advancement has been made in identifying various mechanisms involved in the pathogenesis of ITP, leading to the development of novel treatments targeting these pathways. It seems that new agents that target plasma cells, Bruton tyrosine kinase, FcRn, platelet desialylation, splenic tyrosine kinase, and classical complement pathways are opening new ways to treat ITP. In this study, we reviewed the pathophysiology of ITP and summarized updates in this population's management and treatment options. We also took a closer look at the 315 ongoing trials to investigate their progress status and compare the effectiveness of interventions. May our comprehensive view of ongoing clinical trials serve as a guiding beacon, illuminating the path towards future trials of different drugs in the treatment of ITP patients.
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Affiliation(s)
- Mahda Delshad
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Laboratory Sciences, School of Allied Medical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Zeinab Davoodi-Moghaddam
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Faranoush
- Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Abolghasemi
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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2
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Petito E, Gresele P. Immune attack on megakaryocytes in immune thrombocytopenia. Res Pract Thromb Haemost 2024; 8:102345. [PMID: 38525349 PMCID: PMC10960061 DOI: 10.1016/j.rpth.2024.102345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 02/04/2024] [Indexed: 03/26/2024] Open
Abstract
A State of the Art lecture titled "Immune Attack on Megakaryocytes in ITP: The Role of Megakaryocyte Impairment" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Immune thrombocytopenia (ITP) is an acquired autoimmune disorder caused by autoantibodies against platelet surface glycoproteins that provoke increased clearance of circulating platelets, leading to reduced platelet number. However, there is also evidence of a direct effect of antiplatelet autoantibodies on bone marrow megakaryocytes. Indeed, immunologic cells responsible for autoantibody production reside in the bone marrow; megakaryocytes progressively express during their maturation the same glycoproteins against which ITP autoantibodies are directed, and platelet autoantibodies have been detected in the bone marrow of patients with ITP. In vitro studies using ITP sera or monoclonal antibodies against platelet and megakaryocyte surface glycoproteins have shown an impairment of many steps of megakaryopoiesis and thrombopoiesis, such as megakaryocyte differentiation and maturation, migration from the osteoblastic to the vascular niche, adhesion to extracellular matrix proteins, and proplatelet formation, resulting in impaired and ectopic platelet production in the bone marrow and diminished platelet release in the bloodstream. Moreover, cytotoxic T cells may target bone marrow megakaryocytes, resulting in megakaryocyte destruction. Altogether, these findings suggest that antiplatelet autoantibodies and cellular immunity against bone marrow megakaryocytes may significantly contribute to thrombocytopenia in some patients with ITP. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress. The complete unraveling of the mechanisms of immune attack-induced impairment of megakaryopoiesis and thrombopoiesis may open the way to new therapeutic approaches.
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Affiliation(s)
- Eleonora Petito
- Section of Internal and Cardiovascular Medicine, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Paolo Gresele
- Section of Internal and Cardiovascular Medicine, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
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3
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Chen W, Zhu L, Wang L, Zeng J, Wen M, Xu X, Zou L, Huang F, Huang Q, Qin D, Mei Q, Yang J, Wang Q, Wu J. A Novel Antithrombocytopenia Agent, Rhizoma cibotii, Promotes Megakaryopoiesis and Thrombopoiesis through the PI3K/AKT, MEK/ERK, and JAK2/STAT3 Signaling Pathways. Int J Mol Sci 2022; 23:ijms232214060. [PMID: 36430539 PMCID: PMC9694118 DOI: 10.3390/ijms232214060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cibotii rhizoma (CR) is a famous traditional Chinese medicine (TCM) used to treat bleeding, rheumatism, lumbago, etc. However, its therapeutic effects and mechanism against thrombocytopenia are still unknown so far. In the study, we investigated the effects of aqueous extracts of Cibotii rhizoma (AECRs) against thrombocytopenia and its molecular mechanism. METHODS Giemsa staining, phalloidin staining, and flow cytometry were performed to measure the effect of AECRs on the megakaryocyte differentiation in K562 and Meg-01 cells. A radiation-induced thrombocytopenia mouse model was constructed to assess the therapeutic actions of AECRs on thrombocytopenia. Network pharmacology and experimental verification were carried out to clarify its mechanism against thrombocytopenia. RESULTS AECRs promoted megakaryocyte differentiation in K562 and Meg-01 cells and accelerated platelet recovery and megakaryopoiesis with no systemic toxicity in radiation-induced thrombocytopenia mice. The PI3K/AKT, MEK/ERK, and JAK2/STAT3 signaling pathways contributed to AECR-induced megakaryocyte differentiation. The suppression of the above signaling pathways by their inhibitors blocked AERC-induced megakaryocyte differentiation. CONCLUSIONS AECRs can promote megakaryopoiesis and thrombopoiesis through activating PI3K/AKT, MEK/ERK, and JAK2/STAT3 signaling pathways, which has the potential to treat radiation-induced thrombocytopenia in the clinic.
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Affiliation(s)
- Wang Chen
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Linjie Zhu
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Long Wang
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Jing Zeng
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Min Wen
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Xiyan Xu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - LiLe Zou
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Feihong Huang
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Qianqian Huang
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Dalian Qin
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
- Education Ministry Key Laboratory of Medical Electrophysiology, Southwest Medical University, Luzhou 646000, China
| | - Qibing Mei
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
- Education Ministry Key Laboratory of Medical Electrophysiology, Southwest Medical University, Luzhou 646000, China
| | - Jing Yang
- School of Pharmacy, Southwest Medical University, Luzhou 646000, China
- Education Ministry Key Laboratory of Medical Electrophysiology, Southwest Medical University, Luzhou 646000, China
| | - Qiaozhi Wang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
- Correspondence: (Q.W.); (J.W.); Tel.: 86-18015728611 (Q.W.); 86-13982416641 (J.W.)
| | - Jianming Wu
- School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
- Education Ministry Key Laboratory of Medical Electrophysiology, Southwest Medical University, Luzhou 646000, China
- Correspondence: (Q.W.); (J.W.); Tel.: 86-18015728611 (Q.W.); 86-13982416641 (J.W.)
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Colunga-Pedraza PR, Peña-Lozano SP, Sánchez-Rendón E, De la Garza-Salazar F, Colunga-Pedraza JE, Gómez-De León A, Santana-Hernández P, Cantú-Rodríguez OG, Gómez-Almaguer D. Oseltamivir as rescue therapy for persistent, chronic, or refractory immune thrombocytopenia: a case series and review of the literature. J Thromb Thrombolysis 2022; 54:360-366. [PMID: 35471623 DOI: 10.1007/s11239-022-02651-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2022] [Indexed: 11/28/2022]
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disease that results from antibody-mediated platelet destruction and impaired platelet production. Novel therapies have emerged in the last decade, but 15-20% of patients will relapse or fail and require further therapy. We performed a prospective, single-arm intervention study on seven patients with chronic, persistent, or refractory ITP from the Hospital Universitario "Dr. José E González", in Monterrey, Mexico between 2015 and 2019. Eligible patients received oral oseltamivir 75 mg twice daily for 5 days and were followed up for six months. Most patients received a median of three distinct therapies (range 2-6). Four patients (57.1%) received combined therapy. The median time for any response was 55.5 days (range = 14-150). All patients responded at some point in time (ORR = 100%, six had a proportion of loss of response [PR], and one achieved [CR]). Six months after oseltamivir administration, three patients (42.9%) maintained a response, and one patient had a CR (14.3%). Oseltamivir was well tolerated with a good overall response rate and was useful for treating chronic ITP. We observed an initial increase in the number of platelets; however, this response was not maintained.
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Affiliation(s)
- Perla R Colunga-Pedraza
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Samantha P Peña-Lozano
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Ernesto Sánchez-Rendón
- Internal Medicine Department, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Monterrey, Mexico
| | - Fernando De la Garza-Salazar
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Julia E Colunga-Pedraza
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Andrés Gómez-De León
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Paola Santana-Hernández
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - Olga G Cantú-Rodríguez
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico
| | - David Gómez-Almaguer
- Hematology Service, Hospital Universitario "Dr. José Eleuterio González", Universidad Autonoma de Nuevo León, Francisco I. Madero and Avenida Gonzalitos, Mitras Centro, Z.P. 64460, Monterrey, NL, Mexico.
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5
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Chen DP, Lin WT, Wen YH, Wang WT. Investigation of the correlation between immune thrombocytopenia and T cell activity-regulated gene polymorphism using functional study. Sci Rep 2022; 12:6601. [PMID: 35459882 PMCID: PMC9033768 DOI: 10.1038/s41598-022-10631-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 04/01/2022] [Indexed: 12/29/2022] Open
Abstract
Thrombocytopenia is a condition where the platelet count is under 100 × 109/L, which is caused by various disorders. However, the mechanism of thrombocytopenia is still unclear. Hence, we tried to investigate the correlation between immune thrombocytopenia (ITP) and single nucleotide polymorphisms (SNPs) of genes related to T cell activation. There were 32 ITP patients and 30 healthy controls enrolled in this study. PCR and sequencing were used to find out the significant SNPs, which we focused on the promoter region of CTLA4 and CD28. In this study, the ITP cases were divided into primary ITP group, secondary ITP group, and the combination of the two to the follow-up analysis. Moreover, dual-luciferase reporter assay was used to evaluate the transcription activity of the significant SNP. We found the − 1765_rs11571315 of CTLA4 gene was associated with primary ITP (p = 0.006), secondary ITP (p = 0.008), and the combination of the two (p = 0.003). Moreover, the −318_rs5742909 also had statistical significance in secondary ITP group that was only caused by autoimmune disease (p = 0.019). In functional study, the rs5742909 would decrease 19% of the transcription activity when it carried a T-allele at this position (p = 0.040). It was noted that CTLA4 gene polymorphism was related to ITP but not CD28. According to our results, we surmised that CTLA4 is involved in the pathogenesis of ITP, and the secondary ITP result from the lower CTLA4 expression that leads to T cell over-activation.
