血常规的儿科临床实践教学中的解读(原创).ppt

Ding ZhouzhiDepartment of Pediatrics Bengbu Medical College,血常规在儿科临床实践教学中的解读,2023/1/30,儿科学教研室.临床实践教学,2,CBCBlood Routine,Red Blood CellRBCHemoglubinHbRed blood cell indices:MCV,MCH,MCHCHematocritHCT ReticulocyteRetWhite Blood CellWBC,leukocyteWhite blood cell types WBC differentialNeutrophils,Lymphocytes,Monocytes,Eosinophils,and BasophilsPlatelet(thrombocyte)PLT,BPCMean platelet volume MPV,2023/1/30,儿科学教研室.临床实践教学,3,Why It Is Done,Find the cause of symptoms such as fatigue,weakness,fever,bruising,or weight loss.Check for anemia.See how much blood has been lost if there is bleeding.Diagnosepolycythemia or Check for an infection.Diagnose diseases of the blood,such as leukemia.Check how the body is dealing with some types of drug orradiation treatment.Check how abnormal bleeding is affecting the blood cells and counts.Screen for high and low values before a surgery.See if there are too many or too few of certain types of cells.This may help find other conditions,such as too many eosinophils may mean anallergyorasthmais present.,2023/1/30,儿科学教研室.临床实践教学,4,RBC&Hb,正常值随着年龄的变化而变化。,2023/1/30,4,2023/1/30,儿科学教研室.临床实践教学,5,RBC&Hb,正常值随着年龄的变化而变化。,2023/1/30,2023/1/30,儿科学教研室.临床实践教学,6,RBC&Hb,2023/1/30,6,2023/1/30,儿科学教研室.临床实践教学,7,2023/1/30,7,生后红细胞计数变化,2023/1/30,儿科学教研室.临床实践教学,8,2023/1/30,8,生后Hb的变化 The change of the level of postnatal hemoglobin,回目录2,2023/1/30,儿科学教研室.临床实践教学,9,红细胞增多症,红细胞数目、血红蛋白、红细胞压积和血液总容量显著地超过正常水平。新生儿期RBC7.0109/L，Hb220g/L。儿童时期RBC5.0109/L，Hb180g/L(16g/dl)，红细胞压积大于55%和每公斤体重红细胞容量绝对值超过35ml，排除因急性脱水或烧伤等所致的血液浓缩而发生的相对性红细胞增多，即可诊断。原发性的即真性红细胞增多症继发性的主要是由组织缺氧所引起的。,2023/1/30,9,2023/1/30,儿科学教研室.临床实践教学,10,2023/1/30,10,最低标准 Hb minimum standard in normal children,*-WHO标准(1972)#-联合国儿童基金会标准(1986)*-国内标准(1989)(海拔每1000米，相应诊断标准中Hb4%),2023/1/30,儿科学教研室.临床实践教学,11,2023/1/30,11,RBC&Hb,生理性贫血 Physiologic anemia:Physiologic hemolysis Increased blood volumeTemporary hypofunction of myeloid hematopoiesis,使RBC生成不足,约23月时:RBC降至3.01012/L Hb降到100g/L左右，最低90g/L,生后Hb变化,2023/1/30,儿科学教研室.临床实践教学,12,2023/1/30,12,Graduation of anemia in children,2023/1/30,儿科学教研室.临床实践教学,13,2023/1/30,13,形态分类 Classification of morphology,贫血类型 MCV(fl)MCH(pg)MVHC(%)正常值 8094 2832 3238正细胞性 8094 2832 3238大细胞性 94 32 3238 单纯小细胞性 80 28 3238 小细胞低色素性 80 28 32,2023/1/30,儿科学教研室.临床实践教学,14,2023/1/30,14,形态学与病因学的关系(Relation between morphology and etiology),RBC形态 病因 正细胞性 急性失血,溶血,再障,脾亢,肿瘤,急性感染大细胞性 DNA合成障碍:Vit.B12、叶酸缺乏,幼年性 恶性贫血,药物性贫血,红白血病 单纯小细胞性 缺铁早期,慢性感染,慢性疾病小细胞低色素性 Hb合成障碍:缺铁性贫血,地中海贫血,铁 粒幼性贫血.,慢性失血，铅中毒,2023/1/30,儿科学教研室.