The Pathogenesis, Diagnosis, And Treatment Of Systemic Mast Cell Disorders

系统性肥大细胞疾病的发病机制、诊断和治疗

• 批准号: 10014014
• 负责人: Dean D Metcalfe
• 金额: $ 110.12万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10014014
• 关键词: Adult; Adverse event; Affect; Algorithms; Alleles; Anaphylaxis; Animal Model; Attenuated; Autoimmune Diseases; B-Lymphocytes; Binding; Biological; Biological Assay; Blood specimen; Bone Diseases; Bone Marrow; Bone Marrow Examination; Bone marrow biopsy; CD19 gene; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; Caregivers; Cell Communication; Cell Count; Cell Differentiation process; Cell Proliferation; Cells; Child; Child Care; Childhood; Clinical; Clinical Trials; Complication; Cutaneous; Cutaneous Mastocytosis; Data; Diagnosis; Disease; Disease Progression; Epigenetic Process; Evaluation; Exhibits; Frequencies; Genetic Polymorphism; Hematological Disease; Hematology; Hepatic Stellate Cell; Hepatosplenomegaly; Histopathology; Homeostasis; Human; Individual; Indolent; Indolent Systemic Mastocytosis; Interleukin 6 Receptor; Interleukin-6; Interleukins; Link; Liver; Lymphocyte; Lymphocyte Subset; Measurement; Mediating; Mediator of activation protein; MicroRNAs; Molecular Abnormality; Mus; Mutation; Natural Killer Cells; Osteoblasts; Osteogenesis; Osteopenia; Osteoporosis; Pathogenesis; Pathology; Patients; Pharmaceutical Preparations; Population; Production; Publishing; Quality of life; Randomized; Recording of previous events; Recurrence; Regulation; Reporting; Research; Role; Serum; Severities; Severity of illness; Signal Transduction; Symptoms; Systemic Mastocytosis; Systemic disease; T-Lymphocyte; Therapeutic; Tissues; Tryptase; Tyrosine Kinase Inhibitor; Visit; bone; bone mass; burden of illness; cell type; cytokine; design; extracellular vesicles; mast cell; mastocytosis; molecular vector; mutational status; neoplastic; novel strategies; novel therapeutics; omalizumab; osteoblast differentiation; patient stratification; peripheral blood; prevent; reduce symptoms; response; skin disorder; success; vesicular release

