GASTRIC-MUCOSAL INFILTRATION BY HELICOBACTER-PYLORI FAVORS BACTERIAL SURVIVAL AFTER TREATMENT

Background: Although a number of patient and bacterial factors have be en identified as predictors of treatment failure in Helicobacter pylor i-associated gastritis, the causes of lack of response to treatment ha ve not been fully elucidated. We hypothesized that bacterial infiltrat ion of the gastric mucosa might be one of the factors responsible for treatment failure in patients harbouring the bacterium. Methods: We st udied 182 patients with gastritis who underwent anti-H, pylori treatme nt with different drugs. Gastric biopsies obtained at endoscopy, were examined for electron microscopic features of infiltration and damage, Patients were assigned to different treatment groups, and endoscopy, evaluation of H. pylori status and electron microscopy were repeated a t least 4 weeks after the end of treatment, Results: The overall H. py lori eradication rate was 65%. Eradication was achieved more frequentl y in patients without electron microscopic features of infiltration (8 5%), than in those patients with the bacteria deeply embedded into the gastric mucosa (45%; P < 0.0001). No treatment appeared to be clearly superior for patients with the highest degree of mucosal infiltration . Conclusions: Bacterial mucosal infiltration may facilitate the survi val of H. pylori during antibacterial treatment; moreover, electron mi croscopy may be helpful to identify patients potentially unresponsive to anti-H. pylori treatment.