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Affiliation(s)
- Ding-Ping Chen
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan City, 333, Taiwan, ROC. .,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan County, Taiwan, ROC. .,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan County, Taiwan, ROC.
| | - Wei-Tzu Lin
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan City, 333, Taiwan, ROC
| | - Ying-Hao Wen
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan City, 333, Taiwan, ROC.,Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, ROC
| | - Wei-Ting Wang
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan City, 333, Taiwan, ROC
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Wang Q, Wei J, Jia X, Feng X, Ji Z, Ji X, Shao X. Downregulation of ADAM17 in pediatric immune thrombocytopenia impairs proplatelet formation. BMC Pediatr 2022; 22:164. [PMID: 35354403 PMCID: PMC8966352 DOI: 10.1186/s12887-022-03237-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immune thrombocytopenia (ITP) is the most common etiology of acquired thrombocytopenia diseases in children. ITP is characterized by the immune-mediated decreased formation and excessive destruction of platelets. The pathogenesis and management of pediatric ITP are distinct from adult ITP. A disintegrin and metalloproteinase 17 (ADAM17) mediates the shedding of platelet receptor glycoprotein Ib α (GPIb α) in extracellular domain, functioning in the platelet activation and clearance. Our study aims to probe the roles and mechanisms of ADAM17 in pediatric ITP. METHODS The differently expressed ADAM17 in megakaryocytes was obtained from children with ITP through the next-generation RNA-Sequence. Hematoxylin-eosin and Giemsa staining were performed for cell morphology identification. Flow cytometry was applied to assess autoantibodies against platelets, subtypes of lymphocytes, the surface expression level of ADAM17 and polyploidization of megakaryocytes, as well as the full-length GP Ib α. RESULTS ADAM17 was significantly downregulated in megakaryocytes and platelets in children with ITP. Higher values of PDW and positive autoantibodies presence were observed in children with ITP. Loss of ADAM17 in mice led to defects in proplatelet formation and significantly elevated expression of phosphorylated myosin light chain (p-MLC) in megakaryocytes. CONCLUSIONS Our study indicated that the downregulation of ADAM17 might be an innate cause of inefficient platelet production in pediatric ITP.
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Affiliation(s)
- Qi Wang
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China.
| | - Jia Wei
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China
| | - Xi Jia
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China
| | - Xiao Feng
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China
| | - Zhenghua Ji
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China
| | - Xueqiang Ji
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China
| | - Xuejun Shao
- Department of Clinical Laboratory, Children's Hospital of Soochow University, Suzhou, 215025, Jiangsu Province, China.
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7
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Bagmut IY, Ivanov OS, Sheremet MI, Smirnov SM, Kolisnyk IL, Ivanova JV, Tymchenko MY, Lazirskiy VO. Isolation of megakaryocytes using magnetic cell separation and adverse effects induced by diclofenac toxicity in an experiment. J Med Life 2022; 15:65-70. [PMID: 35186138 PMCID: PMC8852649 DOI: 10.25122/jml-2020-0129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/28/2021] [Indexed: 11/07/2022] Open
Abstract
This study investigates the response of bone marrow (particularly megakaryocytes) in mice under the influence of diclofenac sodium for 10 days using intraperitoneal injection at various doses. A fundamentally new immunomagnetic separation method was applied during the experiment, which helped obtain pure lines of bone marrow cells, particularly megakaryocytes (MC), without admixtures of other cells or their particles. The resulting cells completely retain their structure and can be used in further research. The study determined that different doses of diclofenac sodium have different effects on different groups of diabetes mellitus cells CD34-megakaryocytes. The use of 1.0 mg/ml sharply negatively affects the state of early populations of megakaryocytes (decrease by 80%, p=0.05), a dose of 0.025 mg/ml had the least effect on this population of cells (22.8%, p=0.05). The greatest number of average forms of diabetes mellitus 34 was observed when using a dose of 0.95 mg/ml (22.8%, p=0.05), with a gradual decrease in the dose, the indicator of this group of cells decreased. A dose of 0.03 mg/ml did not affect the quantitative state of megakaryocytes, and a dose of 0.025 mg/ml caused a slight decrease (16.6%, p=0.05). Indicators of mature cells of megakaryocytes CD 34- decreased in all studied groups, however, their maximum value reached a maximum decrease by 0.25 mg/ml (55.2%, p=0.05), the dose of diclofenac sodium 0.03 mg/ml, lower (18.4%, p=0.05). Diclofenac sodium in different doses has different effects on the degree of differentiation of CD 34-. Its introduction positively affects the state of intermediate forms of megakaryocytes, except for minimal doses, while the effect on early and mature forms in all cases turned out to be negative.
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Affiliation(s)
- Irina Yuriivna Bagmut
- Department of Clinical Pathophysiology, Topographic Anatomy and Operative Surgery, Kharkiv Medical Academy of Postgraduate Education, Kharkiv, Ukraine,Irina Yuriivna Bagmut, Department of Clinical Pathophysiology, Topographic Anatomy and Operative Surgery, Kharkiv Medical Academy of Postgraduate Education, Kharkiv, Ukraine. E-mail:
| | - Olexiy Sergiyovych Ivanov
- Department of Clinical Pathophysiology, Topographic Anatomy and Operative Surgery, Kharkiv Medical Academy of Postgraduate Education, Kharkiv, Ukraine
| | - Michael Ivanovich Sheremet
- Surgery Department No1, Bukovinian State Medical University, Chernivtsi, Ukraine,Corresponding Author: Michael Ivanovich Sheremet, Surgery Department No. 1, Bukovinian State Medical University, Chernivtsi, Ukraine. E-mail:
| | | | - Igor Leonidovich Kolisnyk
- Department of Clinical Pathophysiology, Topographic Anatomy and Operative Surgery, Kharkiv Medical Academy of Postgraduate Education, Kharkiv, Ukraine
| | - Julia Viktorivna Ivanova
- Zaytsev V.T. Institute of General and Urgent Surgery of National Academy of Medical Sciences of Ukraine, Kharkiv, Ukraine
| | - Mykhailo Yevgenievich Tymchenko
- Department of Comprehensive Programming for the Development of Urgent Surgery and Intellectual Property Protection, SI ZIGUS NAMSU, Kharkiv, Ukraine
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8
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Baroni Pietto MC, Lev PR, Glembotsky AC, Marín Oyarzún CP, Gomez G, Collado V, Pisoni C, Gomez RA, Grodzielski M, Gonzalez J, Mariño KV, Heller PG, Goette NP, Marta RF. Pathogenic mechanisms contributing to thrombocytopenia in patients with systemic lupus erythematosus. Platelets 2021; 33:743-754. [PMID: 34806522 DOI: 10.1080/09537104.2021.1988547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
SummarySystemic lupus erythematosus (SLE) is an autoimmune condition developing thrombocytopenia in about 10-15% of cases, however, mechanisms leading to low platelet count were not deeply investigated in this illness. Here we studied possible causes of thrombocytopenia, including different mechanisms of platelet clearance and impairment in platelet production. Twenty-five SLE patients with and without thrombocytopenia were included. Platelet apoptosis, assessed by measurement of loss of mitochondrial membrane potential, active caspase 3 and phosphatidylserine exposure, was found to increase in thrombocytopenic patients. Plasma from 67% SLE patients (thrombocytopenic and non-thrombocytopenic) induced loss of sialic acid (Ricinus communis agglutinin I and/or Peanut agglutinin binding) from normal platelet glycoproteins. Concerning platelet production, SLE plasma increased megakaryopoiesis (evaluated using normal human cord blood CD34+ hematopoietic progenitors), but inhibited thrombopoiesis (proplatelet count). Anti-platelet autoantibody depletion from SLE plasma reverted this inhibition. Overall, abnormalities were more frequently observed in thrombocytopenic than non-thrombocytopenic SLE patients and in those with active disease (SLEDAI≥5). In conclusion, platelet clearance due to apoptosis and desialylation, and impaired platelet production mainly due to inhibition of thrombopoiesis, could be relevant mechanisms leading to thrombocytopenia in SLE. These findings could provide a rational basis for the choice of proper therapies to correct platelet counts in these patients.[Figure: see text].