临床实践教学,15,网织红细胞的意义,网织红细胞增多：表示骨髓红细胞生成旺盛，常见于溶血性贫血，特别是急性溶血（高达0.60.8）。急性失血后510天网织红细胞达高峰，2周后恢复正常。网织红细胞减少：提示骨髓增生功能低下。见于再生障碍性贫血，溶血性贫血再生危象、药物性骨髓抑制时，典型再生障碍性贫血，网织红细胞计数常低于0.005.网织红细胞绝对值低于15109/L为再生障碍性贫血的诊断标准之一。,2023/1/30,15,2023/1/30,儿科学教研室.临床实践教学,16,2023/1/30,16,Disaster of Leukecytes,Neoplastic Disorders of Leukocytes MDS;Myelodysplastic syndrome Non-Neoplastic Disorders of Leukocytes,2023/1/30,儿科学教研室.临床实践教学,17,2023/1/30,17,不同年龄的白细胞水平变化,Cord blood:1520109/L612h:2128109/L1w:12109/L1y:10109/L1y:412109/L,Leucocyte,2023/1/30,儿科学教研室.临床实践教学,18,White blood cell types(WBC differential)in Adult,2023/1/30,儿科学教研室.临床实践教学,19,2023/1/30,19,2023/1/30,儿科学教研室.临床实践教学,20,2023/1/30,20,Neoplastic Disorders of Leukocytes,Leukemia(acute,chronic)Lymphocytic Leukemia(ALL,CLL)Non-Lymphocytic Leukemia(myelogenous leukemia)(AML,CML)LymphomaHodgkins lymphomaNon Hodgkin lymphoma Histiocytosis(malignant,Langerhans cell)OthersMultiple myelomaNeuroblastoma etc.,2023/1/30,儿科学教研室.临床实践教学,21,2023/1/30,21,Myelodysplastic syndrome,Refractory anemia(RA):Refractory neutropenia,Refractory anemia with ringed sideroblasts(RARS):Refractory cytopenia with multilineage dysplasiaRefractory anemia with excess blasts(RAEB):Refractory anemia with excess blasts I and II.RAEB was divided into*RAEB-I(5-9%blasts)and RAEB-II(10-19%)blasts,which has a poorer prognosis than RAEB-I.Refractory anemia with excess blasts in transformation(RAEB-T):characterized by 21-30%myeloblasts in the marrow Chronic myelomonocytic leukemia(put in a new category of myelodysplastic-myeloproliferative overlap syndromes.),2023/1/30,儿科学教研室.临床实践教学,22,2023/1/30,22,Non-Neoplastic Disorders of Leukocytes,Qualitative DisordersFunctional defectQuantitative DisordersLeukocytosis:Neutrophilia,Lymphocytosis,Monocytosis,Eosinophilia,BasophiliaLeukopenia:Granulocytopenia(Agranulocytosis),Lymphocytopenia,2023/1/30,儿科学教研室.临床实践教学,23,2023/1/30,23,Defects of Neutrophil Function,Chronic granulomatous disease(慢性肉芽肿性疾病）X-linked or autosomal recessiveInability to generate H2O2Recurrent infections by catalase-positive organisms(Staphylococcus,Serratia,Salmonella)Myeloperoxidase deficiency（髓过氧物酶缺乏）Autosomal recessiveRecurrent candidal infections,2023/1/30,儿科学教研室.