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1、血小板减少症的临床诊治,Platelets,Adult form of the same undifferentiated stem cell as the RBC and the WBC Thrombopoietin (hormone) specializes the stem cell into the thrombocyte Disc shaped without a nucleus Help slow blood loss from damaged vessels by forming a plug Also excrete a chemical the enhances more c
2、lot formation,Platelets,Life span Usually 5-9 days Aged and dead platelets are removed in the liver and spleen by fixed macrophages Normal amounts Between 100,000 and 300,000 in each microliter of blood 2-4 micrometers in diameter,血小板减少的原因,血小板生成减少或无效死亡 遗传性 获得性: 药物、恶性肿瘤、感染、电离辐射、再障、MDS等损伤造血干细胞或影响其在骨髓中
3、增殖所致。这些因素可影响多个造血细胞系统，常伴有不同程度贫血，白细胞减少，骨髓巨核细胞减少 (2) 血小板破坏过多 先天性 获得性：免疫性和非免疫性。免疫性血小板破坏过多常见的有特发性血小板减少和药物性血小板减少。非免疫性血小板减少包括感染、弥漫性血管内凝血、血栓性血小板减少等 (3)血小板在脾内滞留过多：脾功能亢进,重症感染的发病过程,感染,感染严重征象-血小板计数,ICU中，血小板减少的病人住院时间长且死亡率高 有人发现23%的危重病人至少有一次血小板计数10万/mm3,10%的病人5万/mm3 外科急诊ICU血小板减少的病人38%死亡，而对照组仅为20,严重脓毒症(Severe seps
4、is,定义：合并有器官功能障碍、低灌注或低血压 器官功能障碍: 动脉氧分压低(氧合指数PO2/FIO2 2.0mg/dl；凝血功能异常(INR1.5或APTT60秒)；血小板减少(血小板计数2.0mg/dl或35mmol/L) 组织灌注指标:高乳酸盐血症(2mmol/L) 血液动力学指标:动脉血压过低(收缩压SBP 40 mm Hg,小儿最常见的出血性疾病，也是最常见的血小板异常性疾病。主要临床特点为血循环中存在抗血小板抗体，使血小板破坏过多，血小板减少引起皮肤、粘膜自发性出血；骨髓巨核细胞数正常或增多，出血时间延长，血块收缩不良，束臂试验阳性,免疫性血小板减少性紫癜(ITP,基本情况 发病率
5、高（40100/10万），没有明显的地域和种族差别；中国13亿人口中每年发病人数将超过50万，其中急性ITP在儿童多见，发病高峰年龄2-5岁，无性别差异，常在冬春季病毒感染高峰期发病较多。慢性ITP 则多见于20-50岁的成人，女性较男性发病率高3-4倍，发病无季节性，但近年来儿童慢性ITP的发病有增多趋势，研究显示部分ITP的发病与幽门螺旋杆菌(HP)、人类巨细胞病毒(hCMV)等感染有关,诊断依据,1）血小板计数100109/L （2）骨髓巨核细胞增多或正常，有成熟障碍。成熟障碍主要表现为幼稚型和（或）成熟型且无血小板释放的巨核细胞比例增加，巨核细胞颗粒缺乏，胞质少。 （3）皮肤出血点、淤
6、斑和（或）粘膜出血等临床表现。 （4）急性型脾脏多无肿大 （5）具有以下4项中任何1项糖皮质激素治疗有效；脾切除有效；血清血小板相关抗体（PAIg或PAC3）阳性；血小板寿命缩短 （6）排除其他可引起血小板减少的疾病，如再生障碍性贫血、白血病 、骨髓增生异常综合征（MDS）、其他免疫性疾病以及药物性因素,临床分型,急性型 起病急，常有发热，出血一般较重，血小板计数常20109/L，病程6个月 慢性型 起病隐匿，出血一般较轻，血小板计数常为（3080）109/L，病程6个月,病情分度,轻度 血小板计数（BPC）50109/L，一般无自发出血，仅外伤后易发生出血或术后出血过多 中度 25109/L
7、BPC50109/L，有皮肤粘膜出血点或外伤后淤斑、血肿、外伤出血延长，但无广泛出血 重度（具备下列一项者即可）10109/LBPC25109/L，皮肤广泛出血、淤斑或多发血肿，粘膜活动性出血（齿龈渗血、口腔血泡、鼻出血）；消化道、泌尿道或生殖道暴发出血或发生血肿压迫；视网膜出血或咽后壁出血；外伤处出血不止，经一般治疗无效 极重度（具备下列一项即可） BPC10109/L或几乎查不到，皮肤粘膜广泛自发性出血、血肿或出血不止；危及生命的严重出血（包括颅内出血,等级 出血严重程度及生活质量 临床干预,一级 少量出血，紫癜100个，和/或5个、 建议观察 直径3cm的小瘀斑，无粘膜出血 二级 轻微出
8、血，紫癜100个，和/或5个、 观察或选择性治疗 直径3cm的小瘀斑，无粘膜出血 三级 中等量出血，明显的粘膜出血 临床干预使患儿 病情达一/二级 四级 粘膜出血或怀疑有内部出血 紧急临床干预,Primary ITP Primary ITP is an autoimmune disorder characterized by isolated thrombocytopenia (peripheral blood platelet count100 x109/L) in the absence of other causes or disorders that may be associated