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Affiliation(s)
- M Constanza Baroni Pietto
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Paola R Lev
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Ana C Glembotsky
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Cecilia P Marín Oyarzún
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Graciela Gomez
- Departamento De Reumatología, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina
| | - Victoria Collado
- Departamento De Reumatología, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina
| | - Cecilia Pisoni
- Departamento De Reumatología, Centro De Educación Médica E Investigación Clínica "Norberto Quirno" (Cemic), Buenos Aires, Argentina
| | - Ramiro A Gomez
- Departmento De Reumatología, Universidad De Buenos Aires. Hospital De Clínicas "José De San Martín", Buenos Aires, Argentina
| | - Matías Grodzielski
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Jacqueline Gonzalez
- Departmento De Hematología, Hospital General De Agudos Carlos G. Durand, Buenos Aires, Argentina
| | - Karina V Mariño
- Laboratorio De Glicómica Funcional Y Molecular, Instituto De Biología Y Medicina Experimental (Ibyme) Conicet, Buenos Aires, Argentina
| | - Paula G Heller
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
| | - Nora P Goette
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina
| | - Rosana F Marta
- Departamento De Hematología Investigación, Universidad De Buenos Aires. Instituto De Investigaciones Médicas Alfredo Lanari, Buenos Aires, Argentina.,Conicet - Universidad De Buenos Aires. Unidad Ejecutora Idim-conicet (Ue Idim-conicet), Buenos Aires, Argentina
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9
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Bonnard G, Babuty A, Collot R, Costes D, Drillaud N, Eveillard M, Néel A, Espitia A, Masseau A, Wahbi A, Hamidou M, Béné MC, Fouassier M. Platelet features allow to differentiate immune thrombocytopenia from inherited thrombocytopenia. Ann Hematol 2021; 100:2677-2682. [PMID: 34519886 DOI: 10.1007/s00277-021-04651-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/18/2021] [Indexed: 11/26/2022]
Abstract
Immune thrombocytopenia (ITP) is an acquired bleeding disorder, for which no specific diagnostic test exists. Inherited thrombocytopenia (IT) can mimic ITP and lead to unappropriated management with significant morbidity. Here, in small cohorts of these two disorders, we explored whether platelet sialylation and platelet activation could allow to discriminate the two conditions. We also aimed to confirm the value of immature platelet counts in this discrimination. Platelet sialylation and the expression level of P-selectin were assessed by multiparameter flow cytometry. Immature platelets were estimated on a Sysmex XN 9000 analyzer. No significant difference in platelet sialylation was observed between ITP and IT. Contrarily, platelet activation was significantly higher in ITP patients (p = 0.008). The immature platelet fraction, as previously demonstrated, was significantly lower in the ITP group compared to the IT group (p = 0.014). That statistical significance was achieved in this small pilot study suggests that the two easily available assays of immature platelet count and P-selectin expression could help physicians to reach the proper diagnosis in complex cases of thrombocytopenia.
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Affiliation(s)
- Guillaume Bonnard
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France.
- Centre de ressources et de compétences-Maladies hémorragiques constitutionnelles, CHU de Nantes, Nantes, France.
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France.
| | - Antoine Babuty
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France
- Centre de ressources et de compétences-Maladies hémorragiques constitutionnelles, CHU de Nantes, Nantes, France
| | - Romain Collot
- Service D'Hématologie Clinique, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Domitille Costes
- Service D'Hématologie Clinique, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Nicolas Drillaud
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France
- Centre de ressources et de compétences-Maladies hémorragiques constitutionnelles, CHU de Nantes, Nantes, France
| | - Marion Eveillard
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Antoine Néel
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Alexandra Espitia
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Agathe Masseau
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Anaïs Wahbi
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Mohamed Hamidou
- Service de Médecine Interne, Hôtel Dieu, CHU de Nantes, Nantes, France
| | - Marie C Béné
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France
- Centre de ressources et de compétences-Maladies hémorragiques constitutionnelles, CHU de Nantes, Nantes, France
| | - Marc Fouassier
- Service d'Hématologie Biologique, Hôtel Dieu, CHU de Nantes, Nantes, France
- Centre de ressources et de compétences-Maladies hémorragiques constitutionnelles, CHU de Nantes, Nantes, France
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10
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Chen F, McDonald V, Newland A. Experts' review: the emerging roles of romiplostim in immune thrombocytopenia (ITP). Expert Opin Biol Ther 2021; 21:1383-1393. [PMID: 34313512 DOI: 10.1080/14712598.2021.1960979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The management of ITP has in recent years been transformed from reliance on immunosuppressants and splenectomy to targeted therapy with thrombopoietin receptor agonists (TPO-RA) that directly stimulate platelet production in the bone marrow. This has reduced the long-term infective complications and toxicities associated with the use of potent immunosuppressants and splenectomy. The welltolerated romiplostim, itself a novel drug construct called peptibody, has established itself, alongside other TPO-RA as the preferred 2nd line therapy in major international guidelines on treatment of ITP. AREAS COVERED This review summarizes the data from early licensing trials of romiplostim and discusses the real-world experience to date, the unexpected emerging data on treatment-free long-term remission achieved using TPO-RA, and the case for its early introduction in the therapeutic pathway. The emerging risk of thrombosis is also discussed. EXPERT OPINION The use of romiplostim and other TPO-RA will be increasingly brought forward in the management pathway of ITP with the prospect of modifying the long-term outcome of the disease by increasing sustained treatment-free remission. With the prospect of several new targeted therapies been introduced into clinical practice, TPO-RA will likely be a key component of future combination therapies for difficult cases.
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Affiliation(s)
- Frederick Chen
- Department of Clinical Haematology, the Royal London Hospital, Barts Health NHS Trust, London, UK.,Academic Haematology Unit, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK.,Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, London, UK
| | - Vickie McDonald
- Department of Clinical Haematology, the Royal London Hospital, Barts Health NHS Trust, London, UK.,Academic Haematology Unit, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK.,Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine and Dentistry,QMUL, London, UK
| | - Adrian Newland
- Department of Clinical Haematology, the Royal London Hospital, Barts Health NHS Trust, London, UK.,Academic Haematology Unit, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
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11
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Bussel JB, Soff G, Balduzzi A, Cooper N, Lawrence T, Semple JW. A Review of Romiplostim Mechanism of Action and Clinical Applicability. Drug Des Devel Ther 2021; 15:2243-2268. [PMID: 34079225 PMCID: PMC8165097 DOI: 10.2147/dddt.s299591] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/06/2021] [Indexed: 12/17/2022] Open
Abstract
Thrombocytopenia results from a variety of conditions, including radiation, chemotherapy, autoimmune disease, bone marrow disorders, pathologic conditions associated with surgical procedures, hematopoietic stem cell transplant (HSCT), and hematologic disorders associated with severe aplastic anemia. Immune thrombocytopenia (ITP) is caused by immune reactions that accelerate destruction and reduce production of platelets. Thrombopoietin (TPO) is a critical component of platelet production pathways, and TPO receptor agonists (TPO-RAs) are important for the management of ITP by increasing platelet production and reducing the need for other treatments. Romiplostim is a TPO-RA approved for use in patients with ITP in the United States, European Union, Australia, and several countries in Africa and Asia, as well as for use in patients with refractory aplastic anemia in Japan and Korea. Romiplostim binds to and activates the TPO receptor on megakaryocyte precursors, thus promoting cell proliferation and viability, resulting in increased platelet production. Through this mechanism, romiplostim reduces the need for other treatments and decreases bleeding events in patients with thrombocytopenia. In addition to its efficacy in ITP, studies have shown that romiplostim is effective in improving platelet counts in various settings, thereby highlighting the versatility of romiplostim. The efficacy of romiplostim in such disorders is currently under investigation. Here, we review the structure, mechanism, pharmacokinetics, and pharmacodynamics of romiplostim. We also summarize the clinical evidence supporting its use in ITP and other disorders that involve thrombocytopenia, including chemotherapy-induced thrombocytopenia, aplastic anemia, acute radiation syndrome, perisurgical thrombocytopenia, post-HSCT thrombocytopenia, and liver disease.
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Affiliation(s)
- James B Bussel
- Department of Pediatrics, Division of Hematology, Weill Cornell Medicine, New York, NY, USA
| | - Gerald Soff
- Department of Medicine, Hematology Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Adriana Balduzzi
- Clinica Pediatrica Università degli Studi di Milano Bicocca, Ospedale San Gerardo, Monza, Italy
| | | | | | - John W Semple
- Division of Hematology and Transfusion Medicine, Lund University, Lund, Sweden
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada
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12
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Platelet autoantibodies in the bone marrow of patients with immune thrombocytopenia. Blood Adv 2021; 4:2962-2966. [PMID: 32603421 DOI: 10.1182/bloodadvances.2020001846] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/01/2020] [Indexed: 12/17/2022] Open
Abstract
Autoantibodies cause platelet destruction in patients with immune thrombocytopenia (ITP); yet only 50% to 60% of patients have detectable platelet autoantibodies in peripheral blood. We hypothesized that in some ITP patients, platelet autoantibodies are sequestered in the bone marrow where pathological immune reactions target megakaryocytes or newly formed platelets. In this study, we modified the platelet glycoprotein-specific assay to test bone marrow aspiration samples for free platelet autoantibodies or antibodies bound to bone marrow cells in aspirate fluid from patients with ITP (n = 18), patients with nonimmune thrombocytopenia (n = 3), and healthy donors (n = 6). We found that 10 (56%) of 18 patients with ITP had autoantibodies in the bone marrow, including 5 (50%) of 10 with autoantibodies in bone marrow only, and 5 (50%) of 10 with autoantibodies in bone marrow and peripheral blood. In comparison, 6 (33%) of 18 ITP patients had autoantibodies in peripheral blood, most of whom (5 [83%] of 6) also had autoantibodies in bone marrow. Bone marrow autoantibodies were not detected in patients with nonimmune thrombocytopenia or healthy donors; however, peripheral blood autoantibodies were detectable in 1 (33%) of 3 patients with nonimmune thrombocytopenia. The sensitivity of platelet autoantibodies for the diagnosis of ITP increased from 60% (peripheral blood testing) to 72% (peripheral blood and bone marrow testing). Immune reactions limited to the bone marrow may be characteristic of certain subsets of ITP patients.
