Pepsin detection as a diagnostic test for reflux disease

Abstract

Background: The history of pepsin dates back to 1836, when it was discovered by Theodor Schwann. In 1938 Herriott studied the conversion of pepsinogen to pepsin, which is now known to be most aggressive proteolytic enzyme in gastric refluxate. Pepsin has been identified as a biomarker of gastric reflux into the esophagus, the airways and the lungs. Peptest was developed as a non-invasive, sensitive and specific diagnostic test to rapidly identify reflux in patients presenting with a range of symptoms and introduced on to the UK market in August 2010. Methods: Patients diagnosed with the symptoms of gastro esophageal reflux disease (GERD), extra esophageal reflux (EER), laryngopharyngeal reflux (LPR) and various respiratory diseases were tested for the presence of reflux by Peptest. The reflux diagnostic test is based on lateral flow technology and contains two unique anti-pepsin human monoclonal antibodies; one to detect and one to capture pepsin within a clinical sample. The intensity of the pepsin ‘test’ line within the window of the lateral flow device is measured using a Peptest cube reader and the intensity automatically converts to a concentration of pepsin (ng/ml). Results: There are over 100 publications describing the reflux diagnostic activity of Peptest across upper gastrointestinal and airway/lung diseases. Compared to healthy asymptomatic control subjects patients presenting with heartburn were shown to have a significantly higher prevalence of salivary pepsin. There is growing evidence that pepsin is a major aetiological factor in LPR and Peptest is routinely used in many ENT clinics. Key respiratory centres in the UK and the Czech Republic demonstrated similar pepsin positivity in patients presenting with a range of respiratory diseases.