Monocyte to large platelet ratio as a diagnostic tool for pulmonary embolism in patients with acute exacerbation of chronic obstructive pulmonary disease.

INTRODUCTION    A higher prevalence of pulmonary embolism (PE) has been noted among patients with chronic obstructive pulmonary disease (COPD), particularly in those with acute exacerbations of COPD (AECOPD). Due to a similar clinical presentation and the lack of highly specific laboratory tests, there is a common overuse of computed tomography pulmonary angiography (CTPA). The introduction of an additional, simple, and inexpensive diagnostic tool to help in the diagnosis of PE in patients with AECOPD would be of special interest for everyday clinical practice. OBJECTIVES    The aim of the study was to assess the usefulness of the monocyte to large platelet ratio (MLPR) as a diagnostic tool for PE in patients with AECOPD.  PATIENTS AND METHODS    We performed a retrospective evaluation of patients with AECOPD and suspicion of PE who underwent CTPA. The MLPR was investigated as a marker of thrombosis. Receiver operating characteristics (ROC) curve analyses were preformed to measure the accuracy of the MLPR in comparison with CTPA results and to identify the cutoff value for the MLPR. RESULTS    A total of 101 patients (56 men and 45 women; median age, 72 years; range, 37-94 years) were included in the study. The MLPR showed an excellent accuracy in comparison with CTPA results: the area under the ROC curve was 0.945 (95% confidence interval [CI], 0.904-0.986). The MLPR was characterized by a good accuracy of qualitative test parameters, with high sensitivity (100%; 95% CI, 79.6-100) and specificity (85.7%; 95% CI, 75.9-92.6). CONCLUSIONS    The MLPR measurement appears to be a reliable, simple, inexpensive, and widely available test that may help in the differential diagnosis of PE in patients with AECOPD.