Impact of age to ferritin and neutrophil-lymphocyte ratio as biomarkers for intensive care requirement and mortality risk in COVID-19 patients in Makassar, Indonesia

Abstract

Inflammation plays a substantial role in COVID-19 pathophysiology. Ferritin and neutrophil-lymphocyte ratio (NLR) are significant prognostic biomarkers used in COVID-19 patients, although they are affected by other factors such as comorbidities and age. Aging changes the immune system through immunosenescence and inflammaging; however, there are limited number of studies evaluating its effect on ferritin and NLR as part of the complete assessment for intensive care requirement and mortality risk. A single-center retrospective cohort study of 295 COVID-19 patients was performed at the Siloam Hospitals Makassar, South Sulawesi, Indonesia from April to August 2020. After admission, all patients were followed up for clinical outcomes. Patients were grouped into strata based on age (<50 years vs. ≥50 years) and risk groups (low-risk ferritin vs. high-risk ferritin; low-risk NLR vs. high-risk NLR). The endpoints of the study were the intensive care requirements and mortality. Among the 295 COVID-19 patients, 264 survived and 31 deceased. Ferritin and NLR had higher area under curve (AUC) values than other inflammatory parameters and had significantly different outcomes in both mortality and intensive care requirement groups. The combination of ferritin and NLR showed higher AUC values for intensive care requirement and mortality (AUC, 0.783; 95% confidence interval, 0.703–0.864). Multivariate analysis showed that both endpoints were strongly affected by age, ferritin level, and NLR. Age significantly multiplied clinical endpoints in low-risk group patients but not in high-risk group patients. The combination of ferritin and NLR had a better predictive value for intensive care requirement and mortality risk. However, age strongly affects clinical outcome in low-risk groups of both ferritin and NLR groups; hence, it should be considered as an early predictive factor of COVID-19 disease progression.