抗凝剂EDTA-K2致血小板假性减少探讨

目的 探讨乙二胺四乙酸二钾(EDTA-K2)抗凝剂对假性血小板减少(PTCP)的影响及解决方法 .方法 对10例PTCP患者及30名健康体检者在EDTA-K2抗凝静脉血放置1 h后,用全自动血液分析仪进行分析,同时用手工计数血小板(PLT)作为参考值,并以不加抗凝剂的指血直接稀释后在全自动血液分析仪上测定.结果 EDTA-K2抗凝血PLT计数结果 与手工法相比,差异有统计学意义(P<0.001); EDTA-K2抗凝PLT计数结果 与不使用抗凝剂指血相比,差异有统计学意义(P<0.01);而手工法PLT计数结果 与不使用抗凝剂指血结果 相比,差异无统计学意义(P>0.05),患者加EDTA-K2抗凝血作涂片瑞-姬染色,发现血片中有大量PLT聚集,聚集的PLT大小不一、数量不等,而不加抗凝剂的患者指血,则无PLT聚集现象.结论 EDTA-K2对PLT可产生聚集作用,引起PTCP.     

EDTA-K2依赖性血小板假性减少现象分析及纠正方法探讨

目的 探讨抗凝剂乙二胺四乙酸二钾(EDTA-K2)所致血小板聚集对血小板及白细胞计数结果的影响及纠正.方法 对17例EDTA-K2依赖性血小板假性减少症(PTCP)患者的EDTA-K2抗凝血分别于0,5,15,30 min测定血小板(PLT)和白细胞(WBC),另外对同时抽取的新鲜血(不加抗凝剂)即时上机测定和手工法测定PLT和WBC;均取上述标本进行涂片染色显微镜镜检.结果 EDTA-K2抗凝血PLT计数检测结果随待测时间延长越来越低,5,15 min和30 min时测定的PLT数量与0 min时测定的血小板数量比较差异有统计学意义;5 min和15 min时测定的WBC数与0 min时测定的WBC数量差异无统计学意义(P＞0.05),30 min时测定的WBC数少于0 min时测定的WBC数量(P＜0.01);EDTA-K2抗凝血混匀后0 min时测定的WBC和PLT结果与新鲜血(不加抗凝剂)仪器法、手工法测定的结果差异无统计学意义(P＞0.05).结论 EDTA-K2引起PTCP患者的血小板聚集导致血小板假性减低和白细胞假性增高;在临床检验工作中应加强镜检复核,对于首次检测血小板数值减低的标本均应涂片镜检,以确认是否存在抗凝剂所致血小板聚集的现象.对PTCP患者应采用新鲜血(不加抗凝剂)仪器即测法、手工法或EDTA-K2抗凝血混匀后即测等方法检测.     

乙二胺四乙酸三钾导致血小板假性减少分析

目的探讨乙二胺四乙酸三钾（EDTA-K3）在体外引起血小板（PLT）聚集的原因及NaF在体外对EDTA依赖性血小板聚集的抑制作用。方法对6例典型EDTA依赖性血小板假性减少患者和40例对照人群不同抗凝情况下静脉血通过血液分析仪进行血液分析，同时用手工计数血小板作为参考值。结果EDTA-K3抗凝血结果与手工法结果差异有统计学意义（P〈0．001）；EDTA-K3抗凝血结果与不使用抗凝剂手指末梢血的结果差异有统计学意义（P〈0．001）；而手工法结果与不使用抗凝剂手指末梢血的结果相比差异无统计学意义（P〉0．05）；加NaF的抗凝血结果与手工法结果和不使用抗凝剂手指末梢血的测定结果相比差异无统计学意义（P〉0．05）。结论EDTA-K3对血小板可以产生聚集作用，造成血小板计数出现假性偏低；NaF对EDTA依赖性血小板聚集具有抑制作用。     

纠正EDTA-K2抗凝剂致假性血小板减少方法的探讨

目的探讨纠正EDTA-K2抗凝剂致假性血小板减少的方法。方法用Sysmex XE-2100型全自动血液分析仪检测20例健康体检者不同时间3种抗凝血血小板数值及11例EDTA依赖性假性血小板减少症（EDTA-PTCP）患者不同抗凝血在15min血小板数值,同时作手工血小板计数。结果 15~30min内健康体检者EDTA-K2抗凝血血小板数值与手工血小板计数值相比差异无统计学意义（P〉0.05）,不同时间的枸橼酸钠和肝素锂抗凝血血小板数值与手工血小板计数值相比差异有统计学意义（P〈0.05）。EDTA-PTCP患者枸橼酸钠和肝素锂抗凝血在15min内测定的血小板数值与手工血小板计数值相比差异有统计学意义（P〈0.05）。结论枸橼酸钠和肝素锂抗凝剂不可替代EDTA-K2抗凝剂用于全自动血液分析仪血小板的检测,手工血小板计数是目前最为理想的纠正EDTA-K2抗凝剂致假性血小板减少的方法。     

