Histological responses to Helicobacter pylori
infection: gastritis, atrophy and preneoplasia.
Gastroenterol. 1995 Sep;9(3):467-86
-In the initial active phase there are features of acute gastritis
characterised by neutrophil polymorphs in mucous neck region. In severe
infection there is pit abscess formation.
-Cellular swelling and vacuolization, mucin loss and desquamation of
-Erosion and frank ulceration.
-Degenerative and regenerative changes present.
-Regenerative changes - There are hyperplastic neck cells and elongated,
distorted and tubular structures. The cells display cytoplasmic
basophilia, increased mitoses and hyperchromatic nuclei, however the
enlarged nuclei show smooth regular nuclear membrane (D/D dysplasia or
- As the disease progresses there is superimposed chronic inflammation
(Active chronic gastritis)
Neutrophils, eosinophils, basophils, macrophages, monocytes, plasma cells
infiltrate the mucosa.
-Mucosa appears normal in thickness or slightly expanded by mononuclear
-In early stage, lymphocytes and plasma cells are present in the
superficial mucosa mostly along lesser curvature. (Chronic superficial
-The inflammation extends into the glandular compartment.
- Focal epithelial cell dropout is noted.
-There is lymphoid follicle formation with or without germinal centres.
This is a marker for H pylori infection.
-Gradually develops pangastritis.
- There is glandular atrophy (Chronic atrophic gastritis)
-Intestinal metaplasia replaces the gastric glands. H pylori is markedly
decreased in the late stage as intestinal metaplasia creates an
unfavourable environment for H. pylori.
- Gastric atrophy is the end stage of chronic gastritis and is
characterized by thinning of gastric mucosa in the absence of
Parietal and chief cells are decreased in number in the body (autoimmune
gastritis). Antrum shows loss of pyloric glands (type B gastritis).
[ 2 main causes of Atrophic gastritis - i ) H.pylori associated
multifocal atrophic gastritis involving corpus and antrum.
ii) Autoimmune gastritis restricted to the corpus]
Following treatment of H. pylori infection the features of chronic
gastritis with lymphoid follicles may persist .
These features are gradually resolve after few years.
Following long term therapy with proton pump inhibitors there may be
pseudo hypertrophy of parietal cells. Tiny fundic glands cysts lined by
parietal and chief cells may be noted.