Neutrophil-to-lymphocyte and Platelet-to-lymphocyte Ratios in those with Pulmonary Embolism in the Course of Coronavirus Disease 2019

Background:To investigate the levels of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios in those having a pulmonary embolism (PE) in the course of coronavirus disease 2019 (COVID-19). Methods: The records of those having COVID-19 were retrospectively obtained from the hospital automation system. NLR and PLR were measured with the help of patients' blood cell counts. Results: Of 1,452 COVID-19 patients, 17 (1.2%) were diagnosed with PE. Compared with the controls, while leukocyte (p = 0.001), neutrophil (p <0.001), and neutrophil (p = 0.001) percentages, and NLR (p <0.001) and PLR (p = 0.006) had higher values, lymphocyte count (p = 0.004) and lymphocyte percentage (p <0.001) showed lower values in the patients with PE. Compared to the survivors, the non-survivors were found to have increased leukocyte (p <0.001), neutrophil (p <0.001), and neutrophil percentages (p <0.001), NLR (p <0.001) and PLR (p <0.001), and decreased lymphocyte (p <0.001) counts and percentage (p <0.001), hemoglobin (p = 0.005), hematocrit (p = 0.012), and platelet counts (p <0.001). While NLR and PLR cutoffs were found as 4.338 and 187.83 in predicting PE, the cutoff values of NLR and PLR were, respectively, 4.301 and 172.5 in predicting mortality. The logistic regression analysis also revealed that all hematological parameters had no effects on the development of PE. Conclusion: Although NLR and PLR had higher scores in PE patients, no relationship was determined between the levels of NLR and PLR and PE development. Further prospective studies including larger populations are required to enlighten the increased NLR and PLR in PE patients having COVID-19.