sLOX-1 as a differential diagnostic biomarker for acute pulmonary embolism

ObjectiveDiagnosing acute pulmonary embolism (PE) is challenging because of nonspecific clinical symptoms. Soluble lectin-type oxidized low-density lipoprotein receptor (sLOX-1) has differential expression in arterial and venous disease. This study aimed to evaluate the relevance of soluble lectin-type oxidized low-density lipoprotein receptor (sLOX-1) as a diagnostic biomarker for acute PE. MethodsThis observational study was performed at Beijing Anzhen Hospital in China. Patients with PE, aortic dissection (AD), myocardial infarction (MI) and healthy controls were enrolled in this cross-sectional study (n=90 each). Moreover, 730 patients with suspected PE were enrolled in this prospective study. The diagnostic performance of sLOX-1 was assessed using the receiver operating characteristic curve analysis. ResultsIn the development set, sLOX-1 levels were significantly lower in patients with PE than in those with AD, MI, or healthy controls. In the validation cohort, the area under the curve (AUC) of sLOX-1 for patients with PE from other chest pain diseases, particularly from AD was significantly higher than that of D-dimer ({Delta}AUC=0.32; 95%CI, 0.26-0.37; P<0.0001) with 77.0% specificity and 74.5% positive predictive value at the threshold of 600 pg/mL derived from the development set. By integrating sLOX-1 into existing diagnosis strategy (Wells rules combined D-dimer), the number of patients who were further categorized as workup for PE decreased from 417 to 209, with the positive detection rate of computed tomographic pulmonary angiography increased from 35.1% to 67.0%. Six patients with PE were missed in 208 excluded patients at a failure rate of 2.88%. ConclusionsPlasma sLOX-1 is a novel diagnostic tool that can rapidly categorize suspected PE as a workup for PE based on existing diagnostic strategy.