The Helicobacter pylori dupA: A Novel Biomarker for Digestive Diseases

INTRODUCTION Helicobacter pylori (H. pylori) infection affects approximately half of the world’s population. Unless eradicated, it remains in the stomach throughout life. After 1983, discovery of H. pylori as persistent resident of gastric mucosa, changed the traditional thoughts and perspectives regarding (i) having sterile stomach lifelong, (ii) infectious potential links existence with various extra gastric disorders, and (iii) ongoing researches on H. pylori-induced diseases (1). Undeniably, colonization with pathogenic H. pylori results in severe gastroduodenal disorders. H. pylori is well-recognized as an established causative agent associated with a wide variety of upper gastroduodenal diseases ranged from a chronic gastritis to gastric cancer. Surprisingly, gastric colonization with H. pylori induces superficial gastritis in all infected individuals, while only a minority develops to severe symptomatic diseases (2). Notably, rationale underlying this unique distribution of diseases is driven by a sophisticated and mysterious interplay between H. pylori and its host. Broadly defined, the certain pattern of H. pylori-induced digestive disease is strongly influenced by bacterial virulence factors which draw the final outcome of infection (2, 3). It is now firmly established that biomarkers allow us for having an early diagnosis and prediction of medical conditions. Moreover, biomarkers provide opportunity to modify current available protocols to manage the infection and its associated outcomes (4). In this case, a biologic biomarker can be used for early diagnosis of certain digestive disease (e.g., gastric cancer, duodenal ulcer); and even identification of high-risk population for disease prevention. As such, biomarkers are becoming increasingly important tools in clinical settings. Thus, potential applications of biomarkers in infectious diseases such as predicting outcomes would be an interesting area of ongoing research. With this regard, the search for relevant biomarkers that diagnose/predict a clinical condition among the H. pyloriinfected patients is a challenging area of research. Following several suggested H. pylori biomarkers for certain digestive diseases over the past years (5–8), still a biomarker capable of predicting definitive digestive diseases outcome is lacking for clinical settings.