The Role of Different Inflammatory Indices in the Diagnosis of COVID-19

Aim: To assess the role of different inflammatory indices in the diagnosis of COVID-19 infection. Methods: The neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), derived NLR (dNLR), neutrophil to lymphocyte, platelet ratio (NLPR), systemic inflammation index (SII), aggregate index of systemic inflammation (AISI), systemic inflammation response index (SIRI) and C-reactive protein to-lymphocyte ratio (CRP/L) were assessed in 88 COVID-19 patients compared to 41 healthy control subjects. Results: The NLR, PLR, NLPR, SIRI, and CRP/L were significantly increased, while LMR was significantly decreased in COVID-19 patients compared to the control group (P = 0.008, 0.011, <0.001, 0.032, 0.002 and P < 0.001; respectively). The AUC for the assessed indices was LMR (0.738, P = 0.008), NLPR (0.721, P < 0.001), CRP/L (0.692, P = 0.002), NLR (0.649, P 0.001), PLR (0.643, P = 0.011), SIRI (0.623, P = 0.032), dNLR (0.590, P = 0.111), SII (0.571, P = 0.207), and AISI (0.567, P-0.244). Multivariate analysis showed that NLPR 0.011 (OR: 38.751, P = 0.014), and CRP/L >7.6 (OR: 7.604, P = 0.022) are possible independent diagnostic factors for COVID-19 infection. Conclusion: NLPR and CRP/L could be potential independent diagnostic factors for COVID-19 infection.