Combining Serum Interleukin-6 and other Inflammatory Biomarkers to Improve the Prediction of COVID-19 Severity

Objectives: The hyperinflammatory response of (COVID-19) disease 2019 patients impact disease progression. Inflammatory markers could help detect disease early, predict severity and guide treatment.This study was conducted to evaluate if combining baseline inflammatory biomarkers could improve COVID-19 severity prediction. Methods: This study was directed in patients who confirmed COVID-19. Clinical data and laboratory investigations were composed from the hospital's accounts on admission. The level of interleukin (IL)-6 in serum samples was estimated by enzyme-linked immunosorbent assay (ELISA) in all participants. Results: Our findings revealed that Patients in the severe group had significantly higher absolute neutrophil count, ferritin, IL-6, CRP, and procalcitonin (PCT) levels paralleled to non-severe patients. Also, the absolute lymphocyte count was significantly lower. Furthermore, it was found that the area under the curve (AUC) increased to 0.998 and 0.962, respectively, when IL-6 with ferritin or IL-6 with CRP combinations were used to identify non-severe and severe COVID-19 individuals. Conclusion: Combining IL-6 and CRP on admission levels or other inflammatory indicators like ferritin can improve COVID-19 severity prediction and allow for early intervention.