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Li W, Bai Z, Liu J, Tang Y, Yin C, Jin M, Mu L, Li X. Mitochondrial ROS-dependent CD4 +PD-1 +T cells are pathological expansion in patients with primary immune thrombocytopenia. Int Immunopharmacol 2023; 122:110597. [PMID: 37413931 DOI: 10.1016/j.intimp.2023.110597] [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: 04/19/2023] [Revised: 06/23/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023]
Abstract
OBJECTIVE Aberrant-activated T cells, especially CD4+T cells, play a crucial part in the pathogenetic progress of immune thrombocytopenia (ITP). PD-1-mediated signals play a negative part in the activation of CD4+T cells. However, knowledge is limited on the pathogenic characteristics and function of CD4+PD-1+T cells in ITP. MATERIALS AND METHODS The frequency and phenotype including cell activation, apoptosis, and cytokine production of CD4+PD-1+T cells were evaluated by flow cytometry. PD-1 Ligation Assay was performed to assess the function of PD-1 pathway in CD4+T cells. Mitochondrial reactive oxygen species (mtROS) were detected by MitoSOX Red probe. RESULTS Compared with healthy controls (HC), the frequencies of CD4+PD-1+T cells were significantly increased in ITP patients. However, these cells are not exhausted despite PD-1 expression. Besides retaining cytokine-producing potential, these CD4+PD-1+T cells also had a possible B-cell helper function including expressing ICOS, CD84, and CD40L. Moreover, the CD4+PD-1+T cell subset contained higher levels of mitochondrial ROS than CD4+PD-1-T cell subset in patients with ITP. And mtROS inhibition could reduce the secretion of the inflammatory cytokines and regulate the function of CD4+PD-1+T cells. Upon in-vitro T cell receptor (TCR) stimulation of CD4+T cells in the presence of plate-bound PD-L1 fusion protein (PD-L1-Ig), CD4+T cells from ITP patients appeared resistant to such PD-1-mediated inhibition of interferon (IFN)-γ secretion. CONCLUSIONS The CD4+PD-1+T cells were more abundant in patients with ITP. Additionally, this CD4+PD-1+T cell subset may be a potential etiology of ITP and a potential immune therapeutic target for ITP patients in the future.
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Affiliation(s)
- Weiping Li
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China; Department of Hematology, Second Hospital of Dalian Medical University, Liaoning, China
| | - Ziran Bai
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China
| | - Jiaqing Liu
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China
| | - Yawei Tang
- Department of Clinical Laboratory, Second Hospital of Dalian Medical University, Liaoning, China
| | - Chunlai Yin
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China
| | - Minli Jin
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China
| | - Lijun Mu
- Department of Hematology, Second Hospital of Dalian Medical University, Liaoning, China.
| | - Xia Li
- Department of Immunology, College of Basic Medical Science, Dalian Medical University, Liaoning, China.
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Aref S, El Menshawy N, Darwish A, Farag NA. Predictive Value of B reg and Serum IL-10 Concentration Levels for Acute ITP Progression to Chronic Phase. J Pediatr Hematol Oncol 2022; 44:336-341. [PMID: 35129144 DOI: 10.1097/mph.0000000000002414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 12/31/2021] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Pediatric immune thrombocytopenia (ITP) is a potentially life threating autoimmune disorder with different responses to therapy and different bleeding phenotypes in critical organs. The molecular basis for the variable response has not yet been fully elucidated. This study was designed to address the predictive value of regulatory B-cell (B reg ) count and interleukin-10 (IL-10) serum levels for acute ITP patients who progress to chronic phase. The present study included 80 children with acute ITP )38 males and 42 females (with median age of 8 years and 40 matched healthy controls. Assessment of B reg (CD19 + CD24 hi CD38 hi ) was carried out by a multicolor flowcytometry, however, IL-10 serum levels were evaluated by enzyme-linked immunosorbent assay. A significant reduction of B reg percentage and a significant increase in serum IL-10 levels were identified in children with acute ITP as compared with controls ( P <0.001 for both). Fourteen ITP patients passed to chronic phase, while 66 patients achieved remission within 6 months. The absolute B reg was significantly lower, while IL-10 was significantly higher in patients with acute ITP who progressed to chronic phase in comparison with acute ITP patients who achieved complete remission. Cox proportional hazards for ITP chronicity revealed that IL-10 OR was 2.46 (confidence interval: 1.42-4.27; P =0.001) and absolute B reg OR was 0.147 (confidence interval: 0.128-0.624; P =0.005) in the peripheral blood. Therefore, they could predict chronicity in ITP cases. CONCLUSION Reduced B reg count and elevated IL-10 levels in patients with acute ITP at diagnosis can predict chronicity.