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13
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Elzaeem DI, Sharkawi EAE, Zaki EM, Ghobrial AG, El-Fatah ASA, El-Hamed WMA. Comparative study of IgG binding to megakaryocytes in immune and myelodysplastic thrombocytopenic patients. Ann Hematol 2021; 100:1701-1709. [PMID: 33982136 DOI: 10.1007/s00277-021-04556-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 05/04/2021] [Indexed: 11/24/2022]
Abstract
Immune thrombocytopenia (ITP) is a disorder in which autoantibodies are responsible for destruction and decreased production of platelets. In the meantime, thrombocytopenia is frequent in patients with myelodysplastic syndromes (MDS) and immune clearance of megakaryocytes could be a reason. The aim of the present study is to evaluate and compare IgG binding to megakaryocytes in bone marrow of ITP and MDS patients to determine megakaryocytes targeting by autoantibodies in vivo as a mechanism of platelet underproduction in these disorders. The study was carried out on 20 ITP (group I) patients, 20 thrombocytopenic patients with (MDS) (group II), and 20 non-ITP patients as a control (group III) who were admitted to Minia University Hospital. Serial histological sections from bone marrow biopsies were stained for IgG. All patients in group I and 50% of group II patients showed bleeding tendency and the difference was significant (p < 0.001). No patient experienced fatigue in group I while 35% of patients in group II complained of easy fatigability, and the difference was significant (p < 0.008). High IgG antibody binding was found in ITP and MDS compared to the control group but no significant difference between ITP and MDS patients (14/20 (70%) vs. 13/20 (65%)) (p value = 0.736). Antibody binding to megakaryocytes in a proportion of MDS patients suggests that immune-mediated mechanism underlies platelet underproduction in those patients.
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Affiliation(s)
- Doaa I Elzaeem
- Clinical Pathology Department, Faculty of Medicine, Minia University, Cornish Al-Nile Road, PO: 61519, Minia, Egypt
| | - Esmat A El Sharkawi
- Clinical Pathology Department, Faculty of Medicine, Minia University, Cornish Al-Nile Road, PO: 61519, Minia, Egypt
| | - Eman M Zaki
- Clinical Pathology Department, Faculty of Medicine, Assiut University, PO: 71515, Assiut, Egypt
| | - Ayman G Ghobrial
- Clinical Pathology Department, Faculty of Medicine, Minia University, Cornish Al-Nile Road, PO: 61519, Minia, Egypt
| | - Aliaa S Abd El-Fatah
- Internal Medicine Department, Faculty of Medicine, Minia University, PO: 61519, Minia, Egypt
| | - Waleed M Abd El-Hamed
- Clinical Pathology Department, Faculty of Medicine, Minia University, Cornish Al-Nile Road, PO: 61519, Minia, Egypt.
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14
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Marini I, Zlamal J, Faul C, Holzer U, Hammer S, Pelzl L, Bethge W, Althaus K, Bakchoul T. Autoantibody-mediated desialylation impairs human thrombopoiesis and platelet lifespan. Haematologica 2021; 106:196-207. [PMID: 31857361 PMCID: PMC7776251 DOI: 10.3324/haematol.2019.236117] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/11/2019] [Indexed: 11/09/2022] Open
Abstract
Immune thrombocytopenia is a common bleeding disease caused by autoantibody-mediated accelerated platelet clearance and impaired thrombopoiesis. Accumulating evidence suggests that desialylation affects platelet life span in immune thrombocytopenia. Herein, we report on novel effector functions of autoantibodies from immune thrombocytopenic patients which might interfere with the clinical picture of the disease. Data from our study show that a subgroup of autoantibodies is able to induce cleave of sialic acid residues from the surface of human platelets and megakaryocytes. Moreover, autoantibody-mediated desialylation interferes with the interaction between cells and extracellular matrix proteins leading to impaired platelet adhesion and megakaryocyte differentiation. Using a combination of ex vivo model of thrombopoiesis, a humanized animal model, and a clinical cohort study, we demonstrate that cleavage of sialic acid induces significant impairment in production, survival as well as function of human platelets. These data may indicate that prevention of desialylation should be investigated in the future in clinical studies as a potential therapeutic approach to treat bleeding in immune thrombocytopenia.
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Affiliation(s)
- Irene Marini
- Transfusion Medicine, Medical Faculty of Tübingen, University Hospital Tübingen
| | - Jan Zlamal
- Transfusion Medicine, Medical Faculty of Tübingen, University Hospital Tübingen
| | - Christoph Faul
- Department of Internal Medicine II, University Hospital of Tübingen
| | - Ursula Holzer
- Dept. of Pediatric Hematology-Oncology, University Children's Hospital of Tübingen, Germany
| | - Stefanie Hammer
- Center for Clinical Transfusion Medicine, University Hospital of Tübingen, Germany
| | - Lisann Pelzl
- Transfusion Medicine, Medical Faculty of Tübingen, University Hospital Tübingen
| | - Wolfgang Bethge
- Department of Internal Medicine II, University Hospital of Tübingen
| | - Karina Althaus
- Transfusion Medicine, Medical Faculty of Tübingen, University Hospital Tübingen, Germany
| | - Tamam Bakchoul
- Transfusion Medicine, Medical Faculty of Tübingen, University Hospital Tübingen
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15
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Porcelijn L, Schmidt DE, Oldert G, Hofstede-van Egmond S, Kapur R, Zwaginga JJ, de Haas M. Evolution and Utility of Antiplatelet Autoantibody Testing in Patients with Immune Thrombocytopenia. Transfus Med Rev 2020; 34:258-269. [PMID: 33046350 DOI: 10.1016/j.tmrv.2020.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023]
Abstract
To this day, immune thrombocytopenia (ITP) remains a clinical diagnosis made by exclusion of other causes for thrombocytopenia. Reliable detection of platelet autoantibodies would support the clinical diagnosis, but the lack of specificity and sensitivity of the available methods for platelet autoantibody testing limits their value in the diagnostic workup of thrombocytopenia. The introduction of methods for glycoprotein-specific autoantibody detection has improved the specificity of testing and is acceptable for ruling in ITP but not ruling it out as a diagnosis. The sensitivity of these assays varies widely, even between studies using comparable assays. A review of the relevant literature combined with our own laboratory's experience of testing large number of serum and platelet samples makes it clear that this variation can be explained by variations in the characteristics of the tests, including in the glycoprotein-specific monoclonal antibodies, the glycoproteins that are tested, the platelet numbers used in the assay and the cutoff levels for positive and negative results, as well as differences in the tested patient populations. In our opinion, further standardization and optimization of the direct autoantibody detection methods to increase sensitivity without compromising specificity seem possible but will still likely be insufficient to distinguish the often very weak specific autoantibody signals from background signals. Further developments of autoantibody detection methods will therefore be necessary to increase sensitivity to a level acceptable to provide laboratory confirmation of a diagnosis of ITP.
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Affiliation(s)
- Leendert Porcelijn
- Department of Immunohematology Diagnostics, Sanquin Diagnostic Services, Amsterdam, the Netherlands.
| | - David E Schmidt
- Sanquin Research, Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Gonda Oldert
- Department of Immunohematology Diagnostics, Sanquin Diagnostic Services, Amsterdam, the Netherlands
| | | | - Rick Kapur
- Sanquin Research, Department of Experimental Immunohematology, Amsterdam and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jaap Jan Zwaginga
- Department of Immuno-hematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands; Sanquin Research, Center for Clinical Transfusion Research, Leiden, the Netherlands; Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Masja de Haas
- Department of Immunohematology Diagnostics, Sanquin Diagnostic Services, Amsterdam, the Netherlands; Sanquin Research, Center for Clinical Transfusion Research, Leiden, the Netherlands; Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
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16
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Miyashita N, Onozawa M, Yokoyama S, Hidaka D, Hayasaka K, Kunishima S, Teshima T. Anagrelide Modulates Proplatelet Formation Resulting in Decreased Number and Increased Size of Platelets. Hemasphere 2019; 3:e268. [PMID: 31723843 PMCID: PMC6745917 DOI: 10.1097/hs9.0000000000000268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/15/2019] [Accepted: 05/16/2019] [Indexed: 11/25/2022] Open
Abstract
We retrospectively evaluated 48 essential thrombocythemia (ET) patients who were treated in our institute (male/female, 14/34, median age, 61.5 years). In 14 patients treated with anagrelide (ANA), the degree of platelet count reduction (median, -56.6%) was strongly correlated with increase of mean platelet volume (MPV) (median, +11.7%) (R = 0.777). This correlation was not observed in ET patients treated with hydroxycarbamide alone (R = 0.245). The change in size of platelets strongly suggested that ANA affected the final process of platelet production. Thus, we hypothesized that ANA modifies the process by which platelets are released from proplatelets. To verify the association in an in vitro setting, we compared MEG-01 cells treated with PMA ± ANA. The number of platelet-like particles (PLPs) was decreased (P < 0.05) and the size of PLPs estimated by using flow cytometry was significantly increased when MEG-01 cells were treated with PMA + ANA (P < 0.05 vs PMA alone), recapitulating the clinical findings. The cytoplasmic protrusions extending from MEG-01 cells were shorter and thicker and the number of proplatelets was decreased when MEG-01 cells were treated with PMA + ANA (P < 0.01 vs PMA alone). Western blotting analysis showed that ANA treatment resulted in increased phosphorylation of MLC2 and reduced phosphorylation of focal adhesion kinase (FAK). The morphological change of proplatelets were reversed by blebbistatin, a specific inhibitor of myosin II. These findings indicated that ANA modulates the FAK-RhoA-ROCK-MLC2-myosine IIA pathway and suppresses proplatelet maturation, leading to a decrease in platelet count and increase in MPV.
