Bruton's Kinase Inhibitors for the Treatment of Immunological Diseases: Current Status and Perspectives

Translational modelling to predict human pharmacokinetics and pharmacodynamics of a Bruton's tyrosine kinase-targeted protein degrader BGB-16673

BACKGROUND AND PURPOSE

Bifunctional small molecule degraders, which link the target protein with E3 ubiquitin ligase, could lead to the efficient degradation of the target protein. BGB-16673 is a Bruton's tyrosine kinase (BTK) degrader. A translational PK/PD modelling approach was used to predict the human BTK degradation of BGB-16673 from preclinical in vitro and in vivo data.

EXPERIMENTAL APPROACH

A simplified mechanistic PK/PD model was used to establish the correlation between the in vitro and in vivo BTK degradation by BGB-16673 in a mouse model. Human and mouse species differences were compared using the parameters generated from in vitro human or mouse blood, and human or mouse serum spiked TMD-8 cells. Human PD was then predicted using the simplified mechanistic PK/PD model.

KEY RESULTS

BGB-16673 showed potent BTK degradation in mouse whole blood, human whole blood, and TMD-8 tumour cells in vitro. Furthermore, BGB-16673 showed BTK degradation in a murine TMD-8 xenograft model in vivo. The PK/PD model predicted human PD and the observed BTK degradation in clinical studies both showed robust BTK degradation in blood and tumour at clinical dose range.

CONCLUSION AND IMPLICATIONS

The presented simplified mechanistic model with reduced number of model parameters is practically easier to be applied to research projects compared with the full mechanistic model. It can be used as a tool to better understand the PK/PD behaviour for targeted protein degraders and increase the confidence when moving to the clinical stage.

Metabolic Messengers: itaconate

The metabolite itaconate has emerged as an important immunoregulator with roles in antibacterial defence, inhibition of inflammation and, more recently, as an inhibitory factor in obesity. Itaconate is one of the most upregulated metabolites in inflammatory macrophages. It is produced owing to the disturbance of the tricarboxylic acid cycle and the diversion of aconitate to itaconate via the enzyme aconitate decarboxylase 1. In immunology, initial studies concentrated on the role of itaconate in inflammatory macrophages where it was shown to be inhibitory, but this has expanded as the impact of itaconate on other cell types is starting to emerge. This review focuses on itaconate as a key immunoregulatory metabolite and describes its diverse mechanisms of action and its many impacts on the immune and inflammatory responses and in cancer. We also examine the clinical relevance of this immunometabolite and its therapeutic potential for immune and inflammatory diseases.

Targeting Bruton's tyrosine kinase (BTK) as a signaling pathway in immune-mediated diseases: from molecular mechanisms to leading treatments

Bruton's tyrosine kinase (BTK), a nonreceptor tyrosine kinase, plays a remarkable role in the transmission and amplification of extracellular signals to intracellular signaling pathways. Various types of cells use the BTK pathway to communicate, including hematopoietic cells particularly B cells and T cells. The BTK pathway plays a role in controlling the proliferation, survival, and functions of B cells as well as other myeloid cells. First, second, and third-generation BTK inhibitors are currently being evaluated for the treatment of immune-mediated diseases in addition to B cell malignancies. In this article, the available evidence on the action mechanisms of BTK inhibitors is reviewed. Then, the most recent data obtained from preclinical studies and ongoing clinical trials for the treatment of autoimmune diseases, such as pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, systemic lupus erythematosus, Sjögren's disease, rheumatoid arthritis, systemic sclerosis, multiple sclerosis, myasthenia gravis, and inflammatory diseases such as psoriasis, chronic spontaneous urticaria, atopic dermatitis, and asthma are discussed. In addition, adverse effects and complications associated with BTK inhibitors as well as factors predisposing patients to BTK inhibitors complications are discussed.

The potential of Bruton's tyrosine kinase (BTK) inhibitors in the pharmacotherapeutic management of immune and dermatological disease

INTRODUCTION

The review article explores the evolving role of Bruton's tyrosine kinase (BTK) inhibitors in immune-mediated dermatological conditions, addressing significant gaps in current treatment approaches.

