[Consistency analysis of pepsin immunohistochemistry and pepsin test box in the diagnosis of laryngopharyngeal reflux].

Objective:To analyze the consistency of pepsin assay kit, pepsin IHC, reflux symptom index（RSI） and reflux finding score（RFS） in the diagnosis of laryngopharyngeal reflux disease（LPRD）. Methods:The clinical data of 61 inpatients with laryngeal diseases who were admitted to the Department of Otolaryngology, the First Affiliated Hospital of Kunming Medical University from May 2020 to December 2021 were retrospectively analyzed. The RSI and RFS scores, the Formwitz score of pepsin immunohistochemistry, and the results of pepsin detection kit were recorded. ICC group correlation coefficient and Kappa consistency analysis was used for three detection methods. Results:Among 61 patients, 30 cases were positive and 31 cases were negative for the pepsin test kit, with a positive rate of 49.18%. The positive rate of pepsin immunohistochemistry was 45.90%（28/61）, and the diagnostic agreement rate between the two was 70.49%. The consistency between them was high（κ=0.409）. The positive rate of RSI and RFS in diagnosing LPRD was 62.30%（38/61）, and the consistency rate was 73.77% with pepsin detection kit. The consistency between them was high（κ=0.486）. Taking pepsin IHC as the reference standard, the sensitivity, specificity, positive predictive value and negative predictive value of pepsin detection kit were 71.43%（20/28）, 69.70%（23/33）, 66.67%（20/30） and 74.19%（23/31）, respectively. Using RSI and RFS scales as reference criteria, the sensitivity, specificity, positive predictive value and negative predictive value of pepsin detection kit were 89.29%（25/28）, 60.61%（20/33）, 65.79%（25/38） and 86.96%（20/23）, respectively. Analysis of correlation coefficient within ICC group: ICC value was 0.628, 95% confidence interval（0.497-0.741）, the three methods have good consistency. Conclusion:The RSI and RFS scale scores were in good agreement with the pepsin test kit, and the pepsin test kit was also in good agreement with pepsin immunohistochemistry. As a non-invasive diagnostic technique, the pepsin test kit can be widely used in the diagnosis of pharyngeal reflux in combination with pepsin immunohistochemistry and RSI and RFS scale.