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Affiliation(s)
- Naohiro Miyashita
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Masahiro Onozawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Shota Yokoyama
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Daisuke Hidaka
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Koji Hayasaka
- Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan
| | - Shinji Kunishima
- Department of Medical Technology, Gifu University of Medical Science, Seki, Japan
| | - Takanori Teshima
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan.,Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan
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17
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Multiple concomitant mechanisms contribute to low platelet count in patients with immune thrombocytopenia. Sci Rep 2019; 9:2208. [PMID: 30778108 PMCID: PMC6379541 DOI: 10.1038/s41598-018-38086-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 12/20/2018] [Indexed: 11/16/2022] Open
Abstract
Mechanisms leading to low platelet count in immune thrombocytopenia (ITP) involves both decreased production and increased destruction of platelet. However, the contribution of these pathologic mechanisms to clinical outcome of individual patients is uncertain. Here we evaluated different pathogenic mechanisms including in vitro megakaryopoiesis, platelet/megakaryocyte (MK) desialylation and MK apoptosis, and compared these effects with thrombopoyesis and platelet apoptosis in the same cohort of ITP patients. Normal umbilical cord blood-CD34+ cells, mature MK derived cells or platelets were incubated with plasma from ITP patients. Despite inhibition of thrombopoiesis previously observed, megakaryopoiesis was normal or even increased. Plasma from ITP patients affected the sialylation pattern of control platelets and this effect occurred concomitantly with apoptosis in 35% ITP samples. However, none of these abnormalities were observed in control MKs incubated with ITP plasma. Addition of mononuclear cells as immune effectors did not lead to phosphatidylserine exposure in MK, ruling out an antibody-mediated cytotoxic effect. These results suggest that both desialylation and apoptosis may be relevant mechanisms leading to platelet destruction although, they do not interfere with MK function. Analysis of these thrombocytopenic factors in individual patients showed no specific distribution pattern. However, the presence of circulating antiplatelet autoantibodies was associated with higher incidence of abnormalities. In conclusion, the causes of thrombocytopenia are multifactorial and may occur together, providing a rational basis for the use of combination therapies targeting concomitant ITP mechanisms in patients with refractory disease.
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18
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Zeng DF, Chen F, Wang S, Chen SL, Xu Y, Shen MQ, Du CH, Wang C, Kong PY, Cheng TM, Su YP, Wang JP. Autoantibody against integrin α v β 3 contributes to thrombocytopenia by blocking the migration and adhesion of megakaryocytes. J Thromb Haemost 2018; 16:1843-1856. [PMID: 29953749 DOI: 10.1111/jth.14214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Indexed: 01/04/2023]
Abstract
Essentials The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. We analyzed the role of anti-αvβ3 autoantibody in the pathogenesis of ITP in patients. Anti-αvβ3 autoantibody impeded megakaryocyte migration and adhesion to the vascular niche. Anti-αv β3 autoantibody potentially contributes to the pathogenesis of refractory ITP. SUMMARY Background The pathogenesis of immune thrombocytopenia (ITP) has not been fully clarified. Anti-αvβ3 integrin autoantibody is detected in chronic ITP patients, but its contribution to ITP is still unclear. Objectives To clarify the potential role of anti-αvβ3 integrin autoantibody in chronic ITP and the related mechanism. Methods Relationship between levels of anti-αvβ3 autoantibody and platelets in chronic ITP patients was evaluated. The influence of anti-αvβ3 antibody on megakaryocyte (MK) survival, differentiation, migration and adhesion was assessed, and the associated signal pathways were investigated. Platelet recovery and MKs' distribution were observed in an ITP mouse model pretreated with different antibodies. Result In this study, we showed that the anti-αvβ3 autoantibody usually coexists with anti-αIIbβ3 autoantibody in chronic ITP patients, and patients with both autoantibodies have lower platelets. In in vitro studies, we showed that the anti-αvβ3 antibody had no significant effect on the survival and proliferation of MKs, whereas it decreased formations of proplatelet significantly. Anti-αvβ3 antibody impeded stromal cell derived facor-1 alpha (SDF-1α)- mediated migration and inhibited the phosphorylation of protein kinase B. Anti-αvβ3 antibody significantly inhibited MKs' adhesion to endothelial cells and Fibrogen. The phosphorylation of focal adhesion kinase and proto-oncogene tyrosine-protein kinase Src induced by adhesion was inhibited when MKs were pretreated with anti-αvβ3 antibody. In in vivo studies, we showed that injection with anti-αv antibody delayed platelet recovery in a mouse model of ITP. Conclusions These findings demonstrate that the autoantibody against integrin αv β3 may aggravate thrombocytopenia in ITP patients by impeding MK migration and adhesion to the vascular niche, which provides new insights into the pathogenesis of ITP.
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Affiliation(s)
- D F Zeng
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
- Department of Hematology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - F Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - S Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - S L Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Y Xu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - M Q Shen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - C H Du
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - C Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - P Y Kong
- Department of Hematology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - T M Cheng
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Y P Su
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - J P Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China
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19
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Swinkels M, Rijkers M, Voorberg J, Vidarsson G, Leebeek FWG, Jansen AJG. Emerging Concepts in Immune Thrombocytopenia. Front Immunol 2018; 9:880. [PMID: 29760702 PMCID: PMC5937051 DOI: 10.3389/fimmu.2018.00880] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/09/2018] [Indexed: 01/19/2023] Open
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disease defined by low platelet counts which presents with an increased bleeding risk. Several genetic risk factors (e.g., polymorphisms in immunity-related genes) predispose to ITP. Autoantibodies and cytotoxic CD8+ T cells (Tc) mediate the anti-platelet response leading to thrombocytopenia. Both effector arms enhance platelet clearance through phagocytosis by splenic macrophages or dendritic cells and by induction of apoptosis. Meanwhile, platelet production is inhibited by CD8+ Tc targeting megakaryocytes in the bone marrow. CD4+ T helper cells are important for B cell differentiation into autoantibody secreting plasma cells. Regulatory Tc are essential to secure immune tolerance, and reduced levels have been implicated in the development of ITP. Both Fcγ-receptor-dependent and -independent pathways are involved in the etiology of ITP. In this review, we present a simplified model for the pathogenesis of ITP, in which exposure of platelet surface antigens and a loss of tolerance are required for development of chronic anti-platelet responses. We also suggest that infections may comprise an important trigger for the development of auto-immunity against platelets in ITP. Post-translational modification of autoantigens has been firmly implicated in the development of autoimmune disorders like rheumatoid arthritis and type 1 diabetes. Based on these findings, we propose that post-translational modifications of platelet antigens may also contribute to the pathogenesis of ITP.
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Affiliation(s)
- Maurice Swinkels
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Maaike Rijkers
- Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Jan Voorberg
- Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Frank W G Leebeek
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - A J Gerard Jansen
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands.,Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
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Statins for high cholesterol … and for low platelets? Blood 2018; 131:1159-1161. [PMID: 29545404 DOI: 10.1182/blood-2018-01-824888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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21
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Teraz-Orosz A, Cooper N, Crawley JTB, Salles-Crawley II. Detection of anti-platelet antibodies in immune thrombocytopenia by flow cytometry. Br J Haematol 2018. [PMID: 29532906 DOI: 10.1111/bjh.15187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | - Nichola Cooper
- Centre for Haematology, Imperial College London, London, UK
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Nazy I, Kelton JG, Moore JC, Clare R, Horsewood P, Smith JW, Ivetic N, D'Souza V, Li N, Arnold DM. Autoantibodies to thrombopoietin and the thrombopoietin receptor in patients with immune thrombocytopenia. Br J Haematol 2018. [DOI: 10.1111/bjh.15165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ishac Nazy
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
- McMaster Centre for Transfusion Research; Department of Medicine; McMaster University; Hamilton ON Canada
| | - John G. Kelton
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
| | - Jane C. Moore
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
- Department of Pathology and Molecular Medicine; McMaster University; Hamilton ON Canada
| | - Rumi Clare
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
| | - Peter Horsewood
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
| | - James W. Smith
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
| | - Nikola Ivetic
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
- Department of Biochemistry and Biomedical Sciences; McMaster University; Hamilton ON Canada
| | - Vanessa D'Souza
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
- Department of Biochemistry and Biomedical Sciences; McMaster University; Hamilton ON Canada
| | - Na Li
- McMaster Centre for Transfusion Research; Department of Medicine; McMaster University; Hamilton ON Canada
| | - Donald M. Arnold
- Department of Medicine; Michael G. DeGroote School of Medicine; McMaster University; Hamilton ON Canada
- McMaster Centre for Transfusion Research; Department of Medicine; McMaster University; Hamilton ON Canada
- Canadian Blood Services; Hamilton ON Canada
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Perdomo J, Yan F, Leung HHL, Chong BH. Megakaryocyte Differentiation and Platelet Formation from Human Cord Blood-derived CD34+ Cells. J Vis Exp 2017. [PMID: 29364213 DOI: 10.3791/56420] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Platelet production occurs principally in the bone marrow in a process known as thrombopoiesis. During thrombopoiesis, hematopoietic progenitor cells differentiate to form platelet precursors called megakaryocytes, which terminally differentiate to release platelets from long cytoplasmic processes termed proplatelets. Megakaryocytes are rare cells confined to the bone marrow and are therefore difficult to harvest in sufficient numbers for laboratory use. Efficient production of human megakaryocytes can be achieved in vitro by culturing CD34+ cells under suitable conditions. The protocol detailed here describes isolation of CD34+ cells by magnetic cell sorting from umbilical cord blood samples. The necessary steps to produce highly pure, mature megakaryocytes under serum-free conditions are described. Details of phenotypic analysis of megakaryocyte differentiation and determination of proplatelet formation and platelet production are also provided. Effectors that influence megakaryocyte differentiation and/or proplatelet formation, such as anti-platelet antibodies or thrombopoietin mimetics, can be added to cultured cells to examine biological function.
