Clinical roles of plasma D-lactate, endotoxin and diamineoxidase in assessment of intestinal mucosal barrier function post traumatic brain injury

Objective To investigate the roles of plasma D-lactate, endotoxin and diamineoxidase (DAO) in assessment of intestinal mucosal barrier function post traumatic brain injury (TBI). Methods We retrospectively studied 70 patients with TBI (TBI group) admitted to Department of Neurosurgery, the 904th Hospital of the Joint Service of Chinese People′s Liberation Army from January 2017 to August 2018, and 45 healthy subjects were enrolled as well (healthy control group) at the physical examination center during the same period. All TBI patients were treated conservatively or surgically. Peripheral blood of patients and healthy subjects were collected to detect levels of plasma D-lactic acid, endotoxin, and DAO. Further use of Spearman correlation analysis was conducted to determine the correlation between preoperative serum D-lactic acid, endotoxin and DAO and Glasgow Coma Scale (GCS) in patients with TBI. Results Compared with the healthy control group, the levels of D-lactic acid (24.7±9.4 mg/L vs. 9.8±4.0 mg/L), endotoxin (9.1±5.8 U/L vs. 4.0±2.2 U/L) and DAO (36.3±22.6 U/L vs. 15.2±3.6 U/L) were significantly increased (t=9.82, 2.84 and 3.49, respectively, all P<0.05). Further correlation analysis showed that serum D-lactic acid, endotoxin and DAO levels were negatively correlated with preoperative GCS scores (r=-0.543, -0.617 and -0.672, respectively, all P<0.01). Conclusion The preliminary results have suggested that the levels of D-lactic acid, bacterial endotoxin and DAO in the serum could be used as important indexes in evaluation of the intestinal mucosal barrier function in patients post TBI. Key words: Traumatic brain injury; Diamineoxidase; D-lactate; Endotoxin; Intestinal mucosa barrier