THE ROLE OF d-NLR, RDW AND PLR IN PREDICTING CLINICAL SEVERITY IN COVID-19 INFECTION: A SINGLE-CENTER, RETROSPECTIVE OBSERVATIONAL STUDY IN A TERTIARY CARE MEDICAL COLLEGE HOSPITAL IN CENTRAL KERALA

ABSTRACT

Background: The corona virus disease 2019 (COVID-19) caused by SARS-CoV-2 virus has been declared as a global pandemic by WHO. Various hematological parameters may be considered as useful prognostic indicators in COVID-19 infection. Material(s) and Method(s) Age, neutrophil to lymphocyte ratio (NLR), derived-NLR (d-NLR), platelet to lymphocyte ratio (PLR) and red cell distribution width (RDW) of 266 laboratory confirmed COVID-19 patients, at the time of admission, belonging to clinical category B and C were recorded and compared in this single-center, retrospective observational study. The receiver operating characteristic (ROC) curve was applied to determine the thresholds for bio-markers and their prognostic values were assessed. Result(s) A statistically significant elevated NLR (P=0.001), d-NLR ( P=0.001), PLR (P=0.001) and RDW (P=0.026) were noticed in Category C (severe) group when compared to Category B group. From the ROC curve, it was established that d-NLR, NLR and WBC count proved to be a fair distinguisher (area under the curve between 0.7- 0.8) in predicting the clinical severity in COVID-19 patients. NLR and WBC count was found to be having the highest sensitivity of 82%, while d-NLR proved to be highly specific. Elevated age was also significantly associated with illness severity (P=0.001). Conclusion(s) Elevated age, WBC count, NLR, d-NLR, RDW and PLR may be considered as useful prognostic biomarkers for predicting the severity of COVID-19 infection and adverse outcome, with NLR and WBC count showing the highest sensitivity and d-NLR with the highest specificity. Copyright © 2022 Necati Ozpinar. All rights reserved.