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Mendoza A, Álvarez-Román MT, Monzón-Manzano E, Acuña P, Arias-Salgado EG, Rivas-Pollmar I, Martín-Salces M, Martínez de Miguel B, Martínez Montalbán E, Jiménez-Yuste V, Butta N. Study of platelet kinetics in immune thrombocytopenia to predict splenectomy response. Br J Haematol 2024; 204:315-323. [PMID: 37822168 DOI: 10.1111/bjh.19145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/12/2023] [Accepted: 09/05/2023] [Indexed: 10/13/2023]
Abstract
Despite the efficacy of splenectomy for chronic immune thrombocytopenia (ITP), its considerable failure rate and its possible related complications prove the need for further research into potential predictors of response. The platelet sequestration site determined by 111 In-labelled autologous platelet scintigraphy has been proposed to predict splenectomy outcome, but without standardisation in clinical practice. Here, we conducted a single-centre study by analysing a cohort of splenectomised patients with ITP in whom 111 In-scintigraphy was performed at La Paz University Hospital in Madrid to evaluate the predictive value of the platelet kinetic studies. We also studied other factors that could impact the splenectomy outcome, such as patient and platelet characteristics. A total of 51 patients were splenectomised, and 82.3% responded. The splenic sequestration pattern predicted a higher rate of complete response up to 12 months after splenectomy (p = 0.005), with 90% sensitivity and 77% specificity. Neither age, comorbidities, therapy lines nor previous response to them showed any association with response. Results from the platelet characteristics analysis revealed a significant loss of sialic acid in platelets from the non-responding patients compared with those who maintained a response (p = 0.0017). Our findings highlight the value of splenic sequestration as an independent predictor of splenectomy response.
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Affiliation(s)
- Ana Mendoza
- Department of Haematology, La Paz University Hospital, Madrid, Spain
| | - María Teresa Álvarez-Román
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
- Autonomous University of Madrid, Madrid, Spain
| | - Elena Monzón-Manzano
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Paula Acuña
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Elena G Arias-Salgado
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Isabel Rivas-Pollmar
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Mónica Martín-Salces
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
| | | | | | - Víctor Jiménez-Yuste
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
- Autonomous University of Madrid, Madrid, Spain
| | - Nora Butta
- Department of Haematology, La Paz University Hospital, Madrid, Spain
- IdiPAZ, Madrid, Spain
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2
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Norris PAA, Tawhidi Z, Sachs UJ, Cserti-Gazdewich CM, Lin Y, Callum J, Gil Gonzalez L, Shan Y, Branch DR, Lazarus AH. Serum from half of patients with immune thrombocytopenia trigger macrophage phagocytosis of platelets. Blood Adv 2023; 7:3561-3572. [PMID: 37042934 PMCID: PMC10368862 DOI: 10.1182/bloodadvances.2022009423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/21/2023] [Accepted: 04/05/2023] [Indexed: 04/13/2023] Open
Abstract
Humoral antiplatelet factors, such as autoantibodies, are thought to primarily clear platelets by triggering macrophage phagocytosis in immune thrombocytopenia (ITP). However, there are few studies characterizing the capacity and mechanisms of humoral factor-triggered macrophage phagocytosis of platelets using specimens from patients with ITP. Here, we assessed sera from a cohort of 24 patients with ITP for the capacity to trigger macrophage phagocytosis of normal donor platelets and characterized the contribution of humoral factors to phagocytosis. Sera that produced a phagocytosis magnitude greater than a normal human serum mean + 2 standard deviations were considered phagocytosis-positive. Overall, 42% (8/19) of MHC I alloantibody-negative ITP sera were phagocytosis-positive. The indirect monoclonal antibody immobilization of platelet antigens assay was used to detect immunoglobulin G (IgG) autoantibodies to glycoproteins (GP)IIb/IIIa, GPIb/IX, and GPIa/IIa. Autoantibody-positive sera triggered a higher mean magnitude of phagocytosis than autoantibody-negative sera. Phagocytosis correlated inversely with platelet counts among autoantibody-positive patients but not among autoantibody-negative patients. Select phagocytosis-positive sera were separated into IgG-purified and -depleted fractions via protein G and reassessed for phagocytosis. Phagocytosis was largely retained in the purified IgG fractions. In addition, we assessed serum concentrations of C-reactive protein, serum amyloid P, and pentraxin 3 as potential phagocytosis modulators. Pentraxin 3 concentrations correlated inversely with platelet counts among patients positive for autoantibodies. Taken together, sera from approximately half of the patients with ITP studied triggered macrophage phagocytosis of platelets beyond a normal level. An important role for antiplatelet autoantibodies in phagocytosis is supported; a role for pentraxins such as pentraxin 3 may be suggested.