临床实践教学,24,2023/1/30,24,Defects of Neutrophil Function,Chediak-Higashi Syndrome（谢迪亚克东综合征，即白细胞异常色素减退综合征）Autosomal recessiveFused lysosomes giant granules in leukocytesNeutropenia,impaired chemotaxis and bactericidal activityBacterial and fungal infections,defective platelet aggregation(prolonged bleeding time),oculocutaneous albinismAccelerated phase(lymphoproliferative disorder),2023/1/30,儿科学教研室.临床实践教学,25,2023/1/30,Blood diseases in childhood,25,Chediak-Higashi syndrome giant granules in leukocytes,2023/1/30,儿科学教研室.临床实践教学,26,2023/1/30,26,Leukocytosis,Leukocytosis is a white blood cell count(the leukocyte count)above the normal range in the blood.,2023/1/30,儿科学教研室.临床实践教学,27,2023/1/30,27,Vary with age,Cord blood:930109/L612h:2128109/L2w:521109/L6m6y:615109/L6y:4.513.5109/L,Leucocyte,2023/1/30,儿科学教研室.临床实践教学,28,2023/1/30,28,Blood Cell Indices During Gestation and at Birth,2023/1/30,儿科学教研室.临床实践教学,29,2023/1/30,29,Leukemoid reaction,类白血病反应(leukemoid reaction)是指患者在某些情况下出现外周血白细胞显著增高(50109/L)和(或)存在有异常未成熟白细胞，与某些白血病相类似，但随后病程或尸检证实没有白血病。类白血病反应是正常骨髓对某些刺激信号作出的一种反应。,2023/1/30,儿科学教研室.临床实践教学,30,2023/1/30,30,类白血病反应的病因,1.感染是最常见的原因常见病原体有细菌、螺旋体、原虫、病毒等。分为以下几类：(1)粒细胞型类白血病反应：常见于肺炎、脑膜炎、白喉、结核病(主要为粟粒性结核、浸润性结核溶解播散期肺外结核)等重症传染病。(2)淋巴细胞型类白血病反应：常见于百日咳、水痘、传染性单核细胞增多症、传染性淋巴细胞增多症、结核病等。(3)单核细胞型类白血病反应：常见于结核病、巨细胞病毒感染、亚急性细菌性心内膜炎等。(4)嗜酸性粒细胞型类白血病反应：常见于寄生虫感染，如血吸虫病、丝虫病、疟疾、棘球蚴病（包虫病）等。,2023/1/30,儿科学教研室.临床实践教学,31,2023/1/30,31,类白血病反应的病因,2.恶性肿瘤多见于晚期患者肺和胃肠道恶性肿瘤，尤其是转移到肝骨髓后易发生类白血病反应。多发性骨髓瘤、霍奇金病、黑色素瘤骨肉瘤、乳腺癌、绒毛膜上皮癌肿瘤引起的类白血病反应多属粒细胞型亦有类似红白血病，淋巴细胞型较少见并常伴有贫血和血小板减少。,2023/1/30,儿科学教研室.临床实践教学,32,2023/1/30,32,类白血病反应的病因,3.中毒(1)化学因素：如汞、有机磷、苯、亚硝酸盐等中毒。(2)药物性：如砷剂、解热镇痛药、磺胺药、肾上腺素糖皮质激素、锂盐等。还有报道：用大剂量阿糖胞苷治疗急性白血病缓解期引起的类白血病反应，易误诊为“复发”。(3)其他：一氧化碳中毒四氯乙烷中毒、尿毒症、酮症酸中毒、食物中毒等。,2023/1/30,儿科学教研室.临床实践教学,33,2023/1/30,33,类白血病反应的病因,4.急性失血与溶血任何原因引起的大出血、急性血管内溶血。5.急性组织损伤常见于外伤性组织创伤(如颅脑外伤、挤压综合征)、大面积烧伤、电休克等。6.其他疾病变态反应性疾病(如剥脱性皮炎过敏性肺炎)高热中暑电离辐射性疾病脾切除术后,2023/1/30,儿科学教研室.临床实践教学,34,2023/1/30,34,类白血病反应的诊断,1.有明确的病因，如感染中毒、恶性肿瘤等；2.原发病治愈或好转后，类白血病反应可迅速消失；3.血红蛋白、血小板计数大致正常。4.骨髓检查：反应性增生,2023/1/30,儿科学教研室.临床实践教学,35,2023/1/30,35,Neutrophilia,Neutrophil leukocytosis,Neutrophilic granulocytosis年龄大于1个月的儿童和各年龄组成人外周血中性杆状核和分叶核粒细胞计数大于7.5109/L小于1个月的婴儿大于26109/L中性粒细胞比值明显高于同年龄儿童,2023/1/30,儿科学教研室.临床实践教学,36,2023/1/30,36,Neutrophilia,原因：Infections：bacteria,some virusNeoplasms:Hemorrhage,hemolysisHereditaryImmunological inflammation rheumatoid arthritis,vasculitisDrugs glucocorticoids,colony stimulating factors,lithiumMetabolic acidosis,uremia,goutTissue necrosis infarction,burns,trauma,cold,hot,sport,anoxia,emotional,2023/1/30,儿科学教研室.