AREAS COVERED

The review comprehensively discusses the mechanisms of action of BTK inhibitors, including irreversible and reversible inhibitors. Clinical applications of BTK inhibitors in dermatological diseases such as pemphigus, chronic spontaneous urticaria (CSU), hidradenitis suppurativa (HS), systemic lupus erythematosus (SLE), and atopic dermatitis are explored, highlighting recent advancements and ongoing clinical trials. Potential advantages of BTK inhibitors over existing therapies and challenges in translating preclinical findings to clinical outcomes are discussed.

EXPERT OPINION/COMMENTARY

BTK inhibitors represent a promising therapeutic avenue for immune-mediated dermatological conditions, offering oral administration, targeted pathway inhibition, and a favorable safety profile compared to biologic therapies. Ongoing research and clinical trials hold the potential to address unmet needs and reshape the therapeutic landscape in dermatology.

Treating myasthenia gravis beyond the eye clinic

Myasthenia gravis (MG) is one of the most well characterised autoimmune disorders affecting the neuromuscular junction with autoantibodies targeting the acetylcholine receptor (AChR) complex. The vast majority of patients present with ocular symptoms including double vision and ptosis, but may progress on to develop generalised fatiguable muscle weakness. Severe involvement of the bulbar muscles can lead to dysphagia, dysarthria and breathing difficulties which can progress to myasthenic crisis needing ventilatory support. Given the predominant ocular onset of the disease, it is important that ophthalmologists are aware of the differential diagnosis, investigations and management including evolving therapies. When the disease remains localised to the extraocular muscles (ocular MG) IgG1 and IgG3 antibodies against the AChR (including clustered AChR) are present in nearly 50% of patients. In generalised MG this is seen in nearly 90% patients. Other antibodies include those against muscle specific tyrosine kinase (MuSK) and lipoprotein receptor related protein 4 (LRP4). Even though decremental response on repetitive nerve stimulation is the most well recognised neurophysiological abnormality, single fibre electromyogram (SFEMG) in experienced hands is the most sensitive test which helps in the diagnosis. Initial treatment should be using cholinesterase inhibitors and then proceeding to immunosuppression using corticosteroids and steroid sparing drugs. Patients requiring bulbar muscle support may need rescue therapies including plasma exchange and intravenous immunoglobulin (IVIg). Newer therapeutic targets include those against the B lymphocytes, complement system, neonatal Fc receptors (FcRn) and various other elements of the immune system.

Therapeutic potential and recent progression of BTK inhibitors against rheumatoid arthritis

Rheumatoid arthritis (RA) is a complex chronic inflammatory illness that affects the entire physiology of human body. It has become one of the top causes of disability worldwide. The development and progression of RA involves a complex interplay between an individual's genetic background and various environmental factors. In order to effectively manage RA, a multidisciplinary approach is required, as this disease is complicated and its pathophysiological mechanism is not fully understood yet. In majority of arthritis patients, the presence of abnormal B cells and autoantibodies, primarily anti-citrullinated peptide antibodies and rheumatoid factor affects the progression of RA. Therefore, drugs targeting B cells have now become a hot topic in the treatment of RA which is quite evident from the recent trends seen in the discovery of various B cell receptors (BCRs) targeting agents. Bruton's tyrosine kinase (BTK) is one of these recent targets which play a role in the upstream phase of BCR signalling. BTK is an important enzyme that regulates the survival, proliferation, activation and differentiation of B-lineage cells by preventing BCR activation, FC-receptor signalling and osteoclast development. Several BTK inhibitors have been found to be effective against RA during the in vitro and in vivo studies conducted using diverse animal models. This review focuses on BTK inhibition mechanism and its possible impact on immune-mediated disease, along with the types of RA currently being investigated, preclinical and clinical studies and future prospective.

Bruton's tyrosine kinase inhibition for the treatment of allergic disorders

IgE signaling through its high-affinity receptor FcεRI is central to the pathogenesis of numerous allergic disorders. Oral inhibitors of Bruton's tyrosine kinase (BTKis), which are currently Food and Drug Administration-approved for treating B cell malignancies, broadly inhibit the FcεRI pathway in human mast cells and basophils, and therefore may be effective allergen-independent therapies for a variety of allergic diseases. The application of these drugs to the allergy space was previously limited by the low kinase selectivity and subsequent toxicities of early-generation compounds. Fortunately, next-generation, highly selective BTKis in clinical development appear to have more favorable risk-benefit profiles, and their likelihood of being Food and Drug Administration-approved for an allergy indication is increasing. Recent clinical trials have indicated the remarkable and rapid efficacy of the second-generation BTKi acalabrutinib in preventing clinical reactivity to peanut ingestion in adults with peanut allergy. In addition, next-generation BTKis including remibrutinib effectively reduce disease activity in patients with antihistamine-refractory chronic spontaneous urticaria. Finally, several BTKis are currently under investigation in early clinical trials for atopic dermatitis and asthma. In this review, we summarize recent data supporting the use of these drugs as novel therapies in food allergy, anaphylaxis, urticaria, and other allergic disorders. We also discuss safety data derived from trials using both short-term and chronic dosing of BTKis.

