特发性血小板减少性紫癜动物模型建立的研究进展

特发性血小板减少性紫癜(ITP)是常见的免疫性疾病之一,主要表现为外周血血小板计数明显减少,骨髓巨核细胞数正常或增多并伴有成熟障碍,是常见的出血性疾病.鉴于其自身免疫相关的发病特点,ITP的研究大部分建立在与疾病发病机制相似的动物模型上.因此,研究ITP模型的造模方法对ITP的诊断和治疗很有意义.     

原发性血小板减少性紫癜骨髓巨核细胞系形态改变与免疫关系的探讨

<正> 原发性血小板减少性紫癜(ITP)是较常见的出血性疾病。我们详细观察37例慢性ITP骨髓巨核细胞及血小板形态,检测了血小板相关抗体。目的在于观察抗血小板相关抗体对ITP骨髓巨核细胞、血小板的影响,以探讨巨核细胞、血小板量和质的改变对ITP诊断意义。     

CD4+ T 细胞在原发性免疫性血小板减少症中作用机制的研究进展

正原发性免疫性血小板减少症(Immune thrombocytopenic purpura,ITP)属于自身免疫性出血无序性疾病,具有器官特异性~([1])。该病存在血小板减少、血小板生存时间缩短及抗血小板抗体出现、骨髓巨核细胞增多伴成熟障碍等特征。在一些情况下,ITP患者出血并不明显,已经导致了其缩写含义由先前的特发性血小板减少性紫癜修订为免疫性血小板减少症。ITP发病机制复杂,体内多环节、多因素共同     

免疫性血小板减少患者T细胞免疫状态

免疫性血小板减少(Immune thrombocytopenic,ITP)是一种获得性自身免疫功能失调导致的出血性疾病,通常认为与自身抗体产生相关.上世纪人们对该病的研究主要集中在体液免疫方面,发现ITP患者的自身抗体或致敏血小板使其被单核巨噬细胞吞噬,或抑制血小板生成.然而有30%～50%的ITP患者检测不到自身抗体,提示可能存在其他机制.近年ITP患者血小板减少的发病机制已经发生了变化-从传统的自身抗体介导的血小板破坏增加的认识发展到现在多种发病机制的观点,其中包括血小板生成抑制和T细胞所起的不容忽视的作用[1].T细胞介导的对巨核细胞和血小板的细胞毒作用被认为是部分ITP患者的主要发病机制[2].     

羊蹄跟对免疫性血小板减少性紫癜小鼠模型的治疗作用

免疫性血小板减少性紫癜(Immunologic thrombocytopenic purpura,ITP)是一种以血液中血小板计数减少,骨髓中巨核细胞正常或增多,多部位、多脏器自发性出血的常见出血性疾病。其发病机制尚未完全     

特发性血小板减少性紫癜的Tγ细胞缺乏

特发性血小板减少性紫癜(ITP)的特点是产生抗血小板自身抗体引起血小板减少,骨髓巨核细胞数正常或增加。有些报告证实,ITP病人PHA、ConA诱导淋巴细胞转化下降。但对ITP的细胞免疫功能了解太少。近年来根据正常T淋巴细胞的IgG(Tγ)或IgM(Tμ)Fc受体,将其分为两个亚群。     

