ABSTRACT
Background: World Health Organization (WHO) declared Coronavirus disease of 2019 (COVID-19) as a pandemic in March 2020. The disease showed a wide range of severity ranging from being asymptomatic to causing high mortality. Various laboratory parameters were investigated, which could be used as biomarkers to determine the severity of the disease. The objective of the present study was to analyze hematological, coagulation, and immunological markers in mild, moderate, severe, and critical cases of COVID-19 patients and their relation to the outcome. Materials and methods: A retrospective observational study of 1,000 COVID-19-positive hospitalized patients was conducted. Cases were classified into mild, moderate, severe, and critical groups using WHO guidelines. Along with demographic data, hematological, coagulation, and inflammatory parameters were analyzed and correlated with severity and survival. Result: Out of the total 1,000 cases, there were 510 cases in mild, 232 in moderate, 201 in severe, and 57 in the critical category. Increase in total white blood cell count, absolute neutrophil count (ANC), neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), and inflammatory parameters like C-reactive protein (CRP), serum ferritin, lactate dehydrogenase (LDH), interleukin-6 (IL-6), and decrease in absolute lymphocyte count (ALC) showed significant difference with disease severity and survival. Conclusion: These are important biomarkers to predict the prognosis and outcome of COVID-19 patients. As these markers are easily available, they could be used to categorize the patients at an early stage for optimum management.