Serum IFABp and Citrulline levels were prognostic markers of mortality in COVID-19 patients

Coronavirus Disease-2019 (Covid-19) is a globally pandemic and causes severe acute respiratory syndrome. It is commonly associated with gastrointestinal manifestations. Intestinal fatty acid binding protein (IFABp) and citrulline are thought to be potential biomarkers of intestinal function and injury. This study aimed to determine relationship between serum IFABp and citrulline concentrations and mortality in COVID-19 patients. Patients and methods This observational study was performed in medical intensive care unit (ICU) and included patients diagnosed by PCR-confirmed COVID-19 infection. Serum citrulline and IFABp concentrations were measured using ELISA method within first 24 h after ICU admission. The reference range of serum IFABp and serum citrulline concentrations were 19.89–23.30 ng/mL and 15.03–17.41 nmol/mL, respectively. Results A total of 85 critically ill patients were recruited. The mean age of study sample was 70.0±12.4 years. The mean APACHE II score was 20.0±7.1. The most common comorbidities of participants were hypertension (50.6%) and diabetes mellitus (40.0%). During the ICU stay, 34.1% of participants were treated with mechanical ventilation. The median serum IFABp concentrations was 8.01 (IQR: 4.40–13.31) ng/mL. The median serum citrulline value of patients was 5.87 (IQR: 3.99.10) nmol/mL. The ICU mortality rate was 43.5%. ROC analysis showed that the cut off value of serum IFABp and citrulline concentrations to predict ICU mortality were 8.15 ng/mL (AUC: 0.722, 95%Cl: 0.611–0.833, p = 0.001) and 5.99 nmol/L (AUC: 0.671, 95%Cl: 0.551–0.791, p = 0.009) (Fig. 1). Conclusion Our results showed that serum IFABp and citrulline concentrations were better potential biomarkers in critically ill patients infected with COVID-19.