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Yang Y, Gan W, Lin L, Wang L, Wu J, Luo J. Identification of Active Molecules against Thrombocytopenia through Machine Learning. J Chem Inf Model 2024; 64:6506-6520. [PMID: 39109515 DOI: 10.1021/acs.jcim.4c00718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Thrombocytopenia, which is associated with thrombopoietin (TPO) deficiency, presents very limited treatment options and can lead to life-threatening complications. Discovering new therapeutic agents against thrombocytopenia has proven to be a challenging task using traditional screening approaches. Fortunately, machine learning (ML) techniques offer a rapid avenue for exploring chemical space, thereby increasing the likelihood of uncovering new drug candidates. In this study, we focused on computational modeling for drug-induced megakaryocyte differentiation and platelet production using ML methods, aiming to gain insights into the structural characteristics of hematopoietic activity. We developed 112 different classifiers by combining eight ML algorithms with 14 molecule features. The top-performing model achieved good results on both 5-fold cross-validation (with an accuracy of 81.6% and MCC value of 0.589) and external validation (with an accuracy of 83.1% and MCC value of 0.642). Additionally, by leveraging the Shapley additive explanations method, the best model provided quantitative assessments of molecular properties and structures that significantly contributed to the predictions. Furthermore, we employed an ensemble strategy to integrate predictions from multiple models and performed in silico predictions for new molecules with potential activity against thrombocytopenia, sourced from traditional Chinese medicine and the Drug Repurposing Hub. The findings of this study could offer valuable insights into the structural characteristics and computational prediction of thrombopoiesis inducers.
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Affiliation(s)
- Youyou Yang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Wenli Gan
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Lei Lin
- School of Public Health, Southwest Medical University, Luzhou 646000, China
| | - Long Wang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou 646000, China
| | - Jianming Wu
- Basic Medical College, Southwest Medical University, Luzhou 646000, China
| | - Jiesi Luo
- Basic Medical College, Southwest Medical University, Luzhou 646000, China
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
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Brooks MB, Brooks JC, Catalfamo J, Zhu Y, Goggs R, Babasyan S, Wagner B, LeVine DN. Plasma concentration of thrombopoietin in dogs with immune thrombocytopenia. J Vet Intern Med 2024. [PMID: 39143652 DOI: 10.1111/jvim.17152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 07/16/2024] [Indexed: 08/16/2024] Open
Abstract
BACKGROUND Immune thrombocytopenia (ITP) is a common cause of severe thrombocytopenia in dogs. The pathogenesis of nonassociative, primary ITP (pITP) appears complex, with ill-defined thrombopoietic response. OBJECTIVES Develop an immunoassay to measure plasma canine thrombopoietin (TPO) concentration and characterize TPO concentrations in dogs with pITP. ANIMALS Forty-one healthy dogs, 8 dogs in an induced ITP model (3 control, 5 ITP), and 58 pITP dogs. METHODS Recombinant canine TPO (rcTPO) was purchased and its identity confirmed by mass spectrometry. Monoclonal antibodies were raised to rcTPO and used to configure a sandwich ELISA using streptavidin-biotin detection. Assay performance, coefficients of variability, and healthy dog plasma TPO reference interval (RI) were determined, followed by assay of ITP samples. RESULTS Assay dynamic range was 15 pg/mL (lower limit of detection) to 1000 pg/mL TPO, with limit of quantitation of 62 pg/mL. Plasma TPO RI was 0 to 158 pg/mL, with plasma TPO <62 pg/mL for 35/41 healthy dogs. All dogs with induced ITP developed marked increases in plasma TPO concentration. Peak values ranged from 515 to >6000 pg/mL. In contrast, only 2/58 pITP dogs had TPO values above RI. CONCLUSIONS AND CLINICAL IMPORTANCE Plasma TPO concentration is paradoxically low at diagnosis for most dogs with pITP. This finding suggests that ineffective thrombopoiesis contributes to thrombocytopenia in pITP dogs and supports evaluating TPO receptor agonist treatment as used for pITP in humans. The TPO assay provides a new tool to study thrombopoiesis in pITP and other thrombocytopenic syndromes in dogs.
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Affiliation(s)
- Marjory B Brooks
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - James C Brooks
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jim Catalfamo
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Yao Zhu
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Robert Goggs
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Susanna Babasyan
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Bettina Wagner
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Dana N LeVine
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
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Shen N, Qiao J, Jiang Y, Yin H, Li M, Zhu S, Li J. Safety of non‑peptide thrombopoietin receptor agonists in patients with immune thrombocytopenia: A systematic review and meta‑analysis of short‑term double‑blind randomized clinical trials. Exp Ther Med 2023; 26:393. [PMID: 37456173 PMCID: PMC10347292 DOI: 10.3892/etm.2023.12092] [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: 02/22/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023] Open
Abstract
The aim of the present study was to analyze the safety of non-peptide thrombopoietin receptor agonists (TPO-RAs) for immune thrombocytopenia (ITP) treatment. All studies reporting adverse events (AEs) in relation to ITP treatment with eltrombopag, avatrombopag, and hetrombopag were retrieved from PubMed, Web of Science, and Embase databases. RevMan 5.4.1 was used for meta-analysis, heterogeneity and bias analyses. A total of 1,078 patients from seven eligible studies were enrolled. In the enrolled clinical trials, the double-blind period was between 6 weeks and 6 months. The results revealed that the chances of any AEs [relative risk (RR)=1.16; 95% confidence interval (CI), 0.90-1.51; I2=78%; P=0.26], grade 3/4 AEs (RR=1.07; 95% CI, 0.63-1.80; I2=0%; P=0.81), elevated transaminase levels (RR=1.09; 95% CI, 0.68-1.74; I2=0%; P=0.72), thrombosis (RR=1.92; 95% CI, 0.55-6.66; I2=0%; P=0.31) and cataracts (RR=0.83; 95% CI, 0.38-1.83; I2=0%; P=0.65) were not significantly higher in patients with ITP that received non-peptide TPO-RAs compared with patients with ITP treated with a placebo. The present study indicated that non-peptide TPO-RAs were relatively safe for patients with ITP, at least within 6 months of administration.
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Affiliation(s)
- Nan Shen
- Department of Pediatrics, Suqian Hospital Affiliated to Xuzhou Medical University, Suqian, Jiangsu 223800, P.R. China
- Department of Hematology, The Children's Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Jibing Qiao
- Department of Pediatrics, Suqian Hospital Affiliated to Xuzhou Medical University, Suqian, Jiangsu 223800, P.R. China
| | - Yazhou Jiang
- Department of Pediatrics, Suqian Hospital Affiliated to Xuzhou Medical University, Suqian, Jiangsu 223800, P.R. China
| | - Hanjun Yin
- Department of Pediatrics, Suqian Hospital Affiliated to Xuzhou Medical University, Suqian, Jiangsu 223800, P.R. China
| | - Min Li
- Department of Hematology, The Children's Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Suyue Zhu
- Department of Pediatrics, Suqian Hospital Affiliated to Xuzhou Medical University, Suqian, Jiangsu 223800, P.R. China
| | - Jianqin Li
- Department of Hematology, The Children's Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
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Nevil G, Roth M, Gill J, Zhang W, Teicher B, Erickson SW, Gatto G, Smith M, Kolb EA, Gorlick R. Initial in vivo testing of TPO-receptor agonist eltrombopag in osteosarcoma patient-derived xenograft models by the pediatric preclinical testing consortium. Pediatr Hematol Oncol 2021; 38:8-13. [PMID: 32804009 PMCID: PMC8670012 DOI: 10.1080/08880018.2020.1802539] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Eltrombopag is a small molecule, thrombopoietin receptor agonist approved for the treatment of patients with aplastic anemia and chronic immune thrombocytopenia. It is also a polyvalent cation chelator and inhibits leukemia cell proliferation via reduction of intracellular iron. The in vivo efficacy of eltrombopag was tested against a panel of six Pediatric Preclinical Testing Consortium osteosarcoma xenografts at doses of 5 mg/kg/day (moderate dose) and 50 mg/kg/day (high dose). Eltrombopag, at moderate doses, failed to significantly improve event-free survival (EFS) in 6/6 models. At high doses, eltrombopag significantly prolonged EFS in 2/2 models, though the effect size was small. All models tested demonstrated progressive disease. While eltrombopag did not meaningfully inhibit osteosarcoma growth, it also did not stimulate tumor growth, suggesting it may be safely investigated as a supportive care agent to enhance platelet recovery post chemotherapy.