EDTA-K2诱导的血小板聚集对血细胞计数的影响

目的 研究EDTA-K2诱导血小板聚集所引起的血液分析仪计数RBC、WBC及PLT的数值变化.方法 采用血液分析仪检测EDTA-K2抗凝血,同时手工计数标本和涂片镜检,并作相应比较得出结论.结果 血液分析仪检测的部分EDTA-K2抗凝血血小板计教低于手工法计数的结果,而白细胞计数结果却高于后者,二者差别均有临床意义.结论 时于EDTA-K2抗凝的静脉血个别患者可能会发生血小板聚集,从而引起血小板假性减少PTCP(pseudothrombocytopenia),WBC计数假性增高,所以应该引起重视,及时纠正,避免一些不必要的检查和治疗.     

抗凝剂EDTA-K2引起的血小板减少原因分析

目的 探讨抗凝剂乙二胺四乙酸二钾(EDTA-K2)引起血小板减少的相关过程及原因.方法 利用Sysmex XE2100全自动血液分析仪对EDTA-K2与枸橼酸钠两种抗凝剂的血液标本进行血小板 (PLT)与白细胞(WBC)的检测,并与Sysmex KX-21血液分析仪稀释模式及人工镜检的检测结果进行对比和统计学分析,同时对EDTA-K2及枸橼酸钠两种抗凝血在5、30和60 min的PLT与WBC数值进行对比和统计学分析,并对EDTA-K2抗凝血与未抗凝末梢血涂片进行染色,对比观察PLT数目和形态变化.结果 EDTA-K2抗凝血的PLT与WBC数值与枸橼酸钠抗凝血以及KX-21稀释模式和人工镜检的结果对比,差异有统计学意义(P<0.01),EDTA-K2抗凝血在5 min时的PLT与WBC值与30 min及60 min的值之间差异有统计学意义(P<0.01),EDTA-K2抗凝血涂片较未抗凝的末梢血涂片明显出现了大量PLT聚集以及卫星现象.结论 EDTA-K2能促进PLT聚集而导致PLT假性减少,其作用过程在彼此接触后5 min内发生,30 min内全部完成.     

EDTA依赖血小板减少结果分析和纠正措施

目的分析EDTA依赖血小板假性减少症(PTCP)的结果,寻找有效的纠正措施。方法用EDTA-K2抗凝血在Bayer血液分析仪上检测血常规,发现血小板减少对做血涂片,观察血小板聚集警示信息、白细胞九分图3区血小板聚集、血小板散点图,可疑PTCP时再手工计数血小板,并分别用EDTA-K2、枸橼酸钠抗凝15、30、60、120 min检测血小板。结果 PTCP时,血小板聚集警示信息、白细胞九分图3区显示血小板有聚集、血小板散点图出现大血小板,三者均阳性时PTCP敏感度为100%,特异度为88.9%,枸橼酸钠抗凝与手工计数血小板15~120 min 4组数据都基本一致,EDTA-K2抗凝15 min与手工计数和枸橼酸钠抗凝均无差异,30 min时差异不明显(t=1.71,P>0.05),60~120 min时差异有统计学意义(P<0.01)。结论血小板减少时观察血小板聚集警示信息、白细胞九分图3区显示血小板有聚集,与血小板散点图若同时阳性,需重新采血,用EDTA-K2抗凝10 min内上机,或用枸橼酸钠抗凝后检测血小板,可纠正PTCP。     

