Neutrophil-Lymphocyte Ratio (NLR) and Lymphocyte-Monocyte Ratio (LMR) as Covid-19 Screening Parameters

Abstract

Coronavirus Disease 2019 (COVID-19) diagnosis generally uses RT-PCR as the gold standard to detect coronavirus-2 (SARS-CoV-2); however, this method requires advanced laboratory equipment. Alternatively, Neutrophil-Lymphocyte Ratio (NLR) and Lymphocyte-Monocyte Ratio (LMR) can be used to identify viral infection. The study aimed: (1) to compare each NLR and LMR ratio in patients with and without COVID-19 and (2) to test the effectiveness of these ratios in identifying COVID-19. The study was conducted at the Haji Adam Malik Central General Hospital, Medan, Indonesia by acquiring 87 medical records data. The complete hematologic profile was analyzed from patients with and without COVID-19. The NLR and LMR ratio accuracy were analyzed as a screening tool for COVID-19. The AUC of NLR was 0.638, with cut-off ≤ 2.49, 47.6% sensitivity, and 80% specificity; therefore, the NLR accuracy as a screening for COVID-19 was defined as not good (just sufficient) because of AUC <0,7. The AUC of LMR was 0.661, with cut-off ≥ 3.23, 45.2% sensitivity, and 82.2% specificity; therefore, the LMR accuracy as a screening parameter for COVID-19 is defined as not good (just sufficient) because of AUC <0,7. There were significant differences in hematologic profile in neutrophil, lymphocyte, NLR, LMR between the patients in the COVID-19 group and non-COVID-19 group. NLR and LMR cannot be used as a screening tool because the Area Under Curve (AUC) is not good enough (just sufficient) in detecting COVID-19.