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Affiliation(s)
- Salah Aref
- Hematology Unit, Department of Clinical Pathology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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Youssef MAM, Salah Eldin EM, Osman NS. Revolution of Disturbed Bregs and Bmems Lymphocytes Homeostasis in Children With Chronic ITP After High-dose Dexamethasone Rescue Therapy. J Pediatr Hematol Oncol 2022; 44:e96-e100. [PMID: 33974586 DOI: 10.1097/mph.0000000000002160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/04/2021] [Indexed: 11/26/2022]
Abstract
SUMMARY Dexamethasone is approved as second-line therapy in pediatric chronic immune thrombocytopenic purpura (ITP). Several B-cell abnormalities have been described in ITP pathogenesis.This study assessed the effects of high-dose dexamethasone (HD-DXM) on the percentages and absolute counts of CD19+CD24hiCD38hi regulatory (Bregs) and CD19+CD27+ memory B lymphocytes (Bmems) in children with chronic ITP during active bleeding.The study was a prospective case-control, included 20 children with chronic ITP and uncontrolled bleeding. Children received a single daily dose of HD-DXM for 4 days. Blood samples were withdrawn from patients just before HD-DXM therapy and on day 5 to evaluate the platelet counts and flow cytometric analysis of Bregs and Bmem. The patients' platelet counts significantly increased after 5 days of the initiation of therapy (P=0.0001). Bmems percentage and absolute counts were significantly higher in patients before treatment (P=0.0007), and decreased after HD-DXM therapy (P=0.97) compared with the controls. Bregs percentage and absolute counts were significantly lower before treatment (P=0.0003) and increased after HD-DXM (P=0.003). There is a negative correlation between platelet counts and Bregs percentage and absolute count Bmems percentage before and after HD-DXM, whereas a positive correlation between platelets and Bregs before and after dexamethasone has been reported. CONCLUSIONS HD-DXM reestablishes the normal Bregs/Bmems balance. This finding discloses possible involvement of Bregs and Bmems in the pathogenesis of pediatric ITP and provides a novel vision for immune modulation and treatment perspectives.
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Affiliation(s)
| | | | - Naglaa S Osman
- Children's Hospital, Immunology Unit, Faculty of Medicine, Assiut University, Assiut, Egypt
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Abnormalities of bone marrow B cells and plasma cells in primary immune thrombocytopenia. Blood Adv 2021; 5:4087-4101. [PMID: 34507351 PMCID: PMC8945629 DOI: 10.1182/bloodadvances.2020003860] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 06/27/2021] [Indexed: 12/12/2022] Open
Abstract
The disrupted B-cell subsets and compromised immunosuppressive function of regulatory B cells are found in the BM of patients with ITP. The abnormally expressed cytokines and their receptors on B cells contribute to the imbalance of BM B-cell subpopulations in ITP.
Primary immune thrombocytopenia (ITP) is an autoantibody-mediated hemorrhagic disorder in which B cells play an essential role. Previous studies have focused on peripheral blood (PB), but B cells in bone marrow (BM) have not been well characterized. We aimed to explore the profile of B-cell subsets and their cytokine environments in the BM of patients with ITP to further clarify the pathogenesis of the disease. B-cell subpopulations and their cytokine/chemokine receptors were detected by using flow cytometry. Plasma concentrations of cytokines/chemokines were measured by using enzyme-linked immunosorbent assay. Messenger RNA levels of B cell–related transcription factors were determined by using quantitative polymerase chain reaction. Regulatory B cell (Breg) function was assessed by quantifying their inhibitory effects on monocytes and T cells in vitro. Decreased proportions of total B cells, naive B cells, and defective Bregs were observed in patients with ITP compared with healthy controls (HCs), whereas an elevated frequency of long-lived plasma cells was found in BM of autoantibody-positive patients. No statistical difference was observed in plasmablasts or in short-lived plasma cells between patients with ITP and HCs. The immunosuppressive capacity of BM Bregs from patients with ITP was considerably weaker than HCs. An in vivo study using an active ITP murine model revealed that Breg transfusion could significantly alleviate thrombocytopenia. Moreover, overactivation of CXCL13-CXCR5 and BAFF/APRIL systems were found in ITP patient BM. Taken together, B-cell subsets in BM were skewed toward a proinflammatory profile in patients with ITP, suggesting the involvement of dysregulated BM B cells in the development of the disease.