ITP及风湿免疫性疾病血小板及粒细胞相关抗体临床意义探讨

目的 对免疫性血小板减少性紫癜(ITP)患者、健康人群以及伴有血小板减少的风湿免疫性疾病患者(系统性红斑狼疮,类风湿关节炎,干燥综合征)体内血小板相关免疫球蛋白(PAIg)及粒细胞相关免疫球蛋白(Ig)水平的阳性率进行比较,探讨其在免疫性血小板减少性疾病发病中的作用和意义.方法 用Beckman Coulter公司XL流式细胞仪对205例ITP患者、133例健康人及64例伴有血小板减少的风湿免疫性疾病患者的血小板及粒细胞表面相关免疫球蛋白水平检测并进行比较.结果 PAIgG在ITP患者及伴有血小板减少的风湿免疫性疾病患者中均升高,与健康人对照组存在差异;PAIgA的增高仅出现在ITP患者中,与健康人对照组存在差异;而伴有血小板减少的风湿免疫性疾病患者中不增高,与健康人对照组无显著差异.PAIgM的增高仅出现在伴有血小板减少的风湿免疫性疾病患者中,与健康人对照组存在差异,而ITP患者与健康人群对照组无显著差异.三种粒细胞相关抗体则均出现于ITP患者及伴有血小板减少的风湿免疫性疾病患者,与健康人群对照组存在差异.结论 ITP虽然定义为器官特异性免疫性疾病,但受累靶细胞决不仅限于血小板,至少还包括白细胞.免疫性血小板减少疾病发病中普遍存在粒细胞相关抗体的出现.PAIgG并非仅出现在ITP患者,结合PAIgA的增高在临床上可能更支持ITP的诊断;而伴有血小板减少的风湿免疫性疾病患者出现的血小板下降可能主要由PAIgM所介导.     

免疫法 ITP 小鼠模型的建立与鉴定

目的:应用免疫法建立ITP动物模型,模拟疾病的病理状态,进一步分析探讨各项指标以判定疾病模型是否成功。方法:将BALB/c小鼠随机分为两组,即正常组、模型组。模型组按照100μl/20 g剂量向小鼠腹腔内注射1∶4稀释的豚鼠抗BALB/c小鼠血小板血清(GP-APS),隔日1次,隔日检测外周血小板水平。两周后,检测小鼠外周血PAIgG水平、骨髓巨核细胞数量及形态分类,了解骨髓象、脾脏组织病理和脾脏脏器指数变化。结果:GP-APS稀释倍数为1∶128时仍成阳性,说明豚鼠血清中已产生了特异性抗体。与正常组及造模前比较,ITP小鼠模型外周血小板明显降低,抗血小板抗体明显升高,差异有统计学意义(均P0. 05),注射GP-APS后24 h模型小鼠外周血小板数最低。与正常组比较,模型组小鼠骨髓巨核细胞总数明显增加(P0. 05),而产板巨核细胞减少(P0. 01)。同时模型组小鼠脾脏指数明显大于正常组(P0. 01)。结论:与正常组比较,ITP小鼠外周血小板下降、抗血小板抗体升高、骨髓巨核细胞增多并伴成熟障碍,与ITP临床表现基本相符;应用GPAPS免疫法可成功建立ITP小鼠疾病模型。     

特发性血小板减少性紫癜患儿外周血淋巴细胞亚群和血小板抗体及骨髓象的比较

目的研究ITP患儿淋巴细胞亚群、血小板抗体及骨髓象在发病期的变化。方法应用流式细胞术（FCM）检测34例ITP患儿发病期外周血淋巴细胞亚群的水平（CD3＋、CD4＋、CD8＋、CD19＋、CD4＋/CD8＋、NK）。用ELISA法检测血小板表面血小板相关抗体IgG、IgM、IgA。同时抽取患儿骨髓制作骨髓片。结果ITP患儿发病期组CD4＋/CD8＋的比例显著降低,NK细胞显著降低,CD19＋显著增高,ITP患儿组血小板抗体PAIgG、PAIgM和正常对照组比较显著增高（P〈0.01）,同时CD19＋增高与血小抗体PAIgG、PAIgM增高有明显相关性（P〈0.001）。骨髓象中巨核细胞总数和对照组比较显著增高（P〈0.01）,同时原幼巨核细胞总数、颗粒巨核细胞总数明显增高,而产板型巨核细胞总数明显降低。结论ITP患儿存在细胞免疫和体液免疫紊乱。     