EDTA 依赖性血小板减少的分析与对策

目的:探讨EDTA-K2在体外引起血小板假性减少的原因及解决办法。方法:对10例典型的EDTA-K2依赖性血小板减少的患者的静脉血分别用EDTA-K2抗凝、枸橼酸钠抗凝,另取稀释的末梢血并通过血细胞分析仪进行分析,同时手工涂片观察,并用手工计数血小板作为参考进行比较。结果:EDTA-K2抗凝静脉血检测结果与手工计数血小板结果差异有统计学意义(P<0.001),而枸橼酸钠抗凝静脉血检测结果与手工计数血小板结果差异无统计学意义(P>0.05)。且用EDTA-K2抗凝静脉血涂片可观察到成团聚集的血小板,而枸橼酸钠抗凝静脉血涂片可观察到血小板散在分布,无聚集现象。结论:EDTA-K2对血小板可以产生聚集作用,引起血小板假性减少。而选择枸橼酸钠抗凝可以纠正EDTA-K2依赖性的血小板减少。     

不同抗凝剂对血小板检测结果的影响

目的 比较不同抗凝剂对血小板检测结果 的影响.方法 分别采用乙二胺四乙酸二钾(EDTA-K2)、柠檬酸钠两种抗凝剂采血真空管,采集150例随机患者血常规标本,用贝克曼-LH750血细胞全自动分析仪检测.同时对血液标本进行涂片,显微镜观察血小板的凝集状况及对血小板数量进行计数.结果 EDTA-K2与柠檬酸钠抗凝样本显微镜检测血小板聚集情况存在一定差异,采集血液后立即检测,比较结果 差异具有统计学意义(χ2=6.192,P=0.045,P<0.05),2 h与4 h后差异无统计学意义(χ2=0.845,P=0.089;χ2=0.845,P=0.089);2 h与4 h后仪器法检测结果 差异有统计学意义(P<0.05).结论 EDTA-K2可导致血小板假性减少,用柠檬酸钠抗凝能一定程度降低EDTA-K2对血小板计数的影响,同时其他因素(如时间)也会影响血小板假性减少,值得医学工作者注意.     

EDTA-K2抗凝剂对PLT的影响

目的观察研究EDTA-K2抗凝剂对血小板计数(PLT)检测结果的影响,总结其临床经验和临床意义。方法选取我院2010年1月～2012年1月送检的血液标本444份,其中EDTA-K2抗凝静脉血标本应用全自动血细胞分析仪检测PLT有228份,设为A组,对A组中EDTA-K2抗凝静脉血标本检测后结果与镜检结果比较有差异的标本,再联合全自动血细胞分析仪预稀释功能检测PLT有198份,设为B组,直接取末梢血应用人工计数测定PLT有216份,设为C组,分别参考镜检结果作为金标准,观察对比三组PLT测定的结果。结果 A组PLT测定值显著低于B组和C组,比较差异非常显著(P<0.05),具有统计学意义;B组和C组间PLT检测值比较无明显差异(P>0.05),无统计学意义。结论加入EDTA-K2抗凝静脉血标本应用全自动血细胞分析仪检测PLT的结果存在PLT假性降低的可能,临床建议可采取EDTA-K2抗凝静脉血标本联合全自动血细胞分析仪的预稀释功能或者直接取末梢血应用人工计数测定PLT,能够提高检测准确率,而前者操作更为简便,且能有效减少EDTA-K2抗凝剂造成的PLT测定误差,适用于临床大批量标本的检测,具有重要的临床应用价值。     

EDTA依赖的假性血小板减少的实验分析与对策

本研究旨在了解临床常见的EDTA依赖的假性血小板减少的发生率及其解决方法.对2010年1月-2013年5月间住院的71 535例,在血常规检测时有血小板减少的1326例患者进行了对比分析,并对其中EDTA-K2抗凝剂导致的假性血小板减少病例87例改用枸橼酸钠抗凝剂再次分析检测,同时涂片瑞-姬氏染色油镜下观察血小板形成分布情况.结果表明：87例EDTA-K2抗凝剂血小板数值为（56±27）×109/L,换用枸橼酸钠抗凝剂在同一仪器上检测,其血小板数值为（185±39）×109/L,两者结果用配对t检验分析,统计学上结果有显著性差异（t=1.83,P＜0.01）.EDTA-K抗凝剂导致的假性血小板减少,其发生率为0.12％,占血小板减少总数的6.56％.结论：EDTA-K2抗凝剂导致的假性血小板减少发生率为0.12％,极易误诊.对血小板计数＜100×109/L的标本应进行涂片复查.发现有血小板聚集的情况应改用枸橼酸钠抗凝剂进行再次检测,以防发生误诊误治.     

