Evaluation of whole blood profile as a tool in COVID-19 diagnosis and screening. A cross-sectional study

Backgroung: the COVID-19 epidemic began in December 2019, and the shortage of diagnostic resources has affected the reported data on the number of cases, resulting in variations in reported cases between countries. This situation underscores the necessity for a deeper understanding of SARS-CoV-2 pathophysiology, including blood profiles and potential predictors. Methods: hematological variables were studied in 200 patients diagnosed with COVID-19, before the vaccination period started. We analyzed hemogram parameters: erythrocytes, hemoglobin, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV) mean corpuscular hemoglobin concentration (MCHC), hematocrit, red cell distribution width (RDW), platelets, mean platelet volume (MPV), leukocytes, neutrophils, lymphocytes, neutrophils/lymphocytes ratio and Platelet-to-Lymphocyte Ratio (PLR), up to 9 days after positive result for COVID-19. Results: the positive COVID-19 group presented a higher mean age, as well as a higher frequency of male individuals. Erythrocyte, hemoglobin, hematocrit and MCH values were significantly lower, while RDW and PLR showed higher values in the positive group. Leukocytes, neutrophil and the neutrophil/lymphocyte ratio presented higher values in the positive COVID-19 group. Conclusion: data showed that the hemogram, a low-cost, minimally invasive exam, supports diagnosis and screening of COVID-19, allowing better evaluation of the disease course and assisting medical decisions facing lack of resources in a pandemic situation.