乙二胺四乙酸依赖性假性血小板减少症检测方法探讨

Investigation on the detection method for EDTA-dependent pseudothrombocytopenia

目的探讨乙二胺四乙酸依赖性假性血小板减少症(EDTA-PTCP)几种检测方法的可靠性。方法对5例EDTA-PTCP患者和20位健康体检者同时用经乙二胺四乙酸二钾(EDTA-K2)、枸橼酸钠和肝素锂三种抗凝管及末梢血稀释的方式采集标本,分别用血液分析仪在三种抗凝管采集标本后5 min、30 min、60 min测定血小板计数,采集末梢血用显微镜手工计数血小板,对所有标本涂片染色观察血小板形态。结果 5例EDTA-PTCP患者EDTA-K2采血管采血后30 min和60 min血小板计数(PLT)比5 min时测定结果显著偏低,差异具有统计学意义(P<0.05)。DTA-PTCP患者EDTA-K2采血后30 min和60 min抗凝血涂片染色均见明显的血小板聚集现象,而健康体检者EDTA-K2抗凝血涂片及未抗凝血直接涂片染色见血小板散在分布。在采血30 min后测定,EDTA-K2采血管PLT明显低于枸橼酸钠、肝素锂及手工计数结果,差异均具有统计学意义(P<0.05);20例健康体检者在采血后5 min、30 min、60 min时EDTA-K2采血管PLT与枸橼酸钠、肝素锂、手工计数的结果比较差异均无统计学意义(P>0.05)。结论对疑似EDTA-PTCP患者可以用EDTA-K2采血管重新采血立即测定,或不使用抗凝剂直接抽血立即测定,也可以使用枸橼酸钠或肝素锂抗凝管初步确认,同时涂片染色并手工计数得到正确的结果。

Objective To investigate the reliability of the methods for detecting EDTA-dependent pseudo- thrombocytopenia （EDTA-PTCP）. Methods Blood samples were collected from 5 patients of EDTA-PTCP and 20 healthy subjects by three anticoagulant tubes （EDTA-K~, sodium citrate and heparin lithium） and peripheral blood dilu- tion. Platelets were determined by haematology analyzer 5 min, 30 rain, 60 min after the samples were collected by an- ticoagulant tubes, as well as determined manually under the microscope for peripheral blood samples collected. Smear staining was performed to observe platelet morphology. Results In the five DTA-PTCP patients, the platelet count of EDTA-K2 anticoagulant tube was significantly lower at 30 min and 60 min after sample collection than at 5 rain （P〈0.05）. Platelet of EDTA-K： anticoagulant tube from the 5 patients showed significant aggregation during smear staining, while the platelet of EDTA-K2 anticoagulant tube from the 20 healthy subjects and the peripheral blood （man- ual counting） showed scattered distribution. 30 min after blood collection, the platelet count of EDTA-K2 anticoagu- lant tube was significantly lower than that of sodium citrate anticoagulant tube, heparin lithium anticoagulant tube, manual counting （P〈0.05）. In 20 healthy subjects, no significant difference exist in the results between EDTA-K2 anti- coagulant tube and sodium citrate anticoagulant tube, heparin lithium anticoagulant tube, manual counting （P〉0.05）. Conclusion For suspected patients of EDTA-PTCP, blood samples can be collected by EDTA-K~ anticoagulant tube or draw directly without anticoagulant for immediate platelet determination. Samples can also be collected by using so- dium citrate or lithium heparin anticoagulant tube for initial identification. Smear staining and manual counting should be performed to obtain correct results.