27例乙二胺四乙酸依赖性假性血小板减少特点及临床分析

目的分析乙二胺四乙酸(EDTA)导致血小板聚集的特点,探讨与此现象有关的危险因素。方法用Sysmex XN-3000对2014年1月至2015年8月间的30 700例EDTA-K3抗凝标本测定,其中27例发生EDTA依赖性假性血小板减少(EDTA-PTCP)。再次采集27例患者的EDTA-K3和枸橼酸钠抗凝血标本进行测定并制作血涂片,显微镜检观察血小板分布,同时采集指血手工计数血小板。分析27例患者的生化指标,并与50例非EDTA-PTCP体检健康者结果对比。结果 EDTA抗凝血血小板数明显低于枸橼酸钠抗凝血,差异有统计学意义(P0.05),而枸橼酸钠抗凝血与手工法结果相近(P0.05)。EDTA-PTCP患者丙氨酸氨基转移酶(ALT)、血糖(Glu)、三酰甘油(TG)比健康者高,而高密度脂蛋白(HDL)要比健康者低,差异有统计学意义(P0.05)。结论 EDTA引起假性血小板减少的程度取决于患者对EDTA的敏感度,该现象的存在可能与高血脂、高血糖有关。当发生EDTA-PTCP时,应更换抗凝剂或者手工计数血小板,从而避免漏诊。     

Pseudothrombocytopenia in plateletpheresis donors

BACKGROUND: EDTA pseudothrombocytopenia (PTCP) is an in vitro artifact in which the anticoagulation of blood with EDTA is associated with in vitro agglutination of platelets, resulting in a spuriously low platelet count. In apheresis donors, whole-blood samples for complete blood counts are routinely drawn into tubes anti-coagulated with EDTA. STUDY DESIGN AND METHODS: Records of apheresis donors were examined to identify persons in whom the postdonation counts were less than 100 × 10(9) per L. Identified donors were studied to confirm the presence of PTCP by drawing blood samples into EDTA, heparin, and trisodium citrate for serial platelet counts at room-temperature incubation. Platelet counts in citrated plasma were measured before and after the addition of EDTA. A single HLA-matched component from an identified PTCP donor was monitored for response by corrected count increment in the recipient. RESULTS: A total of nine donations were identified, involving 2 donors from a population of 945 donors (prevalence 0.2%). On testing, both donors were confirmed to have PTCP. The addition of EDTA to citrated plasma did not affect the platelet count. Response in a recipient to an HLA-matched component showed an acceptable corrected count increment. CONCLUSION: PTCP may occur in plateletpheresis donors and result in needless medical referral or donor deferral. PTCP does not appear to alter the yield content of the component or to be passively transferred to a recipient.     

An unusual cause of mismanagement in an acute myocardial infarction case: pseudothrombocytopenia

Thrombocytopenia determined by an automated counter may represent a benign, incidental finding in an asymptomatic patient or a potentially life-threatening disorder. Even if the low platelet count actually is a benign condition itself, in some conditions, any delay resulting from this condition consequently may be seriously hazardous. Low platelet count may alter the decision of heparin administration, which is an essential part of management during acute coronary syndromes. EDTA-dependent pseudothrombocytopenia (PTCP) is reported to have a prevalence of 0.1% in a general hospital; however, it is also reported that around 15% of the patients referred for a specialized center for isolated thrombocytopenia are actually cases of PTCP. In this report, we describe a patient with PTCP who could not receive reperfusion therapy during acute myocardial infarction because of the low platelet counts reported by an automated counter.     

White blood cell counts by automated and manual methods with backlighting.

White blood cell (WBC) counts were compared in the presence of "backlighting" using the Coulter S-Plus Jr and a manual system. Platelet aggregates and large platelets in specimens anticoagulated with ethylenediamine tetraacetic acid (EDTA) cause interference and prompt the WBC count on the Coulter S-Plus Jr to backlight. This means that the background behind the count on the data terminal display lights up, alerting the operator to a questionable result. A total of 29 automated backlighted WBC counts of blood samples collected in sodium and potassium salts of EDTA tubes were compared with the results by hemocytometer method. Values for WBC count by both methods showed good agreement. Smear examination detected platelet clumps and large platelets in 66% of the Na 2EDTA tubes. Only low WBC counts prompted backlighting in K 3EDTA. tubes. Liquid K 3EDTA is a preferred anticoagulant for whole blood analysis because of its rapid solubility, eliminating clumping of platelets and thus backlighting.     