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Affiliation(s)
- Grace Nevil
- Division of Pediatric Oncology, MD Anderson Children’s Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Michael Roth
- Division of Pediatric Oncology, MD Anderson Children’s Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jonathan Gill
- Division of Pediatric Oncology, MD Anderson Children’s Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Wendong Zhang
- Division of Pediatric Oncology, MD Anderson Children’s Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | | | - Gregory Gatto
- RTI International, Research Triangle Park, North Carolina, USA
| | - Malcom Smith
- National Cancer Institute, Bethesda, maryland, USA
| | - E. Anders Kolb
- Division of Pediatric Hematology/Oncology, A.I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Richard Gorlick
- Division of Pediatric Oncology, MD Anderson Children’s Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Zhu Q, Yang S, Zeng W, Li M, Guan Z, Zhou L, Wang H, Liu Y, Gao Y, Qiu S, Chen C, Li H, Zheng S, Yuan Y, Zhang H, Pan X. A Real-World Observation of Eltrombopag and Recombinant Human Thrombopoietin (rhTPO) in Lymphoma Patients With Chemotherapy Induced Thrombocytopenia. Front Oncol 2021; 11:701539. [PMID: 34490101 PMCID: PMC8418194 DOI: 10.3389/fonc.2021.701539] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/31/2021] [Indexed: 11/13/2022] Open
Abstract
This real-world, observational study aimed to assess and compare the clinical efficacy and safety of eltrombopag with recombinant human thrombopoietin (rhTPO) in the treatment of chemotherapy induced thrombocytopenia (CIT) in patients with lymphoma. One hundred and fifty-three patients who experienced grade 3 or 4 thrombocytopenia after chemotherapy for lymphoma were enrolled, 51 of which were treated with eltrombopag, 50 with rhTPO, and 52 patients with no drug treatment were served as the control group. The lowest platelet level and mean platelet counts at Day 5, Day 7, and Day 10 were significantly higher in both the eltrombopag group (P=.041,.003,.000,.000) and rhTPO group (P=.005,.005,.000,.000) than the control, but there was no difference between treatment with eltrombopag and rhTPO. Similarly, days required for the recovery of platelet counts to ≥50×109/L and ≥75×109/L were not different between the two treatment groups but significantly higher than the control group (P <.05). Rates of bleeding and platelet transfusion were all significantly reduced in patients treated with eltrombopag (P=.031,.032) or rhTPO (P=.017,.009) when compared to the control. Treatment-related adverse events (AEs) were reported in 7 (13.7%) and 6 (12.0%) patients in the eltrombopag and rhTPO groups, respectively, all being mild and transient in nature. In conclusion, both eltrombopag and rhTPO were effective and safe in the treatment of thrombocytopenia after chemotherapy for lymphoma.
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Yu Y, Wang M, Hou Y, Qin P, Zeng Q, Yu W, Guo X, Wang J, Wang X, Liu G, Chu X, Yang L, Feng Y, Zhou F, Sun Z, Zhang M, Wang X, Wang Z, Ran X, Zhao H, Wang L, Zhang H, Bi K, Li D, Yuan C, Xu R, Wang Y, Zhou Y, Peng J, Liu X, Hou M. High-dose dexamethasone plus recombinant human thrombopoietin vs high-dose dexamethasone alone as frontline treatment for newly diagnosed adult primary immune thrombocytopenia: A prospective, multicenter, randomized trial. Am J Hematol 2020; 95:1542-1552. [PMID: 32871029 DOI: 10.1002/ajh.25989] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/19/2020] [Accepted: 08/29/2020] [Indexed: 12/24/2022]
Abstract
We conducted a prospective, multicenter, randomized, controlled clinical trial to compare the efficacy and safety of high-dose dexamethasone (HD-DXM) plus recombinant human thrombopoietin (rhTPO), vs HD-DXM alone in newly diagnosed adult immune thrombocytopenia (ITP) patients. Enrolled patients were randomly assigned to receive DXM plus rhTPO or DXM monotherapy. Another 4-day course of DXM was repeated if response was not achieved by day 10 in both arms. One hundred patients in the HD-DXM plus rhTPO arm and 96 patients in the HD-DXM monotherapy arm were included in the full analysis set. So, HD-DXM plus rhTPO resulted in a higher incidence of initial response (89.0% vs 66.7%, P < .001) and complete response (CR, 75.0% vs 42.7%, P < .001) compared with HD-DXM monotherapy. Response rate at 6 months was also higher in the HD-DXM plus rhTPO arm than that in the HD-DXM monotherapy arm (51.0% vs 36.5%, P = .02; sustained CR: 46.0% vs 32.3%, P = .043). Throughout the follow-up period, the overall duration of response was greater in the HD-DXM plus rhTPO arm compared to the HD-DXM monotherapy arm (P = .04), as estimated by the Kaplan-Meier analysis. The study drugs were generally well tolerated. In conclusion, the combination of HD-DXM with rhTPO significantly improved the initial response and yielded favorable SR in newly diagnosed ITP patients, thus could be further validated as a frontline treatment for ITP. This study is registered as clinicaltrials.gov identifier: NCT01734044.
