Hematologic biomarkers in COVID-19: Correlation with disease severity and mortality

Aims & Objectives: The aims and objectives of present study were to evaluate the various Hematological parameters including Neutrophil- lymphocyte ratio (NLR), Platelet-lymphocyte ratio (PLR) in COVID- 19 patients and controls and to study correlation of these parameters with each other and with disease severity Patients/Materials & Methods: A prospective cross sectional study was conducted on 506 Covid-19 positive patients and 50 controls over a period of two months (June to July 2020) The cases were subclassified based on disease severity into mild to moderate (n = 337), severe (n = 118) and very severe (n = 51) and into survivors (n = 473) and non survivors (n = 33) based on survivor status Results: There were statistically significant differences in WBC count, Absolute neutrophil count (ANC), Absolute lymphocyte count (ALC), absolute monocyte count (AMC), NLR, PLR, RDW SD and RDW CV between covid cases vs controls;among the clinical subgroups and among the survivors and non survivors There was a significant strong positive correlation between various parameters, that is, NLR and MLR (r: 0 852, p = 0), MPV and PDW (r: 0 912, p = 0), MPV and PLCR (r:0 956, p = 0), PDW and PLCR (r:0 893, p = 0) NLR (AUC: 0 676, p = 0) was the best single parameter and NLR + RDW-CV was best combination parameter as per area under curve (0 871) of ROC to distinguish severe from mild to moderate disease Discussion & Conclusion: Leucocytosis, neutrophilia, lymphopenia and monocytosis were characteristic while NLR and NLR + RDWCV emerged as the most effective single and combination CBC parameters in distinguishing mild to moderate and severe cases respectively