Abstract

Introduction: The gold standard diagnostic tool for COVID-19 is real‐time reverse‐transcription polymerase chain reaction (PCR) which is not available in every healthcare institution. There is a need for faster, cheaper, and available tests. This study aimed to determine if eosinophil levels, neutrophil-lymphocyte ratio (NLR), ferritin C-reactive protein (CRP) ratio (FCR), and D-dimer to CRP ratio (DCR) can be used as biomarkers in the early diagnosis of pre-COVID-19 healthy individuals.
Materials and Methods: 289 previously healthy COVID-19 patients and 152 SARS-CoV-2 PCR negative healthy controls were included in the study. Two patient groups were compared by examining the parameters such as white blood count (WBC), neutrophil, monocyte, eosinophil, and red blood cell distribution width (RDW) obtained at the time of hospital admission before using any kind of medication.
Results: Eosinophil levels, FLR, DCR, and NLR remained significantly lower, whereas DCR, FLR, and CRP lymphocyte ratio (CLR) were found to be higher in the COVID-19 group.
Conclusion: High levels of RDW, FLR, and CLR whereas low levels of WBC, monocyte, NLR, FCR, and DCR may predict COVID-19 in patients with no comorbidities.

Key words: Ferritin lymphocyte ratio, monocyte lymphocyte ratio, COVID-19