树突状细胞参与免疫性血小板减少症发病机制的研究进展

<正>免疫性血小板减少症(Immune thrombocytopenia,ITP)是一种免疫异常介导的出血性疾病,主要表现为外周血中血小板减少,皮肤、黏膜及内脏出血,其发病机制复杂,尚未完全明了。ITP是临床上最常见的自身免疫性出血性疾病,故有必要对其发病机制深入研究,以便指导临床治疗。目前ITP的发病机制主要涉及:(1)经典的体液免疫机制即ITP患者体内产生了针对血小板膜表面糖蛋白的自身抗     

Effects of the multidrug resistance-1 gene on drug resistance in primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune disorder that is characterized by low platelet count. Glucocorticoids (GCs) resistance is a great challenge in the treatment of ITP. P-glycoprotein (P-gp) is a widely studied protein, which is associated with drug resistance. However, in ITP, the functional activity and immune regulation mechanism of P-gp remain uncertain. In this study, we evaluated the expression and functional activity of P-gp in different lymphocyte subsets, explored the correlation between P-gp function and GCs resistance and investigated the role of P-gp in ITP pathogenesis. Results indicated that the functional activity and mRNA level of P-gp were significantly higher in GCs-nonresponsive patients than in GCs-responsive patients with ITP. However, these differences in P-gp were only significant in CD8⁺ T cells. P-gp function was related to disease activity rather than GCs therapy. P-gp was involved in secreting granzyme B and perforin, maintaining autoreactive lymphocytes survival and enhancing autologous platelets lysis in ITP. In conclusion, over-functional P-gp might play an important role in the pathogenesis of ITP and induce GCs resistance in nonresponsive ITP patients. The blockage of P-gp could be a promising therapeutic approach for GCs-resistant patients with ITP.     

Clinical correlates in patients with elevated platelet-associated immunoglobulins

Studies are reported pertaining to platelet-associated IgG (PAIgG) and IgM (PAIgM) in patients with thrombocytopenias considered possibly immune-mediated on clinical grounds. Approximately 14 percent of all patients with these disorders had elevated PAIgM but normal levels of PAIgG. Of patients with classic autoimmune thrombocytopenia (ITP), there was a trend toward more frequently normal levels of PAIgG in chronic ITP compared with patients with acute ITP, but this was not statistically significant. Patients with acute ITP had higher levels of PAIgG and PAIgM in general than those with chronic ITP. Patterns of PAIgG and/or PAIgM elevation were not significantly different when chronic and acute ITP were compared, nor when childhood ITP was compared with adult ITP. Patients with immune thrombocytopenias owing to malignant disorders were likely to have lower levels of PAIgG compared with those with classic ITP. Treated patients with immune thrombocytopenias showed a trend toward earlier response to therapy if they had only elevated PAIgG as opposed to elevated PAIgM alone or elevated PAIgM and PAIgG (p = 0.17). There appear to be great overlaps in the patterns and quantities of PAIgG and PAIgM in patients with immune-mediated thrombocytopenias in widely varied clinical settings. This suggests some underlying common pathophysiologic mechanisms for thrombocytopenia in these clinically diverse disorders. It is believed that the data are most consistent with the hypothesis that thrombocytopenia in patients with elevated PAIgG and/or PAIgM is most probably of immune origin even in such diverse disorders as systemic lupus erythematosus, cirrhosis of the liver, lymphoma, leukemia, cancer, or septic conditions, as well as in ITP.     

Małopłytkowość – wskazania do zastosowania cytokin płytkotwórczych

The most common cause of isolated thrombocytopenia is primary immune thrombocytopenia (ITP). For patients failing initial corticosteroid-based treatment and with refractory ITP post-splenectomy, thrombopoietin receptor agonists are indicated. Two of this thrombopoiesis-stimulating agents have been approved for use in ITP – eltrombopag, formulated for oral administration, once a day and romiplostim, which is administered weekly as a subcutaneous injection.     

