Biomarkers of severity and outcome among adult COVID-19 positive patients admitted to a tertiary referral hospital

ABSTRACT

Background Studies have suggested several biomarkers related to disease progression, severity and outcome of COVID-19 infection including lymphocyte count, neutrophil count, neutrophil lymphocyte ration (NLR), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), platelet count, procalcitonin (PCT), interleukin 6 (IL-6), D-dimer, troponin, creatine kinase (CK), aspartate aminotransferase (AST) and many others.1 These biomarkers were found to have significant roles in the monitoring among COVID-19 patients and will help clinicians in the management protocols. Lymphopenia was found to be associated with poor outcome and predicts disease severity among patients with COVID-19.2 These studies have reported that more severe outcomes and disease progression of COVID-19 infection occur with lymphopenic patients particularly among younger patients.2 Patients with lymphopenia were reported to have a 3-fold higher risk of developing severe COVID-19.3 Higher neutrophil count and NLR have been observed among severe COVID-19 cases as much as 5.9-fold compared to patients with mild and moderate infection.4 Marked increase in the CRP level and its association with IL6 6 also reported to predict disease severity in its early stages especially among critical patients who need more aggressive management.5 Studies have also shown the association between elevated ESR, D-dimer and IL-6 with severe COVID-19 infection among older patients aged >60 years old.6 Coagulopathies were also reported among critical COVID-19 patients and the association between thrombocytopenia and COVID-19 severity and mortality was suggested.7 The multitude of studies that were conducted to determine useful laboratory markers to predict severe outcomes and mortality form COVID-19 was exorbitant. Method We conducted a prospective cohort observational study among adult patients aged 18 years old and above who presented with signs and symptoms of COVID-19 infection (cough, fever, difficulty/shortness of breath and malaise) and history of exposure to COVID-19 at the Emergency Department (ED) of King Saud University Medical City in Riyadh, Saudi Arabia. Sub analysis of 245 COVID (+) patients with severity and mortality showed that patients who were admitted to the ICU had significantly higher levels of WBC count (p=0.030), neutrophils (p<0.001), N/L ratio (p<0.001), D-dimer (p=0.006), potassium (p=0.009), ferritin (p<0.001), CRP (p<0.001), ESR (p=0.024), cortisol (p=0.037) and longer hospital stay (p<0.001) but significantly lower levels of haemoglobin (p=0.027) and FT3 (p<0.001) compared to patients who were not admitted to the ICU.