The relationship between serum C-reactive protein to albumin ratio and the severity and prognosis of COVID-19

Aims: During the Coronavirus Disease 2019 (COVID-19) pandemic, early identification of especially severe and critical cases may improve prognosis. In this context, laboratory parameters play an important role. This study investigated the relationship between the serum C-reactive protein (CRP)/albumin ratio (CAR) and disease prognosis in patients with COVID-19. Methods: This study included patients who were hospitalized with a possible or confirmed diagnosis of COVID-19 at the Chest Diseases Clinic of the University of Health Sciences Dışkapı Yıldırım Beyazıt Training and Research Hospital Health Practice and Research Center between March 1, 2020, and March 31, 2021. Data on the patients were retrospectively reviewed using the hospital’s record system. A total of 444 patients were included in the study and divided into two groups: those with a diagnosis of severe disease (n=141) and those without (n=303). The serum CAR was compared between the two groups. In addition, the relationship between CAR and demographic, clinical, and laboratory findings was evaluated. Results: The mean CAR in the group with severe disease was found to be 36.1, while it was 17.1 in the group without severe disease, and the difference was statistically significant (p<0.001). ROC analyses showed that CAR had higher area under the curve (AUC) values compared to CRP alone in predicting severe disease, the development of complications, need for respiratory support or intensive care, and mortality. The optimal threshold values identified for CAR were as follows: 26.06 for predicting severe disease (sensitivity 66%, specificity 64%), 26.04 for complications (sensitivity 61%, specificity 62%), 26.06 for intensive care need (sensitivity 63%, specificity 62%), 25.21 for need for respiratory support (sensitivity 60%, specificity 60%), and 27.2 for mortality (sensitivity 62%, specificity 59%). These findings demonstrate that an increased CAR level is significantly associated with poor prognosis in COVID-19 patients. The Relationship Between Serum C-Reactive Protein to Albumin Ratio and the Severity of COVID-19 Conclusion: The data obtained indicate that the CRP to albumin ratio (CAR) is a potential biomarker for predicting severe disease and poor prognosis in COVID-19 patients. Therefore, integrating CAR into the clinical evaluation process may contribute to the early identification of high-risk patients and the timely implementation of appropriate treatment approaches.