Performance of the Quantitative Latex Immunoturbidimetric D-dimer Assay for the Diagnosis of Acute Pulmonary Embolism at Rafik Hariri University Hospital

   Background and aims: The diagnostic workup for pulmonary embolism (PE) includes D-dimer assay and computed tomographic angiography. Several D-dimer assays have been approved for PE diagnosis with different sensitivity and specificity. We aimed to study the sensitivity and specificity of the quantitative latex agglutination D-dimer assay used in a referral teaching hospital in Lebanon for the diagnosis of acute PE. Methods: Using a retrospective chart review, we studied ۳۰۰ patients who had D-dimer test at Rafik Hariri University Hospital in the period between January ۱, ۲۰۱۲ and December ۳۱, ۲۰۱۳. Accordingly, ۹۳ patients had a CT angiography after being suspected to have acute PE. A statistical table ۲*۲ was used to compare the results of CT angiography and D-dimer test. Results: Thirteen patients (۱۳.۹۷%) had PE and ۶۰ patients (۶۴.۵۱%) had positive D-dimer test. Quantitative latex agglutination D-dimer assay had a sensitivity of ۶۹%, specificity of ۳۶%, and negative predictive value of ۸۸%. False positive ratio was also ۶۴%. Moreover, the receiver operating characteristic (ROC) curve was obtained with an area under the curve measuring ۰.۵۲۷. Conclusion: Quantitative latex agglutination D-dimer assay has a high negative predictive value; thus, it can exclude a PE diagnosis if it is associated with low clinical pretest probability.

Keywords:

Pulmonary embolism , D-Dimer , Latex agglutination , Lebanon