Gastric Pathology Flashcards
What is gastritis?
Mucosal inflammatory response
What causes acute gastritis?
Imbalance between mucosal defense and acid environment, if either one is not balanced then inflammation occurs
What does acid damage lead to?
Superficial inflammation, erosion, ulcers
What is the difference between erosion and ulcers?
Erosion: loss of superficial epithelium
Ulcers: loss of mucosal layer
What does the presence of neutrophils indicate?
Acute gastritis
If there is no neutrophils –> gatsropathy
What happens if acute gastritis is left untreated?
It can lead to bleeding –> acute erosive hemorrhagic gastritis and perforation
What are the symptoms of acute gastritis?
Usually asymptomatic disease
Mild epigastric pain, nausea, vomiting, or coffee-ground hematemesis & melena in severe cases
What are the protective factors of the stomach?
Surface mucus secretion
Bicarbonate secretion into mucus
Mucosal blood flow
Epithelial regenerative capacity
Elaboration of prostaglandins
What are the risk factors for gastritis?
H. pylori infections
NSAIDs
Tobacco
Alcohol
Gastric hyperacidity
Duodenal-gastric reflux
Ischemia
Shock
Bile reflux
Uremic patients
Chemotherapy and radiation
Old age
How are ureic patients more vulnerable to gastritis?
Inhibition of gastric bicarbonate transporters by ammonium ions, cannot neutralise
How is old age a risk for gastritis?
Decrease in mucin and bicarbonate secretion which are factors that explain the increaser susceptibility of older adults
How is ingestion of harsh chemicals, acids and bases a risk factor for gastritis?
Severe gastric mucosal damage due to direct injury
What is stress-related mucosal disease?
Extensive burn –> curling ulcers (in the proximal duodenum)
What does the increase in intracranial pressure and brain injury cause?
Cushing ulcers (in the stomach, duodenum and esophagus)
How do shock and sepsis contribute to stress-related mucosal disease?
It leads to the formation of stress ulcers (local ischemia caused by systemic hypotension or decreased blood flow resulting from stress-induced splanchnic vasoconstriction
What is the range of the severity of the stress-related mucosal disease?
Range from shallow erosions to multiple deep, penetrating ulcers (perforation & bleeding)
How do you end stress-related mucosal disease?
Complete reepithelization and healing
What are ICU patients given in stress-related mucosal disease?
Prophylactic PPI in order to reduce HCl
What is the pathology of acute gastritis?
Diffusely hyperaemic gastric mucosa, hemorrhagic inflammation
What is the pathology of gastropathy?
Gastropathy with erosions superficial mucosa is eroded away
What is chronic gastritis?
Chronic inflammation of the stomach
What are the main causes of chronic gastritis?
H. pylori gastritis or chronic autoimmune gastritis
What other factors could cause chronic gastritis?
NSAIDs
Radiation
Bile reflux
System diseases
What are examples of systemic diseases that cause chronic gastritis?
Crohn disease, amyloidosis, graft vs host disease
What are the symptoms of chronic gastritis like compared to acute gastritis?
Less severe but more persistent
What are the symptoms of chronic gastritis?
Nausea & upper abdominal pain (typical)
Vomiting and hematemesis (rare)
What is the most common cause of gastritis?
H. pylori chronic gastritis, causes about 90% of the cases
Which part of the stomach is mainly affected in h. pylori gastritis?
The antrum of the stomach
What is the pathogenesis of H. pylori chronic gastritis?
H. pylori secretes creases and proteases with inflammation which will weaken the mucosal defence –> ulceration
What is the patients’ main complain with H. pylori chronic gastritis?
Epigastric abdominal pain and later peptic ulcer disease and complications
What is the pathogenesis of H. pylori chronic gastritis in the body or fundus?
Body or fundus gastritis –> multiform atrophic gastritis with patchy mucosal atrophy –> reduced parietal cells & decrease secretion of acid
What does reduced parietal cell mass and decreased acid secretion lead to in h. pylori of the fundus/body?
Intestinal metaplasia (increase in goblet cells) which increases the risk of adenocarcinoma
What determines H. pylori pathogenesis?
Virulence factors and host factors
What are some examples of the virulence factors of h. pylori?
Flagella
Urease
Adhesion (LPS, O-antigens)
Toxins
What are some examples of host factors regarding H. pylori?
Increased expression of proinflammatory cytokines
Decreased expression of the anti-inflammatory cytokine which is associated with the development of pan-gastritis & cancer
Iron deficiency
What are examples of proinflammatory cytokines?
TNF
IL-1β
What is an example of an anti-inflammatory cytokine?
IL-10
What are the different diagnostic techniques for h. pylori?
Non-invasive serologic test for antibodies
Fecal bacterial antigene detection
Urea breath test
Gastric biopsy
Bacterial culture
Bacterial DNA detection by PCR
Biopsy
What is one of the limitations of the non-invasive serologic test?
Detects active & prior infections, so in the case that you have previously been exposed to h. pylori but you are infected now as well the test will not be able to show the results
What is the urea breath test?
A test that depends on the generation of ammonia by the bacterial urease, the more the ammonia –> positive test
Why is it important to perform biopsies for h. pylori infections?
To check for progression, especially because of the increased risk of adenocarcinoma
What colour cells are neutrophils?
Pale pink
What are the pathological features of h. pylori?
- Intraepithelial and lamina propria neutrophils infiltration
- Lymphoid aggregates with germinal centres & subepithelial plasma cells within lamina propria
- Represent an indued form of MALT, that has the potential to transform into lymphoma
- Spiral-shaped H. pylori highlighted by the WS silver stain
Are lymphoid cells commonly found in the stomach?
No, under healthy conditions, there is no lymphoid cells in the stomach
Where are the h. pylori micro-organisms abundant?
Within surface mucus
What is chronic autoimmune gastritis?
Autoimmune destructon of gastric parietal cells, type IV hypersensitivity reaction in body and fundus
What kind of cells is type IV hypersensitivity reaction mediated by?
CD4+ and T-lymphocytes
What % of patients are affected by chronic autoimmune gastritis?
Less than 10% of chronic gastritis
What do the auto-antibodies attack in autoimmune gastritis?
Parietal cells and intrinsic factor
What happens during chronic autoimmune gastritis?
Defective acid secretion
Reduced serum pepsinogen I concentration
Megaloblastic anemia
Atrophy of mucosa with intestinal metaplasia
What is the most common cause of diffuse atrophic gastritis?
Chronic autoimmune gastritis
What does defective acid secretion in chronic autoimmune gastritis lead to?
Achlorhydia –> due to increased gastrin levels because of astral G-cell hyperplasia which can lead to endocrine cell hyperplasia (tumor)