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Potential Diagnostic Approaches for Prediction of Therapeutic Responses in Immune Thrombocytopenia. J Clin Med 2021; 10:jcm10153403. [PMID: 34362187 PMCID: PMC8347743 DOI: 10.3390/jcm10153403] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/13/2022] Open
Abstract
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder in which, via unresolved mechanisms, platelets and megakaryocytes (MKs) are targeted by autoantibodies and/or T cells resulting in increased platelet destruction and impairment of MK function. Over the years, several therapeutic modalities have become available for ITP, however, therapeutic management has proven to be very challenging in several cases. Patients refractory to treatment can develop a clinically worsening disease course, treatment-induced toxicities and are predisposed to development of potentially life-endangering bleedings. It is therefore of critical importance to timely identify potential refractory patients, for which novel diagnostic approaches are urgently needed in order to monitor and predict specific therapeutic responses. In this paper, we propose promising diagnostic investigations into immune functions and characteristics in ITP, which may potentially be exploited to help predict platelet count responses and thereby distinguish therapeutic responders from non-responders. This importantly includes analysis of T cell homeostasis, which generally appears to be disturbed in ITP due to decreased and/or dysfunctional T regulatory cells (Tregs) leading to loss of immune tolerance and initiation/perpetuation of ITP, and this may be normalized by several therapeutic modalities. Additional avenues to explore in possible prediction of therapeutic responses include examination of platelet surface sialic acids, platelet apoptosis, monocyte surface markers, B regulatory cells and platelet microparticles. Initial studies have started evaluating these markers in relation to response to various treatments including glucocorticosteroids (GCs), intravenous immunoglobulins (IVIg) and/or thrombopoietin receptor agonists (TPO-RA), however, further studies are highly warranted. The systematic molecular analysis of a broad panel of immune functions may ultimately help guide and improve personalized therapeutic management in ITP.
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Semple JW, Rebetz J, Maouia A, Kapur R. An update on the pathophysiology of immune thrombocytopenia. Curr Opin Hematol 2021; 27:423-429. [PMID: 32868673 DOI: 10.1097/moh.0000000000000612] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
: Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder mediated by antiplatelet autoantibodies and antigen-specific T cells that either destroy platelets peripherally in the spleen or impair platelet production in the bone marrow. There have been a plethora of publications relating to the pathophysiology of ITP and since January of 2019, at least 50 papers have been published on ITP pathophysiology. PURPOSE OF REVIEW To summarize the literature relating to the pathophysiology of ITP including the working mechanisms of therapies, T-cell and B-cell physiology, protein/RNA/DNA biochemistry, and animal models in an attempt to unify the perceived abnormal immune processes. RECENT FINDINGS The most recent pathophysiologic irregularities associated with ITP relate to abnormal T-cell responses, particularly, defective T regulatory cell activity and how therapeutics can restore these responses. The robust literature on T cells in ITP points to the notion that ITP is a disease initiated by faulty self-tolerance mechanisms very much like that of other organ-specific autoimmune diseases. There is also a large literature on new and existing animal models of ITP and these will be discussed. It appears that understanding how to specifically modulate T cells in patients with ITP will undoubtedly lead to effective antigen-specific therapeutics. CONCLUSIONS ITP is predominately a T cell disorder which leads to a breakdown in self tolerance mechanisms and allows for the generation of anti-platelet autoantibodies and T cells. Novel therapeutics that target T cells may be the most effective way to perhaps cure this disorder.