BTK signaling-a crucial link in the pathophysiology of chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is an inflammatory skin disorder that manifests with itchy wheals, angioedema, or both for more than 6 weeks. Mast cells and basophils are the key pathogenic drivers of CSU; their activation results in histamine and cytokine release with subsequent dermal inflammation. Two overlapping mechanisms of mast cell and basophil activation have been proposed in CSU: type I autoimmunity, also called autoallergy, which is mediated via IgE against various autoallergens, and type IIb autoimmunity, which is mediated predominantly via IgG directed against the IgE receptor FcεRI or FcεRI-bound IgE. Both mechanisms involve cross-linking of FcεRI and activation of downstream signaling pathways, and they may co-occur in the same patient. In addition, B-cell receptor signaling has been postulated to play a key role in CSU by generating autoreactive B cells and autoantibody production. A cornerstone of FcεRI and B-cell receptor signaling is Bruton tyrosine kinase (BTK), making BTK inhibition a clear therapeutic target in CSU. The potential application of early-generation BTK inhibitors, including ibrutinib, in allergic and autoimmune diseases is limited owing to their unfavorable benefit-risk profile. However, novel BTK inhibitors with improved selectivity and safety profiles have been developed and are under clinical investigation in autoimmune diseases, including CSU. In phase 2 trials, the BTK inhibitors remibrutinib and fenebrutinib have demonstrated rapid and sustained improvements in CSU disease activity. With phase 3 studies of remibrutinib ongoing, it is hoped that BTK inhibitors will present an effective, well-tolerated option for patients with antihistamine-refractory CSU, a phenotype that presents a considerable clinical challenge.

Impact of the clinically approved BTK inhibitors on the conformation of full-length BTK and analysis of the development of BTK resistance mutations in chronic lymphocytic leukemia

Inhibition of Bruton's tyrosine kinase (BTK) has proven to be highly effective in the treatment of B-cell malignancies such as chronic lymphocytic leukemia (CLL), autoimmune disorders and multiple sclerosis. Since the approval of the first BTK inhibitor (BTKi), Ibrutinib, several other inhibitors including Acalabrutinib, Zanubrutinib, Tirabrutinib and Pirtobrutinib have been clinically approved. All are covalent active site inhibitors, with the exception of the reversible active site inhibitor Pirtobrutinib. The large number of available inhibitors for the BTK target creates challenges in choosing the most appropriate BTKi for treatment. Side-by-side comparisons in CLL have shown that different inhibitors may differ in their treatment efficacy. Moreover, the nature of the resistance mutations that arise in patients appears to depend on the specific BTKi administered. We have previously shown that Ibrutinib binding to the kinase active site causes unanticipated long-range effects on the global conformation of BTK (Joseph, R.E., et al., 2020, https://doi.org/10.7554/eLife.60470 ). Here we show that binding of each of the five approved BTKi to the kinase active site brings about distinct allosteric changes that alter the conformational equilibrium of full-length BTK. Additionally, we provide an explanation for the resistance mutation bias observed in CLL patients treated with different BTKi and characterize the mechanism of action of two common resistance mutations: BTK T474I and L528W.

B cells and antibodies in refractory immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired bleeding disorder mediated by pathogenic autoantibodies secreted by plasma cells (PCs) in many patients. In refractory ITP patients, the persistence of splenic and bone marrow autoreactive long-lived PCs (LLPCs) may explain primary failure of rituximab and splenectomy respectively. The reactivation of autoreactive memory B cells generating new autoreactive PCs contributes to relapses after initial response to rituximab. Emerging strategies targeting B cells and PCs aim to prevent the settlement of splenic LLPCs with the combination of anti-BAFF and rituximab, to deplete autoreactive PCs with anti-CD38 antibodies, and to induce deeper B-cell depletion in tissues with novel anti-CD20 monoclonal antibodies and anti-CD19 therapies. Alternative strategies, focused on controlling autoantibody mediated effects, have also been developed, including SYK and BTK inhibitors, complement inhibitors, FcRn blockers and inhibitors of platelet desialylation.

