Pepsin And Bile Acids Detection In Saliva For The Diagnosis Of Sub-types Of Gastroesophageal Reflux Disease

1 BackgroundGastroesophageal reflux disease(GERD)is a common digestive disease,and its prevalence is increasing year by year,impacting more and more people's quality of life.However,the diagnostic methods of GERD are limited.At present,the existing diagnostic methods still have some limitations,such as low sensitivity and reasonable specificity,high cost,poor patient tolerance,etc.they have some degree of missed diagnosis and misdiagnosed rates.Finding a new diagnostic method with high efficiency,high sensitivity and specificity,low cost,and non-invasiveness has become an urgent need.Reflux detection is a hot spot in current research.Finding a method with high efficiency,Typical new diagnostic methods such as high sensitivity and feasibility,low cost,and non-invasiveness have become an urgent need.Reflux contents detection has become a hot field of research directions in recent years.2 PurposeTo study the differences of salivary pepsin and bile acid concentrations in patients with different types and different symptoms of GERD,and to explore the diagnostic value of salivary pepsin and bile acid detection in GERD.3 Materials and methodsFrom January 2018 to June 2019,104 patients who were treated in the outpatient department of the Guangdong Provincial People's Hospital and hospitalized during the same period of time were chosen in the GERD group,and 43 healthy volunteers were recruited as the normal control group.According to clinical characteristics,the GERD group is divided into 4 performance subgroups:the esophageal performance group,extraesophageal performance group,anxiety and depression group,non-anxiety and non-depression group.According to the symptoms,the GERD group is divided into other 8 subgroups:heartburn group,acid reflux group,reflux group,chest pain group,cough group,pharyngeal paresthesia group,belching group,and bitter-mouthed group.The saliva of the study subjects was collected in the morning waking time and 2 hours after lunch.The concentrations of total pepsin(TPP)and total bile acid(TBA)in saliva were detected by ELISA,and the differences were compared in the study.The saliva detection was evaluated by the receiver operating curve analysis method(ROC)to evaluate the diagnostic efficacy,sensitivity and specificity of TPP and TB A detection in saliva.4 Results4.1 In the morning waking time,the salivary TPP concentration in the normal control group and the GERD group were 7.0(5.1,9.1)ng/mL and 27.1(9.7,50.3)ng/mL respectively,and the TPP concentration at 2h after lunch were 7.4(5.2,9.4)ng/mL and 32.4(14.0,58.7)ng/mL respectively.The salivary TPP concentration in the GERD group was significantly higher than that in the control group in the morning waking time and 2 hours after lunch(P<0.01),but there was no statistical difference in salivary TPP concentration in each group between its morning waking time and 2 hours after lunch(P>0.05).There was no statistically significant difference in TPP concentrations between the 4 performance subgroups(P>0.05).4.2 In the morning waking time,the salivary TBA concentration in the normal control group and the GERD group were 7.17±2.37 umol/L and 7.79±3.42 umol/L respectively,and the TBA concentration at 2h after lunch were 12.63±4.99 umol/L and 18.38±2.27 umol/L respectively.The postprandial salivary TBA concentration was significantly higher than that in the morning waking time(P<0.01),but there was no statistical difference in salivary TBA concentration between these two groups in the morning waking time(P>0.05),and the TPP concentration was no statistically difference among the 4 performance subgroups(P>0.05).4.3 The concentrations of the salivary TBA and TPP had no statistically difference in the postprandial samples between Heartburn,acid reflux,reflux,chest pain,cough,pharyngeal paresis,belching,and bitter-mouth subgroups.(P>0.05).4.4 In the morning waking time,the area-under-the-curve(AUC)of the salivary TPP(AUC)was 0.766±0.047(95%CI 0.675?0.858,P<0.001),and the AUC of the salivary TPP at 2h after lunch was 0.781±0.045(95%CI 0.692?0.870,P<0.001),when the salivary TPP at 2h after lunch was>41.33ng/mL,the sensitivity was 82.8%and the specificity was 73.3%.In the morning,the AUC of the salivary TBA was 0.515±0.064(95%CI 0.389?0.641,P=0.817),and the AUC of salivary TBA at 2h after lunch was 0.474±0.070(95%CI 0.338?0.611,P=0.685).5 Conclusion5.1 The salivary TPP concentration of GERD patients is higher than that of normal people,and the increase of TPP is not related to symptoms.Salivary pepsin detection can be used as a non-invasive new method for diagnosing GERD,it has a high sensitivity and specificity and is worthy of clinical application.5.2 Postprandial salivary TBA in GERD patients is higher than that in normal people.The TBA concentration is not related to symptoms and has a certain relationship with eating.The salivary bile acid test has no diagnostic efficacy for GERD but its diagnostic value deserves further investigation.