Li S, Fan L K, Wu W, Zhao Y Q, Wang S J
Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medicine Sciences, Beijing 100730, China.
Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medicine Sciences, Beijing 100730, China.
Zhonghua Xue Ye Xue Za Zhi. 2019 May 14;40(5):411-416. doi: 10.3760/cma.j.issn.0253-2727.2019.05.012.
To assess the diagnostic values of latex immunoturbidimetric assay (LIA) and particle immunofiltration assay (PIFA) for heparin-induced thrombocytopenia (HIT) . 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. 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. 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.
评估乳胶免疫比浊法（LIA）和颗粒免疫过滤法（PIFA）对肝素诱导的血小板减少症（HIT）的诊断价值。对2016年5月至2018年7月我院94例疑似HIT患者的样本进行这两种免疫测定的前瞻性分析。血液科医生还收集并分析了他们的病历和进一步的随访数据，分别得出4Ts评分并确诊HIT。评估了这两种免疫测定的性能特征，包括敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。还根据4Ts评分计算了它们的检测后概率（PTP）。94例病例中，15例（16.0%）HIT呈阳性，其中4Ts评分为中等的37例中有6例（16.2%），4Ts评分为高的15例中有9例（60.0%）。PIFA的操作特征为：敏感性100.0%（15/15），特异性51.9%（41/80），PPV为28.3%（15/53），NPV为100.0%（41/41）。4Ts评分中等和高分组的阳性PTP分别为28.7%和75.7%，而阴性PTP均为0。在制造商设定的临界值下，LIA的操作特征为：敏感性66.7%（10/15），特异性94.9%（75/79），PPV为71.4%（10/14），NPV为93.8%（75/80）。4Ts评分中等组的阳性和阴性PTP分别为71.8%和6.3%，而在高分组中分别为95.2%和34.4%。受试者工作特征（ROC）分析表明，LIA优于PIFA，两种测定联合使用明显优于单一检测。4Ts评分仍然是诊断HIT的重要工具。将临床评分与肝素/PF4抗体检测相结合可以提高确诊或排除HIT的准确性。虽然PIFA在诊断价值上不如LIA，但其易用性和100%的NPV具有主要优势。两种检测联合使用可以获得更高的诊断价值。
