Experimental animal studies have shown that H. pylori shares several antigenic regions in common with acid secreting cells in gastric mucosa. Antibodies triggered by H. pylori destroy acid secreting cells due to this antigenic mimicry. H. pylori infection is very common in humans, and about half of the infected patients develop atrophic changes over the years. In end stage severe atrophy, H. pylori disappears and signs of a previous infection are difficult to detect.
This research, lead by Dr. L Veijola and her colleagues in the University of Helsinki, Finland, has recently been published on January 7 , 2010 in World Journal of Gastroenterology. This study also confirmed the findings of previous studies that the serum markers of autoimmune gastritis appear with increasing frequency in patients with H. pylori infection, when the acid secreting capacity vanishes. The prevention of autoimmune atrophic gastritis, and thus pernicious anaemia, by eradicating the H. pylori would make the lifelong vitamin B12 substitution therapy unnecessary.