OBJECTIVE: To investigate the relationship between
Helicobacter pylori and gastric mucosa in control and duodenal
ulcer patients at the electron microscopic level.
METHODS: Three antral biopsies were taken from each of 20
normal control volunteers and 30 duodenal ulcer patients
presented to the gastroenterology unit at Jordan University
Hospital for upper endoscopic examination. Each specimen was
fixed and processed for electron microscopic study.
RESULTS: Two types of Helicobacter pylori were observed
and identified by their morphology at electron microscopy. The
first one was characterized by double external smooth membranes
and homogeneous cytoplasmic contents, and the second type with a
characteristic ring-shaped intracytoplasmic vacuole. Electron
microscopic examination of normal controls showed normal gastric
mucosa and a small number of Helicobacter pylori in 12 out of 20
controls. However, in duodenal ulcer patients, 5 different
patterns of interaction between the Helicobacter pylori and
gastric mucosa were observed in relation to the severity of the
disease. In duodenal ulcer patients, various types of epithelial
damage was seen accompanied with a decrease or absence of mucous
secretion and with more colonization of bacteria.
CONCLUSION: The morphology and pathogenesis of
Helicobacter pylori was described in duodenal ulcer patients,
and 5 different patterns of contact between Helicobacter pylori
and surface epithelium were recognized causing variable degrees
of microvillous atrophy and reduced mucous secretion. The
vacuolated type of Helicobacter pylori was more adherent to the
damaged epithelium and there was a direct relationship between
the epithelial damage and bacterial load. In the normal
controls, no epithelial damage and scanty bacteria were
observed. The various types of epithelial changes of gastric
mucosa has initiated more research at electron microscopic level
on the immune mechanism of the gastric mucosa to determine the
underlying cause of the varying severity of the disease.
Faculty of Medicine, Department of Anatomy and Histology,
University of Jordan, Amman, 11942, Jordan.