Helicobacter pylori-induced chronic active gastritis in Saudi patients with special reference to the ultrastructural pathology

The present study was designed to address the most characteristic features of Helicobacter pylori (H. pylori)-induced chronic active gastritis in Saudi patients and to use transmission electron microscopy (TEM) to shed some light on the nature of the bacillary and coccoid forms of H. pylori that still carries some debate. In which, 40 antral biopsies were obtained from 40 patients presented for dyspeptic disorders at Aseer Central Hospital, Abha, Saudi Arabia. Each specimen was divided into two parts for light and TEM examinations. Thirty-three (82.5 %) out of the 40 specimens were positive for H. pylori as shown by Giemsa stain. The presence of H. pylori was confirmed by immunostaining with a polyclonal rabbit anti-H. pylori primary antibody in 36 cases of the examined 40 antral biopsies (90 %) including all Giemsa-positive cases. Histologically, 30 of the Giemsa-positive cases (90 %) showed chronic active gastritis characterized by infiltration of gastric mucosa with neutrophils, eosinophils, lymphocytes and plasma cells. In 18 H. pylori positive patients (54.5 %), gastric glands appeared destructed and infiltrated with neutrophils. There was also intestinal goblet cell metaplasia of gastric glands in 2 (6 %) of H. pylori-affected patients. Examination of 10 randomly selected H. pylori positive specimens with TEM showed two forms of H. pylori, bacillary and coccoid forms, infecting gastric mucosa. Both forms were seen extracellularly in mucus layer and intercellular spaces and intracellularly in gastric epithelial cells. Interestingly, bacillary forms were seen in endocytic vesicle transforming into coccoid forms inside gastric epithelial cells. In conclusions, most of the presented patients showed histopathological features of chronic active gastritis. Ultrastructurally, bacillary form represents the main extracellular form of Helicobacter pylori and coccoid form might be formed in the gastric epithelial cells as a kind of bacillary transformation.