Ginsberg J S, Brill-Edwards P A, Demers C, Donovan D, Panju A
Department of Medicine, McMaster University, Hamilton, Canada.
Chest. 1993 Dec;104(6):1679-84. doi: 10.1378/chest.104.6.1679.
To determine whether measurement of D-dimer, using an enzyme-linked immunosorbent assay (ELISA) with a cutoff of 300 ng/ml, and a latex agglutination assay with a cutoff of 500 ng/ml, is clinically useful in patients with suspected pulmonary embolism (PE).
Prospective cohort.
Tertiary care referral center, university-affiliated hospital.
Two hundred twenty-one consecutive patients with clinically suspected PE.
All patients had blood drawn to measure levels of D-dimer and underwent ventilation/perfusion (V/Q) lung scanning and bilateral impedance plethysmography (IPG); pulmonary angiography was performed in nine patients. Patients were classified as follows: (1) PE-positive; positive pulmonary angiography or high probability V/Q scan or non-high-probability V/Q scan and either abnormal IPG (either at presentation or on serial testing and confirmed by contrast venography) or symptomatic thromboembolic event within 3 months of presentation; or (2) PE-negative; normal V/Q scan or normal pulmonary angiography or non-high-probability V/Q scan and either normal serial IPG or abnormal IPG with normal venography and absence of symptomatic venous thromboembolism within 3 months of followup. Forty-three patients were classified as PE positive and 178 patients were classified as PE negative.
The sensitivities, specificities, positive predictive values, and negative predictive values of the ELISA and latex agglutination assay were calculated for all patients and for the subgroup of patients with non-high-probability V/Q scans. The ELISA D-dimer, using a cutoff of 300 ng/ml, showed a sensitivity and negative predictive value of 100 percent in all patients and patients with non-high-probability V/Q scans, but the corresponding specificities were only 26 percent and 13 percent, respectively. The latex agglutination assay for D-dimer using a cutoff of 500 ng/ml showed the following: sensitivities of 84 percent in all patients and 90 percent in patients with non-high-probability scans, negative predictive values of 93 percent in all patients, and 98 percent in patients with non-high-probability scans and specificities of 56 percent in all patients and 55 percent in patients with non-high-probability scans.
This study demonstrates that an ELISA D-dimer result of less than 300 ng/ml excludes PE but occurs in a small proportion of patients with clinically suspected PE. The latex agglutination assay, using a cutoff of 500 ng/ml, has potential clinical utility in excluding PE in the subgroup of patients with clinically suspected PE and non-high-probability V/Q scans. However, the 95 percent confidence interval on the observed sensitivity of the latex agglutination assay in patients with non-high-probability V/Q scans is wide. Therefore, these promising results should be confirmed in a large clinical trial before the latex agglutination assay is used to make management decisions.
确定采用酶联免疫吸附测定法（ELISA），临界值为300 ng/ml，以及乳胶凝集测定法，临界值为500 ng/ml，检测D - 二聚体对于疑似肺栓塞（PE）患者是否具有临床应用价值。
前瞻性队列研究。
三级医疗转诊中心，大学附属医院。
连续221例临床疑似PE患者。
所有患者均采血检测D - 二聚体水平，并接受通气/灌注（V/Q）肺扫描和双侧阻抗体积描记法（IPG）检查；9例患者接受了肺血管造影。患者分为以下两类：（1）PE阳性；肺血管造影阳性或V/Q扫描高度可能或V/Q扫描非高度可能且IPG异常（就诊时或系列检查时，经静脉造影证实）或就诊后3个月内出现症状性血栓栓塞事件；或（2）PE阴性；V/Q扫描正常或肺血管造影正常或V/Q扫描非高度可能且系列IPG正常或IPG异常但静脉造影正常且随访3个月内无症状性静脉血栓栓塞。43例患者被分类为PE阳性，178例患者被分类为PE阴性。
计算了ELISA和乳胶凝集测定法在所有患者以及V/Q扫描非高度可能患者亚组中的敏感性、特异性、阳性预测值和阴性预测值。ELISA法检测D - 二聚体，临界值为300 ng/ml，在所有患者及V/Q扫描非高度可能患者中敏感性和阴性预测值均为100%，但相应特异性分别仅为26%和13%。乳胶凝集测定法检测D - 二聚体，临界值为500 ng/ml，结果如下：所有患者中敏感性为84%，V/Q扫描非高度可能患者中为90%；所有患者中阴性预测值为93%，V/Q扫描非高度可能患者中为98%；所有患者中特异性为56%，V/Q扫描非高度可能患者中为55%。
本研究表明，ELISA法检测D - 二聚体结果小于300 ng/ml可排除PE，但在临床疑似PE患者中仅占一小部分。乳胶凝集测定法，临界值为500 ng/ml，对于临床疑似PE且V/Q扫描非高度可能的患者亚组排除PE具有潜在临床应用价值。然而，V/Q扫描非高度可能患者中乳胶凝集测定法观察到的敏感性的95%置信区间较宽。因此，在乳胶凝集测定法用于指导治疗决策之前，这些有前景的结果应在大型临床试验中得到证实。
