Utilization of C-Reactive Protein Test as a Predictor of Lung Injury in Patients with Coronavirus Disease 2019

Background: C-reactive protein (CRP) test can be used at coronavirus disease 2019 (COVID-19) screening clinics as a point of care test. The aim of this study was to determine whether CRP test can be used as an indicator of lung injury. Methods: In all, 98 patients with COVID-19 were enrolled for this study. We collected medical records and laboratory results of the patients. Chest radiographic findings were classified into five groups. We analyzed the correlation between laboratory tests and the grade of lung injury. Results: In patients with COVID-19, increased CRP and erythrocyte sedimentation rate (ESR), and lymphocytopenia were noted. CRP, ESR, and segmented neutrophils were found to be positively correlated while albumin and lymphocyte were negatively correlated with lung injury grade. CRP levels showed the highest correlation coefficient of 0.858. Based on the chest radiographs, the sensitivity and specificity of CRP was 100% and 77.8%, respectively. Within the reference range of CRP, abnormal chest radiograph was not recognized. In addition, initial and subsequent increase in CRP levels in patients with unremarkable chest radiograph could be associated with aggravated lung injury. Conclusions: CRP test showed a sensitivity of 100% in detection of lung injury, and the level was proportional to the extent of lung lesions. Therefore, CRP test will be useful as a predictor of lung injury in patients with COVID-19. KCI Citation Count: 0