临床实践教学,37,2023/1/30,37,中性粒细胞型类白血病反应,白细胞计数50109/L，或外周血白细胞计数50109/L，但出现原粒、幼粒细胞成熟中性粒细胞胞质中常出现中毒性颗粒和空泡碱性磷酸酶积分明显增高骨髓象除了有粒细胞增生和左移现象外，没有白血病细胞的形态异常,2023/1/30,儿科学教研室.临床实践教学,38,2023/1/30,38,Lymphocytosis,Absolute lymphocytosis：the absolute lymphocyte countAdult:4109/LOlder children 7109/LInfants 9109/LRelative lymphocytosis Adult:40%Children:,2023/1/30,儿科学教研室.临床实践教学,39,2023/1/30,39,Cause of Lymphocytosis,Infections:Acute infection:Infectious mononucleosis,infectious lymphocytosis,hepatitis and CMV,pertussis(百日咳)，chicken poxChronic infection:TB,Brucellosis(布氏杆菌病)Some protozoal infections:toxoplasmosis and American trypanosomiasis(锥虫病)Post-Splenectomy StateAn autoimmune disorder causing ongoing(chronic)inflammation：Crohns disease，Ulcerative colitis，Vasculitis,2023/1/30,儿科学教研室.临床实践教学,40,2023/1/30,40,淋巴细胞型类白血病反应,白细胞数明显增多，超过50109/L，其中40%以上为淋巴细胞；若白细胞20%，并出现幼淋巴细胞；骨髓象除了有淋巴细胞增生外，没有白血病细胞的形态异常,2023/1/30,儿科学教研室.临床实践教学,41,2023/1/30,41,Monocytosis,0.95109/L 或比值明显升高Causes:Chronic Inflammation：Infections:tuberculosis,brucellosis,listeriosis,subacute bacterial endocarditis,syphilis,and other viral infections and many protozoal and rickettsial infections(e.g.kala azar,malaria).Immunologic disorders:Autoimmune diseases and vasculitis chronic neutropenia and myeloproliferative disorders.,2023/1/30,儿科学教研室.临床实践教学,42,2023/1/30,42,单核细胞型类白血病反应,白细胞30l09/L，单核细胞30%；若白细胞5%；骨髓象除了有单核细胞增生外，没有白血病细胞的形态异常,2023/1/30,儿科学教研室.临床实践教学,43,2023/1/30,43,Eosinophilia,0.45109/L Causes:Allergic disorders Parasitic infectionsSome forms of malignancySystemic autoimmune diseases(e.g.SLE)Some forms of vasculitis Coccidioidomycosis(球孢子菌病),Interstitial nephropathy Hyperimmunoglobulin E syndrome,2023/1/30,儿科学教研室.临床实践教学,44,2023/1/30,44,嗜酸粒细胞型类白血病反应,外周血嗜酸性粒细胞明显增加但无幼稚嗜酸粒细胞；骨髓中原始细胞比例不增高，嗜酸性粒细胞形态无异常,2023/1/30,儿科学教研室.临床实践教学,45,2023/1/30,45,特发性嗜酸粒细胞增多综合征 Idiopathic hypereosinophilic syndrome,血中嗜酸粒细胞数量大于1.5109/L，并持续达6个月以上而无明显病因的一种疾病。主要损害心、肺、肝、皮肤以及神经系统。若不采取治疗，80以上的病人会在2年之内死亡；而治疗后80以上的病人能继续存活。治疗：强的松或羟基脲若病人对强的松和羟基脲无效，可选择其他各种药物，或白细胞去除术。,2023/1/30,儿科学教研室.临床实践教学,46,2023/1/30,46,嗜酸粒细胞增多-肌痛综合征,一种嗜酸粒细胞增多并伴有肌痛、压痛、疲乏、肿胀、关节痛、咳嗽、呼吸急促、皮疹以及神经系统异常的疾病。该综合征少见。见于服用了大量色氨酸的患者停用色氨酸后可持续数周至数月，并能引起持久的神经损害，甚至偶可导致死亡目前不能治愈；一般建议理疗康复。,2023/1/30,儿科学教研室.临床实践教学,47,2023/1/30,47,Basophilia,0.2109/LAllergic disordersInfection viral,TBInflammation juvenile rheumatoid arthritis,ulcerative colitisNeoplasms chronic myeloproliferative disorders,basophilic leukemia,carcinomaEndocrine diabetes mellitus,myxedema,estrogen therapy,2023/1/30,儿科学教研室.