The role of angiopoietin‐2 and surfactant protein‐D levels in SARS‐CoV‐2‐related lung injury: A prospective, observational, cohort study

Alay, Handan; Laloglu, Esra

INTRODUCTION: Coronavirus disease‐2019 (COVID‐19) is a respiratory disease whose clinical manifestation ranges from asymptomatic to severe respiratory failure. The purpose of this study was to investigate the place of serum surfactant‐D (SP‐D) and angiopoetin‐2 (Ang‐2) levels in predicting severity of disease in patients diagnosed with COVID‐19. METHODS: Sixty‐four patients diagnosed with COVID‐19 between September 2020 and February 2021, 50 patients diagnosed with community‐acquired pneumonia and a 50‐member healthy control group were included in the study. Plasma samples and clinical data were collected within 72 h after admission, during hospital stay. Serum SP‐D and Ang‐2 concentrations were measured using the enzyme‐linked immunosorbent assay. RESULTS: SP‐D and Ang‐2 levels were significantly higher in the mild–moderate pneumonia and severe/critical patient groups compared to the asymptomatic and noncomplicated COVID‐19 patients (p < 0.001 for all groups). Serum SP‐D and Ang‐2 levels of severe‐critical COVID‐19 patients were significantly higher than CAP patients (p < 0.001). Powerful correlation was present between clinical severity of COVID‐19 and SP‐D and Ang‐2 levels (r = 0.885 p < 0.001 and r = 0.913 p < 0.001, respectively). Cut‐off values of 37.7 ng/ml (AUC = 0.763, p < 0.001, 95% confidence interval [CI] = 0.667–0.860) for SP‐D and 4208.3 pg/ml (AUC = 0.659, p = 0.004, 95% CI = 0.554–0.763) for Ang‐2 were identified as predictors of COVID‐19 disease at receiver operating characteristic curve analysis. CONCLUSION: SP‐D and Ang‐2 are predictive factors in differentiating COVID‐19 patients and determining severity of disease. These data may be important for the initiation of treatment in the early stage of the disease in patients with COVID‐19.