Assessment of diagnostic and prognostic laboratory biomarkers in severe COVID-19 patients admitted to intensive care unit.

Coronavirus disease (COVID-19) is a global pandemic. In the first two years of the pandemic, nearly 15 million people died worldwide. Accurate and rapid laboratory diagnosis of COVID-19 infection is one of the milestones of pandemic control. Therefore, this study aimed to compare the diagnostic and prognostic accuracy of mainly used laboratory biomarkers (CRP, ferritin, IL-6, D-dimer, procalcitonin, and LDH) in the sera of severe COVID-19 Egyptian patients, to assess the most appropriate biomarker used in severe COVID-19 patients. A total of 120 COVID-19 patients and 50 normal controls were enrolled into our study. Demographic data, hospitalization time, medical history, oxygen saturation, respiratory rate, oxygen supply, laboratory findings and thorax tomography of the patients were obtained from the hospital electronic information system retrospectively. Our results revealed that the serum levels of CRP, ferritin, IL-6, D-dimer, PCT and LDH were highly significantly increased in severe COVID-19 patients as compared to normal controls (p < 0.001), and in non-survivors as compared to survivors (p < 0.001). By using ROC curve analysis, IL-6 appeared to be the most sensitive and specific marker with 80.9% sensitivity and 84.9% specificity; followed by LDH with 85.1% sensitivity and 82.8% specificity in the prediction of death. In conclusion CRP and IL-6 could be the most appropriate biomarkers in the diagnosis of severe COVID-19 disease, while IL-6 and LDH may be good predictors of mortality between severe COVID-19 patients.