临床实践教学,48,2023/1/30,48,红白血病型类白血病反应,外周血白细胞及有核红细胞总数50109/L并有幼稚粒细胞；若白细胞总数2%骨髓中除粒细胞系增生外，尚有红细胞系增生,2023/1/30,儿科学教研室.临床实践教学,49,2023/1/30,49,浆细胞型类白血病反应,白细胞总数增多或不增多，外周血浆细胞2%骨髓中除浆细胞系增生外，无原始细胞明显增生等白血病征象,2023/1/30,儿科学教研室.临床实践教学,50,2023/1/30,50,Leukopenia,外周血白细胞绝对计数持续低于4.0109/L Granulopenia：Neutropenia，eosinopenia，basopeniaLymphocytopenia,2023/1/30,儿科学教研室.临床实践教学,51,2023/1/30,51,Neutropenia,中性粒细胞减少症是血循环池中性多形核细胞(PMN)绝对值1.5 109/L(儿童期)，或1.0109/L(婴儿期)时所出现的一组综合征。轻型(1.01.5109/L)中型(0.51.0109/L)重型(0.5 109/L)(Agranulocytosis),2023/1/30,儿科学教研室.临床实践教学,52,2023/1/30,52,发病机制,粒细胞生成减少或无效生成粒细胞破坏丧失过多，粒细胞寿命缩短粒细胞分布异常综合前3种机制。,2023/1/30,儿科学教研室.临床实践教学,53,2023/1/30,53,Causes of Neutropenia,骨髓(1)骨髓损伤：药物：包括细胞毒和非细胞毒药物；放射线；化学物质：如苯、DDT、二硝基苯酚、砷酸、铋、一氧化氮等；某些先天性和遗传性中性粒细胞减少：如Kostmann综合征、伴先天性白细胞缺乏的网状发育不全、伴粒细胞生成异常的中性粒细胞减少等；免疫性疾患：如系统性红斑狼疮、类风湿性关节炎等；感染：细菌性感染，如伤寒、副伤寒、布鲁菌病、粟粒性结核；病毒感染，如肝炎、艾滋病等；血液病：如骨髓转移瘤、骨髓纤维化、淋巴瘤、白细胞减少的白血病、再生障碍性贫血、多发性骨髓瘤、恶性组织细胞增生症等,2023/1/30,儿科学教研室.临床实践教学,54,2023/1/30,54,Causes of Neutropenia,骨髓(2)成熟障碍：获得性：如叶酸缺乏、维生素B12缺乏、恶性贫血、严重的缺铁性贫血等；恶性和其他克隆性疾病：如骨髓增生异常综合征、阵发性睡眠性血红蛋白尿症等,2023/1/30,儿科学教研室.临床实践教学,55,2023/1/30,55,Causes of Neutropenia,2.外周血(1)中性粒细胞外循环池转换至边缘池(即假性中性粒细胞减少)：遗传性良性假性中性粒细胞减少症；获得性：如严重鶒的细菌感染，恶性营养不良病，疟疾等。(2)血管内扣留：如由补体介导的白细胞凝集素所致的肺内扣留、脾功能亢进所致的脾内扣留等。,2023/1/30,儿科学教研室.临床实践教学,56,2023/1/30,56,Causes of Neutropenia,3.作用于血管外(1)利用增多鶒：如严重的细菌、真菌、病毒或立克次体感染、过敏性疾患等。(2)破坏增多：如脾功能亢进等。,2023/1/30,儿科学教研室.临床实践教学,57,2023/1/30,57,Treatmen of Neutropenia,病因治疗抗感染升中性粒细胞数的治疗 骨髓移植,2023/1/30,儿科学教研室.临床实践教学,58,2023/1/30,58,Treatmen of Neutropenia,抗感染只有发热而无脓毒血症表现者，尽量在门诊治疗以避免医院内继发感染严重中性粒细胞减少患者出现发热时，应以急诊患者对待，立即收入院治疗，有条件时应予逆向隔离。在进行皮肤、咽喉、血、尿、大便等部位的病菌培养检查后，立即给予经验性广谱抗生素治疗,2023/1/30,儿科学教研室.临床实践教学,59,2023/1/30,59,Treatmen of Neutropenia,抗感染若病原菌明确患者，则根据药敏试验改用针对性的窄谱抗生素若未发现病原菌，但经治疗后病情得以控制者在病情治愈后仍应继续给予口服抗生素714天若未发现病原菌，且经前述处理3天后病情无好转，对病情较轻者可停用经验性抗生素治疗，再次进行病原菌培养，若病情较重者应在原有治疗基础上加用抗真菌药，如两性霉素B等,2023/1/30,儿科学教研室.临床实践教学,60,2023/1/30,60,Treatmen of Neutropenia,升中性粒细胞数的治疗(1)促白细胞生成药：目前在临床上应用的很多，如维生素B6、维生素B4、利血生、肌苷、脱氧核苷酸、雄激素、碳酸锂等，但均缺乏肯定和持久的疗效，因此，初治患者可选用12种，每46周更换一组，直到有效，若连续数月仍不见效者，不必再继续使用。(2)免疫抑制药治疗：如糖皮质激素、硫唑嘌呤、环磷酰胺、大剂量人血丙种球蛋白输注等，对部分患者，如抗中性粒细胞抗体阳性或由细胞毒T细胞介导的骨髓衰竭患者等有效。(3)集落刺激因子治疗(4)中性粒细胞输注:由于中性粒细胞在外周血和组织中的生存期短，因此至少1次/d，连续3天方可起效。,2023/1/30,儿科学教研室.临床实践教学,61,2023/1/30,61,Lymphopenia,1.5109/L(adults)3.0109/L(children)Decreased productionImmunodeficiency syndromesHodgkin lymphomaIncreased destructionDrugsRadiationAIDSLoss of lymphocytesCollagen vascular diseasesLoss of lymphIncreased central venous pressure,2023/1/30,儿科学教研室.