Elevated interleukin-27 enhances the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines in primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired, organ-specific, autoimmune disease with many immune dysfunctions. Interleukin-27 (IL-27) can regulate T cell differentiation. However, it is unclear whether IL-27 correlates with the dysfunctions of T cell differentiation in ITP patients. Thus, to determine the roles of IL-27 in ITP, we studied the expression of IL-27/IL-27 receptor in ITP patients. The results indicated that the levels of IL-27 in the plasma of untreated active ITP patients were higher than in normal controls. We next evaluated the contribution of IL-27 to T cell differentiation. Our results indicated that IL-27 increased T-bet expression, inhibited GATA-3 and ROR-γt expression, and promoted the secretion of tumor necrosis factor-α, interferon-γ, and granzyme B of peripheral blood mononuclear cells from ITP patients. Also, we confirmed that IL-27 induced the differentiation of T helper (Th)-1 and Tc1 cells. In conclusion, IL-27 might play an important role in the pathogenesis of ITP by inducing the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines.     

Serologic aspects of treating immune thrombocytopenic purpura using intravenous Rh immune globulin

In patients with immune thrombocytopenic purpura (ITP), IgG autoantibody-coated platelets are phagocytized by mononuclear macrophages, primarily in the spleen. Intravenous Rh immune globulin (IV RhIG) has been used since 1983 to treat D(+), nonsplenectomized patients with ITP. The beneficial therapeutic effect of IV RhIG is attributed to competitive inhibition of phagocytosis of IgG-coated platelets by IgG anti-D-coated D(+) red blood cells (reticuloendothelial or Fc receptor blockade). Following infusions of IV RhIG in D(+) ITP patients, the direct and indirect antiglobulin tests become transiently positive, reflecting passively transferred anti-D and other alloantibodies that were present in the infused IV RhIG. These consistent and predictable serologic findings contrast with the inconsistent and weak anti-D reactivity observed when D(-) women are treated with relatively small doses of intramuscular RhIG for Rh immunoprophylaxis. The pathophysiology of ITP and the effect of infusing IV RhIG in patients with ITP are illustrated in this review, using computer-generated figures.     

Circulating immune complexes and platelet IgG in various diseases

Correlation between platelet associated IgG (PAIgG), platelet count, and plasma polyethylene glycol (PEG) precipitable IgG immune complex (IC) like material was tested in normal subjects and patients with immune thrombocytopenia (ITP), systemic lupus erythematosus (SLE) and various types of liver disease. Elevated IC were observed in 27% and 22% of ITP and recovered ITP, respectively. A significant inverse correlation between platelet count and PAIgG was demonstrable in the ITP group. A significant direct correlation between platelet count and IC was found only in SLE patients. Impaired reticuloendothelial cell (RE) Fc receptor function in SLE patients is suggested as a possible explanation for the data. If receptor function was normal in SLE patients, lower IC levels and lower platelet counts would have been expected.     

Autosensitization and immune complexes in chronic idiopathic thrombocytopenic purpura.

Argument exists as to whether platelet damage in chronic idiopathic thrombocytopenic purpura (ITP) is mediated by an autoimmune response to platelet antigen or by immune complexes. We have studied thirty-nine patients with ITP for evidence of (i) sensitization to platelet antigen, using a macrophage migration inhibition factor (MIF) assay, (ii) circulating immune complexes, using a Clq deviation technique, and (iii) serum-induced platelet 'immunoinjury', using a 3H-serotonin release assay. Eighty-one per cent of the patient group had a migration index of less than 0.8 (normal range 0.8-1.3), while 91% of those tested had a serum factor (presumably immune complexes) which bound to labelled Clq. The serotonin release assay was abnormal in 32% of twenty-two patients, and the results of this test bore no clear relationship to either those of the Clq deviation test or the MIF results. We conclude that most patients with ITP are sensitized to platelet-associated antigen, and have circulating immune complexes. The contribution of these factors to platelet destruction and the nature of the antigen in the complexes remain to be demonstrated. The serotonin release assay is less sensitive, non-specific, and has limited value in the diagnosis of ITP.     