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Affiliation(s)
- Yafei Yu
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
| | - Miaomiao Wang
- Department of Pediatrics The Second Hospital, Cheeloo College of Medicine, Shandong University Jinan China
| | - Yu Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
| | - Ping Qin
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
| | - Qingshu Zeng
- Department of Hematology The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Wenzheng Yu
- Department of Hematology Binzhou Medical University Hospital Binzhou China
| | - Xinhong Guo
- Department of Hematology The First Affiliated Hospital of Xinjiang Medical University Urumqi China
| | - Jingxia Wang
- Department of Hematology Liaocheng People’s Hospital Liaocheng China
| | - Xiaomin Wang
- Department of Hematology Xinjiang Uiger Municipal People’s Hospital Urumqi China
| | - Guoqiang Liu
- Department of Hematology Shengli Oilfield Central Hospital Dongying China
| | - Xiaoxia Chu
- Department of Hematology Yantai Yuhuangding Hospital Yantai China
| | - Lan Yang
- Department of Hematology Xijing Hospital, Fourth Military Medical University Xi’an China
| | - Ying Feng
- Department of Hematology The Second Affiliated Hospital of Guangzhou Medical University Guangdong China
| | - Fang Zhou
- Department of Hematology Military General Hospital Jinan China
| | - Zhaogang Sun
- Department of Hematology Taian City Central Hospital Taian China
| | - Mei Zhang
- Department of Hematology The First Affiliated Hospital of Xi’an Jiaotong University Xi’an China
| | - Xin Wang
- Department of Hematology Shandong Provincial Hospital Affiliated to Shandong University Jinan China
| | - Zhencheng Wang
- Department of Hematology Zibo Central Hospital Zibo China
| | - Xuehong Ran
- Department of Hematology Weifang People’s Hospital Weifang China
| | - Hongguo Zhao
- Department of Hematology The Affiliated Hospital of Qingdao University Qingdao China
| | - Lei Wang
- Department of Hematology Qingdao Municipal Hospital Qingdao China
| | - Haiyan Zhang
- Department of Hematology Linyi People’s Hospital Linyi China
| | - Kehong Bi
- Department of Hematology Shandong Provincial Qianfoshan Hospital Jinan China
| | - Daqi Li
- Department of Hematology Jinan Central Hospital Jinan China
| | - Chenglu Yuan
- Department of Hematology Qilu Hospital (Qingdao), Shandong University Qingdao China
| | - Ruirong Xu
- Department of Hematology Shandong Provincial Hospital of Traditional Chinese Medicine Jinan China
| | - Yili Wang
- Department of Hematology Weihai Municipal Hospital Weihai China
| | - Yuhong Zhou
- Department of Hematology Zhejiang Provincial Hospital of TCM Hangzhou China
| | - Jun Peng
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
| | - Xin‐guang Liu
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
| | - Ming Hou
- Department of Hematology, Qilu Hospital, Cheeloo College of Medicine Shandong University Jinan Shandong China
- Shandong Province Key Laboratory of Hematology/Immunology, Creative Studio of Scientific and Technologic Leading Talents Qilu Hospital, Shandong University Jinan China
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Hernández-Sánchez JM, Bastida JM, Alonso-López D, Benito R, González-Porras JR, De Las Rivas J, Hernández Rivas JM, Rodríguez-Vicente AE. Transcriptomic analysis of patients with immune thrombocytopenia treated with eltrombopag. Platelets 2019; 31:993-1000. [PMID: 31838946 DOI: 10.1080/09537104.2019.1702156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the last years, the use of thrombopoietin receptor agonists (TPO-RA), eltrombopag and romiplostim, has improved the management of immune thrombocytopenia (ITP). Moreover, eltrombopag is also active in patients with aplastic anemia and myelodysplastic syndrome. However, their mechanisms of action and signaling pathways still remain controversial. In order to gain insight into the mechanisms underlying eltrombopag therapy, a gene expression profile (GEP) analysis in patients treated with this drug was carried out. Fourteen patients with chronic ITP were studied by means of microarrays before and during eltrombopag treatment. Median age was 78 years (range, 35-87 years); median baseline platelet count was 14 × 109/L (range, 2-68 × 109/L). Ten patients responded to the therapy, two cases relapsed after an initial response and the remaining two were refractory to the therapy. Eltrombopag induced relevant changes in the hematopoiesis, platelet activation and degranulation, as well as in megakaryocyte differentiation, with overexpression of some transcription factors and the genes PPBP, ITGB3, ITGA2B, F13A1, F13A1, MYL9 and ITGA2B. In addition, GP1BA, PF4, ITGA2B, MYL9, HIST1H4H and HIST1H2BH, genes regulated by RUNX1 were also significantly enriched after eltrombopag therapy. Furthermore, in non-responder patients, an overexpression of Bcl-X gene and genes involved in erythropoiesis, such as SLC4A1 and SLC25A39, was also observed. To conclude, overexpression in genes involved in megakaryopoiesis, platelet adhesion, degranulation and aggregation was observed in patients treated with eltrombopag. Moreover, an important role regarding heme metabolism was also present in non-responder patients.
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Affiliation(s)
- Jesús María Hernández-Sánchez
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
| | - José María Bastida
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
| | - Diego Alonso-López
- Bioinformatics Unit, Cancer Research Center (CSIC-USAL) , Salamanca, Spain
| | - Rocío Benito
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
| | - José Ramón González-Porras
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
| | | | - Jesús María Hernández Rivas
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
| | - Ana Eugenia Rodríguez-Vicente
- Department of Hematology, Hospital Universitario Salamanca , Salamanca, Spain.,IBSAL,IBMCC-Cancer Research Center, University of Salamanca , Salamanca, Spain
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Eltrombopag: Efficacy and Safety in Steroid Refractory Lupus-Associated Immune Thrombocytopenia. J Clin Rheumatol 2019; 26:274-278. [PMID: 31166214 DOI: 10.1097/rhu.0000000000001083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Eltrombopag, a thrombopoietin receptor agonist, is effective in chronic immune thrombocytopenia (ITP). The data in lupus ITP are sparse. This study aimed to assess the efficacy and safety of eltrombopag in lupus ITP. METHODS This is a single-center study conducted between 2012 and 2017 of 12 subjects with systemic lupus erythematosus-associated ITP. Patients with inadequate or suboptimal response to steroids and other immunosuppressants treated with eltrombopag were included in the study. Time taken for response to therapy (defined as platelets >1 lakh), dose, duration of treatment, and adverse effects of the drug were noted. RESULTS A total of 12 subjects were included in the study. The median platelet count at initiation of eltrombopag was 19,000 per μL. The time taken for response to therapy was 8 days. The median platelet count at 1-month follow-up was 241,000 per μL. All patients were concurrently treated with steroids and other immunosuppressants. Sustained benefit after stopping eltrombopag was noted in all patients. No adverse events including thrombotic complication were noted. CONCLUSIONS Eltrombopag is a new drug in our arsenal for treatment of ITP in lupus. It is a rapidly effective, safe, and orally administered medication. It indirectly contributes to reduction in the dose of steroids and immunosuppressants, thereby minimizing their cumulative adverse effects. It is a promising and safe option for the treatment of lupus-associated thrombocytopenia, but this needs further confirmation from multicenter, multiethnic, randomized controlled trials.
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Abstract
Avatrombopag (Doptelet®) is an orally bioavailable, small molecule thrombopoietin receptor agonist that has been developed by Dova Pharmaceuticals for the treatment of thrombocytopenic disorders. In May 2018 avatrombopag received its first global approval, in the USA, for use in the treatment of thrombocytopenia in adult patients with chronic liver disease (CLD) who are scheduled to undergo a procedure. A Marketing Authorization Application for use of avatrombopag in this indication was submitted to the EMA in April 2018. Clinical development of avatrombopag in the treatment of other thrombocytopenic disorders, including immune thrombocytopenic purpura and chemotherapy-induced thrombocytopenia, is ongoing. This article summarizes the milestones in the development of avatrombopag leading to this first approval for the treatment of thrombocytopenia in adult patients with CLD.
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Pecci A, Ragab I, Bozzi V, De Rocco D, Barozzi S, Giangregorio T, Ali H, Melazzini F, Sallam M, Alfano C, Pastore A, Balduini CL, Savoia A. Thrombopoietin mutation in congenital amegakaryocytic thrombocytopenia treatable with romiplostim. EMBO Mol Med 2019; 10:63-75. [PMID: 29191945 PMCID: PMC5760853 DOI: 10.15252/emmm.201708168] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Congenital amegakaryocytic thrombocytopenia (CAMT) is an inherited disorder characterized at birth by thrombocytopenia with reduced megakaryocytes, which evolves into generalized bone marrow aplasia during childhood. Although CAMT is genetically heterogeneous, mutations of MPL, the gene encoding for the receptor of thrombopoietin (THPO), are the only known disease‐causing alterations. We identified a family with three children affected with CAMT caused by a homozygous mutation (p.R119C) of the THPO gene. Functional studies showed that p.R119C affects not only ability of the cytokine to stimulate MPL but also its release, which is consistent with the relatively low serum THPO levels measured in patients. In all the three affected children, treatment with the THPO‐mimetic romiplostim induced trilineage hematological responses, remission of bleeding and infections, and transfusion independence, which were maintained after up to 6.5 years of observation. Recognizing patients with THPO mutations among those with juvenile bone marrow failure is essential to provide them with appropriate substitutive therapy and prevent the use of invasive and unnecessary treatments, such as hematopoietic stem cell transplantation or immunosuppression.
