Idiopathic thrombocytopenic purpura

Idiopathic(autoimmune) thrombocytopenic purpura(ITP) is characterized by thrombocytopenia and normal to increased numbers of megakaryocytes. ITP is a disease caused by circulating autoantibodies that react with the platelet membrane. It is thought that platelet-associated IgG(PAIgG) plays an important role in the mechanism of ITP, since increases in PAIgG are closely related to decreases in platelet count in patients with this disease. However, it is possible that PAIgG includes immune complex and platelet antibodies to human platelet alloantigens(HPA) other than autoantibodies. There have been several recent reports on autoantibodies to glycoprotein IIb/IIIa and Ib/IX. Although the etiology of ITP remains unclear, both genetic and environmental factors appear to be involved in it. With respect to the genetic aspects of ITP, the human leukocyte antigen (HLA) haplotype of patients is considered a potentially important factor in etiology. Various methods have been used for the treatment of chronic ITP. However, splenectomy and corticosteroids are still the mainstays of therapy. Because of the heterogeneity of the disease, however, approximately 20% of cases are refractory to these treatments. New therapy of chronic or refractory ITP with thrombopoietin, antiCD40 ligand antibody, and Helicobactor pylori eradication have recently been reported.     

Idiopathic thrombocytopenic purpura during remission of thrombotic thrombocytopenic purpura

Three patients were treated empirically with anti-platelet agents, prednisone, plasmapheresis, and prostacyclin for the classical clinical syndrome of thrombotic thrombocytopenic purpura (TTP). All three patients initially responded, then relapsed after one to 13 months with a clinical picture characteristic of immunogenic thrombocytopenic purpura (ITP). At relapse, all three had thrombocytopenia without microangiopathy or other causes of thrombocytopenia. All responded to splenectomy. This complication of TTP may become more common with improved survival in TTP. Recognition may prevent inappropriate therapy.     

Idiopathic thrombocytopenic purpura in adults

Idiopathic thrombocytopenic purpura (ITP) is a primary immune thrombocytopenia that is typically manifested in adults by acute bleeding, severe thrombocytopenia, and normal to increased megakaryocytes in the bone marrow. Labeling studies suggest that most patients with ITP have an IgG antibody directed against the platelet membrane resulting in sequestration in the spleen, and that sequestration in other organs such as the liver bodes a poor prognosis. Splenectomy and/or corticosteroids remain the mainstay of therapy, with permanent remissions induced in 75% of patients. We review alternative forms of therapy such as immunosuppressive agents, high-dose gamma-globulin, and others to enable the practicing physician to select the best treatment for patients refractory to standard therapy. Age appears to influence response to therapy and morbidity, with advancing age imparting a poorer prognosis.     

Idiopathic thrombocytopenic purpura in children

Idiopathic thrombocytopenic purpura is a disorder characterized by antibody-mediated platelet destruction. Other than thrombocytopenia and its consequences, the physical and laboratory examination of the child with ITP is normal. The prognosis in children is excellent; 90 percent will recover spontaneously within one year. Serious hemorrhage is uncommon and conservative management is appropriate. Aspirin and potential trauma should be avoided. Transfusions are rarely necessary or helpful. Corticosteroids may cause a more rapid rise in the platelet count but do not influence the long-term prognosis.     

Idiopathic thrombocytopenic purpura in children

In children the rate of acute, transient ITP is much higher than the chronic form of ITP. Often acute childhood ITP is a para- or postinfectious event. Pathophysiologically bleeding symptoms mainly depend on the ratio between normal or increased platelet production and early destruction of platelets. The management of ITP has to be focused on the individual bleeding symptoms rather than to the platelet count (see staging system). Today's treatments are directed against the disturbed immune response. As recent guidelines and surveys demonstrate opinion based recommendations have to be challenged by evidence based clinical research in ITP (see www.unibas.ch/itpbasel).     