临床实践教学,62,2023/1/30,62,Blood routine,Liuhong,male,2 years old,Fever and sore throat for 2 daysRBC 3.021012/L Hb 92g/LWBC 11109/LN:0.68,L:0.32,catalogue2,2023/1/30,儿科学教研室.临床实践教学,63,2023/1/30,63,blood platelet,100300109/L,回目录2,2023/1/30,儿科学教研室.临床实践教学,64,血小板增多症,原发性血小板增多症是一种原因不明的骨髓增生性疾病，本病的主要特点是外周血中血高，伴有出血倾向，血栓形成，肝脾肿大和粒细胞增多等。到底达到多少才能诊断？到底达到多少需要治疗？,2023/1/30,64,2023/1/30,儿科学教研室.临床实践教学,65,Primary ITP,Primary ITP is an autoimmune disorder characterized by isolated thrombocytopenia(peripheral blood platelet count 100109/L)in the absence of other causes or disorders that may be associated with thrombocytopenia.欧洲仍定义为 peripheral blood platelet count 150109/LThe 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 always be present.,2023/1/30,儿科学教研室.临床实践教学,66,The IWG and American Society of Hematology based their recommendations for the use of an upper threshold platelet count of 100 109/L on three considerations:,A study demonstrating that patients presenting with a platelet count between 100 and 150109/L have only a 6.9%chance of developing a persistent platelet count of less than 100109/L over 10 years of follow-up;Recognition that in non-Western ethnicities normal values in healthy individuals may be between 100 and 150109/L,The hypothesis that a cut-off value of 100109/L would reduce concern over the mild“physiological”thrombocytopenia associated with pregnancy.,2023/1/30,儿科学教研室.临床实践教学,67,Primary ITP,Primary ITP is an autoimmune disorder characterized by isolated thrombocytopenia(peripheral blood platelet count 100109/L)in the absence of other causes or disorders that may be associated with thrombocytopenia.欧洲仍定义为 peripheral blood platelet count 150109/LThe 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 always be present.,2023/1/30,儿科学教研室.临床实践教学,68,The IWG and American Society of Hematology based their recommendations for the use of an upper threshold platelet count of 100 109/L on three considerations:,A study demonstrating that patients presenting with a platelet count between 100 and 150109/L have only a 6.9%chance of developing a persistent platelet count of less than 100109/L over 10 years of follow-up;Recognition that in non-Western ethnicities normal values in healthy individuals may be between 100 and 150109/L,The hypothesis that a cut-off value of 100109/L would reduce concern over the mild“physiological”thrombocytopenia associated with pregnancy.,2023