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Affiliation(s)
- Alessandro Pecci
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
| | - Iman Ragab
- Hematology-Oncology Unit, Pediatric Hospital, Ain Shams University, Cairo, Egypt
| | - Valeria Bozzi
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
| | - Daniela De Rocco
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Serena Barozzi
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
| | | | - Heba Ali
- Hematology-Oncology Unit, Pediatric Hospital, Ain Shams University, Cairo, Egypt
| | - Federica Melazzini
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
| | - Mohamed Sallam
- Department of Clinical Pathology, Ain Shams University, Cairo, Egypt
| | - Caterina Alfano
- Maurice Wohl Clinical Neuroscience Institute, King's College, London, UK.,Fondazione Ri.MED, Palermo, Italy
| | - Annalisa Pastore
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Carlo L Balduini
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
| | - Anna Savoia
- Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy .,Department of Medical Sciences, University of Trieste, Trieste, Italy
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[Eltrombopag for refractory thrombocytopenia in patients with allogeneic hematopoietic stem cell transplantation]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2018; 37:1065-1069. [PMID: 28088971 PMCID: PMC7348487 DOI: 10.3760/cma.j.issn.0253-2727.2016.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
目的 观察艾曲波帕治疗异基因造血干细胞(allo-HSCT)移植后难治性血小板减少的疗效及安全性。 方法 2015年5月1日至2016年5月1日,应用艾曲波帕治疗10例allo-HSCT后难治性血小板减少(糖皮质激素等治疗无效)患者。10例患者中,男、女各5例,中位年龄34(17~54)岁。急性髓系白血病5例,急性淋巴细胞白血病3例,重型再生障碍性贫血2例。同胞HLA配型全相合移植1例,单倍型相合移植9例。allo-HSCT至接受艾曲波帕治疗的中位时间为221(73~917) d。艾曲波帕剂量为50~75 mg/d(口服)。 结果 5例(50%)患者获得完全有效(PLT≥50×109/L且脱离血小板输注),用药30 d累积完全有效率为35.7%,治疗后达到第1次PLT≥50×109/L的中位时间为16(10~56) d。至随访截止,3例完全有效患者已分别停药39、342、84 d, PLT均≥100×109/L。5例患者无效。未发生药物相关不良反应。 结论 艾曲波帕对于部分allo-HSCT后难治性血小板减少患者有效且耐受性良好,值得进一步研究。
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12
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Xie C, Zhao H, Bao X, Fu H, Lou L. Pharmacological characterization of hetrombopag, a novel orally active human thrombopoietin receptor agonist. J Cell Mol Med 2018; 22:5367-5377. [PMID: 30156363 PMCID: PMC6201220 DOI: 10.1111/jcmm.13809] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/29/2018] [Indexed: 01/07/2023] Open
Abstract
Nonpeptide thrombopoietin receptor (TPOR/MPL) agonists, such as eltrombopag, have been used to treat thrombocytopenia of various aetiologies. Here, we investigated the pharmacological properties of hetrombopag, a new orally active small‐molecule TPOR agonist, in preclinical models. Hetrombopag specifically stimulated proliferation and/or differentiation of human TPOR‐expressing cells, including 32D‐MPL and human hematopoietic stem cells, with low nanomolar EC50 values through stimulation of STAT, PI3K and ERK signalling pathways. Notably, hetrombopag effectively up‐regulated G1‐phase–related proteins, including p‐RB, Cyclin D1 and CDK4/6, normalized progression of the cell cycle, and prevented apoptosis by modulating BCL‐XL/BAK expression in 32D‐MPL cells. Moreover, hetrombopag and TPO acted additively in stimulating TPOR‐dependent signalling, promoting cell viability, and preventing apoptosis. Orally administered hetrombopag specifically promoted the viability and growth of 32D‐MPL cells in hollow fibres implanted into nude mice with much higher potency than that of the well‐known TPOR agonist, eltrombopag, in association with activation of TPOR‐dependent signal transduction in vivo. Taken together, our findings indicate that, given its favourable pharmacological characteristics, hetrombopag may represent a new, orally active, small‐molecule TPOR agonist for patients with thrombocytopenia.
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Affiliation(s)
- Chengying Xie
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Huajun Zhao
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Xubin Bao
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Haoyu Fu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Liguang Lou
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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13
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Treatment characteristics, efficacy and safety of thrombopoietin analogues in routine management of primary immune thrombocytopenia. Blood Coagul Fibrinolysis 2018; 29:374-380. [DOI: 10.1097/mbc.0000000000000726] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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14
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Langer HF, Verschoor A. Crosstalk between platelets and the complement system in immune protection and disease. Thromb Haemost 2017; 110:910-9. [DOI: 10.1160/th13-02-0102] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 07/15/2013] [Indexed: 12/22/2022]
Abstract
SummaryPlatelets have a central function in repairing vascular damage and stopping acute blood loss. They are equally central to thrombus formation in cardiovascular diseases such as myocardial infarction and ischaemic stroke. Beyond these classical prothrombotic diseases, immune mediated pathologies such as haemolytic uraemic syndrome (HUS) or paroxysmal nocturnal haemoglobinuria (PNH) also feature an increased tendency to form thrombi in various tissues. It has become increasingly clear that the complement system, part of the innate immune system, has an important role in the pathophysiology of these diseases. Not only does complement influence prothrombotic disease, it is equally involved in idiopathic thrombocytopenic purpura (ITP), an autoimmune disease characterised by thrombocytopenia. Thus, there are complex interrelationships between the haemostatic and immune systems, and platelets and complement in particular. Not only does complement influence platelet diseases such as ITP, HUS and PNH, it also mediates interaction between microbes and platelets during systemic infection, influencing the course of infection and development of protective immunity. This review aims to provide an integrative overview of the mechanisms underlying the interactions between complement and platelets in health and disease.
