Carditis at the interface between GERD and Helicobacter pylori infection.

Inflammation of the gastric cardia ('carditis') is a histological diagnosis. It seems reasonable to transfer histological criteria of the updated Sydney classification from the distal stomach to the cardia as long as a special classification of inflammation of the esophagogastric junction is lacking. The two best characterized causes of carditis are Helicobacter pylori infection and gastroesophageal reflux disease (GERD). However, the causal contribution and interference of these two factors are highly controversial, as is the clinical relevance of carditis in terms of eliciting symptoms or conferring an increased cancer risk. Variability of studies on carditis is based on conflicting concepts of the normal anatomy of the esophagogastric junction. Cardia-type mucosa (CM) apparently exists at birth as a tiny circular area, and extends to a larger area in adulthood. This implies that cardia-type mucosa is largely metaplastic. Metaplastic CM may evolve in the lower esophagus as a consequence of GERD. It is a general phenomenon that H. pylori-induced gastritis also involves the gastric cardia, irrespective whether the cardia is lined by fundus-type mucosa or CM. The contribution of GERD to inflammation of CM in H. pylori-negative individuals is, however, highly controversial. Prevalence of carditis in GERD patients fluctuates between 10 and 97%. Hence, because of its high frequency and low specificity, carditis can currently not be considered as a clinical entity. The role of carditis for the increasing incidence of cancer of the esophagogastric junction requires careful studies that include accurate description of the area with adequate biopsy protocols.