Time-to-event assessment for the discovery of the proper prognostic value of clinical biomarkers optimized for COVID-19

Ferreira, J. R.; Ribeiro, V. H. A.; Cossetin, M.; Figueredo, M. V. M.; Cardoso, C. Q.; Almeida, B. M.

In the early days of the pandemic, clinical blood-originated biomarkers for COVID-19 have been investigated to predict patient mortality. A straightforward decision tree with three variables, i.e., lactic dehydrogenase (LDH), high-sensitivity C-reactive protein (CRP), and lymphocyte percentage, has been proposed previously, with more than 90% accuracy. In this work, we highlight the importance of the cohort made publicly available, especially at the beginning of the pandemic where open data were still limited, and complement the findings by incorporating further evaluation. Results confirmed poor short-term prognosis to abnormal levels of some laboratorial indicators, such as LDH, CRP, lymphocytes, interleukin-6, and procalcitonin. Our findings could also provide insights into COVID-19 research, such as key levels of fibrin degradation products, which are directly associated with the Dimerized plasmin fragment D and could indicate active coagulation and thrombosis. Still, we highlight here the prognostic value of interleukin-6, a cytokine that induces inflammatory response.