不合格血液标本的原因分析及对策

目的分析不合格血液标本产生的原因和制定相应对策,确保分析前环节的标本质量。方法回顾性分析2008年至2012年复旦大学附属中山医院检验科接收住院患者不合格血液标本5 933例。以不合格率描述不合格标本的情况,采用PearsonX2检验比较不同种类的抗凝管发生标本凝块和标本量少的风险。结果 2008年至2012年真空采血系统采集的血液标本的不合格率分别为1.49‰、0.76‰、0.52‰、0.50‰和0.47‰,呈现明显的下降趋势;血液标本的6大不合格原因依次为标本凝块、标本量少、标本抽错管、条码问题、送检超时和重复采血。其中以柠檬酸钠抗凝管发生标本凝块和标本量少的情况最多。结论检验科需加强与护理部和临床部门之间的联系,及时沟通反馈不合格标本的情况,寻找原因并制定和实施改善措施,共同努力确保分析前环节的血液标本质量。     

Evaluation of argatroban and DUP 714 as anticoagulants for blood gas, electrolyte and ionized calcium analyses

The objective of this study was to determine if the thrombin inhibitors Argatroban and DUP 714 could anticoagulate whole blood without influencing the analyses of blood gases, electrolytes, ionized calcium or CO-oximetry. The anticoagulant potency of DUP 714 (0.5-68 micromol/l) and Argatroban (1.5-390 micromol/l) was evaluated using the activated partial thromboplastin time (APTT), prothrombin time (PT) and whole blood clot time (WBCT). APTT and the PT were measured using a Behring Fibrintimer. APTT was found to be more sensitive to prolongation by both of the thrombin inhibitors than were the PT or WBCT assays. DUP 714 was found to a more potent anticoagulant than Argatroban. DUP 714 anticoagulated specimens (>2.2 micromol/l) did not clot for at least 2 days, whereas Argatroban preserved specimens (390 micromol/l) clotted within 5.5 h of collection. No statistically significant changes in the measurement of pH, PCO2, PO2, Na, K, ionized calcium, oxyhaemoglobin, deoxyhaemoglobin, methaemoglobin or carboxyhaemoglobin (measured using a Corning 288 Blood Gas/Electrolyte Analyzer and a Coming 270 CO-oximeter) were detected in DUP 714 (34 micromol/l) or Argatroban (390 micromol/l) anticoagulated whole blood specimens. In conclusion, DUP 714 and Argatroban are suitable anticoagulants for preserving blood prior to blood gas and electrolyte analyses.     

Quality specification in haematology: the automated blood cell count

BACKGROUND: Quality specifications for automated blood cell counts include topics that go beyond the traditional analytic stage (imprecision, inaccuracy, quality control) and extend to pre- and post-analytic phases. METHODS: In this review pre-analytic aspects concerning the choice of anticoagulants, maximum conservation times and differences between storage at room temperature or at 4 degrees C are considered. For the analytic phase, goals for imprecision and bias obtained with various approaches (ratio to biologic variation, state of the art, specific clinical situations) are evaluated. For the post-analytic phase, medical review criteria (algorithm, decision limit and delta check) and the structure of the report (general part and comments), which constitutes the formal act through which a laboratory communicates with clinicians, are considered. RESULTS: K2EDTA is considered the anticoagulant of choice for automated cell counts. Regarding storage, specimens should be analyzed as soon as possible. Storage at 4 degrees C may stabilize specimens from 24 to 72 h when complete blood count (CBC) and differential leucocyte count (DLC) is performed. For precision, analytical goals based on the state of the art are acceptable while for bias this is satisfactory only for some parameters. CONCLUSIONS: In haematology quality specifications for pre- and analytical phases are important, but the review criteria and the quality of the report play a central role in assuring a definite clinical value.     

临床送检不合格血液标本1063份分析

目的探讨造成临床送检血液标本不合格类型及原因,以提高检验质量。方法收集1063份不合格血液标本资料,按标准进行分类整理。结果 1063份不合格血液标本中凝血实验标本765份(72.0%),其中抗凝标本凝固227份(29.6%)、溶血252份(32.9%),脂血159份(20.8%)、标本量不准116份(15.2%),标本错误11份(1.4%)。血常规标本119份(18.7%),其中抗凝标本凝固98份(49.2%)、标本量不准97份(48.7%)、标本错误4份(2.0%);红细胞沉降率标本99份(9.3%),其中抗凝标本凝固52份(52.5%),标本量不准47份(47.5%)。结论医护人员了解不合格标本对检验结果的影响,熟练掌握检验血液标本的采集技术。