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Affiliation(s)
- Jose Perdomo
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales;
| | - Feng Yan
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales
| | - Halina H L Leung
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales
| | - Beng H Chong
- Haematology Research Unit, St George and Sutherland Clinical School, University of New South Wales; Haematology Department, St George and Sutherland Hospitals
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Grodzielski M, Di Buduo CA, Goette NP, Lev PR, Soprano PM, Heller PG, Balduini A, Marta RF. Autoantibodies in immune thrombocytopenia affect the physiological interaction between megakaryocytes and bone marrow extracellular matrix proteins. Br J Haematol 2017; 183:319-323. [DOI: 10.1111/bjh.14977] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matías Grodzielski
- Institute of Medical Research A Lanari; University of Buenos Aires; Buenos Aires Argentina
- Department of Experimental Haematology; Institute of Medical Research (IDIM); National Scientific and Technical Research Council (CONICET); University of Buenos Aires; Buenos Aires Argentina
| | - Christian A. Di Buduo
- Department of Molecular Medicine; University of Pavia; Pavia Italy
- Biotechnology Research Laboratories; IRCCS San Matteo Foundation; Pavia Italy
| | - Nora P. Goette
- Institute of Medical Research A Lanari; University of Buenos Aires; Buenos Aires Argentina
| | - Paola R. Lev
- Institute of Medical Research A Lanari; University of Buenos Aires; Buenos Aires Argentina
- Department of Experimental Haematology; Institute of Medical Research (IDIM); National Scientific and Technical Research Council (CONICET); University of Buenos Aires; Buenos Aires Argentina
| | - Paolo M. Soprano
- Department of Molecular Medicine; University of Pavia; Pavia Italy
- Biotechnology Research Laboratories; IRCCS San Matteo Foundation; Pavia Italy
| | - Paula G. Heller
- Institute of Medical Research A Lanari; University of Buenos Aires; Buenos Aires Argentina
- Department of Experimental Haematology; Institute of Medical Research (IDIM); National Scientific and Technical Research Council (CONICET); University of Buenos Aires; Buenos Aires Argentina
| | - Alessandra Balduini
- Department of Molecular Medicine; University of Pavia; Pavia Italy
- Biotechnology Research Laboratories; IRCCS San Matteo Foundation; Pavia Italy
- Department of Biomedical Engineering; Tufts University; Medford MA USA
| | - Rosana F. Marta
- Institute of Medical Research A Lanari; University of Buenos Aires; Buenos Aires Argentina
- Department of Experimental Haematology; Institute of Medical Research (IDIM); National Scientific and Technical Research Council (CONICET); University of Buenos Aires; Buenos Aires Argentina
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25
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Pavkovic M, Petlichkovski A, Karanfilski O, Cevreska L, Stojanovic A. FC gamma receptor polymorphisms in patients with immune thrombocytopenia. ACTA ACUST UNITED AC 2017; 23:163-168. [PMID: 28942727 DOI: 10.1080/10245332.2017.1377902] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Immune thrombocytopenia (ITP) is an autoimmune blood disease of unknown etiology. The aim of our study was to investigate a possible role of FCGR2A and FCGR3A polymorphisms in the development of primary ITP. METHODS We analyzed 125 adult patients with ITP and 120 healthy controls. Genotyping was performed by using PCR-RFLP methods. RESULTS Our results showed significantly higher frequency of high-affinity FCGR3A-158V allele in patients with ITP compared with control subjects (47.2% versus 37.5%; p = 0.037). We did not find significant differences in the genotype distribution or allele frequencies for FCGR2A-131H/R between patients and controls, p = 0.652 and p = 0.478. In the groups of patients with unresponsive and responsive ITP we found significantly different genotype distribution and allele frequencies for FCGR3A, p = 0.036 and p = 0.008 respectively. There was no significant difference in genotype and allele frequencies for FCGR2A between these two groups of patients. Our results confirmed that the combination of high-affinity FCGR2A-131H and FCGR3A-158V allele was more common in patients with ITP than in controls (55% versus 40%; p = 0.024). CONCLUSION Our results suggest possible role of FCGR3A polymorphism in the etiology, development and clinical outcome of ITP, but larger prospective studies are needed to confirm these results.
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Affiliation(s)
- Marica Pavkovic
- a University Clinic for Hematology , Faculty of Medicine , Skopje , Republic of Macedonia
| | - Aleksandar Petlichkovski
- b Institute for Immunobiology and Human Genetics , Faculty of Medicine , Skopje , Republic of Macedonia
| | - Oliver Karanfilski
- a University Clinic for Hematology , Faculty of Medicine , Skopje , Republic of Macedonia
| | - Lidija Cevreska
- a University Clinic for Hematology , Faculty of Medicine , Skopje , Republic of Macedonia
| | - Aleksandar Stojanovic
- a University Clinic for Hematology , Faculty of Medicine , Skopje , Republic of Macedonia
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Audia S, Mahévas M, Samson M, Godeau B, Bonnotte B. Pathogenesis of immune thrombocytopenia. Autoimmun Rev 2017; 16:620-632. [DOI: 10.1016/j.autrev.2017.04.012] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 03/17/2017] [Indexed: 01/19/2023]
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27
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Low-level light treatment ameliorates immune thrombocytopenia. Sci Rep 2016; 6:38238. [PMID: 27901126 PMCID: PMC5128784 DOI: 10.1038/srep38238] [Citation(s) in RCA: 251] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/07/2016] [Indexed: 11/08/2022] Open
Abstract
Immune thrombocytopenia (ITP) is an immune-mediated acquired bleeding disorder characterized by abnormally low platelet counts. We reported here the ability of low-level light treatment (LLLT) to alleviate ITP in mice. The treatment is based on noninvasive whole body illumination 30 min a day for a few consecutive days by near infrared light (830 nm) transmitted by an array of light-emitting diodes (LEDs). LLLT significantly lifted the nadir of platelet counts and restored tail bleeding time when applied to two passive ITP models induced by anti-CD41 antibody. The anti-platelet antibody hindered megakaryocyte differentiation from the progenitors, impaired proplatelet and platelet formation, and induced apoptosis of platelets. These adverse effects of anti-CD41 antibody were all mitigated by LLLT to varying degrees, owing to its ability to enhance mitochondrial biogenesis and activity in megakaryocytes and preserve mitochondrial functions in platelets in the presence of the antibody. The observations argue not only for contribution of mitochondrial stress to the pathology of ITP, but also clinical potentials of LLLT as a safe, simple, and cost-effective modality of ITP.
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28
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Goette NP, Glembotsky AC, Lev PR, Grodzielski M, Contrufo G, Pierdominici MS, Espasandin YR, Riveros D, García AJ, Molinas FC, Heller PG, Marta RF. Platelet Apoptosis in Adult Immune Thrombocytopenia: Insights into the Mechanism of Damage Triggered by Auto-Antibodies. PLoS One 2016; 11:e0160563. [PMID: 27494140 PMCID: PMC4975454 DOI: 10.1371/journal.pone.0160563] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/21/2016] [Indexed: 11/26/2022] Open
Abstract
Mechanisms leading to decreased platelet count in immune thrombocytopenia (ITP) are heterogeneous. This study describes increased platelet apoptosis involving loss of mitochondrial membrane potential (ΔΨm), caspase 3 activation (aCasp3) and phosphatidylserine (PS) externalization in a cohort of adult ITP patients. Apoptosis was not related to platelet activation, as PAC-1 binding, P-selectin exposure and GPIb-IX internalization were not increased. Besides, ITP platelets were more sensitive to apoptotic stimulus in terms of aCasp3. Incubation of normal platelets with ITP plasma induced loss of ΔΨm, while PS exposure and aCasp3 remained unaltered. The increase in PS exposure observed in ITP platelets could be reproduced in normal platelets incubated with ITP plasma by adding normal CD3+ lymphocytes to the system as effector cells. Addition of leupeptin -a cathepsin B inhibitor- to this system protected platelets from apoptosis. Increased PS exposure was also observed when normal platelets and CD3+ lymphocytes were incubated with purified IgG from ITP patients and was absent when ITP plasma was depleted of auto-antibodies, pointing to the latter as responsible for platelet damage. Apoptosis was present in platelets from all patients carrying anti-GPIIb-IIIa and anti-GPIb auto-antibodies but was absent in the patient with anti-GPIa-IIa auto-antibodies. Platelet damage inversely correlated with platelet count and decreased during treatment with a thrombopoietin receptor agonist. These results point to a key role for auto-antibodies in platelet apoptosis and suggest that antibody-dependent cell cytotoxicity is the mechanism underlying this phenomenon.
