ABO and Immunogenetic Variation in the Pathogenesis of Heparin-Induced Thrombocytopenia

肝素诱导的血小板减少症发病机制中的 ABO 和免疫遗传学变异

• 批准号: 10439313
• 负责人: Jason Hansen Karnes
• 金额: $ 45.73万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10439313
• 关键词: ABO blood group system; Acute; Address; Adverse reactions; Affect; Alleles; Antibodies; Antibody Formation; Biological; Biological Assay; Biological Markers; Blood; Cardiovascular Diseases; Cells; Cellular Indexing of Transcriptomes and Epitopes by Sequencing; Clinical; Computerized Medical Record; Coupled; DNA; Data; Detection; Family; Genes; Genetic; Genetic Determinism; Genetic Drift; Genomics; Genotype; Guide RNA; HLA Antigens; Helper-Inducer T-Lymphocyte; Heparin; Immune; Immunogenetics; Immunogenomics; Incidence; Incubated; Individual; Knowledge; Life; Measures; Mediating; Membrane Proteins; Mission; Modeling; Molecular; Odds Ratio; Outcome; PF4 Gene; Pathogenesis; Pathogenicity; Pathology; Patients; Phase; Population; Population Heterogeneity; Prevention; Prevention strategy; Preventive; Proliferating; Public Health; Publishing; RNA; Reaction; Research; Resolution; Risk; Role; Sample Size; Sampling; Staphylococcal Enterotoxin B; T-Cell Activation Pathway; T-Cell Proliferation; T-Cell Receptor; Testing; Th2 Cells; Thromboembolism; United States National Institutes of Health; Variant; Work; adverse drug reaction; base; biobank; blood group; clinical practice; clinical translation; cohort; deep sequencing; diagnostic strategy; direct application; experimental study; genome wide association study; genome-wide; genomic variation; heparin-induced thrombocytopenia; immunopathology; innovation; insight; mortality; overexpression; programs; racial diversity; transcriptome; transcriptome sequencing

ABSTRACT Despite decades of research into the immunopathology of heparin-induced thrombocytopenia (HIT), an unpredictable, life-threatening, immune-mediated adverse reaction to heparin treatment, a fundamental knowledge gap regarding the cause of HIT remains. The inability to predict HIT represents a considerable liability associated with heparin, which is given to 12 million individuals or one third of all hospitalized patients every year. Because the exact cellular and molecular mechanisms underlying HIT have yet to be identified, including intrinsic immune cell roles and the difference between pathogenic and non-pathogenic antibodies, there is an essential need to apply alternative approaches to understand the biological basis for HIT and to identify clinically implementable biomarkers. The PI’s central hypothesis is that immunogenomic variation impacts HIT pathogenesis and can be used to differentiate non-pathogenic and pathogenic PF4/heparin antibodies, which are produced by immune cell populations intrinsic to HIT. Based on strong preliminary data that constitute the largest genome-wide association study (GWAS) for HIT, the working hypothesis is that the presence of the HLA-DRB3*01:01 allele combined with proliferating Vβ 5.1 family T-Cell receptor (TCR) clonotypes in Th2 cells predisposes patients to pathogenic PF4/heparin antibody production, and these antibodies result in high HIT risk in patients with the ABO O blood group. We will pursue three Specific Aims (SAs) to test the central hypothesis: (SA1) Determine the role of ABO variation in HIT; (SA2) Determine the influence of genomic variation on PF4/heparin antibody production; and (SA3) Identify intrinsic immune cell involvement in HIT. In SA #1, deep ABO sequencing data will be utilized in our large cohort of functional assay-confirmed HIT patients to elucidate the role of ABO variability in HIT. In SA #2, we will perform several GWAS to determine genetic influences of PF4/heparin antibody production, including diverse populations, and differentiate genetic influences on pathogenic versus non-pathogenic antibodies. In SA#3, we will sample paired cell populations during the acute phase of HIT and after HIT resolution and conduct focused single cell (sc) studies to determine proliferation of TCR clonotypes and activated cell populations using sc-RNA-TCR-CITE-seq. Our studies overcome major limitations of previous genomic studies of HIT by incorporating large, diverse cohorts, a PF4/heparin antibody- positive case group, and functional assay confirmation of HIT cases. This work is technically and conceptually innovative as it leverages a sc-RNA-TCR-CITE-seq approach, utilizes large, unique HIT cohorts, and advances an original model of HIT immunopathogenesis. We expect to provide mechanistic insights into HIT pathology and advance a framework for clinical translation of HIT biomarkers with direct application to other adverse drug reactions. The proposed studies leverage large-scale biological data to distinguish patients pre-disposed to HIT, potentially shifting clinical practice from treatment to prevention through biomarker-guided heparin treatment.

摘要 尽管对肝素诱导的血小板减少症（HIT）的免疫病理学进行了数十年的研究， 不可预测的，危及生命的，免疫介导的肝素治疗不良反应，一个基本的 关于HIT原因的知识差距仍然存在。无法预测命中率是一个相当大的负担 与肝素有关，每年有1200万人或三分之一的住院患者服用肝素， 年因为HIT的确切细胞和分子机制尚未确定，包括 内在免疫细胞的作用和致病性和非致病性抗体之间的差异，有一个 基本需要应用替代方法来了解HIT的生物学基础，并在临床上识别 可实施的生物标志物。PI的中心假设是免疫基因组学变异影响HIT 发病机制，并可用于区分非致病性和致病性PF 4/肝素抗体， 由HIT固有的免疫细胞群产生。根据构成该报告的强有力的初步数据， 最大的全基因组关联研究（GWAS）的HIT，工作假设是， HLA-DRB 3 *01：01等位基因联合增殖性Vβ 5.1家族T细胞受体（TCR）克隆型在Th 2细胞中的表达 使患者易于产生致病性PF 4/肝素抗体，这些抗体导致高HIT风险 ABO O血型的患者。我们将追求三个具体目标（SA）来检验中心假设： (SA1)确定ABO变异在HIT中的作用;（SA 2）确定基因组变异对HIT的影响。 PF 4/肝素抗体产生;和（SA 3）鉴定HIT中的内在免疫细胞参与。在SA #1中，深度 ABO测序数据将用于我们的大型功能测定证实的HIT患者队列，以阐明 ABO变异性在HIT中的作用。在SA #2中，我们将进行几次GWAS以确定 PF 4/肝素抗体的产生，包括不同的人群，并区分遗传对 致病性抗体与非致病性抗体。在SA#3中，我们将在急性期对配对细胞群进行采样。 在HIT阶段和HIT消退后，进行聚焦单细胞（sc）研究，以确定 使用sc-RNA-TCR-CITE-seq.我们的研究克服了 通过纳入大的、不同的队列、PF 4/肝素抗体， 阳性病例组和HIT病例的功能测定确认。这项工作在技术上和概念上 创新，因为它利用了sc-RNA-TCR-CITE-seq方法，利用了大型独特的HIT队列， HIT免疫发病机制的原始模型。我们希望能为HIT病理学提供机制性的见解 并提出一个框架，用于临床翻译HIT生物标志物，直接应用于其他不良药物 反应.拟议的研究利用大规模的生物学数据来区分易患HIT的患者， 通过生物标志物指导的肝素治疗，可能将临床实践从治疗转向预防。