Eosinophil count, neutrophil-to-lymphocyte ratio, and pentraxin-3 level as predictors of clinical severity in SARS-CoV-2 patients

Background: New biomarkers are urgently needed to predict the severity of patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Eosinophil count and neutrophil-to-lymphocyte ratio (NLR) are new biomarkers for the severity of viral infection. Pentraxin 3 (PTX3) is a natural humoral immune mediator that can bind to viruses, complement, and apoptotic cells, and can trigger T-helper type 1 (Th1) to produce pro-inflammatory cytokines and their levels increase depending on the severity of the disease. Materials and Methods: This was a case-control study consisting of 66 patients infected with SARS-CoV-2 who were divided into critical patients (Group C) and noncritical patients (Group N). We obtained lab samples from the subjects upon admission. We then analyzed the data using the Mann–Whitney U test, receiving operator characteristic (ROC) analysis, and chi-square test with odds ratio (OR) to test the hypothesis. Results: Median eosinophil count, NLR, and PTX3 levels in Group C were 0 ×103/µL, 13.53 and 608.73 pg/mL, compared to 0.11 ×103/µL, 1.94 and 28.50 pg/mL in Group N. The ROC analysis showed good predictive ability for eosinophil count, NLR, and PTX3 with area under the curve (AUC) of 0.913, 0.988, and 0.942 to predict coronavirus disease-2019 (COVID-19) severity. At the cutoff eosinophil count of 0.035 × 103/µL, NLR 4.13 and PTX3 114.51 pg/mL, the OR values were 17.5, 320, and 72.5 (P < 0.05) with a sensitivity of 84.8%, 97.0%, and 90.9% and specificity 75.8%, 90.9%, and 87.9%. Conclusions: Eosinophil count, NLR, and PTX3 levels can be used as predictors of clinical severity in SARS-CoV-2. Eosinophil count of <0.035 ×103/µL, NLR >4.13, and PTX3 level >114.51 pg/mL are risk factors for critical conditions for COVID-19.