CORRELATIONAL STUDY OF NEUTROPHIL-TO LYMPHOCYTE RATIO AND BIOMARKERS (IL-6, CRP, ESR, FERRITIN) WITH COVID-19 SEVERITY

Background: India is 5^th worst hit nation by COVID-19 with 5.2 lacs deaths attributable to the disease. To counteract this global tragedy, many research articles have highlighted the role of various haematological and inflammatory biomarkers in assessing the severity of the disease.

Materials and Methods: A retrospective analysis of 100 RT-PCR confirmed COVID-19 patients was undertaken. The patients were initially categorised into mild, moderate, and severe categories based on SpO2 levels & clinical symptoms at the time of admission. The blood sample was analysed for haematological and inflammatory biomarkers including NLR, IL-6, CRP, ESR and Serum ferritin. The data obtained was compared between severe and non-severe (mild+moderate) categories.

Results: On correlating NLR with disease severity, patients with non-severe disease had a mean of 3.7 whereas it was 6.7 in the severe group, signaling that patient with severe disease had significantly high NLR compared to non-severe patients. The inflammatory markers studied, ESR, CRP & Serum ferritin- all three of them showed markedly increased mean values in severe patients. However, in our study, IL-6 levels were not found to correlate with severity of COVID-19. On performing ANOVA t test, NLR, ESR and serum ferritin were found to be significantly correlated with disease severity (p-value<0.05) but no significant correlation was found with IL-6.

Conclusions: Our study highlights the importance of taking into consideration the values of NLR, ESR, CRP and serum ferritin as a screening tool at the time of initial presentation of COVID-19 patients to triage those requiring intensive care for optimum utilisation of limited resources.