Contribution of neutrophil/lymphocyte ratio to the diagnostic efficiency of computed tomography and polymerase chain reaction in COVID-19 patients

BACKGROUND: 6.5% of the country’s population was diagnosed with COVID-19 disease. Computed tomography scanning and polymerase chain reaction tests are considered reliable methods for the detection of COVID-19. However, the specificity and reliability of polymerase chain reaction tests and ground-glass opacity (GGO) on thorax computed tomography images in diagnosing COVID-19 are still being disputed. Our aim was to compare the neutrophil/lymphocyte ratio, whose efficiency in differentiating between viral and bacterial infections has previously been studied, with computed tomography and polymerase chain reaction for COVID-19 diagnosis. MATERIALS AND METHODS: This was a retrospective study that included patients treated in a tertiary care hospital emergency service pandemic polyclinic between 14 March and 1 June 2020. The neutrophil/lymphocyte ratios of patients with polymerase chain reaction tests and ground-glass opacities on computed tomography were calculated. The neutrophil/lymphocyte ratios of polymerase chain reaction-negative patients with computed tomography images were compared with the neutrophil/lymphocyte ratios of polymerase chain reaction-positive patients with computed tomography images. RESULTS: A total of 631 patients were included in this study. Thorax computed tomography scans were obtained from all patients. The mean neutrophil/lymphocyte ratio of patients with ground-glass opacities was 3.50 ± 2.12, whereas that of patients without ground-glass opacities was 2.90 ± 2.01. This difference was also statistically significant. Polymerase chain reaction swab samples were obtained from 282 patients (44.7%). The mean neutrophil/lymphocyte ratio of polymerase chain reaction-positive patients was 2.38 ± 1.02, whereas that of polymerase chain reaction-negative patients was 3.97 ± 2.25. The difference was statistically significant. CONCLUSION: Many studies are undoubtedly required to determine the efficiency of the neutrophil/lymphocyte ratio in COVID-19 diagnosis. However, we postulate that evaluating the neutrophil/lymphocyte ratio along with computed tomography and polymerase chain reaction can assist in the diagnosis of patients.