Clinical study on the level of neutrophil extracellular trap in the bile of patients with choledocholithiasis / 中华消化杂志

ABSTRACT

Objective:To investigate the activation level of neutrophil extracellular trap (NET) in the bile of patients with choledocholithiasis and its clinical significance.Methods:From May 2021 to October 2022, 130 patients underwent endoscopic retrograde cholangiopancreatography (ERCP) at the Department of Gastroenterology, the First Affiliated Hospital of Anhui Medical University were enrolled. The patients were divided into choledocholithiasis group (90 cases) and non-choledocholithiasis group (40 cases), and the choledocholithiasis group was further divided into large stone group (maximum diameter >1 cm, 36 cases) and small stone group (maximum diameter≤1 cm, 54 cases). The bile samples were collected from 130 patients during operation and 16 choledocholithiasis patients with nasobiliary drainage at 24 h after operation.The levels of myeloperoxidase(MPO), neutrophilelastase(NE), and citrullinated histone H3(CitH3) in bile were detected by enzyme-linked immunosorbent assay.The levels of MPO, NE, and CitH3 were compared between choledocholithiasis group and non-choledocholithiasis group, between large stone group and small stone group, as well as between choledocholithiasis patients before ERCP and after ERCP. Mann-Whitney U test and Wilcoxon signed rank test were used for statistical analysis. Results:The levels of MPO, NE and CitH3 in the bile of choledocholithiasis group were 32.6 U/L(28.5 U/L), 30.6 ng/L(35.2 ng/L) and 0.37 μg/L(0.73 μg/L), respectively, which were all higher than those of non-choledocholithiasis group (19.9 U/L(36.4 U/L), 18.2 ng/L(27.4 ng/L), and 0.10 μg/L(0.25 μg/L)), and the differences were statistically significant ( Z=2.91, 3.20 and 3.34; P=0.004, 0.001 and 0.001). The levels of MPO, NE and CitH3 of large stone group were 47.0 U/L(49.4 U/L), 48.4 ng/L(39.5 ng/L) and 0.83 μg/L(1.08 μg/L), respectively, which were all higher than those of small stone group (29.3 U/L(17.5 U/L), 24.0 ng/L(25.8 ng/L), and 0.27 μg/L(0.45 μg/L)), and the differences were statistically significant ( Z=2.01, 3.58 and 3.63; P=0.044, <0.001 and <0.001). The levels of MPO, NE and CitH3 in the bile of choledocholithiasis patients after ERCP significantly decreased compare with those before ERCP (19.4 U/L(19.8 U/L) vs. 33.6 U/L(36.7 U/L), 12.7 ng/L(15.1 ng/L) vs. 22.7 ng/L(25.9 ng/L), 0.05 μg/L(0.12 μg/L) vs. 0.14 μg/L(0.27 μg/L)), and the differences were statistically significant ( Z=3.52, 3.30 and 3.18; all P<0.001). Conclusion:The activation level of NET in the bile of patients with choledocholithiasis increase, while the activation level of NET decrease after ERCP, which indicate that NET may be involved in the formation of choledocholithiasis.