Screening for and combining serum intestinal barrier-related biomarkers to predict the disease severity of AECOPD

Abstract

In the patients with AECOPD, the gut displays ischemia, anoxia and oxidative stress, which lead to the intestinal barrier failure. Therefore, it is desirable to screen for effective intestinal barrier-related biomarkers to monitor the disease severity. We conducted a prospective observational study in 40 patients with AECOPD and 10 patients with stable COPD. The serum levels of I-FABP, citrulline, D-Lactate, DAO, and α-GST, as well as the APACHE II scores were recorded. Person correlation analysis, logistic regression models and receiver operating characteristic (ROC) curve analyses were used in our study. Patients with AECOPD had significantly higher levels of I-FABP, D-Lactate, and DAO than did those with stable COPD. However, the serum citrulline level was significantly decreased in the patients with stable COPD than in those with AECOPD and the serum α-GST was not significantly changed. Additionally, we observed that there was a higher levels of I-FABP, D-Lactate, and DAO and a lower level of citrulline in patients with severe COPD than in patients with nonsevere COPD [APACHE II (nonsevere COPD) <20; APACHE II (severe COPD) ≥20]. Correlation analysis showed that I-FABP and D-Lactate had a significantly positive correlations with the APACHE II score, and citrulline had a significantly negative correlations with the APACHE II score. Following, treatment, the levels of I-FABP and D-lactate were decreased and the level of citrulline was increased. Moreover, we screened out the citrulline and DAO, which independently affected the diagnosis of severe COPD by stepwise logistics regression analysis. Additionally, we found that the combination of serum citrulline and DAO can more effectively diagnose the severe COPD than any single biomarker can, which may be a supportive and convenient method that can be used clinically. Serum I-FABP, citrulline and D-Lactate could be used to assess the disease severity. Citrulline and DAO can diagnose the severe COPD and the combination is more effective.