The preclinical discovery and development of orelabrutinib as a novel treatment option for B-cell lymphoid malignancies

INTRODUCTION

Bruton's tyrosine kinase (BTK) inhibitors have recently been approved for clinical use against several B-cell indolent lymphoid malignancies, both as single agents or in combination. One second-generation BTK inhibitor that is being developed for the treatment of B-cell hematological malignancies, as well as for autoimmune disorders, is orelabrutinib.

AREAS COVERED

This paper reviews recent developments in the use of orelabrutinib against B-cell indolent lymphoid malignancies such as chronic lymphocytic leukemia, mantle cell lymphoma, diffuse large B-cell lymphoma, Waldenstrom macroglobulinemia and central nervous system lymphoma. Google Scholar and PubMed were initially searched for articles, and the corpus of articles was broadened by reviewing the references of the identified papers. All were in English. The corpus comprised papers from 2016 to April 2023. In addition, a manual search was performed of conference proceedings from the last five years of The American Society of Hematology, American Society of Clinical Oncology and the European Hematology Association.

EXPERT OPINION

Orelabrutinib is an active drug in indolent and aggressive B-cell lymphoid malignancies. It demonstrates high selectivity, good efficacy and an excellent safety profile. Nevertheless, further clinical trials are required to optimize its use. In addition, several other highly selective BTK inhibitors are being examined in early-phase studies.

New small molecules in dermatology: for the autoimmunity, inflammation and beyond

OBJECTIVE AND DESIGN

The discovery of new inflammatory pathways and the mechanism of action of inflammatory, autoimmune, genetic, and neoplastic diseases led to the development of immunologically driven drugs. We aimed to perform a narrative review regarding the rising of a new class of drugs capable of blocking important and specific intracellular signals in the maintenance of these pathologies: the small molecules.

MATERIALS/METHODS

A total of 114 scientific papers were enrolled in this narrative review.

RESULTS

We describe in detail the families of protein kinases-Janus Kinase (JAK), Src kinase, Syk tyrosine kinase, Mitogen-Activated Protein Kinase (MAPK), and Bruton Tyrosine Kinase (BTK)-their physiologic function and new drugs that block these pathways of intracellular signaling. We also detail the involved cytokines and the main metabolic and clinical implications of these new medications in the field of dermatology.

CONCLUSIONS

Despite having lower specificity compared to specific immunobiological therapies, these new drugs are effective in a wide variety of dermatological diseases, especially diseases that had few therapeutic options, such as psoriasis, psoriatic arthritis, atopic dermatitis, alopecia areata, and vitiligo.

Novel Immunotherapies for Myasthenia Gravis

Myasthenia gravis (MG), a prototype autoimmune neurological disease, had its therapy centred on corticosteroids, non-steroidal broad-spectrum immunotherapy and cholinesterase inhibitors for several decades. Treatment-refractory MG and long-term toxicities of the medications have been major concerns with the conventional therapies. Advances in the immunology and pathogenesis of MG have ushered in an era of newer therapies which are more specific and efficacious. Complement inhibitors and neonatal Fc receptor blockers target disease-specific pathogenic mechanisms linked to myasthenia and have proven their efficacy in pivotal clinical studies. B cell-depleting agents, specifically rituximab, have also emerged as useful for the treatment of severe MG. Many more biologicals are in the pipeline and in diverse stages of development. This review discusses the evidence for the novel therapies and the specific issues related to their clinical use.

Design and Characterization of a Novel Venetoclax-Zanubrutinib Nano-Combination for Enhancing Leukemic Cell Uptake and Long-Acting Plasma Exposure