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Affiliation(s)
- Abdulgabar Salama
- Charité - Universitätsmedizin Berlin, Germany - Institute of Transfusion Medicine, Berlin, Germany
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16
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Desborough M, Estcourt LJ, Doree C, Trivella M, Hopewell S, Stanworth SJ, Murphy MF. Alternatives, and adjuncts, to prophylactic platelet transfusion for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation. Cochrane Database Syst Rev 2016; 2016:CD010982. [PMID: 27548292 PMCID: PMC5019360 DOI: 10.1002/14651858.cd010982.pub2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people with thrombocytopenia. Although considerable advances have been made in platelet transfusion therapy since the mid-1970s, some areas continue to provoke debate especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding. OBJECTIVES To determine whether agents that can be used as alternatives, or adjuncts, to platelet transfusions for people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation are safe and effective at preventing bleeding. SEARCH METHODS We searched 11 bibliographic databases and four ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 4), MEDLINE (OvidSP, 1946 to 19 May 2016), Embase (OvidSP, 1974 to 19 May 2016), PubMed (e-publications only: searched 19 May 2016), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (searched 19 May 2016). SELECTION CRITERIA We included randomised controlled trials in people with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation who were allocated to either an alternative to platelet transfusion (artificial platelet substitutes, platelet-poor plasma, fibrinogen concentrate, recombinant activated factor VII, desmopressin (DDAVP), or thrombopoietin (TPO) mimetics) or a comparator (placebo, standard care or platelet transfusion). We excluded studies of antifibrinolytic drugs, as they were the focus of another review. DATA COLLECTION AND ANALYSIS Two review authors screened all electronically derived citations and abstracts of papers identified by the review search strategy. Two review authors assessed risk of bias in the included studies and extracted data independently. MAIN RESULTS We identified 16 eligible trials. Four trials are ongoing and two have been completed but the results have not yet been published (trial completion dates: April 2012 to February 2017). Therefore, the review included 10 trials in eight references with 554 participants. Six trials (336 participants) only included participants with acute myeloid leukaemia undergoing intensive chemotherapy, two trials (38 participants) included participants with lymphoma undergoing intensive chemotherapy and two trials (180 participants) reported participants undergoing allogeneic stem cell transplantation. Men and women were equally well represented in the trials. The age range of participants included in the trials was from 16 years to 81 years. All trials took place in high-income countries. The manufacturers of the agent sponsored eight trials that were under investigation, and two trials did not report their source of funding.No trials assessed artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin.Nine trials compared a TPO mimetic to placebo or standard care; seven of these used pegylated recombinant human megakaryocyte growth and differentiation factor (PEG-rHuMGDF) and two used recombinant human thrombopoietin (rhTPO).One trial compared platelet-poor plasma to platelet transfusion.We considered that all the trials included in this review were at high risk of bias and meta-analysis was not possible in seven trials due to problems with the way data were reported.We are very uncertain whether TPO mimetics reduce the number of participants with any bleeding episode (odds ratio (OR) 0.40, 95% confidence interval (CI) 0.10 to 1.62, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce the risk of a life-threatening bleed after 30 days (OR 1.46, 95% CI 0.06 to 33.14, three trials, 209 participants, very low quality evidence); or after 90 days (OR 1.00, 95% CI 0.06 to 16.37, one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce platelet transfusion requirements after 30 days (mean difference -3.00 units, 95% CI -5.39 to -0.61, one trial, 120 participants, very low quality evidence). No deaths occurred in either group after 30 days (one trial, 120 participants, very low quality evidence). We are very uncertain whether TPO mimetics reduce all-cause mortality at 90 days (OR 1.00, 95% CI 0.24 to 4.20, one trial, 120 participants, very low quality evidence). No thromboembolic events occurred for participants treated with TPO mimetics or control at 30 days (two trials, 209 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed or quality of life.One trial with 18 participants compared platelet-poor plasma transfusion with platelet transfusion. We are very uncertain whether platelet-poor plasma reduces the number of participants with any bleeding episode (OR 16.00, 95% CI 1.32 to 194.62, one trial, 18 participants, very low quality evidence). We are very uncertain whether platelet-poor plasma reduces the number of participants with severe or life-threatening bleeding (OR 4.00, 95% CI 0.56 to 28.40, one trial, 18 participants, very low quality evidence). We found no trials that looked at: number of days on which bleeding occurred, time from randomisation to first bleed, number of platelet transfusions, all-cause mortality, thromboembolic events or quality of life. AUTHORS' CONCLUSIONS There is insufficient evidence to determine if platelet-poor plasma or TPO mimetics reduce bleeding for participants with haematological malignancies undergoing intensive chemotherapy or stem cell transplantation. To detect a decrease in the proportion of participants with clinically significant bleeding from 12 in 100 to 6 in 100 would require a trial containing at least 708 participants (80% power, 5% significance). The six ongoing trials will provide additional information about the TPO mimetic comparison (424 participants) but this will still be underpowered to demonstrate this level of reduction in bleeding. None of the included or ongoing trials include children. There are no completed or ongoing trials assessing artificial platelet substitutes, fibrinogen concentrate, recombinant activated factor VII or desmopressin in people undergoing intensive chemotherapy or stem cell transplantation for haematological malignancies.
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Affiliation(s)
| | - Lise J Estcourt
- NHS Blood and TransplantHaematology/Transfusion MedicineOxfordUK
| | - Carolyn Doree
- NHS Blood and TransplantSystematic Review InitiativeJohn Radcliffe HospitalOxfordUKOX3 9BQ
| | - Marialena Trivella
- University of OxfordCentre for Statistics in MedicineBotnar Research CentreWindmill RoadOxfordUKOX3 7LD
| | - Sally Hopewell
- University of OxfordOxford Clinical Trials Research UnitNuffield Department of Orthopaedics, Rheumatology and Musculoskeletal SciencesWindmill RoadOxfordOxfordshireUKOX3 7LD
| | - Simon J Stanworth
- Oxford University Hospitals NHS Foundation Trust and University of OxfordNational Institute for Health Research (NIHR) Oxford Biomedical Research CentreJohn Radcliffe Hospital, Headley WayHeadingtonOxfordUKOX3 9BQ
| | - Michael F Murphy
- Oxford University Hospitals NHS Foundation Trust and University of OxfordNHS Blood and Transplant; National Institute for Health Research (NIHR) Oxford Biomedical Research CentreJohn Radcliffe HospitalHeadingtonOxfordUK
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Fiore M, Saut N, Alessi MC, Viallard JF. Successful use of eltrombopag for surgical preparation in a patient with ANKRD26-related thrombocytopenia. Platelets 2016; 27:828-829. [PMID: 27276516 DOI: 10.1080/09537104.2016.1190446] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Mathieu Fiore
- a Laboratoire d'Hématologie, CHU de Bordeaux , Pessac , France.,b Centre de Référence des Pathologies Plaquettaires , France
| | - Noémie Saut
- b Centre de Référence des Pathologies Plaquettaires , France.,c UMR Inserm 1062, Inra 1260, Aix-Marseille Université, CHU de La Timone , Marseille , France
| | - Marie-Christine Alessi
- b Centre de Référence des Pathologies Plaquettaires , France.,c UMR Inserm 1062, Inra 1260, Aix-Marseille Université, CHU de La Timone , Marseille , France
| | - Jean-François Viallard
- d Service de Médecine Interne et Maladies Infectieuses, CHU de Bordeaux , Pessac , France
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18
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Bone marrow niche in immune thrombocytopenia: a focus on megakaryopoiesis. Ann Hematol 2016; 95:1765-76. [PMID: 27236577 DOI: 10.1007/s00277-016-2703-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 05/23/2016] [Indexed: 12/18/2022]
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by increased bleeding tendency and thrombocytopenia. In fact, the precise pathogenesis of this disease is still not clear. Megakaryopoiesis involves complete differentiation of megakaryocyte (MK) progenitors to functional platelets. This complex process occurs in specific bone marrow (BM) niches composed of several hematopoietic and non-hematopoietic cell types, soluble factors, and extracellular matrix proteins. These specialized microenvironments sustain MK maturation and localization to sinusoids as well as platelet release into circulation. However, MKs in ITP patients show impaired maturation and signs of degradation. Intrinsic defects in MKs and their extrinsic environment have been implicated in altered megakaryopoiesis in this disease. In particular, aberrant expression of miRNAs directing MK proliferation, differentiation, and platelet production; defective MK apoptosis; and reduced proliferation and differentiation rate of the MSC compartment observed in these patients may account for BM defects in ITP. Furthermore, insufficient production of thrombopoietin is another likely reason for ITP development. Therefore, identifying the signaling pathways and transcription factors influencing the interaction between MKs and BM niche in ITP patients will contribute to increased platelet production in order to prevent incomplete MK maturation and destruction as well as BM fibrosis and apoptosis in ITP. In this review, we will examine the interaction and role of BM niches in orchestrating megakaryopoiesis in ITP patients and discuss how these factors can be exploited to improve the quality of patient treatment and prognosis.
