Significance of immune-inflammatory markers in predicting clinical outcome of COVID-19 patients.

Background: The epidemic of coronavirus disease 2019 (COVID-19) has been rapidly spreading on a global scale affecting many countries and territories. There is rapid onset of generalized inflammation resulting in acute respiratory distress syndrome. We, thus, aimed to explore the potential of immune-inflammatory parameters in predicting the severity of COVID-19.

Materials And Methods: Age, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), Lactate Dehydrogenase (LDH), C-reaction protein (CRP), and procalcitonin (PCT) of 611 patients with laboratory-confirmed COVID-19 were investigated and compared. Patients were divided on the basis of severity and survival into two groups. Data were expressed as mean or median values and percentages. The receiver operating characteristic curve was applied to determine the optimal cut-off values of these biomarkers.

Results: The median age was 50 years and the male to female ratio was 3.7:1. The mean NLR, LMR, PLR, LDH, CRP, and Procalcitonin for the non-severe group were 4.16, 10.8, 133.7, 666.1, 49.9, and 0.15, respectively. In the severe group mean values of the above-mentioned immune-inflammatory markers were 17.8, 4.69, 268.2, 1277, 158.6, and 3.05, respectively. Elevated levels were significantly associated with disease severity. In ROC curve analysis, NLR had the largest area under the curve at 0.923 with the highest specificity (0.83) and sensitivity (0.88).

Conclusion: This study shows that NLR, PLR, LDH, CRP, and Procalcitonin may be a rapid, widely available, useful predictive factor for determining the severity of COVID-19 patients.