凝血酶原时间ISI/INR系统测定中的一些问题及改进意见

目的对凝血酶原时间(PT)测定ISI/INR系统出现的一些问题提出相应的改进建议。方法对上海市12家医院在用的仪器和匹配的PT试剂,对日常使用的正常血浆平均凝血酶原时间(MNPT)作调研实测,将结果进行分析;调查试剂的仪器特定(spec ific)国际敏感度指数(ISI)值与世界卫生组织(WHO)的手工法ISI定标值之间的差异;用2种已知国际标准化比值(INR)的异常参比血浆代替WHO的ISI系统作质控并行比较。结果12家中有4家日常使用的平均正常凝血酶原时间(MNPT)明显偏离实测值,分别为0.8、0.9、1.0和1.8 s。用WHO CRM149R参比,用手工法标定的凝血活酶和109 mmol枸橼酸钠抗凝的不同PT值血标本,在Sysm ex1500型、C.2000型仪器上测定试剂的仪器特定ISI,其结果比手工法分别减少4.1%和4.7%,但采用HEPES-枸橼酸钠抗凝剂标本时,2种型号仪器的特定ISI比手工法分别减少16.7%及7.7%。用已知INR异常参比血浆,国产品与进口品对照的结果良好。结论受调研12家中,有4家血凝分析仪器调研时实测的MNPT明显偏离日常使用值。有几家医院试剂的仪器特定ISI值也存在问题,建议纠正。用已知INR异常参比血浆代替WHO手工法标定凝血活酶ISI法作质控,使用简便,又不需MNPT参数,值得推广。

Some problem and improvement suggestion of international sensitivity index/international normalized ratio system in the determination of prothrombin time

Objective To investigate the problem of the deviation of international sensitivity index/international normalized ratio(ISI/INR) system and suggest measures of correction to be taken. Methods The mean normal prothrombin time(MNPT) value was routinely determined by investigation and the deviation of the MNPTs between the investigated and those used everyday were studied.The difference between the instrumentreagent specific ISI and the ISI calibrated by orthogonal regression analysis(ORA) method was also investigated.Two assigned INR plasmas were studied as quality control alternatives of reference thromboplastin and compared in parallel. Results Of four from twelve laboratories the MNPTs were largely deviated from that assigned by 0.8,0.9,1.0 and 1.8 s.Using the 109 mmol citrated plasma,the specific ISI of model Sysmex 1500 and model C.2000 were less 4.1% and 4.7% than manual method respectively.However,the specific ISI would be less 16.7% and 7.7% respectively by using plasma with HEPES-citrate as anticoagulatnt.The local made INR assigned plasma kit gave favorable results when compared with the imported products. Conclusions The MNPTs of four laboratories of twelve hospitals significantly deviated from that routinely determined.The instrumentreagent specific ISI deviated in several laboratories where the corrections were suggested.Local made assigned INR plasma can be used as an alternative quality control material for prothrombin time(PT) determination by its simplicity to use and without the parameter of MNPT.