Idiopathic thrombocytopenic purpura following viral infection

The reason why causes idiopathic thrombocytopenic purpura(ITP) was usually unknown. However, we clinically experience these cases after some viral infections. Viral infection can induce the autoimmune diseases including ITP. Probably most of acute and/or chronic ITP may be immunologically caused by molecular mimicry, and antibodies formed in response to viral infection may cross-react with antigenic targets naturally present on platelet. We explain the two reports on the chronic ITP following viral infections of influenza A and hepatitis C in detail.     

Plasmapheresis for thrombotic thrombocytopenic purpura (TTP)

A 70-year-old woman with thrombotic thrombocytopenic purpura (TTP) was treated with plasmapheresis using fresh frozen plasma as a fluid replacement. Complete recovery and lasting remission were observed. It appears that plasmapheresis combined with massive fresh frozen plasma can be an effective mode of treatment for patients who were, otherwise, refractory to conventional therapy.     

59例小儿特发性血小板减少性紫癜检验结果分析

目的 分析特发性血小板减少性紫癜(ITP)小儿患者骨髓巨核细胞及血小板形态学改变和过敏指标的结果变化.方法 对59例ITP小儿患者进行骨髓巨核细胞形态、血小板形态观察及嗜酸性粒细胞计数和过敏原三项检测,并对21例骨髓形态学检验大致正常的对照组,进行同样实验.结果 91.5％ITP患儿骨髓巨核细胞浆上可见空泡、50.8％可见幼稚巨核细胞产板现象、88.1％出现血小板形态异常、83.1％骨髓嗜酸性粒细胞增多、72.9％血清IgE升高,与对照组比较差异有统计学意义(P＜0.05).结论 巨核细胞形态学改变对确诊ITP有重要意义,骨髓嗜酸性粒细胞增多及血清IgE水平增高,有助于ITP鉴别诊断和治疗.     

血小板特异性自身抗体检测在特发性血小板减少性紫癜中的意义

目的 检测特发性血小板减少性紫癜(ITP)患者体内的血小板特异性自身抗体与临床严重程度和临床疗效间的关系. 方法 应用改良的单克隆抗体特异性俘获血小板抗原(MAIPA)法检测血小板膜糖蛋白(GPⅡ bⅢa、GPIb)特异性自身抗体. 结果 ITP组(40例),10例为单一抗GPⅡ b Ⅲa抗体阳性.6例为单一抗GPIbα抗体阳性,20例为双抗体阳性,4例为双抗体阴性.非免疫性血小板减少组与正常对照组均为阴性.抗GPⅡbⅢa抗体(b=-0.071,P<0.01)、抗GPlbα抗体(b=-0.092,P<0.01)均与采血时血小板计数呈显著负相关.治疗后,双抗体阳性组8例治疗无效,单抗体阳性组(16例)1例治疗无效(χ2=6.09,P<0.05). 结论 血小板特异性自身抗体检测对鉴别特发性和非免疫性血小板减少症有一定价值.抗体种类与临床疗效有一定关系.     

Disorders associated with autoimmune thrombocytopenic purpura (ATP)

Idiopathic thrombocytopenic purpura(ITP) was originally defined as a thrombocytopenia without apparent causes. However, it is currently considered as one of the autoimmune diseases, autoimmune thrombocytopenia(ATP) caused by increased platelet destruction by anti-platelet antibodies. ATP is associated with various disorders, including other autoimmune diseases, lymphoproliferative disorders, and infection. However, significance of the association of ATP with these disorders is not clear in some cases. When activity of these disorders is low, standard treatments for ITP are effective for thrombocytopenia. Otherwise, treatments for the primary disorders are necessary.     

Anti-Kell (K1) in idiopathic thrombocytopenic purpura

A transiently occurring anti-Kell antibody was observed in a 2 1/2-year- old child who had idiopathic thrombocytopenic purpura after recovery from an upper respiratory tract infection. The antibody was probably of the IgM class. There was no history of prior blood transfusion.