The predictive value of laboratory biomarkers in defining COVID-19 severity

IntroductionThe COVID-19 outbreak poses a serious hazard to human health. We aimed to correlate between the severity of clinical presentation and hematological (CBC including: lymphocyte count, neutrophil to lymphocyte ratio) and immunological (CRP, serum ferritin, D-Dimer) laboratory results of COVID-19 cases. Material and methodsAll COVID-19 positive cases that were admitted to Aswan University Hospitals were prospectively collected and classified into either severe or non-severe COVID-19 cases rendering to prerequisite for ICU admission. All the demographic, clinical characteristics, HRCT results and the basic laboratory biomarkers at time of admission were collected.ResultsThe severe case group (n=71) had considerably higher mean levels of WBCs, absolute neutrophils, absolute lymphocytes, CRP, D-dimer, NLR and ferritin than the non-severe case group (n=137) (p <0.0001 considerably). However, CRP and serum ferritin are considered the independent risk factors for COVID-19 severity (p= 0.009 & 0.033 respectively). Moreover, at a cut-off point (5.73), the sensitivity of NLR ratio to predict the case severity was low (43%) but higher specificity (93.2%). Similarly, at a cut-off point of (1.56), the sensitivity and specificity of D-dimer were (60.6% and 78.1% respectively). Furthermore, at a cut-off point of (256.5), the sensitivity of serum ferritin to predict severity was high (90.1%) but low specificity (38.0%).