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19
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Thromboembolism in patients with immune thrombocytopenia (ITP): a meta-analysis of observational studies. Int J Hematol 2016; 103:655-64. [DOI: 10.1007/s12185-016-1974-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 02/07/2023]
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20
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Balduini A, Di Buduo CA, Kaplan DL. Translational approaches to functional platelet production ex vivo. Thromb Haemost 2015; 115:250-6. [PMID: 26353819 DOI: 10.1160/th15-07-0570] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/11/2015] [Indexed: 12/13/2022]
Abstract
Platelets, which are released by megakaryocytes, play key roles in haemostasis, angiogenesis, immunity, tissue regeneration and wound healing. The scarcity of clinical cures for life threatening platelet diseases is in a large part due to limited insight into the mechanisms that control the developmental process of megakaryocytes and the mechanisms that govern the production of platelets within the bone marrow. To overcome these limitations, functional human tissue models have been developed and studied to extrapolate ex vivo outcomes for new insight on bone marrow functions in vivo. There are many challenges that these models must overcome, from faithfully mimicking the physiological composition and functions of bone marrow, to the collection of the platelets generated and validation of their viability and function for human use. The overall goal is to identify innovative instruments to study mechanisms of platelet release, diseases related to platelet production and new therapeutic targets starting from human progenitor cells.
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Affiliation(s)
- Alessandra Balduini
- Alessandra Balduini, Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA, Tel.: +1 617 627 2580, Fax: +1 617 627 3231, E-mail:
| | | | - David L Kaplan
- David L. Kaplan, Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA, Tel.: +1 617 627 2580, Fax: +1 617 627 3231, E-mail:
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21
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Pecci A. Diagnosis and treatment of inherited thrombocytopenias. Clin Genet 2015; 89:141-53. [PMID: 25920516 DOI: 10.1111/cge.12603] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/23/2015] [Accepted: 04/23/2015] [Indexed: 12/26/2022]
Abstract
Knowledge in the field of inherited thrombocytopenias (ITs) has greatly improved over the last 15 years. Several new genes responsible for thrombocytopenia have been identified leading to the definition of novel nosographic entities and to a much better characterization of the phenotypes of these diseases. To date, ITs encompass 22 disorders caused by mutations in 24 genes and characterized by different degrees of complexity and great variability in prognosis. Making a definite diagnosis is important for setting an appropriate follow-up, choosing the best treatments and providing proper counseling. Despite the abovementioned progress, diagnosis of ITs remains difficult and these disorders are still underdiagnosed. The purpose of this review is to provide an updated guide to the diagnosis of ITs based on simple procedures. Moreover, the currently available therapeutic options for these conditions are recapitulated and discussed.
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Affiliation(s)
- A Pecci
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation and University of Pavia, Pavia, Italy
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22
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Tronik-Le Roux D, Nicola MA, Vaigot P, Nurden P. Single thrombopoietin dose alleviates hematopoietic stem cells intrinsic short- and long-term ionizing radiation damage. In vivo identification of anatomical cell expansion sites. Radiat Res 2015; 183:52-63. [PMID: 25564715 DOI: 10.1667/rr13742.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hematopoietic stem cells (HSC) are essential for maintaining the integrity of complex and long-lived organisms. HSC, which are self-renewing, reconstitute the hematopoietic system through out life and facilitate long-term repopulation of myeloablated recipients. We have previously demonstrated that when mice are exposed to sublethal doses of ionizing radiation, subsets of the stem/progenitor compartment are affected. In this study we examine the role of thrombopoietin (TPO) on the regenerative capacities of HSC after irradiation and report the first demonstration of efficacy of a single injection of TPO shortly after in vivo exposure to ionizing radiation for reducing HSC injury and improving their functional outcome. Our results demonstrate that TPO treatment not only reduced the number of apoptotic cells but also induced a significant modification of their intrinsic characteristics. These findings were supported by transplantation assays with long-term HSC that were irradiated or unirradiated, TPO treated or untreated, in CD45.1/CD45.2 systems and by using luciferase-labeled HSC for direct bioluminescence imaging in living animals. Of particular importance, our data demonstrate the skull to be a highly favorable site for the TPO-induced emergence of hematopoietic cells after irradiation, suggesting a TPO-mediated relationship of primitive hematopoietic cells to an anatomical component. Together, the data presented here: provide novel findings about aspects of TPO action on stem cells, open new areas of investigation for therapeutic options in patients who are treated with radiation therapy, and show that early administration of a clinically suitable TPO-agonist counteracts the previously observed adverse effects.
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Affiliation(s)
- Diana Tronik-Le Roux
- a CEA, SRHI, Institute of Emerging Diseases and Innovative Therapies (iMETI), 75010 Paris, France
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23
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Mitchell WB, Pinheiro MP, Boulad N, Kaplan D, Edison MN, Psaila B, Karpoff M, White MJ, Josefsson EC, Kile BT, Bussel JB. Effect of thrombopoietin receptor agonists on the apoptotic profile of platelets in patients with chronic immune thrombocytopenia. Am J Hematol 2014; 89:E228-34. [PMID: 25132654 DOI: 10.1002/ajh.23832] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/11/2014] [Accepted: 08/12/2014] [Indexed: 11/11/2022]
Abstract
Platelet survival depends upon mediators of apoptosis e.g., Bcl-xL, Bax, and Bak, which are regulated by thrombopoietin (TPO)-mediated AKT signaling. Thrombopoietin receptor (TPO-R) signaling might decrease platelet and/or megakaryocyte apoptosis and increase the platelet count. This study therefore explored anti-apoptotic effects of TPO-R-agonists in vivo on platelets of patients with immune thrombocytopenia. Patients received eltrombopag or romiplostim for two weeks. Total, immature, and large platelet counts were assessed as were Bcl-xL inhibitor assay; Bcl-xL Western blot; and flow cytometric (FACS) analysis of the AKT-signaling pathway. Eight/ten patients had platelet responses to eltrombopag and all three to romiplostim. Platelet sensitivity to apoptosis by Bcl-xL inhibition was greater in pretreatment patients than controls. This sensitivity normalized after one week of therapy, but surprisingly returned to pretreatment levels at week two. FACS analysis revealed increased AKT-pathway signaling after one week, followed by a decrease at week two. Platelet counts correlated with the Bcl-xL /Bak ratio. Platelet survival may be enhanced by TPO-R-agonists as a transient decrease in platelet sensitivity to apoptosis was accompanied by transient activation of AKT. However, this mechanism has only a short-lived effect. Megakaryocytes and platelets already present at the start of TPO-R-agonist treatment appear to respond differently than those generated de novo.
