Dynamics of inflammatory markers, neutrophil lymphocyte ratio, platelet lymphocyte ratio in COVID-19 deaths

Introduction: Various inflammatory markers and laboratory parameters were identified as the predictors of severity and mortality in COVID -19 infection. However, the progression of inflammatory markers and their gender difference in COVID-19 deaths has not been extensively studied. The study aim was to analyze the progression of inflammatory markers, neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) in COVID-19 deaths, and analyzed the correlation between NLR, PLR and inflammatory markers. Materials and methods: A retrospective observational study based on records was done on 104 patients who died due to COVID-19 infection. In addition to baseline investigations, NLR (Neutrophil Lymphocyte ratio), PLR (Platelet Lymphocyte Ratio), ferritin, D-dimer and CRP (C reactive protein) was collected for all patients on day one, day three and day five. Results: Out of 104 patients, 68 were males and 36 were females. Mean NLR was 5.7, 7.3 & 7.5 on day one, three and five respectively. Mean PLR was 145.9, 166.6 and 173.7 on day one, three and five respectively. Mean CRP was 37.6mg/l, 51mg/l & 57.2mg/l, mean ferritin was 780.9ng/ml, 852.5ng/ml &1033ng/ml and mean D-dimer was 2373ng/ml, 3149ng/ml & 3686ng/ml on day one, three and five respectively. There was a strong positive correlation of NLR with ferritin (0.598), CRP (0.663) and D-dimer (0.53) on day one and on day five, but only a weakly positive correlation observed on day three. There was a negative correlation between PLR and inflammatory markers. No significant difference in the inflammatory markers and their progression was noted between males and females. Conclusion: In this retrospective cohort study of 104 COVID-19 deaths, there was progressive increase of inflammatory markers. Serial measurements of inflammatory markers help in early identifications of patients who may deteriorate. Progression of NLR has strong correlation with inflammatory markers and could be used as a surrogate marker to prioritise treatment in resource limited settings.