摘要目的 比较颗粒免疫过滤法(PIFA)和乳胶免疫比浊法(LIA)检测肝素/血小板因子4(PF4)复合物抗体在诊断肝素诱导的血小板减少症(HIT)中的效力.方法 前瞻性分析2016年5月至2018年7月连续送检至我院行肝素/PF4复合物抗体(HIT抗体)检测的94例疑诊HIT患者的临床资料、检测结果,并随访治疗方案及疗效.根据患者临床资料评估4Ts评分、结合患者临床结局诊断或排除HIT,并据此分析单独或联合应用PIFA法及LIA法的灵敏度、特异度、阳性预测值(PPV)、阴性预测值(NPV),并以4Ts评分为先验概率分析其诊断HIT的后验概率(PTP).结果 在94例患者中,15例(16.0％)患者临床诊断为HIT,中危组37例中有6例(16.2％),高危组15例中有9例(60.0％).PIFA法的诊断效力:灵敏度100％(15/15),特异度51.9％(41/80),PPV 28.3％ (15/53),NPV 100％ (41/41),4Ts评分中危、高危的阳性PTP分别为28.7％、75.7％,阴性PTP均为0％.LIA的诊断效力:灵敏度66.7％(10/15),特异度94.9％ (75/79),PPV 71.4％ (10/14),NPV 93.8％ (75/80),4Ts评分中危、高危的阳性PTP分别为71.8％、95.2％,阴性PTP分别为6.3％、34.4％.受试者工作特征(ROC)曲线分析显示,LIA法诊断价值大于PIFA法,两种检测方法联合应用优于单一检测方法.结论 4Ts评分系统是临床诊断HIT的重要依据,联合肝素/PF4抗体检测可提高确诊和除外HIT的准确性.尽管LIA法的诊断价值优于PIFA法,PIFA法以其100％的NPV和临床操作方便性也具备一定优势.联合应用两种方法检测可获得更高的诊断效力.

abstractsObjectives To assess the diagnostic values of latex immunoturbidimetric assay (LIA)and particle immunofiltration assay (PIFA) for heparin-induced thrombocytopenia (HIT).Methods Samples from 94 patients with suspected HIT from May 2016 to July 2018 in our hospital were prospectively analyzed by the two immunoassays.Their medical records and further follow-up data were also collected and analyzed by our hematologists to make the 4Ts scores and confirm the diagnosis of HIT,respectively.Performance characteristics of the two immunoassays were assessed,including sensitivity,specificity,positive predictive value (PPV) and negative predictive value (NPV).Their post-test probabilities (PTP) were also calculated based on the 4Ts score.Results Among 94 cases,15 (16.0％)had a positive HIT,including 6 of 37 (16.2％) with an intermediate,and 9 of 15 (60.0％) with a high 4Ts score.PIFA operating characteristics were:sensitivity 100.0 ％ (15/15),specificity 51.9 ％ (41/80),PPV 28.3％ (15/53),NPV 100.0％ (41/41).The positive PTP in intermediate and high 4Ts score group were 28.7％ and 75.7％,respectively,while negative PTP were all 0.At manufacturers' cutoffs,LIA operating characteristics were:sensitivity 66.7％ (10/15),specificity 94.9％ (75/79),PPV 71.4％ (10/14) and NPV 93.8％ (75/80).The positive and negative PTP in intermediate 4Ts score group were 71.8％ and 6.3％,while 95.2％ and 34.4％ in high 4Ts score group,respectively.Receiver operating characteristic (ROC) analysis manifested that LIA was preferable than PIFA,and combining the 2 assays together was significantly better than single test.Conclusions 4Ts score is still an important tool for the diagnosis of HIT.Combining clinical score with heparin/PF4 antibody assay can increase the accuracy of confirming or excluding HIT.Although PIFA is inferior to LIA in the diagnostic value,its user friendliness and 100％ NPV have major advantages.Combining the 2 assays together can achieve a higher diagnostic value.