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Affiliation(s)
- Peter A. A. Norris
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
| | - Zoya Tawhidi
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
| | - Ulrich J. Sachs
- Institute for Clinical Immunology, Transfusion Medicine, and Haemostasis, Justus Liebig University, Giessen, Germany
- Department of Thrombosis and Haemostasis, Giessen University Hospital, Giessen, Germany
| | - Christine M. Cserti-Gazdewich
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Laboratory Medicine Program, University Health Network, Toronto, ON, Canada
- University of Toronto Quality in Utilization, Education and Safety in Transfusion Research Program, University of Toronto, Toronto, ON, Canada
| | - Yulia Lin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- University of Toronto Quality in Utilization, Education and Safety in Transfusion Research Program, University of Toronto, Toronto, ON, Canada
- Precision Diagnostics and Therapeutics Program, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Jeannie Callum
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- University of Toronto Quality in Utilization, Education and Safety in Transfusion Research Program, University of Toronto, Toronto, ON, Canada
- Department of Pathology and Molecular Medicine, Kingston Health Sciences Centre and Queen’s University, Kingston, ON, Canada
| | - Lazaro Gil Gonzalez
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
| | - Yuexin Shan
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
| | - Donald R. Branch
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- University of Toronto Quality in Utilization, Education and Safety in Transfusion Research Program, University of Toronto, Toronto, ON, Canada
- Department of Medicine, University of Toronto, Toronto, ON, Canada
- Division of Hematology, Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Alan H. Lazarus
- Innovation and Portfolio Management, Canadian Blood Services, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Unity Health Toronto, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
- University of Toronto Quality in Utilization, Education and Safety in Transfusion Research Program, University of Toronto, Toronto, ON, Canada
- Department of Medicine, University of Toronto, Toronto, ON, Canada
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5
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Singh A, Uzun G, Bakchoul T. Primary Immune Thrombocytopenia: Novel Insights into Pathophysiology and Disease Management. J Clin Med 2021; 10:jcm10040789. [PMID: 33669423 PMCID: PMC7920457 DOI: 10.3390/jcm10040789] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 01/19/2023] Open
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disorder defined by a significantly reduced number of platelets in blood circulation. Due to low levels of platelets, ITP is associated with frequent bruising and bleeding. Current evidence suggests that low platelet counts in ITP are the result of multiple factors, including impaired thrombopoiesis and variations in immune response leading to platelet destruction during pathological conditions. Patient outcomes as well as clinic presentation of the disease have largely been shown to be case-specific, hinting towards ITP rather being a group of clinical conditions sharing common symptoms. The most frequent characteristics include dysfunction in primary haemostasis and loss of immune tolerance towards platelet as well as megakaryocyte antigens. This heterogeneity in patient population and characteristics make it challenging for the clinicians to choose appropriate therapeutic regimen. Therefore, it is vital to understand the pathomechanisms behind the disease and to consider various factors including patient age, platelet count levels, co-morbidities and patient preferences before initiating therapy. This review summarizes recent developments in the pathophysiology of ITP and provides a comprehensive overview of current therapeutic strategies as well as potential future drugs for the management of ITP.
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Affiliation(s)
- Anurag Singh
- Institute for Clinical and Experimental Transfusion Medicine (IKET), University Hospital of Tuebingen, 72076 Tuebingen, Germany;
| | - Günalp Uzun
- Centre for Clinical Transfusion Medicine, University Hospital of Tuebingen, 72076 Tuebingen, Germany;
| | - Tamam Bakchoul
- Institute for Clinical and Experimental Transfusion Medicine (IKET), University Hospital of Tuebingen, 72076 Tuebingen, Germany;
- Centre for Clinical Transfusion Medicine, University Hospital of Tuebingen, 72076 Tuebingen, Germany;
- Correspondence: ; Tel.: +49-7071-29-81601
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