9、 with thrombocytopenia. The diagnosis of primary ITP remains one of exclusion; no robust clinical or laboratory parameters are currently available to establish its diagnosis with accuracy. The main clinical problem of primary ITP is an increased risk of bleeding, although bleeding symptoms may not a
10、lways be present. Secondary ITP All forms of immune-mediated thrombocytopenia except primary ITP,Proposed definitions of disease,BLOOD, 12 MARCH 2009 VOLUME 113, NUMBER 11,Standardization of terminology, definitions and outcome criteria in immune thrombocytopenic purpura of adults and children: repo
11、rt from an international working group,The acronym ITP should be followed by the name of the associated disease (for thrombocytopenia after exposure to drugs, the terms “drug-induced” should be used) in parentheses: for example, “secondary ITP (lupus-associated),” “secondary ITP (HIV-associated),” a
12、nd “secondary ITP (drug-induced).” For manuscript titles, abstracts,and so on, definitions such as lupus-associated ITP or HIV-associated ITP can also be used,BLOOD, 12 MARCH 2009 VOLUME 113, NUMBER 11,Phases of the disease 1. Newly diagnosed ITP within 3 months from diagnosis 2.Persistent ITP betwe
13、en 3 to 12 months from diagnosis. Includes patients not reaching spontaneous remission or not maintaining complete response off therapy. 3.Chronic ITP lasting for more than 12 months 4.Severe ITP Presence of bleeding symptoms at presentation sufficient to mandate treatment, or occurrence of new blee
14、ding symptoms requiring additional therapeutic intervention with a different platelet-enhancing agent or an increased dose,BLOOD, 12 MARCH 2009 VOLUME 113, NUMBER 11,难治性ITP的诊断标准,国际协作组： 脾切除无效或有效后复发 存在严重的ITP或需要治疗(包括但不局限于低剂量的皮质激素)的严重出血。仅需单独应用常规或附加治疗的病人不是难治性的 除外其他引起血小板减少的疾病。 国内采用的标准: 病程6个月, 正规皮质激素治疗无效及达
15、那唑、其它常用免疫抑制剂或脾切除无效, 血小板计数 30109/L。除外继发性免疫性血小板减少性紫癜, 如系统性红斑狼疮、抗磷脂抗体综合征、骨髓增生异常综合征等。 George JN等认为，只有脾切除无效的ITP患者才能被诊断为难治性ITP，因为牌切除是治疗ITP最有效、最持久的方法,Refractory ITP Definition (all should be met) Failure to achieve at least R or loss of R after splenectomy* Need of treatment(s) (including, but not limited
16、to, low dose of corticosteroids) to minimize the risk of clinically significant bleeding.Need of on-demand or adjunctive therapy alone does not qualify the patient as refractory. Primary ITP confirmed by excluding other supervened causes of thrombocytopenia Definition of on-demand therapy Any therapy used to temporarily increase the platelet count sufficiently to safely perform invasive procedures or in case of major bleeding or trauma Definition of adjunctive therapy Any non-ITP specific therap