Leukemia remains incurable partly due to difficulties in reaching and maintaining therapeutic drug concentrations in the target tissues and cells. Next-generation drugs targeted to multiple cell checkpoints, including the orally active venetoclax (Bcl-2 target) and zanubrutinib (BTK target), are effective and have improved safety and tolerability compared to conventional, nontargeted chemotherapies. However, dosing with a single agent frequently leads to drug resistance; asynchronous coverage due to the peak-and-trough time-course of two or more oral drugs has prevented drug combinations from simultaneously knocking out the respective drugs' targets for sustained leukemia suppression. Higher doses of the drugs may potentially overcome asynchronous drug exposure in leukemic cells by saturating target occupancy, but higher doses often cause dose-limiting toxicities. To synchronize multiple drug target knockout, we have developed and characterized a drug combination nanoparticle (DcNP), which enables the transformation of two short-acting, orally active leukemic drugs, venetoclax and zanubrutinib, into long-acting nanoformulations (VZ-DCNPs). VZ-DCNPs exhibit synchronized and enhanced cell uptake and plasma exposure of both venetoclax and zanubrutinib. Both drugs are stabilized by lipid excipients to produce the VZ-DcNP nanoparticulate (d ~ 40 nm) product in suspension. The VZ-DcNP formulation has enhanced uptake of the two drugs (VZ) in immortalized leukemic cells (HL-60), threefold over that of its free drug counterpart. Additionally, drug-target selectivity of VZ was noted with MOLT-4 and K562 cells that overexpress each target. When given subcutaneously to mice, the half-lives of venetoclax and zanubrutinib were extended by approximately 43- and 5-fold, respectively, compared to an equivalent free VZ. Collectively, these data suggest that VZ in VZ-DcNP warrant consideration for preclinical and clinical development as a synchronized and long-acting drug-combination for the treatment of leukemia.

Synthesis and Preclinical Evaluation of a Novel Fluorine-18-Labeled Tracer for Positron Emission Tomography Imaging of Bruton's Tyrosine Kinase

Bruton's tyrosine kinase (BTK) is a target for treating B-cell malignancies and autoimmune diseases. To aid in the discovery and development of BTK inhibitors and improve clinical diagnoses, we have developed a positron emission tomography (PET) radiotracer based on a selective BTK inhibitor, remibrutinib. [18F]PTBTK3 is an aromatic, 18F-labeled tracer that was synthesized in 3 steps with a 14.8 ± 2.4% decay-corrected radiochemical yield and ≥99% radiochemical purity. The cellular uptake of [18F]PTBTK3 was blocked up to 97% in JeKo-1 cells using remibrutinib or non-radioactive PTBTK3. [18F]PTBTK3 exhibited renal and hepatobiliary clearance in NOD SCID (non-obese diabetic/severe combined immunodeficiency) mice, and the tumor uptake of [18F]PTBTK3 in BTK-positive JeKo-1 xenografts (1.23 ± 0.30% ID/cc) was significantly greater at 60 min post injection compared to the tumor uptake in BTK-negative U87MG xenografts (0.41 ± 0.11% ID/cc). In the JeKo-1 xenografts, tumor uptake was blocked up to 62% by remibrutinib, indicating the BTK-dependent uptake of [18F]PTBTK3 in tumors.

Targeting B cells and plasma cells in autoimmune diseases: From established treatments to novel therapeutic approaches

Autoimmune diseases are characterized by the recognition of self-antigens by the immune system, which leads to inflammation and tissue damage. B cells are directly and indirectly involved in the pathophysiology of autoimmunity, both via antigen-presentation to T cells and production of proinflammatory cytokines and/or autoantibodies. Consequently, B lineage cells have been identified as therapeutic targets in autoimmune diseases. B cell depleting strategies have proven beneficial in the treatment of rheumatoid arthritis (RA), systemic lupus erythematous (SLE), ANCA-associated vasculitis (AAV), multiple sclerosis (MS), and a wide range of other immune-mediated inflammatory diseases (IMIDs). However, not all patients respond to treatment or may not reach (drug-free) remission. Moreover, B cell depleting therapies do not always target all B cell subsets, such as short-lived and long-lived plasma cells. These cells play an active role in autoimmunity and in certain diseases their depletion would be beneficial to achieve disease remission. In the current review article, we provide an overview of novel strategies to target B lineage cells in autoimmune diseases, with the focus on rheumatic diseases. Both advanced therapies that have recently become available and more experimental treatments that may reach the clinic in the near future are discussed.

