HLA antigens in idiopathic thrombocytopenic purpura

The lymphocytes of 52 patients with the clinical diagnosis of idiopathic thrombocytopenic purpura (ITP) were typed for the HLA-A,-B and-C antigens, and of 27 of those patients also for the DR antigens. ITP proved not to be significantly associated with any of the HLA-A,-B,-C or-DR antigens tested for. On the platelets of 35 of these 52 patients, autoantibodies were detected in the direct immunofluorescence test. In these 35 patients with autoimmune thrombocytopenia (AITP), an increased frequency of HLA-Bw38 was found (14.3% versus 2.6% in controls). The frequency of none of the HLA antigens was significantly increased in the group of 17 ITP patients without demonstrable autoantibodies. The difference in association with HLA-Bw38 between AITP and ITP without demonstrable autoantibodies was not significant.     

Platelet antibodies in idiopathic thrombocytopenic purpura.

An immunofluorescence (IF) technique for the detection of antibodies was applied to idiopathic thrombocytopenic purpura (ITP). Serum platelet antibodies were found in thirteen out of twenty-two patients (59 percent) with active disease, but in only four out of fifteen patients (27 percent) who had attained remission. Direct tests for platelet-associated IgG were positive in 36 and 44 percent of these patients respectively. In two cases IgM was observed on the patients' platelet membranes. C3 was not detedted on patients' platelets. Platelet-associated IgG was also found in several other disorders and its occurrence is not therefore diagnostic of ITP. In addition, serum platelet antibodies do not indicate specifically ITP as they may also be due to previous isoimmunization. Antibodies in the sera of patients with ITP generally did not fix Clq and in most cases bound to platelets only in the presence of EDTA. In contrast, isoantibodies often fixed Clq and they had equal affinity for platelets suspended in ACD or EDTA plasma. This was confirmed by quantitative data on IgG binding by platelets obtained by measuring 125-I-labelled protein A uptake. The simplicity of the IF technique permits its routine application and the technique may give useful information with respect to the nature of the antibodies. It must, however, be considered of limited value in the diagnosis of ITP.     

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.     

特发性血小板减少性紫癜患者协同刺激分子的表达

目的：探讨特发性血小板减少性紫癜（ITP）患者外周血淋巴细胞CD80、CD86及其配体CD28的表达情况。方法：应用免疫荧光标记和流式细胞技术检测34例ITP患者和34名正常人外周血淋巴细胞协同刺激分子CD80、CD86及其配体CD28的表达。结果：ITP患者外周血淋巴细胞CD80、CD86表达率（4.21±2.27%,7.19±5.16%）均明显高于正常对照组（2.34±0.87%,4.08±1.96%,p〈0.01）。结论：ITP患者CD28/CD80和CD28/CD86协同刺激分子过度表达,协同刺激分子CD80、CD86与ITP发病密切相关。     

One-day intravenous therapy with high-dose gamma-globulin for idiopathic thrombocytopenic purpura

The effects of one-day intravenous therapy with gamma-globulin in a 25-year-old man with idiopathic thrombocytopenic purpura are reported. The patient showed resistance to prednisolone and had bleeding tendency. The thrombocytopenia improved after the intravenous administration of gamma-globulin at a dose of 1 g/kg. Splenectomy was carried out. The results suggested that the usual dose of gamma-globulin is not always necessary. The half-dose increased the platelet count.     

Functional properties of lymphocytes in idiopathic thrombocytopenic purpura

Idiopathic or immune thrombocytopenic purpura (ITP) is characterized by antibody-mediated destruction of platelets. The etiology is unknown. We postulated that increased autoantibody production in ITP might be attributable to either increased or prolonged expression of CD40 ligand (CD40L, CD154) in T or B lymphocytes, as has been previously observed in systemic lupus erythematosus (SLE). In addition, we hypothesized that ITP is characterized by increased levels of interleukin 4 (IL-4), a prototypic Th2 cytokine which, along with CD40 ligation, is required for B cell differentiation and production of several IgG subclasses. Cell surface CD154 expression was measured in freshly-isolated and in vitro-activated peripheral blood lymphocytes of sixteen ITP patients and eight healthy volunteers. Plasma levels of IL-4 and the prototypic Th1 cytokine interferon-gamma (IFNγ) were determined. We observed that CD154 expression in unstimulated and in vitro-activated lymphocytes did not differ between ITP patients and healthy controls. Plasma levels of the Th2 cytokine IL-4 were significantly higher in the ITP patients. These studies indicate that overexpression of CD154 in lymphocytes is unlikely to be a primary pathophysiological defect in most patients with ITP. The data support that in addition to cell membrane antigens such as CD154, soluble cytokines such as IL-4 should be considered as potential targets for therapy in this disease.     

Platelet aggregation in chronic idiopathic thrombocytopenic purpura.

A method for washing platelets by albumin density gradient separation has been modified to prepare platelet rich plasma of thrombocytopenic patients for platelet aggregation studies. The concentration procedure, consisting of centrifuging platelets into a specific gravity gradient between plasma and 40-45% aqueous solution of bovine albumin, does not affect platelet aggregation adversely. Platelet aggregation in eight patients with chronic idiopathic thrombocytopenic purpura was determined by this method. On the basis of the results the patients could clearly be divided into two groups: four patients with normal aggregation and four with a qualitative platelet defect. In contrast to the other patients, the group with an in vitro platelet functional defect all had more prolonged bleeding times and the presence of a serum antiplatelet antibody.     

Chemotherapy in a patient with prior history of idiopathic thrombocytopenic purpura

We described a 67 years old small-cell lung cancer patient with a prior history of idiopathic thrombocytopenic purpura (ITP) who was treated with successful chemotherapy. It is probably safe to administer chemotherapeutic agents for some cancer patients with prior history of ITP, but it is important to prevent or minimize the toxicities of these chemotherapeutic agents.     

急性特发性血小板减少性紫癜免疫功能的观察

目的：探讨急性特发性血小板减少性紫（ITP）患儿细胞因子：血清可溶性白介素－2受体（sIL-2R)、白介素－6（IL－6）,免疫球蛋白轻链,心磷脂抗体（ACA）及淋巴细胞亚群的变化。方法：应用化学发光法,速率散射比浊法,ELISA法及AKP－ABC。结果：急性ITP患儿治疗前sIL-2R、IL－6升高,轻链κλ降低与正常对照P＜0．01,3个月后恢复至对照组近似水平（P均＞0．05）。ACA阳性率占70．37％。CD^ 4细胞减少,CD^ 8细胞增多,CD^ 4/CD^ 8比值下降（P均＜0．01）。结论：为临床提供判断疗效及估计预后较血小板（BPC）计数更可靠的依据,也为免疫调节剂治疗提供理论依据。