Gastritis and Peptic Ulceration Flashcards
List 6 protective factors of the gastric mucosal barrier
Lipid monolayer Mucus gel layer HCO3- secretion from mucous cells Gastric blood flow carries away H+ Tight junctions of epithelial cells Rapid cell turnover
How do prostaglandins protect the mucosal barrier?
Inhibit HCl secretion
Stimulate HCO3-, phospholipid and mucus secretion
Increase mucosal blood flow
Modify local inflammation
What is the acute gastritis?
Acute response to injury which heals in a few days
What are the most common causes of gastritis?
Chemical injury, alcohol or drugs Stress Shock (decreased mucosal blood flow) Burns Head injury Septicaemia Staphylococcal food poisoning
What histological features are seen in acute gastritis?
Oedema
Erosion with a layer of coagulative necrosis
When are PPIs prescribed?
Treatment of gastritis or peptic ulcer
Prophylactically for patients in ICU with head injuries, shock, burns, etc.
What is the difference between an erosion and an acute ulcer?
Erosion affects only mucosa
Acute ulcer extends past muscularis mucosae into submucosa
What are Curling ulcers?
Ulcers in the duodenum associated with severe burns/trauma
What are Cushing ulcers?
Gastric and duodenal ulcers in persons with intracranial injury
What are the 3 main types of chronic gastritis?
Autoimmune
Helicobacter-associated
Chemical
What is the pathogenesis of autoimmune chronic gastritis?
Immune-mediated destruction of acid-secreting tubules
Atrophy of mucosa, no production of gastric acid
Loss of IF leading to pernicious anaemia
Hypergastrinaemia leads to nodular ECL hyperplasia (can cause malignancy)
Describe the regions of the stomach affected by the 3 types of chronic gastritis
AI: corpus only
What circulating autoAbs are present in AI gastritis?
To H+/K+ ATPase on parietal cell membrane
To IF
To gastrin receptor
What are the histological findings in AI gastritis?
Atrophy of acid secreting tubules
Intestinal and pyloric gland metaplasia
Chronic inflammation
N.B. In corpus only
What causes chronic chemical gastritis?
Reflux of bile and alkaline duodenal juice
Longterm aspirin, NSAIDs
What are the histological findings in chemical gastritis?
Epithelial desquamation Hyperplasia of gastric pits Oedema Hyperplasia of lamina propria Mild inflammatory cell infiltrate
What occurs in acute H. pylori infection?
Neutrophilic gastritis with acute inflammation
Progresses to chronic infection within 3-4 weeks
What are the histological findings in chronic H. pylori infection?
Acute inflammation of gastric pits (foveolitis) with intraepithelial neutrophils and pit abscess
Lymphocytes and plasma cells in lamina propria
Moderate mucosal atrophy
Intestinal metaplasia
What are some possible longterm sequelae of chronic H. pylori infection?
PUD
Intestinal metaplasia may predispose to dysplasia and adenocarcinoma
MALToma
IDA
Atrophic gastritis (can cause B12 deficiency)
What are the 2 major patterns of H. pylori gastritis and what is the difference between them?
Antrum-predominant: increased acid production with risk of duodenal ulcer and gastric metaplasia
Pan-gastritis: reduced acid production causing atrophy, intestinal metaplasia and gastric ulcer
When does intestinal metaplasia occur in the stomach?
With reduced stomach acid (more closely resembles the intestinal environment)
