Chronic Gastritis f Lecture 7 This organism, formerly known as Campylobacter pylori, is a curved spirochete-like bacterium, of which two major genotypes exist.This organism colonizes the gastric mucosa (particularly the antrum and cardia) in a variety of ways: free in mucus, surface adhesion, and intercellularly. H. pylori has been found in 90% of patients with chronic gastritis, 95% with duodenal ulcer disease, 70% with gastric ulcer, and 50% with gastric carcinoma.
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Chronic Gastritis fLecture 7
This organism, formerly known as Campylobacter pylori, is a curved spirochete-like bacterium, of which two major genotypes exist.This organism colonizes the gastric mucosa (particularly the antrum and cardia) in a variety of ways: free in mucus, surface adhesion, and intercellularly.
H. pylori has been found in 90% of patients with chronic gastritis, 95% with duodenal ulcer disease, 70% with gastric ulcer, and 50% with gastric carcinoma.
Enteroendocrine cells, Stem cells. Gastric gland are comprised of two major components: foveola (crypt,
pit) and secretory portion (adenomere).
DefinitionChronic gastritis is defined as the
presence of
chronic inflammatory changes in the mucosa leading eventually to
mucosal atrophy &epithelial metaplasia.The two main features of this disease are infiltration of the lamina propria by
inflammatory cells and atrophy of the glandular epithelium.
BEtiology/types/classification
90%
Less than 10%
Nonimmune gastritis
Body-predominant
Antral-predominant
Less common etiologies• RADIATION INJURY, • CHRONIC BILE REFLUX, • MECHANICAL INJURY, AND • SYSTEMIC DISEASE such as Crohn disease, amyloidosis, or graft-versus-
host disease.
Nonimmune Gastritis
Autoimmune gastritis is characterized by:
• Antibodies to parietal cells (Oxyntic Cells) and intrinsic factor
• Toxins (CagA, VacA) and release of• noxious chemicals by the recruited
neutrophils.Alcohol, tobacco, duodenal reflux (reflux gastritis), allergy to foods, and various drugs (particularly anti-inflammatory agents).
• After initial exposure to H.pylori, gastritis may
develop in two patterns:
•1. antral- type (Hypersecretory)
with high acid production and higher risk for the
development of duodenal ULCER, and
• 2. pangastritis (Environmental Gastritis)with multifocal mucosal atrophy, with low acid secretion and increased risk for
carcinoma.
Four features are linked to H. pylori virulence:
1. Flagella, which allow the bacteria to be motile in viscous mucus
2.Urease, which generates ammonia from endogenous urea and thereby elevates local gastric pH
3.Adhesins that enhance their bacterial adherence to surface foveolar cells
4. Toxins, such as cytotoxin-associated gene A (CagA), that may be involved in ulcer or cancer development by poorly defined mechanisms
• Chronic Inflammatory cell infiltration
• Mucosal Atrophy ( Autoimmune Gastritis)
• Intestinal (Goblet Cell) metaplasiaSeen in H Pylori & Autoimmune gastritis not chemical.
Pyloric MetaplasiaIntestinal Metaplasia
Intestinal metaplasia: Type I (complete), Type II (Incomplete)
Neutrophils, plasma cells
Type B Type A
AntPan
Ant Pan
Clinical Features /DiagnosisHistologic identification of the organism, Serologic test for antibodies to H. pylori,Fecal bacterial detection, The urea breath test based on the generation of ammonia by the bacterial urease.
• Gastric biopsy specimens can also be analyzed by
• the rapid UREASE test,
• bacterial culture, or• bacterial DNA detection by PCR.
Treatment• Combinations of antibiotics and proton pump
inhibitors. • Individuals with H. pylori gastritis usually improve
after treatment, although RELAPSES can occur after incomplete eradication or re-infection.
• Prophylactic and therapeutic vaccine development is still at an early stage of development.
Clarithromycin, Amoxicillin/ Flagyl, Omeprazole
Chronic superficial gastritis• If the inflammatory infiltrate is limited to the
foveolar region and unaccompanied by glandular atrophy, the condition is designated as chronic superficial gastritis.
• Subtle epithelial abnormalities seen in this form include a reduced amount of cytoplasmic mucin, nuclear and nucleolar enlargement, and some increase in foveolar mitoses.
Chronic atrophic gastritis• When the inflammation is more extensive and
accompanied by glandular atrophy, the condition is termed Chronic atrophic gastritis and
is further categorized as mild, moderate, or severe by roughly estimating the thickness of the glandular portion in relation to the thickness of the whole mucosa.
Consequences of Chronic Gastritis
•PEPTIC ULCER DISEASE•Adenocarcinomas
Cancer Risk• The long-term risk of gastric carcinoma for
persons with H. pylori-associated chronic gastritis is
increased about fivefold relative to the normal population.
• For autoimmune gastritis, the risk for cancer is in the range of 2% to 4% of affected individuals, which is well above that of the normal population.