Investigation of megakaryocyte apoptosis in children with acute and chronic idiopathic thrombocytopenic purpura

OBJECTIVE: Although the platelet destruction shows a primary role in the thrombocytopenia of idiopathic thrombocytopenic purpura (ITP), it has been demonstrated that impaired platelet production may also contribute to the severity of thrombocytopenia in ITP. The present study examined megakaryocyte apoptosis in bone marrow aspirates of children with acute and chronic ITP and investigated the role of megakaryocyte apoptosis in ITP pathophysiology. METHODS: Thirteen children diagnosed with acute ITP and eight children diagnosed with chronic ITP comprised the study group. Ten children, who were hospitalized for scoliosis operation but healthy otherwise, comprised the control group. In all children, megakaryocytes were isolated from the same amount of bone marrow aspirate samples using MACS CD61 MicroBeads (Miltenyl Biotec, Auburn, CA, USA). Megakaryocyte apoptosis was studied with transferase-mediated d-UTP-bitin nick end-labeling method. RESULTS: Isolated megakaryocyte counts did not differ significantly between acute ITP, chronic ITP and control groups. The percentage of apoptotic megakaryocytes did not differ significantly between acute ITP group and control group and between chronic ITP group and control group. The percentage of apoptotic megakaryocytes in patients with chronic ITP was significantly lower than the patients with acute ITP. There was no correlation between the percentage of apoptotic megakaryocytes and platelet counts of the cases. CONCLUSIONS: Increased megakaryocytic apoptosis does not play a role in the pathogenesis of dysmegakaryopoiesis and impaired platelet production in children with ITP. Decreased megakaryocyte apoptosis in cases with chronic ITP may be due to suppression of megakaryocyte maturation, as the terminal phase of the megakaryocyte lifespan is characterized by the onset of apoptosis.     

Lepirudin as a safe alternative for effective anticoagulation in patients with known heparin-induced thrombocytopenia undergoing percutaneous coronary intervention: case reports.

Heparin-induced thrombocytopenia (HIT) is a well-documented complication of heparin anticoagulation therapy. Heparin's frequent use in the cardiovascular population poses a significant challenge for managing patients with HIT in need of percutaneous coronary intervention (PCI). We describe four patients with HIT who successfully underwent PCI without thrombotic or hemorrhagic complications while on lepirudin.     

A case of severe neonatal thrombocytopenia with schizencephaly associated with anti-HPA-1 b and anti-HPA-2a

We report a family with a neonate who was severely damaged by intracranial haemorrhages. These probably occurred before the 20th week of gestation. The neonate had a moderate thrombocytopenia. In the maternal serum anti-HPA-1b and anti-HPA-2a alloantibodies were detected. Third-generation assays were applied to identify the alloantibodies. No other cause for the bleeding was found. Probably the combination of anti-HPA-1b and anti-HPA-2a alloantibodies, directed against the platelet fibrinogen receptor and the von Willebrand receptor, respectively, induced a thrombocytopenia and a thrombocytopathy.     

Failure of the platelet-activating-factor antagonist WEB 2086 BS for treatment of chronic autoimmune thrombocytopenia

Summary Thirteen patients with chronic autoimmune thrombocytopenia (AITP) were treated for 14 days with daily oral doses of 120 mg of the novel platelet-activating-factor (PAF) antagonist WEB 2086 BS. Clinical bleeding symptoms remained essentially unchanged in 9 patients and became more pronounced in the post-treatment period in 4 patients. In no case was an increase in platelet counts observed. While the PAF antagonist was well tolerated subjectively during treatment, most patients exhibited a prolongation of the sensitive hemostasis time (a modified bleeding time test) after treatment, but the Duke bleeding time was not changed. We conclude that the PAF antagonist WEB 2086 BS is ineffective for treatment of chronic AITP and should be used with caution in thrombocytopenic patients.     

Age as the major predictive factor of long-term response to splenectomy in immune thrombocytopenic purpura

Sixty-one consecutive patients undergoing splenectomy for chronic immune thrombocytopenia were retrospectively evaluated. Platelet response was considered as complete (CR) when platelet count rose to > 100 x 109/l, partial (PR) when 30-100 x 109/l or absent (NR) if otherwise. Follow-up (mean time 7.6 years) was possible in 54 patients. Forty-eight patients (88%) had an immediate response to splenectomy (39 CR, 9 PR) whereas six (12%) were NR. Thirty-six responders (67%) had sustained remission (31 CR; 5 PR) without further treatment; thrombocytopenia recurred in 12 patients (33%). The probability curve of continued remission showed a constant relapse-rate during the first 36 months; a further step of relapse was observed beginning 70 months after surgery. The only positive predictive factor for the long-term response to splenectomy was age < 40 (P < 0.005). Neither duration of thrombocytopenia nor previous response to medical treatment (steroids and/or intravenous immunoglobulins) were related to splenectomy response.     

