[Pepsin and bile acids detection in saliva for the diagnosis of gastroesophageal reflux disease]

Objective: To identify the value of the detection of pepsin and bile acids in saliva for the diagnosis of gastroesophageal reflux disease(GERD). Methods: From January 2018 to June 2019, 104 GERD patients and 43 healthy people in Guangdong Provincial People's Hospital were recruited. The 104 patients of GERD group were divided into four sub-groups, including esophageal symptoms GERD group, extraesophageal symptoms GERD group, anxiety or depression group, non-anxiety and non-depression group. Saliva was collected on waking in morning and 2 h after finishing lunch. The concentration of the total pepsin(TPP) and total bile acids(TBA) from saliva was detected by ELISA method. Receiver operating characteristics analysis was used to identify the sensitivity and specificity of the saliva pepsin and bile acids detection. Results: The concentration of TPP in morning waking samples and postprandial samples in the GERD group was 27.1(9.7,50.3) μg/L and 32.4(14.0,58.7) μg/L, the concentration of TBA in postprandial samples was (18.4±2.3)μmol/L, and these levels were significantly higher than that of the control group [7.0(5.1, 9.1) μg/L, 7.4(5.2, 9.4) μg/L, (12.6±5.0)μmol/L](P<0.01). The concentration of TBA in morning waking samples had no significant difference between these two groups(P>0.05). The concentration of TPP and TBA had no significant difference among the four GERD sub-groups(P>0.05).Pepsin in postprandial saliva samples had moderate diagnostic value for GERD, when the saliva pepsin concentration in postprandial samples was higher than 41.33 μg/L, it had a sensitivity of 82.8% and a specificity of 73.3%. The bile acids in saliva had no significant diagnostic value for GERD. Conclusions: Pepsin detection in saliva has a high level of sensitivity and specificity for diagnosing GERD. However, bile acids in saliva has no significant diagnostic value for GERD.