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Affiliation(s)
- Nora P. Goette
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Ana C. Glembotsky
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Paola R. Lev
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Matías Grodzielski
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Geraldine Contrufo
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | | | - Yesica R. Espasandin
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Dardo Riveros
- Departamento de Hematología, Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno” (CEMIC), Buenos Aires, Argentina
| | - Alejandro J. García
- Laboratorio de Citometría de Flujo, Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno” (CEMIC), Buenos Aires, Argentina
| | - Felisa C. Molinas
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Paula G. Heller
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
| | - Rosana F. Marta
- Departamento de Hematología Investigación. Instituto de Investigaciones Médicas A. Lanari-IDIM, Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires, Argentina
- * E-mail:
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Kohn B, Bal G, Chirek A, Rehbein S, Salama A. Treatment of 5 dogs with immune-mediated thrombocytopenia using Romiplostim. BMC Vet Res 2016; 12:96. [PMID: 27283401 PMCID: PMC4901510 DOI: 10.1186/s12917-016-0718-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/01/2016] [Indexed: 12/29/2022] Open
Abstract
Background Immune thrombocytopenia (ITP) in dogs is analogous to that in humans. Romiplostim, a novel thrombopoietin receptor (TPO-R) agonist, is currently used for the treatment of refractory ITP in humans, but not in dogs. Here, we describe the response to romiplostim in five dogs with refractory ITP. Five dogs with severe and refractory ITP (three primary and two secondary) received romiplostim subcutaneously. Four dogs were administered 3–5 μg/kg and one dog received 10–13 μg/kg body weight once weekly. Results Romiplostim was well-tolerated and administration was associated with an increase in platelet counts in all five dogs. Four of the five dogs entered remission and relapses were not observed over a follow-up period of 3–10 months. Conclusions Romiplostim is effective in the treatment of ITP in dogs at least as well as in humans. This finding may help to develop and use new therapeutics for ITP in dogs and humans.
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Affiliation(s)
- Barbara Kohn
- FB Veterinärmedizin, Klinik für Kleine Haustiere, Freie Universität Berlin, Oertzenweg 19 b, 14163, Berlin, Germany
| | - Gürkan Bal
- Institut für Transfusionsmedizin, Charité - Universitätsklinikum, Augustenburger Platz 1, 13353, Berlin, Germany
| | - Aleksandra Chirek
- FB Veterinärmedizin, Klinik für Kleine Haustiere, Freie Universität Berlin, Oertzenweg 19 b, 14163, Berlin, Germany
| | - Sina Rehbein
- FB Veterinärmedizin, Klinik für Kleine Haustiere, Freie Universität Berlin, Oertzenweg 19 b, 14163, Berlin, Germany
| | - Abdulgabar Salama
- Institut für Transfusionsmedizin, Charité - Universitätsklinikum, Augustenburger Platz 1, 13353, Berlin, Germany.
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Lebreton L, Tuffigo M, Pillois X, Fiore M. [New perspectives on the role of αIIbβ3 integrin in defective megakaryopoiesis]. Med Sci (Paris) 2016; 32:290-6. [PMID: 27011248 DOI: 10.1051/medsci/20163203014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In recent years, the understanding of the molecular mechanisms involved in platelet production (megakaryopoiesis) has extremely increased, thanks to the study of genetic diseases causing inherited thrombocytopenia. Among the wide variety of transmembrane receptors covering the platelet membrane, αIIbβ3 integrin is the major one, allowing platelets to aggregate upon the occurrence of vascular breach. Platelet counts are usually normal in patients with αIIbβ3 deficiency, suggesting that its role for normal platelet production and morphology is very limited. However, recently, new clinical observations of genetic diseases provided evidence against this hypothesis, bringing new data on the role of αIIbβ3 integrin in defective megakaryopoiesis.
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Affiliation(s)
- Louis Lebreton
- Université Victor Segalen, 146, rue Léo Saignat, 33000, Bordeaux, France
| | - Marie Tuffigo
- Université Victor Segalen, 146, rue Léo Saignat, 33000, Bordeaux, France - Laboratoire d'hématologie, CHU de Bordeaux, avenue Magellan, 33604, Pessac, France
| | - Xavier Pillois
- Centre de référence des pathologies plaquettaires, avenue Magellan, 33604, Pessac, France
| | - Mathieu Fiore
- Laboratoire d'hématologie, CHU de Bordeaux, avenue Magellan, 33604, Pessac, France - Centre de référence des pathologies plaquettaires, avenue Magellan, 33604, Pessac, France
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31
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Di Buduo CA, Alberelli MA, Glembostky AC, Podda G, Lev PR, Cattaneo M, Landolfi R, Heller PG, Balduini A, De Candia E. Abnormal proplatelet formation and emperipolesis in cultured human megakaryocytes from gray platelet syndrome patients. Sci Rep 2016; 6:23213. [PMID: 26987485 PMCID: PMC4796794 DOI: 10.1038/srep23213] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/02/2016] [Indexed: 12/19/2022] Open
Abstract
The Gray Platelet Syndrome (GPS) is a rare inherited bleeding disorder characterized by deficiency of platelet α-granules, macrothrombocytopenia and marrow fibrosis. The autosomal recessive form of GPS is linked to loss of function mutations in NBEAL2, which is predicted to regulate granule trafficking in megakaryocytes, the platelet progenitors. We report the first analysis of cultured megakaryocytes from GPS patients with NBEAL2 mutations. Megakaryocytes cultured from peripheral blood or bone marrow hematopoietic progenitor cells from four patients were used to investigate megakaryopoiesis, megakaryocyte morphology and platelet formation. In vitro differentiation of megakaryocytes was normal, whereas we observed deficiency of megakaryocyte α-granule proteins and emperipolesis. Importantly, we first demonstrated that platelet formation by GPS megakaryocytes was severely affected, a defect which might be the major cause of thrombocytopenia in patients. These results demonstrate that cultured megakaryocytes from GPS patients provide a valuable model to understand the pathogenesis of GPS in humans.
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Affiliation(s)
- Christian A Di Buduo
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo Foundation, Pavia, Italy
| | - Maria Adele Alberelli
- Department of Internal Medicine, Policlinico Agostino Gemelli, Catholic University, Rome, Italy
| | - Ana C Glembostky
- Hematology Research, Instituto de Investigaciones Médicas Alfredo Lanari, University of Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Gianmarco Podda
- Medicina III, Azienda Ospedaliera San Paolo, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
| | - Paola R Lev
- Hematology Research, Instituto de Investigaciones Médicas Alfredo Lanari, University of Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Marco Cattaneo
- Medicina III, Azienda Ospedaliera San Paolo, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
| | - Raffaele Landolfi
- Department of Internal Medicine, Policlinico Agostino Gemelli, Catholic University, Rome, Italy
| | - Paula G Heller
- Hematology Research, Instituto de Investigaciones Médicas Alfredo Lanari, University of Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Alessandra Balduini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo Foundation, Pavia, Italy.,Department of Biomedical Engineering, Tufts University, Medford, MA, USA
| | - Erica De Candia
- Department of Internal Medicine, Policlinico Agostino Gemelli, Catholic University, Rome, Italy
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32
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Perdomo J. Role of romiplostim in splenectomized and nonsplenectomized patients with immune thrombocytopenia. Immunotargets Ther 2016; 5:1-7. [PMID: 27529057 PMCID: PMC4970631 DOI: 10.2147/itt.s80648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Romiplostim is a thrombopoietin receptor agonist (TPO-RA) used for the treatment of adult primary immune thrombocytopenia (ITP). ITP is an autoimmune condition characterized by low platelet counts due to increased destruction and reduced platelet production. First-line interventions include corticosteroids, anti-D, and intravenous immunoglobulins, while second-line therapies comprise splenectomy, rituximab, cyclosporine A, and TPO-RAs. The recognition that compromised platelet production is a critical part of the pathogenesis of ITP prompted the development of therapeutic strategies based on the stimulation of the TPO receptor. TPO-RAs enhance megakaryocyte proliferation, increase platelet production, and lead to a reduction in bleeding episodes in ITP patients. This review will summarize current data on the TPO-RA romiplostim, with a particular focus on its relation to splenectomy.
