免疫性血小板减少性紫癜的发病机制与临床研究进展

免疫性血小板减少性紫癜(Immune thrombocytopenic purpura,ITP)是自身抗体介导的血小板减少综合征,自身抗原的主要成分是血小板一种或多种糖蛋白;细胞免疫也是血小板破坏的一个重要原因.目前ITP的诊断仍是临床排除性诊断,分为原发性与继发性两种.ITP治疗的目的是使患者血小板计数提高到安全水平.肾上腺糖皮质激素仍是ITP的首选药物,静脉输注丙种球蛋白(IVIg)用于控制严重出血与重度血小板减少,脾切除仍是治疗慢性ITP的主要手段.血小板生成素(TPO)类似物可能成为新的治疗方法.对成人慢性ITP患者应常规进行幽门螺杆菌(Hp)筛查,阳性患者应根除Hp.     

血小板生成素受体激动剂的临床应用及研究进展

血小板减少症为临床常见的疾病,可见于血液系统疾病与非血液系统疾病.随着对促血小板生成药物研究的深入,血小板生成素受体激动剂（TPORA）罗米司亭及艾曲泊帕的临床应用,可有效提高患者血小板计数,为治疗血小板减少症提供新的治疗方法.笔者拟就TPORA的作用机制、其在血液系统疾病及肝病相关的血小板减少症中的临床应用的进展进行综述.     

Long-term Efficacy of Pegylated Recombinant Human Megakaryocyte Growth and Development Factor in Therapy of Aplastic Anemia

We describe a patient with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) who developed an extramedullary blast crisis in the central nervous system (CNS) and then a subcutaneous tumor of the neck during treatment with imatinib mesylate. Administered 400 mg of imatinib mesylate after the diagnosis of chronic-phase CML, the patient achieved a complete cytogenetic remission 4 months later. However, he developed a mixed myeloid/B-cell blast crisis with additional karyotype abnormalities only in the CNS during a complete cytogenetic remission in the bone marrow. Several doses of intrathecal chemotherapy and whole-brain irradiation were effective in treating the blast crisis in the CNS. After 7 months of complete cytogenetic remission, the patient experienced a subcutaneous tumor in the right neck. A biopsy of the tumor revealed a mixed myeloid/T-cell blast crisis. The cytogenetic analysis showed that the blast crisis clone in the neck tumor was different from that of the CNS. An increased dose of imatinib mesylate was ineffective in treating the neck tumor. Irradiation to the right neck was therefore undertaken. This case suggests that the development of a clone resistant to imatinib mesylate is not always detected in the bone marrow and that multiple Ph-positive clones have the potential to become transformed into a blast crisis.     

Thrombocytopenia associated with chronic liver disease

Thrombocytopenia (platelet count <150,000/microL) is a common complication in patients with chronic liver disease (CLD) that has been observed in up to 76% of patients. Moderate thrombocytopenia (platelet count, 50,000/microL-75,000/microL) occurs in approximately 13% of patients with cirrhosis. Multiple factors can contribute to the development of thrombocytopenia, including splenic platelet sequestration, bone marrow suppression by chronic hepatitis C infection, and antiviral treatment with interferon-based therapy. Reductions in the level or activity of the hematopoietic growth factor thrombopoietin (TPO) may also play a role. Thrombocytopenia can impact routine care of patients with CLD, potentially postponing or interfering with diagnostic and therapeutic procedures including liver biopsy, antiviral therapy, and medically indicated or elective surgery. Therapeutic options to safely and effectively raise platelet levels could have a significant effect on care of these patients. Several promising novel agents that stimulate TPO and increase platelet levels, such as the oral platelet growth factor eltrombopag, are currently in development for the prevention and/or treatment of thrombocytopenia. The ability to increase platelet levels could significantly reduce the need for platelet transfusions and facilitate the use of interferon-based antiviral therapy and other medically indicated treatments in patients with liver disease.     

Plasma thrombopoietin level and platelet indices in hemodialysis patients receiving recombinant human erythropoietin

We focused on thrombocytopenia in hemodialysis patients (HD) receiving recombinant human erythropoietin (rHuEPO) and investigated thrombopoietin (TPO) level and platelet indices. We analyzed platelet parameters including mean platelet volume (MPV), platelet-crit (PCT), mean platelet component (MPC) concentration and platelet count (PLT) using ADVIA 2120 in 375 HD patients. This study included 25 HD patients undergoing treatment with rHuEPO at 9000 IU/week. These patients were divided into two groups by reference PLT of 130 × 10⁹/l [eight patients with low PLT (L-PLT group) and 17 patients with normal PLT (N-PLT group)], and TPO level and platelet indices in each group were compared with those in nine HD patients not receiving rHuEPO. In HD patients, the mean value of MPV was slightly higher and the mean values of PLT, PCT, and MPC were significantly lower than those in healthy controls. TPO levels were significantly higher in patients receiving rHuEPO than in patients not receiving rHuEPO. However, no significant difference was found between TPO levels in patients in the L-PLT group and patients in the N-PLT group. TPO levels were not correlated with PLT in these patients and that MPC levels decreased remarkably regardless of PLT.     

脓毒症患者血小板下降与感染性休克发生的相关性

目的：分析脓毒症患者血小板下降情况及其与感染性休克发生的相关性。方法回顾性分析45例脓毒症患者血小板正常范围内下降（同时测同一时间点的TPO水平）与感染性休克发生前后的变化,以及发生感染性休克与未发生休克的脓毒症患者血小板计数变化（同一时间TPO水平）并同APACHEⅢ（急性生理学及慢性健康状况评分系统Ⅲ）评分对比分析得出。结果脓毒症患者诊断前PLT水平为（187.7＆#177;51.73）＆#215;109/L;脓毒症诊断后PLT水平为（126.1＆#177;38.71）＆#215;109/L,二者差异具有统计学意义（t=5.743,P＜0.001）;24例脓毒症未发生休克患者PLT下降,为（49.44＆#177;49.50）＆#215;109/L;21例感染休克患者PLT水平下降,为（90.19＆#177;44.86）＆#215;109/L;二者差异具有统计学意义（t=-2.896,P＜0.001）。脓毒症患者诊断前后血小板计数下降和感染休克发生后血小板计数下降与APACHEⅢ评分均呈正相关关系（r=0.449、0.978,P＜0.001）。结论血小板计数下降作为脓毒症患者病情变化的单独风险依据,可观察抗炎与促炎平衡状态的指标,无论血小板计数在否正常范围,下降的趋势更为重要。     

Eltrombopag-related renal vein thromboembolism in a patient with immune thrombocytopenia: A case report

BACKGROUNDEltrombopag is an orally administered thrombopoietin receptor agonist linked to a heightened risk of treatment-related thromboembolism. Both venous and arterial thromboses have been documented in the medical literature.CASE SUMMARYIn the absence of nephropathy, a 48-year-old patient receiving eltrombopag for immune thrombocytopenia (ITP) developed renal vein thrombosis and pulmonary embolism. The renal vein thrombus spontaneously resolved during subsequent anticoagulant treatment, restoring venous circulation.CONCLUSIONA rapid upsurge in platelets, rather than their absolute number, may trigger thrombotic events in this setting. For patients at high thrombotic risk, individualized eltrombopag dosing and vigilance in platelet monitoring are perhaps needed during treatment of ITP.