Allele specific qPCR is widely used to identify and assess KIT D816V in the peripheral blood of adults with mastocytosis in order to facilitate diagnosis, assessment of disease burden and response to therapy. To examine the value of this assay in children with cutaneous mastocytosis, in FY 2019, we completed and published the assessment of data on 65 children with pediatric-onset cutaneous and systemic mastocytosis by correlating KIT mutation status with clinical findings, serum tryptase levels and bone marrow histopathology. We concluded that KIT D816V in peripheral blood was exclusively found in children known to have both cutaneous and systemic disease; and correlated with serum tryptase and disease severity. These findings formed the basis of an algorithm which may be used by care-givers to assist in arriving at the decision to perform a bone marrow biopsy in children presenting with cutaneous mastocytosis. In FY 2019, we continued research on extracellular vesicles (EVs)that associate with hematologic disorders and are reported as vectors of molecular information that effect other cell types. In FY 2019, we thus completed and published an examination of blood samples from patients with systemic mastocytosis (SM) and found EVs with a mast cell signature including the presence of tryptase, FcepsilonRI, MRGPRX2 and KIT. The concentration of these EVs correlated with parameters of disease including levels of serum tryptase and hepatosplenomegaly. We then questioned if SM-EVs might affect hepatic stellate cells, given the abnormal liver pathology associated with mastocytosis. We found that mastocytosis EVs are taken up by hepatic stellate cells (HSCs) and this interaction altered the proliferation, cytokine production and differentiation of these cells. This data is consistent with the conclusion that SM-EVs have the potential to influence cells outside the hematological compartment, and that therapeutic approaches for treatment of SM should in part target inhibition of the effects of EVs on target tissues. In FY 2019, we also expanded these studies to examine the effect of EVs on bone formation, as osteoporosis is a major complication of systemic mastocytosis and correlates with the presence of mast cell infiltrates in the bone marrow. We found that EVs released by neoplastic mast cells and present in the serum of patients with SM (SM-EVs) block osteoblast differentiation and functionality in culture; and when injected into mice reduce the expression of osteoblast markers. We also found evidence that these EVs contain microRNAs linked to osteogenesis regulation; and were able to demonstrate that miRNA-30a and miRNA-23a mediate the inhibition of osteoblast differentiation/maturation by SM-EVs. We thus concluded that SM-EVs and neoplastic mast cell-derived EVs deliver miRNAs that epigenetically attenuate osteoblast function and alter bone homeostasis which results in reduction of bone mass. These findings reinforce the possibility of novel approaches targeted to EVs in the management of bone disease in patients with mast cell proliferative disorders. In FY 2019, we performed a study where we examined lymphocyte populations in patients with mastocytosis to explore whether an excess mast cell burden might influence specific subsets of lymphocytes. We found that patients with mastocytosis exhibited a significantly lower median frequency and absolute cell count of both circulating CD8+ T cells and Natural Killer cells accompanying a significantly increased ratio of CD4+/C8+ T cells. Stratification of patients according to clinical manifestations further revealed that CD19+CD21lowCD38low B cells were significantly higher in patients with a history of autoimmune disease and counts of terminally differentiated CD4+ T cells were significantly higher in patients with osteoporosis or osteopenia. These data suggest the need for further studies on abnormalities in lymphocyte subsets and the attendant clinical consequences in both mast cell proliferative and activation disorders. Unexplained anaphylaxis may occur in patients with mastocytosis and such episodes may be quite severe. Omalizumab has been proposed as a potential therapeutic strategy to reduce the number of anaphylactic episodes in patients with systemic mastocytosis and short-term studies seem to validate this approach. In FY 2019, we reported the success of the use of omalizumab in prevent recurrent episodes of anaphylaxis over a 12-year period in two patients with systemic anaphylaxis and where the drug was well tolerated without adverse events related to administration. In both patients, anaphylactic episodes were rare. There was also an improvement in cutaneous manifestations in both individuals, along with a significant reduction in serum tryptase and bone marrow mast cell burden in one patient. Our report supports the design of long-term controlled trials for the use of omalizumab as a therapeutic option for patients with clonal disorders of mast cells. Patients with indolent (non-aggressive) systemic mastocytosis are not candidates for cytoreductive therapy and are generally treated with symptomatic therapy that only partly decreases symptoms. There is, however, a documented association between severity of mastocytosis and elevated serum levels of interleukin IL-6. Furthermore, mast cells have been shown to double their rate of division and exhibit increased reactivity and release of mediators when cultured in the presence of IL-6. In addition, in an animal model of mastocytosis, anti-IL-6 has been shown to slow disease progression. In FY 2019 we thus initiated a clinical trial where adults with indolent systemic mastocytosis are randomized and treated with sarilumab which binds to the IL 6 receptor and inhibits IL 6 associated human mast cell signaling, proliferation and reactivity (decreased mediator release). Over a four-month period, evaluations at study visits will include quality of life and symptom assessments and measurement of serum tryptase levels. Bone marrow examinations will be performed at the onset and conclusion of the study.

等位基因特异性qPCR被广泛用于鉴定和评估肥大细胞增多症成人外周血中的KIT D816V，以方便诊断、评估疾病负担和治疗反应。为了检验该检测在患有皮肤肥大细胞增多症的儿童中的价值，在2019财年，我们通过将KIT突变状态与临床表现、血清胰蛋白酶水平和骨髓组织病理学相关联，完成并发表了对65名患有儿科发病皮肤和全身肥大细胞增多症的儿童的数据评估。我们的结论是，KIT D816V外周血只存在于已知有皮肤和全身性疾病的儿童中；并与血清胰蛋白酶和疾病严重程度相关。这些发现构成了一种算法的基础，该算法可被护理人员用于帮助决定是否对皮肤肥大细胞增多症患儿进行骨髓活检。