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Affiliation(s)
- William Beau Mitchell
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
- Laboratory of Platelet Biology; New York Blood Center; New York New York
| | - Mariana P. Pinheiro
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
| | - Nayla Boulad
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
| | | | - Michele N. Edison
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
| | - Bethan Psaila
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
- Department of Haematology; Hammersmith Hospital, Imperial College London; London United Kingdom
| | - Marissa Karpoff
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
| | - Michael J. White
- The Walter and Eliza Hall Institute of Medical Research; Parkville Australia
| | - Emma C. Josefsson
- The Walter and Eliza Hall Institute of Medical Research; Parkville Australia
| | - Benjamin T. Kile
- The Walter and Eliza Hall Institute of Medical Research; Parkville Australia
| | - James B. Bussel
- Division of Pediatric Hematology/Oncology; Weill Cornell Medical College; New York New York
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Mihăilă RG, Cipăian RC. Eltrombopag in chronic hepatitis C. World J Gastroenterol 2014; 20:12517-12521. [PMID: 25253952 PMCID: PMC4168085 DOI: 10.3748/wjg.v20.i35.12517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 04/09/2014] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis C is a public health problem worldwide. Unfortunately, not all patients may benefit from antiviral therapy due to thrombocytopenia. Its causes are represented by portal hypertension and platelet sequestration in the spleen, decreased serum levels or activity of thrombopoietin, the bone marrow suppression induced by hepatitis C virus and a possible adverse effect of interferon. Thrombopoietin receptor analogs may contribute to increase platelet counts in these patients. Eltrombopag binds to another region of the thrombopoietin receptor compared to endogenous thrombopoietin and stimulates the proliferation and maturation of megakaryocytes and the platelet production in a dose-dependent manner. Eltrombopag has proven its effectiveness for the treatment of patients with primary immune thrombocytopenia. Its indication for other hemopathies or situations (like thrombocytopenia secondary to chemo- or radiotherapy, acute leukemia, myelodysplastic syndroms, acquired and hereditary bone marrow failure, and platelet donors) is under study. Eltrombopag may be particularly useful in patients with advanced chronic hepatitis or liver cirrhosis who require antiviral treatment. We present a minireview on the results of treatment with eltrombopag in patients chronically infected with hepatitis C virus, highlighting the benefits and mentioning possible adverse effects. In some studies eltrombopag increased the number of virological responses after clasical antiviral treatment of patients with chronic hepatitis C and reduced the transfusional requirements of those who had to be subjected to invasive surgery. Eltrombopag is a solution for many of these patients, which allows them receiving antiviral therapy and sometimes getting a sustained virological response, but they must be well monitored to prevent possible thromboembolic or bone marrow complications or liver failure occurrence.
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Autoimmune and other cytopenias in primary immunodeficiencies: pathomechanisms, novel differential diagnoses, and treatment. Blood 2014; 124:2337-44. [PMID: 25163701 DOI: 10.1182/blood-2014-06-583260] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autoimmunity and immune dysregulation may lead to cytopenia and represent key features of many primary immunodeficiencies (PIDs). Especially when cytopenia is the initial symptom of a PID, the order and depth of diagnostic steps have to be performed in accordance with both an immunologic and a hematologic approach and will help exclude disorders such as systemic lupus erythematosus, common variable immunodeficiency, and autoimmune lymphoproliferative syndromes, hemophagocytic disorders, lymphoproliferative diseases, and novel differential diagnoses such as MonoMac syndrome (GATA2 deficiency), CD27 deficiency, lipopolysaccharide-responsive beige-like anchor (LRBA) deficiency, activated PI3KD syndrome (APDS), X-linked immunodeficiency with magnesium defect (MAGT1 deficiency), and others. Immunosuppressive treatment often needs to be initiated urgently, which impedes further relevant immunologic laboratory analyses aimed at defining the underlying PID. Awareness of potentially involved disease spectra ranging from hematologic to rheumatologic and immunologic disorders is crucial for identifying a certain proportion of PID phenotypes and genotypes among descriptive diagnoses such as autoimmune hemolytic anemia, chronic immune thrombocytopenia, Evans syndrome, severe aplastic anemia/refractory cytopenia, and others. A synopsis of pathomechanisms, novel differential diagnoses, and advances in treatment options for cytopenias in PID is provided to facilitate multidisciplinary management and to bridge different approaches.
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Vlachaki E, Sousos N, Perifanis V, Kaiafa G, Onoufriadis I, Hatzitolios A, Boura P. Is there a role for low-dose eltrombopag as maintenance therapy in the treatment of immune thrombocytopenia? Acta Haematol 2014; 133:78-82. [PMID: 25170628 DOI: 10.1159/000361075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 03/05/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND/AIM Thrombopoietin receptor agonists (romiplostim and eltrombopag) have recently been licensed for the treatment of thrombocytopenia in patients with chronic immune thrombocytopenia (ITP) with an insufficient response to corticosteroids, immunoglobulins or splenectomy. In the present case series, we present 4 nonresponding patients with chronic ITP who achieved maintenance of complete response (CR) for a period of at least 6 months on eltrombopag treatment administered in a modified regimen of 25 mg for 2, 3 or 5 days a week. METHODS The present study is a retrospective, nonconsecutive case series of 4 eltrombopag-treated patients with chronic ITP. Secondary ITP had been excluded in each patient, first-line therapy had failed and splenectomy had been refused. Furthermore, each patient was treated with eltrombopag, which resulted in a CR for a mean of 2 months. Consequently, decreased eltrombopag dosages have been able to maintain long-term CR. RESULTS/CONCLUSION Despite the low quality of evidence, our study results support the use of reduced-dose eltrombopag as a maintenance therapy after achieving CR. It seems a very promising strategy for the effective maintenance of response, improving health-related quality of life, lowering costs and possibly improving the safety in the treatment of ITP.
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Affiliation(s)
- Efthymia Vlachaki
- Hematological Laboratory, Second Department of Internal Medicine, General Hospital Hippokrateon, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Chronic myelomonocytic leukemia prognostic classification and management: evidence base and current practice. Curr Hematol Malig Rep 2014; 9:301-10. [PMID: 25142910 DOI: 10.1007/s11899-014-0225-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Chronic myelomonocytic leukemia is a clonal malignancy of the ageing hematopoietic stem cell characterized by a biased differentiation leading to persistent monocytosis and inconstant hypersensitivity of myeloid progenitors to granulo-monocyte colony-stimulating factor (GM-CSF). Cytogenetic abnormalities identified in 30-40 % of patients and gene mutations detected in every patient can be used to stratify patients into risk groups that guide the therapeutic choices. TET2, SRSF2, ASXL1, and genes of the Ras pathway are the most frequently mutated genes, with ASXL1 mutations negatively affecting the disease outcome. Allogeneic stem cell transplantation is the first option to consider, especially in younger patients with poor prognostic factors. There is no firm clinical guideline in transplant-ineligible patients, but hypomethylating agents might be an interesting option. A consensus prognostic scoring system and specific response criteria are now required to facilitate the evaluation of new therapeutic strategies in clinical trials specifically dedicated to this disease.
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Abstract
Thrombocytopenia is one of the most common hematologic disorders, characterized by an abnormally low number of platelets from multiple causes. The normal count of thrombocytes (platelets) is between 150,000 and 450,000 per microliter. The clinical expression of thrombocytopenia has broad variation from asymptomatic to life-threatening bleeding. Various syndromes and diseases are associated with thrombocytopenia. Thrombocytopenia is sometimes a first sign of hematologic malignancies, infectious diseases, thrombotic microangiopathies, and autoimmune disorders, and is also a common side effect of many medications. There are more than 200 diseases that include low number of platelets among their symptoms. A brief discussion of the most common etiologies and management of them is provided in this review.
