肝素诱导的血小板减少症抗体检测在妊娠期患者中的诊断效能评价

Evaluation of diagnostic efficacy of heparin-induced thrombocytopenia antibodies in pregnant women

目的研究肝素诱导的血小板减少症(HIT)抗体在妊娠期患者HIT的临床诊断效能。方法纳入疑似HIT的妊娠期患者135例,有34例患者诊断为HIT,其中19例并发血栓栓塞事件。采用ACL TOP 700型血液凝固仪以微粒凝集法测定HIT混合抗体,采用ACL AcuStar发光分析仪以化学发光法测定IgG特异性抗体。结果混合抗体和IgG特异性抗体诊断HIT的cut-off值分别为0.865 U/mL和0.885 U/mL时,诊断HIT的敏感性分别为85.3%和94.1%,特异性分别为74.0%和79.4%;预测血栓风险的cut-off值分别为1.810 U/mL和1.680 U/mL时,敏感性为47.4%和57.9%,特异性为60.0%和73.3%。生存分析和Cox回归分析显示,混合抗体和IgG特异性抗体均不能提示患者血栓栓塞事件风险的增加(Log-rank χ~2分别为0.154和3.647,P值分别为0.694和0.056),预测血栓风险的风险比(HR)值分别为0.908(95%CI:0.461~1.788)和0.616(95%CI:0.310~1.224),P均>0.05。结论 HIT抗体检测对妊娠期人群的临床诊断效能低于其他类型患者,且HIT抗体水平与血栓栓塞事件无关联,不能作为预测妊娠期患者血栓风险的评价指标。

Objective To study the clinical performance of detecting PF4(platelet factor 4)antibodies for diagnosis of heparin-induced thrombocytopenia(HIT)in pregnant patients.Methods The study included 135 pregnant patients with suspected HIT,of which 34 patients were diagnosed as HIT,among them 19 complicated with thromboembolic events.ACL TOP 700 coagulation analyzer(particle gel immunoassay)was used to assay the whole antibody to PF4 in plasma of HIT patients.ACL AcuStar chemiluminescent analyzer(chemiluminescent immunoassay)was used to assay the IgG-specific PF4 antibody.Results When the cut-off threshold value of whole antibodies and IgG-specific antibody for the diagnosis of HIT was 0.865 U/mL and 0.885 U/mL respectively,and the sensitivity for diagnosis of HIT was 85.3%and 94.1%and the specificity was 74.0%and 79.4%respectively.When the cut-off threshold value of the whole antibody for predicting thrombosis risk was 1.810 U/mL,the sensitivity was 47.4%and the specificity was 60.0%.When the cut-off threshold value of the specific antibody for predicting thrombosis risk was 1.680 U/mL,the sensitivity was 57.9%and the specificity was 73.3%.The survival analysis and COX proportional regression analysis showed that both the detections of whole antibody and IgG-specific antibody could not suggest the increased risk of thromboembolic events in the patients(Log-rankχ20.154 and 3.647,P values 0.694 and 0.056,respectively),and the HR value for prediction of thrombosis risk was 0.908(95%CI:0.461 to 1.788)and 0.616(95%CI:0.310 to 1.224),respectively.Conclusion The diagnostic performance of PF4 antibody detection in pregnant patients with suspected HIT was lower than that in the patients with other types of disease.There was no relationship between the level of PF4 antibodies in HIT and thromboembolic events.The antibodies could not be used as an evaluation index for predicting thrombotic risk in pregnant population.