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Affiliation(s)
- Jose Perdomo
- Hematology Research Unit, St George and Sutherland Clinical School, University of New South Wales, Kogarah, NSW, Australia
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33
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Bhoria P, Varma N, Malhotra P, Varma S, Luthra-Guptasarma M. Immunodiagnosis of platelet activation in immune thrombocytopenia through scFv antibodies cognate to activated IIb3 integrins. MAbs 2015; 7:1212-20. [PMID: 26301697 DOI: 10.1080/19420862.2015.1075681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by low platelet count and presence of IgG autoantibodies to platelet surface glycoproteins, such as α IIbβ3 and GPIb/IX. Our previous work has shown that platelets in ITP patients exist in an activated state. Two different marker-based approaches are used to study the course of platelet activation: (1) binding of PAC-1 antibody, signifying a change in αIIbβ3 conformation, and (2) expression of P-selectin, signifying alpha granule content release from platelets. Here, we describe the development of a new scFv antibody (R38) that, compared with PAC-1, appears to better distinguish between platelets of ITP patients and healthy controls. Notably, R38 was generated using commercially sourced resting-state integrin that was coated on a microtiter plate. Its ability to distinguish between ITP patients and healthy controls thus suggests that inadvertent integrin activation caused by coating involves a conformational change and exposure of a cryptic epitope. This report also describes for the first time the potential use of an scFv antibody in the immunodiagnosis of platelet activation in ITP patients.
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Affiliation(s)
- Preeti Bhoria
- a Department of Internal Medicine ; Postgraduate Institute of Medical Education and Research ; Chandigarh , India
| | - Neelam Varma
- b Hematology; Postgraduate Institute of Medical Education and Research ; Chandigarh , India
| | - Pankaj Malhotra
- a Department of Internal Medicine ; Postgraduate Institute of Medical Education and Research ; Chandigarh , India
| | - Subhash Varma
- a Department of Internal Medicine ; Postgraduate Institute of Medical Education and Research ; Chandigarh , India
| | - Manni Luthra-Guptasarma
- c Immunopathology; Postgraduate Institute of Medical Education and Research ; Chandigarh , India
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Rivière É, Viallard JF, Guy A, Kilani B, Vieira-Dias J, Pons AC, Couffinhal T, Pellegrin JL, James C. Intrinsically impaired platelet production in some patients with persistent or chronic immune thrombocytopenia. Br J Haematol 2015; 170:408-15. [DOI: 10.1111/bjh.13444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Affiliation(s)
- Étienne Rivière
- Internal Medicine Department; Bordeaux University Hospital Centre; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Jean-François Viallard
- Internal Medicine Department; Bordeaux University Hospital Centre; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Alexandre Guy
- Internal Medicine Department; Bordeaux University Hospital Centre; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Badr Kilani
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Juliana Vieira-Dias
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Anne C. Pons
- Laboratory of Haematology; Bordeaux University Hospital Centre; Pessac France
| | - Thierry Couffinhal
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
| | - Jean-Luc Pellegrin
- Internal Medicine Department; Bordeaux University Hospital Centre; Pessac France
| | - Chloé James
- Adaptation Cardiovasculaire à l'Ischémie; University of Bordeaux; Pessac France
- Adaptation Cardiovasculaire à l'Ischémie; INSERM; Pessac France
- Laboratory of Haematology; Bordeaux University Hospital Centre; Pessac France
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35
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Espasandin YR, Glembotsky AC, Grodzielski M, Lev PR, Goette NP, Molinas FC, Marta RF, Heller PG. Anagrelide platelet-lowering effect is due to inhibition of both megakaryocyte maturation and proplatelet formation: insight into potential mechanisms. J Thromb Haemost 2015; 13:631-42. [PMID: 25604267 DOI: 10.1111/jth.12850] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/04/2015] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND OBJECTIVES Anagrelide represents a treatment option for essential thrombocythemia patients. It lowers platelet counts through inhibition of megakaryocyte maturation and polyploidization, although the basis for this effect remains unclear. Based on its rapid onset of action, we assessed whether, besides blocking megakaryopoiesis, anagrelide represses proplatelet formation (PPF) and aimed to clarify the underlying mechanisms. METHODS AND RESULTS Exposure of cord blood-derived megakaryocytes to anagrelide during late stages of culture led to a dose- and time-dependent inhibition of PPF and reduced proplatelet complexity, which were independent of the anagrelide-induced effect on megakaryocyte maturation. Whereas anagrelide was shown to phosphorylate cAMP-substrate VASP, two pharmacologic inhibitors of the cAMP pathway were completely unable to revert anagrelide-induced repression in megakaryopoiesis and PPF, suggesting these effects are unrelated to its ability to inhibit phosphodiesterase (PDE) 3. The reduction in thrombopoiesis was not the result of down-regulation of transcription factors which coordinate PPF, while the myosin pathway was identified as a candidate target, as anagrelide was shown to phosphorylate the myosin light chain and the PPF phenotype was partially rescued after inhibition of myosin activity with blebbistatin. CONCLUSIONS The platelet-lowering effect of anagrelide results from impaired megakaryocyte maturation and reduced PPF, both of which are deregulated in essential thrombocythemia. These effects seem unrelated to PDE3 inhibition, which is responsible for anagrelide's cardiovascular side-effects and antiplatelet activity. Further work in this field may lead to the potential development of drugs to treat thrombocytosis in myeloproliferative disorders with an improved pharmacologic profile.
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Affiliation(s)
- Y R Espasandin
- Departamento de Hematología Investigación, Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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36
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Arnold DM, Nazi I, Toltl LJ, Ross C, Ivetic N, Smith JW, Liu Y, Kelton JG. Antibody binding to megakaryocytes in vivo in patients with immune thrombocytopenia. Eur J Haematol 2015; 95:532-7. [PMID: 25684257 DOI: 10.1111/ejh.12528] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2014] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder caused by increased platelet destruction and impaired platelet production. Antibody binding to megakaryocytes may occur in ITP, but in vivo evidence of this phenomenon is lacking. METHODS We determined the proportion of megakaryocytes bound with immunoglobulin G (IgG) in bone marrow samples from primary patients with ITP (n = 17), normal controls (n = 13) and thrombocytopenic patients with myelodysplastic syndrome (MDS; n = 10). Serial histological sections from archived bone marrow biopsies were stained for CD61 and IgG. IgG binding and the number of bone marrow megakaryocytes were determined morphologically by a hematopathologist with four assessors after a calibration exercise to ensure consistency. RESULTS The proportion of ITP patients with high IgG binding (>50% of bone marrow megakaryocytes) was increased compared with normal controls [12/17 (71%) vs. 3/13 (23%), P = 0.03]. However, the proportion of ITP patients with high IgG binding was no different than thrombocytopenic patients with MDS [12/17 (71%) vs. 7/10 (70%), P = 1.00]. IgG binding was associated with increased megakaryocyte numbers. Like platelet-associated IgG, megakaryocyte-associated IgG is related to thrombocytopenia but may not be specific for ITP. CONCLUSION Mechanistic studies in ITP should focus on antibody specificity and include thrombocytopenic control patients.
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Affiliation(s)
- Donald M Arnold
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Canadian Blood Services, Hamilton, Ontario, Canada
| | - Ishac Nazi
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Lisa J Toltl
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Catherine Ross
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Nikola Ivetic
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - James W Smith
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Yang Liu
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John G Kelton
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
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Iraqi M, Perdomo J, Yan F, Choi PYI, Chong BH. Immune thrombocytopenia: antiplatelet autoantibodies inhibit proplatelet formation by megakaryocytes and impair platelet production in vitro. Haematologica 2015; 100:623-32. [PMID: 25682608 DOI: 10.3324/haematol.2014.115634] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 02/02/2015] [Indexed: 12/11/2022] Open
Abstract
Primary immune thrombocytopenia is an autoimmune disease mediated by antiplatelet autoantibodies that cause platelet destruction and suppression of platelet production. In vitro effects of autoantibodies on megakaryocyte production and maturation have been reported recently. However, the impact of these autoantibodies on crucial megakaryocyte functions, proplatelet formation and subsequent platelet release, has not been evaluated. We examined the effects of serum and IgG from 19 patients with immune thrombocytopenia using day 8 or 9 megakaryocytes (66.3 ± 10.6% CD41(+)), derived from cord blood hematopoietic stem cells (CD34(+)). The number of proplatelet-bearing megakaryocytes, the number of platelets released in the culture, total megakaryocyte numbers, ploidy pattern and caspase activation were measured at various times after treatment. After 5 days of treatment the number of proplatelet-bearing megakaryocytes was significantly decreased by 13 immune thrombocytopenia autoantibodies relative to the control group (P<0.0001) and this decrease was accompanied by a corresponding reduction of platelet release. Other features, including total megakaryocyte numbers, maturation and apoptosis, were not affected by immune thrombocytopenia antibodies. Treating the megakaryocytes with the thrombopoietin receptor agonists romiplostim and eltrombopag reversed the effect of the autoantibodies on megakaryocytes by restoring their capacity to form proplatelets. We conclude that antiplatelet antibodies in immune thrombocytopenia inhibit proplatelet formation by megakaryocytes and hence the ability of the megakaryocytes to release platelets. Treatment with either romiplostim or eltrombopag regenerates proplatelet formation from the megakaryocytes.
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Affiliation(s)
- Muna Iraqi
- Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Australia Centre for Vascular Research, University of New South Wales, Australia
| | - Jose Perdomo
- Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Australia Centre for Vascular Research, University of New South Wales, Australia
| | - Feng Yan
- Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Australia Centre for Vascular Research, University of New South Wales, Australia Haematology Department, St George and Sutherland Hospitals, Sydney, Australia
| | - Philip Y-I Choi
- Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Australia Centre for Vascular Research, University of New South Wales, Australia
| | - Beng H Chong
- Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Australia Centre for Vascular Research, University of New South Wales, Australia Haematology Department, St George and Sutherland Hospitals, Sydney, Australia
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