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Affiliation(s)
- Marina Izak
- NY Presbyterian Hospital and Weill Cornell Medical College, Division of Pediatric Hematology Oncology525 East 68th Street, Payson Pavilion 695, New York, NY 10065USA
- Assaf Harofeh Medical Center, Beer YakovZerifin 70300Israel
| | - James B. Bussel
- NY Presbyterian Hospital and Weill Cornell Medical College, Division of Pediatric Hematology Oncology525 East 68th Street, Payson Pavilion 695, New York, NY 10065USA
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Zhu XJ, Shi Y, Zhang F, Yao QM, Liu YX, Shan NN, Wang D, Peng J, Xu J, Hou M. Reduced tumour necrosis factor receptor superfamily 13C inversely correlated with tumour necrosis factor superfamily 13B in patients with immune thrombocytopenia. Br J Haematol 2014; 166:783-91. [PMID: 24889407 DOI: 10.1111/bjh.12958] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 04/01/2014] [Indexed: 01/06/2023]
Affiliation(s)
- Xiao-juan Zhu
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Yan Shi
- Department of Haematology; Qilu Hospital, Shandong University; Jinan China
- The Key Laboratory of Cardiovascular Remodeling and Function Research; Chinese Ministry of Education and Chinese Ministry of Health; Jinan China
| | - Feng Zhang
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Qing-min Yao
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Yan-xia Liu
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Ning-ning Shan
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Dan Wang
- Department of Research; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Jun Peng
- Department of Haematology; Qilu Hospital, Shandong University; Jinan China
- The Key Laboratory of Cardiovascular Remodeling and Function Research; Chinese Ministry of Education and Chinese Ministry of Health; Jinan China
| | - Jian Xu
- Department of Haematology; Provincial Hospital affiliated to Shandong University; Jinan China
| | - Ming Hou
- Department of Haematology; Qilu Hospital, Shandong University; Jinan China
- The Key Laboratory of Cardiovascular Remodeling and Function Research; Chinese Ministry of Education and Chinese Ministry of Health; Jinan China
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30
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Liesveld JL, Phillips GL, Becker M, Constine LS, Friedberg J, Andolina JR, Milner LA, DeBolt J, Smudzin T, Hyrien O, Erickson-Miller CL, Johnson BM, Dawson KL, Chen Y. A phase 1 trial of eltrombopag in patients undergoing stem cell transplantation after total body irradiation. Biol Blood Marrow Transplant 2013; 19:1745-52. [PMID: 24120380 DOI: 10.1016/j.bbmt.2013.10.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 10/01/2013] [Indexed: 11/30/2022]
Abstract
Stem cell transplantation can be associated with significant periods of thrombocytopenia, necessitating platelet transfusions and contributing to the risk of bleeding. Thrombopoietin receptor agonists have been shown to enhance platelet counts in other clinical settings, and so a phase 1 clinical trial was conducted to assess the safety, pharmacokinetics, and maximum tolerated dose of once-daily eltrombopag in patients undergoing stem cell transplantation with conditioning regimens containing total body irradiation ≥400 cGy. Eltrombopag was examined at dosage levels of 75, 150, 225, and 300 mg given orally once daily for 27 days, starting at 24 to 48 hours post-transplantation. Pharmacokinetic sampling was performed over a 24-hour period after the first dose of eltrombopag, as well as during the second week of treatment (steady-state). Nineteen patients were enrolled, 15 of whom completed protocol treatments. Three patients completed each dose level up to 225 mg, and 6 completed treatment at the highest dose of 300 mg. Four patients were replaced because drug compliance was <75% of planned doses. No dose-limiting toxicities were observed in this heterogeneous post-transplantation patient population. Common adverse events were related to standard stem cell transplantation. One episode of pulmonary embolus occurred 9 days after discontinuation of eltrombopag, and the only other thromboembolic episode was a grade 2 catheter-related clot. We conclude that up to 27 days of once-daily dosing of eltrombopag after stem cell transplantation is well tolerated.
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Affiliation(s)
- Jane L Liesveld
- Department of Medicine, Hematology/Oncology Division, University of Rochester Medical Center, Rochester, New York
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31
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Wörmann B. Clinical indications for thrombopoietin and thrombopoietin-receptor agonists. Transfus Med Hemother 2013; 40:319-25. [PMID: 24273485 PMCID: PMC3822275 DOI: 10.1159/000355006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 08/14/2013] [Indexed: 12/16/2022] Open
Abstract
Thrombocytopenia is a common hematologic disorder. Stimulation of thrombopoiesis may reduce the risk for thrombocytopenia-induced bleeding, prevent severe thrombocytopenia, and reduce the need for platelet transfusion. The key cytokine is thrombopoietin (TPO). It regulates proliferation and maturation of megakaryocytes as well as platelet production. TPO is synthesized in the liver. Development of TPO from the laboratory into a therapeutic tool has turned out to be an unexpected challenge. Clinical trials on first-generation thrombopoietic growth factors were stopped in 2001. At present, second-generation thrombopoiesis-stimulating agents have only been approved as orphan drugs for third-line therapy of patients with chronic immune thrombocytopenia. Larger groups in need are patients with myelodysplastic syndrome, chemotherapy-induced thrombocytopenia, other forms of hereditary and acquired bone marrow failure, hepatitis C infections, or liver cirrhosis.
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Affiliation(s)
- Bernhard Wörmann
- Medizinische Klinik mit Schwerpunkt Hämatologie, Onkologie und Tumorbiologie, Ambulantes Gesundheitszentrum, Charité Universitätsmedizin Berlin – Campus Virchow Klinikum, Berlin, Germany
- Deutsche Gesellschaft für Hämatologie und Medizinische Onkologie, Berlin, Germany
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32
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Pecci A. Pathogenesis and management of inherited thrombocytopenias: rationale for the use of thrombopoietin-receptor agonists. Int J Hematol 2013; 98:34-47. [PMID: 23636669 DOI: 10.1007/s12185-013-1351-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 04/18/2013] [Accepted: 04/19/2013] [Indexed: 12/30/2022]
Abstract
Knowledge in the field of inherited thrombocytopenias (ITs) has considerably improved over the recent years. In the last 5 years, nine new genes whose mutations are responsible for thrombocytopenia have been identified, and this also led to the recognition of several novel nosographic entities, such as thrombocytopenias deriving from mutations in CYCS, TUBB1, FLNA, ITGA2B/ITGB3, ANKRD26 and ACTN1. The identification of novel molecular alterations causing thrombocytopenia together with improvement of methodologies to study megakaryopoiesis led to considerable advances in understanding pathophysiology of ITs, thus providing the background for proposing new treatments. Thrombopoietin-receptor agonists (TPO-RAs) represent an appealing therapeutic hypothesis for ITs and have been tested in a limited number of patients. In this review, we provide an updated description of pathogenetic mechanisms of thrombocytopenia in the different forms of ITs and recapitulate the current management of these disorders. Moreover, we report the available clinical and preclinical data about the role of TPO-RAs in ITs and discuss the rationale for the use of these molecules in view of pathogenesis of the different forms of thrombocytopenia of genetic origin.
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Affiliation(s)
- Alessandro Pecci
- Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation, University of Pavia, Piazzale Golgi, 27100 Pavia, Italy.
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Deutsch VR, Tomer A. Advances in megakaryocytopoiesis and thrombopoiesis: from bench to bedside. Br J Haematol 2013; 161:778-93. [PMID: 23594368 DOI: 10.1111/bjh.12328] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Megakaryocytopoiesis involves the commitment of haematopoietic stem cells, proliferation and terminal differentiation of megakaryocytic progenitors (MK-p) and maturation of megakaryocytes (MKs) to produce functional platelets. This complex process occurs in specialized niches in the bone marrow where MKs align adjacent to vascular endothelial cells, form proplatelet projections and release platelets into the circulation. Thrombopoietin (THPO, TPO) is the primary growth factor for the MK lineage and necessary at all stages of development. THPO is constitutively produced in the liver, and binds to MPL (c-Mpl) receptor on platelets and MKs. This activates a cascade of signalling molecules, which induce transcription factors to drive MK development and thrombopoiesis. Decreased turnover rate and platelet number result in increased levels of free THPO, which induces a concentration-dependent compensatory response of marrow-MKs to enhance platelet production. Newly developed thrombopoietic agents operating via MPL receptor facilitate platelet production in thrombocytopenic states, primarily immune thrombocytopenia. Other drugs are available for attenuating malignant thrombocytosis. Herein, we review the regulation of megakaryocytopoiesis and platelet production in normal and disease states, and the innovative drugs and therapeutic modalities to stimulate or decrease thrombopoiesis.
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Affiliation(s)
- Varda R Deutsch
- The Haematology Institute, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
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