Introduction
The coronavirus disease caused by the Coronavirus-2 virus (SARS-CoV-2), which is especially destructive in the respiratory tract, still impacts worldwide, although more than one year has passed since the first appearance of the virus and vaccination studies have been carried out. Patients show a broad spectrum of clinical manifestations, ranging from asymptomatic infection to severe respiratory failure resulting in death. In symptomatic patients, clinical manifestations of the disease begin less than a week later, consisting of fever (body temperature 37-38-C), cough, nasal congestion, and fatigue (1). Pneumonia mainly occurs in the second or third week of symptomatic infection (2,3). Common laboratory findings include lymphopenia, the elevation of liver enzymes and lactate dehydrogenase, and inflammation markers such as ferritin, C-reactive protein, and erythrocyte sedimentation rate. Although white blood cells, neutrophils, eosinophils, platelets, and other blood cells, including CD8 cell counts, are partial predictors in distinguishing between mild and severe COVID-19, their significance is still unclear. Parameters and rates obtained from tests such as hemogram and biochemistry, which are fast, easy, and accessible, and routinely studied in the clinic, have been the subject of many studies to detect biomarkers aimed at evaluating the course of the disease.
Although the disease course cannot be predicted precisely, biomarkers that can predict the severity of this disease will make an important contribution to personalized treatment. Early awareness of the clinical course will also help reduce mortality. Our aim in this study is to evaluate the laboratory markers used in patients diagnosed or suspected of COVID-19 and to develop parameters that can be used to predict mortality.