Could Eosinopenia be a simple, fast and reliable biomarker in diagnosis of Covid-19?

Abstract

Objective: Monitoring CBC subsets, particularly eosinophils. and inflammation markers, during admission and treatment of severe COVID-19 patients, can reveal key indicators of disease progression and stage to provide a basis for diagnosis and treatment for clinicians. Method: Our study is a retrospective case-control study. After taking aproval of Ministry of Health and Ethics Committee, the recorded clinical, laboratory and radiological data of 30 patients who were diagnosed with Covid-19, between 15 March and 15 June 2020, were compared with 30 healthy person by using appropriate statistical methods. Results: Both patients and conrols included 10 (33.3%) females and 20 (66.6%) males with a mean age of 57.2 ± 15.46 and 60.07 ± 20.59 respectively. Eosinophil counts of the patients on admission were significantly lower than the controls (p <0.001). Eosinophil counts one week after admission were increased significantly compared to the admission levels (p= 0.004). Neutrophil/Eosinophil ratio, which is a reliable indicator of 'Eosinopenia' in patients on admission was significantly higher than that of one week later (p= 0.041). EO1, NE1, NE2, PLT2/LYM2, LYM1/CRP1 and LYM2/CRP2 were the most predictive indexes. The AUCs of them were; 0.856, 0.778, 0.719, 0.738, 0.747 and 0.702 respectively, the cut-off values were; 0.04, 3.32, 3.21, 144,59, 1.99 and 7.84 respectively, the sensitivity and specificity were 66.7% and 93.3% for EO1; 53.3% and 93.3% for NE1; 46.7% and 93.3% for NE2; and 80.1% and 80.5% for PLT2/LYM2; and 100% and 66.7% for LYM1/CRP1and 100% and 53.3% for LYM2/CRP2; respectively. Conclusions: Tracking of CBC subsets, particularly Eosinophil, and CBC indexes is helpful in the early screening, diagnosis, treatment and follow up of critical COVID-19 patients.