神经纤毛蛋白-1(NRP-1)在原发免疫性血小板减少症发病机制中的作用

目的探讨神经纤毛蛋白-1(NRP-1)在调节性T细胞(Treg)上的表达与其配体信号素3A(Sema3A)、转化生长因子β1(TGF-β1)以及1型辅助T细胞(Th1)和2型辅助T细胞(Th2)之间平衡的关系。方法纳入2014年3月至2015年5月就诊的62例ITP患者(新诊断ITP 33例、慢性ITP 29例),以同期30名健康体检者作为正常对照组。流式细胞术检测Treg细胞NRP-1表达,酶联免疫吸附法(ELISA)检测血浆Sema3A、TGF-β1、IFN-γ和IL-4水平,实时聚合酶链式反应(RT-PCR)检测外周血NRP-1、Sema3A、TGF-β1 mRNA表达水平。分别采用单因素方差和独立样本t检验进行三组间和两组间比较,用Spearman相关系数评估NRP-1、Sema3A、TGF-β1 mRNA表达的相关性。结果与慢性ITP组和正常对照组比较,新诊断ITP组Treg细胞NRP-1表达降低[分别为(0.15±0.03)%、(0.33±0.15)%、(0.46±0.06)%,P<0.01],血浆Sema3A水平升高[分别为(8.10±1.32)μg/L、(7.41±1.30)μg/L、(2.88±0.82)μg/L,P<0.01],血浆TGF-β1水平降低[分别为(16.50±3.36)μg/L、(35.17±10.26)μg/L、(41.00±10.02)μg/L,P<0.01],血浆IFN-γ水平升高[分别为(17.21±2.80)ng/L、(10.23±1.59)ng/L、(8.18±3.27)ng/L,P<0.01],Th1/Th2(IFN-γ/IL-4)比值升高(分别为1.29±0.30、0.72±0.16、0.61±0.27,P<0.01)。新诊断ITP、慢性ITP组NRP-1、Sema3A mRNA的表达均低于正常对照组(P<0.01)。新诊断ITP组NRP-1 mRNA表达与Sema3A、TGF-β1 mRNA表达均呈正相关。结论NRP-1可能参与ITP的发病机制。     

Powikłania infekcyjne i autoimmunologiczne w przewlekłej białaczce limfocytowej

Profound disturbances of different elements of the immune system in chronic lymphocytic leukemia (CLL) lead to impaired elimination of allogeneic antigens, like pathogenic microorganisms, and deficient tolerance of self-antigens, which is responsible for autoimmunological disorders. Susceptibility to infections in CLL patients is due to disease-related immunodeficiency, mainly hypogammaglobulinemia, and aggravated by myelo- and immunosuppressive properties of currently used antileukemic drugs, especially alkylating agents and purine analogues. Severe infections occur in the majority of CLL patients, they may be life-threatening and shortening the patients’ survival. They affect most frequently the respiratory system, and are caused mainly by Gram-positive and Gram-negative bacteria and common viruses like Herpes and Varicella-Zoster. In some patients, especially those treated with purine analogues, opportunistic infections can occur. There are no generally admitted guidelines for the prophylaxis of infections. Vaccinations against influenza and encapsulated bacteria, intravenous immunoglobulins and prophylaxis with cotrimoxazol and antiviral drugs for selected patients under purine analogues or alemtuzumab have been proposed. Autoimmune hemolytic anemia (AIHA) due to the production of anti-erythrocyte autoantibodies is the most common autoimmunological complication of CLL, especially in patients with positive direct antiglobulin test (DAT). It can be also triggered by alkylating agents and purine analogues. The treatment of AIHA includes corticosteroids, rituximab, immunosuppressive agents and splenectomy. Autoimmune thrombocytopenia, pure red cell aplasia, autoimmune neutropenia and non-hematological autoimmune manifestations can also occur.     

原发免疫性血小板减少症患者CD4+T细胞CD28的表达及其与IFN-γ/IL-10比率的关系

目的 研究原发免疫性血小板减少症(ITP)患者治疗前、后,外周血CD4+的T淋巴细胞中共刺激分子CD28的表达及与IFN-γ/IL-10比率的关系.方法 采用流式细胞术分析30例ITP患者糖皮质激素治疗前、后和26例正常对照外周血CD4+T细胞上CD28表达率,用ELISA双夹心法检测外周血血清中IFN-γ和IL-10的水平,评价CD4+ CD28+与IFN-γ/IL-10平衡状态、血小板计数之间的关系.结果 ITP患者治疗前CD4+ CD28+的表达显著高于正常对照组(P＜0.05),治疗后与正常对照组比较,差异无统计学意义(P>0.05);ITP患者治疗前IFN-γ水平较正常对照组显著增高,IL-10水平显著降低,IFN-γ/IL-10比值显著增高(P＜0.01),治疗后与正常对照组比较,差异无统计学意义(P>0.05);ITP患者治疗前CD4+ CD28+与IFN-γ/IL-10比值呈正相关(P＜0.05),与血小板计数呈负相关(P＜0.05).结论 共刺激分子CD28与ITP免疫紊乱密切相关,可能通过参与Th1优势状态形成而在ITP的发病中发挥一定作用.     

B cell elimination in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder with a worldwide distribution, potentially life-threatening with considerable morbidity. The elimination of pathogenic B cells has emerged as a rational therapeutic option. Many open label studies have reported encouraging results in which clinical and serological remission have invariably been described, often enabling the reduction of steroid and immunosuppressive treatment. However, the results from randomized controlled studies have been disappointing and several questions remain to be answered. In this review we will focus on results of B cell direct depletion in the treatment of patients with systemic lupus erythematosus.