Abnormal lipid rafts related ganglioside expression and signaling in T lymphocytes in immune thrombocytopenia patients

Aberrant T lymphocytes signaling is considered to play a crucial role in the abnormal immune state of primary immune thrombocytopenia (ITP). Lipid raft has been verified to engage in the T cell receptor (TCR)-mediated T lymphocytes signal transduction. Whether lipid raft-associated T cells signal transduction has impact on the pathogenesis of ITP is still unconfirmed. In this study, we aimed to reveal the abnormality in structure and function of lipid rafts (LRs) in CD4⁺ and CD8⁺ T lymphocytes of patients with ITP. Our results showed that there was an increased lipid raft aggregation in ITP patients, while this kind of increase would not be influenced by platelet counts or therapeutic regimes. Stimulation by anti-CD3/CD28 monoclonal antibodies promoted enhanced lipid raft clustering in T lymphocytes of ITP patients compared with negative controls. Methyl-β-cyclodextrin (MβCD) could block the abnormal lipid raft aggregation and disrupt the TCR-mediated T cells proliferation and cytokines secretion, including both proinflammatory cytokines and anti-inflammatory cytokines. The spontaneous activation of T lymphocytes from ITP patients might be due to the elevated co-localization of protein tyrosine phosphatase (PTP) CD45 and lipid rafts in patients’ CD4⁺ and CD8⁺ T lymphocytes. These findings suggest that the autoactivation of T lymphocytes from ITP patients may lead to the abnormality in lipid raft structure and raft-anchored proteins, and the changes conversely promote the TCR-mediated T cells activation of ITP patients.     

MHC class I-associated peptides identified from normal platelets and from individuals with idiopathic thrombocytopenic purpura

Major histocompatibility complex (MHC) class I molecules bind and display peptide antigens on the cell surface. CD8(+) T lymphocytes recognize peptides in association with class I proteins to initiate a cytotoxic immune response. To understand the specificity of such immune responses and to facilitate the development of therapies for disease, it is important to identify MHC-presented peptides. In this study, platelets, easily obtainable and often associated with immune-mediated disease, were selected to identify MHC class I-associated peptides. MHC-associated peptides presented on platelets of normal individuals and individuals with idiopathic thrombocytopenic purpura (ITP) were characterized. ITP is characterized by the premature immune destruction of platelets. It is associated with the production of antiplatelet autoantibodies, most often targeting platelet membrane GPIIb/IIIa or GPIb/IX. In addition to characterizing five fully and several partially sequenced peptides from platelets, the peptide GPRGA(L/I)S(L/I)(L/I) was identified from four of the five ITP patients. The anchor motif of this peptide correlates with the presence of the HLA-B7 allele. A BLAST search identified this peptide as GPIb (4-12). In conclusion, platelets from normal and ITP individuals can present peptides from general cellular proteins and platelet specific proteins, such as GPIb, to the immune system via MHC class I.     

原发性血小板减少性紫癜患者T细胞受体Vβ亚家族基因的表达特点

目的：了解原发性血小板减少性紫癜（ITP）患者T细胞受体 Vβ亚家族基因表达特点。 方法： 采用反转录酶－多聚酶链反应（RT-PCR）方法检测5例ITP患者外周血T细胞TCR Vβ 24个亚家族基因表达情况，10例正常人作为对照。 结果： 正常人外周血T细胞表达全部24个TCR Vβ亚家族，而5例ITP患者外周血T细胞仅表达4-11个Vβ亚家族，主要为Vβ2（100％）和Vβ3（100％），其次为Vβ19（80％）和Vβ21（80％）部分。全部样本未检测出Vβ4、Vβ6、Vβ17、Vβ20、Vβ24亚家族表达。 结论： ITP患者外周血T细胞TCR Vβ基因谱系呈限制性表达，与其存在细胞免疫功能异常有关。