Heterogeneity of antibody-secreting cells infiltrating autoimmune tissues

The humoral response is frequently dysfunctioning in autoimmunity with a frequent rise in total serum immunoglobulins, among which are found autoantibodies that may be pathogenic by themselves and/or propagate the inflammatory reaction. The infiltration of autoimmune tissues by antibody-secreting cells (ASCs) constitutes another dysfunction. The known high dependency of ASCs on the microenvironment to survive combined to the high diversity of infiltrated tissues implies that ASCs must adapt. Some tissues even within a single clinical autoimmune entity are devoid of infiltration. The latter means that either the tissue is not permissive or ASCs fail to adapt. The origin of infiltrated ASCs is also variable. Indeed, ASCs may be commonly generated in the secondary lymphoid organ draining the autoimmune tissue, and home at the inflammation site under the guidance of specific chemokines. Alternatively, ASCs may be generated locally, when ectopic germinal centers are formed in the autoimmune tissue. Alloimmune tissues with the example of kidney transplantation will also be discussed own to their high similarity with autoimmune tissues. It should also be noted that antibody production is not the only function of ASCs, since cells with regulatory functions have also been described. This article will review all the phenotypic variations indicative of tissue adaptation described so for at the level of ASC-infiltrating auto/alloimmune tissues. The aim is to potentially define tissue-specific molecular targets in ASCs to improve the specificity of future autoimmune treatments.

Bruton's Tyrosine Kinase Inhibitors: The Next Frontier of B-Cell-Targeted Therapies for Cancer, Autoimmune Disorders, and Multiple Sclerosis

Bruton's tyrosine kinase (BTK) is an important protein belonging to the tyrosine kinase family that plays a key role in the intracellular signaling and proliferation, migration, and survival of normal and malignant B-lymphocytes and myeloid cells. Understanding the role of BTK in the B-cell signaling pathway has led to the development of BTK inhibitors (BTKi) as effective therapies for malignancies of myeloid origin and exploration as a promising therapeutic option for other cancers. Given its central function in B-cell receptor signaling, inhibition of BTK is an attractive approach for the treatment of a wide variety of autoimmune diseases that involve aberrant B-cell function including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). Here, we review the role of BTK in different cell signaling pathways, the development of BTKi in B-cell malignancies, and their emerging role in the treatment of MS and other autoimmune disorders.

Current Perspectives: Evidence to Date on BTK Inhibitors in the Management of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system leading to demyelination and neurodegeneration. Basic and translational studies have shown that B cells and myeloid cells are critical players for the development and course of the disease. Bruton's tyrosine kinase (BTK) is essential for B cell receptor-mediated B cell activation and for normal B cell development and maturation. In addition to its role in B cells, BTK is also involved in several functions of myeloid cells. Although significant number of disease-modifying treatments (DMTs) have been approved for clinical use in MS patients, novel targeted therapies should be studied in refractory patients and patients with progressive forms of the disease. On the basis of its role in B cells and myeloid cells, BTK inhibitors can provide attractive therapeutic benefits for MS. In this article, we review the main effects of BTK inhibitors on different cell types involved in the pathogenesis of MS and summarise recent advances in the development of BTK inhibitors as novel therapeutic approaches in different MS clinical trials. Available data regarding the efficacy and safety of these drugs are described.

TCR CDR3 Sequencing as a Clue to Elucidate the Landscape of Dysimmunity in Patients with Primary Immune Thrombocytopenia

Background: Primary immune thrombocytopenia (ITP) is an autoimmune disorder. The existence of autoreactive T cells has long been proposed in ITP. Yet the identification of autoreactive T cells has not been achieved, which is an important step to elucidate the pathogenesis of ITP. Methods: ITP patients’ peripheral blood was collected prior to the treatment and one month after initiating dexamethasone treatment per related therapeutic guideline. Serum cytokines were profiled to examine T cell subtypes imbalance using a protein chip. TCR Vβ analysis in CD8+T cells of ITP patients, and TCR CDR3 DNA sequencing of CD4+T and CD8+T cells were performed to determine the autoreactive T cells’ clones. Results: Cytokine profiling revealed imbalanced distribution of T cells subtypes, which was confirmed by CD4+T and CD8+T cells’ oligoclonal expansion of TCR Vβ analysis and TCR CDR3 DNA sequencing. VDJ segments were found to be more frequently presented in ITP patients, when compared with health controls. There was an individualized CD4+T cell or CD8+T cell CDR3 sequence in each ITP patient. Conclusions: The present study revealed that T cell clones expanded in ITP patients’ peripheral blood, and each clone had an individualized TCR CDR3 sequence. The expanded T cell clones preferred to use some specific VDJ segment. Further studies are warranted to get access to individualized treatment such as Car-T in patients with ITP.