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Affiliation(s)
- John W Semple
- Division of Hematology and Transfusion Medicine, Lund University.,Clinical Immunology and Transfusion Medicine, Office of Medical Services, Region Skåne, Lund, Sweden
| | - Johan Rebetz
- Division of Hematology and Transfusion Medicine, Lund University
| | - Amal Maouia
- Division of Hematology and Transfusion Medicine, Lund University
| | - Rick Kapur
- Sanquin Research, Department of Experimental Immunohematology, Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Lin X, Xu A, Zhou L, Zhao N, Zhang X, Xu J, Feng S, Zheng C. Imbalance of T Lymphocyte Subsets in Adult Immune Thrombocytopenia. Int J Gen Med 2021; 14:937-947. [PMID: 33776472 PMCID: PMC7989055 DOI: 10.2147/ijgm.s298888] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/08/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Primary immune thrombocytopenia (ITP) is defined as an acquired autoimmune disease characterized by isolated thrombocytopenia. This work is to further clarify the relationship between T cell immune dysfunction and the pathogenesis of ITP. METHODS 37 adult patients with ITP were selected and were classified into newly diagnosed ITP (nITP, n = 13), persistent ITP (pITP, n = 6) and chronic ITP (cITP n = 18). The frequency of cytotoxic T lymphocytes (Tc1, Tc2, and Tc17) and helper T cells (Th1, Th2, and Th17), Tregs, and the expression of chemokine receptors and PD-1 on CD4+ T cells were investigated by flow cytometry. Plasma levels of T cell-related cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, IL-17) were measured by cytometric beads array (CBA). RESULTS The percentage of Tc1 in cITP was greatly higher than nITP and healthy controls (p < 0.05, p < 0.01). The percentage of Treg in nITP and cITP groups was remarkably lower than those in healthy control group (p < 0.05, p < 0.001); and according to platelet count analysis (PLT<50x109/L or PLT>50x109/L), Treg cells in ITP group were significantly lower than those in healthy control group (p < 0.001, p < 0.05). The percentage of CD4+CXCR3+ of cITP was significantly higher than healthy controls and nITP (p < 0.01, p < 0.05). The percentage of CD4+CCR6+ in cITP was significantly higher than healthy controls and nITP (p < 0.001, p < 0.05). The expression of PD-1 in cITP patients was higher than healthy control (p < 0.05), but there was no significant difference among nITP, pITP and cITP (p = 0.25). The levels of IL-2, IFN-γ and TNFα in nITP group and cITP group were significantly higher than those in healthy control group (p < 0.01, p < 0.05; p < 0.01, p < 0.05; p < 0.05, p < 0.05), and the level of IL-10 in nITP group was significantly higher than that in pITP group (p < 0.05). CONCLUSION Our results suggest that T lymphocyte immune dysfunction does exist in adult ITP patients and plays an important role in the pathogenesis of ITP.
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Affiliation(s)
- Xiuxiu Lin
- Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Anhui Xu
- Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Li Zhou
- Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Na Zhao
- Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Xinhui Zhang
- Department of Hematology, Anhui Provincial Hospital, Anhui Medical University, Hefei, People’s Republic of China
| | - Jin Xu
- Wannan Medical College, Wuhu, People’s Republic of China
| | - Shanglong Feng
- Department of Hematology, Anhui Provincial Hospital, Anhui Medical University, Hefei, People’s Republic of China
| | - Changcheng Zheng
- Department of Hematology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
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Cellular immune dysregulation in the pathogenesis of immune thrombocytopenia. Blood Coagul Fibrinolysis 2020; 31:113-120. [PMID: 31977328 DOI: 10.1097/mbc.0000000000000891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
: Immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease characterized by immune-mediated increased platelet destruction and decreased platelet production, resulting from immune intolerance to autoantigen. The pathogenesis of ITP remains unclear, although dysfunction of T and B lymphocytes has been shown to be involved in the pathogenesis of ITP. More recently, it is found that dendritic cells, natural killer, and myeloid-derived suppressor cells also play an important role in ITP. Elucidating its pathogenesis is expected to provide novel channels for the targeted therapy of ITP. This article will review the role of different immune cells in ITP.
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