Gastro-duodenal disease Flashcards
With the pathologist series 4a: -Helicobacter pylori -GORD - Barrett’s oesophagus - coeliac disease
What diseases may be the associated with H. Pylori?
Associations
- peptic ulcer disease (95% of duodenal ulcers, 75% of gastric ulcers)
- gastric cancer
- B cell lymphoma of MALT tissue (eradication of H pylori results causes regression in 80% of patients)
- atrophic gastritis
What type of an organism H Pylori is?
Helicobacter pylori is a Gram negative bacteria
Management of H. Pylori
Management - eradication may be achieved with a 7 day course of:
- a proton pump inhibitor + amoxicillin + clarithromycin, or
- a proton pump inhibitor + metronidazole + clarithromycin
Signs and symptoms of H. Pylori infection
- 85% of infected people asymptomatic
- Acute -> acute gastritis: abdominal pain, nausea
- Chronic: dyspepsia like symptoms -> bloating, belching/burping, abdominal pain, vomiting, dark stool
Investigations in H. Pylori
- blood antibody test
- stool antigen test
- carbon urea breath test
- endoscopic biopsy
What’s that?
Normal gastric mucosa
What’s that?
Inflammatory gastritis / H. Pylori -> foll of ‘blue dots’ = inflammatory cells
How does Helicobacter Pylori survive in the stomach (considering it’s an acidic environment)?
- H. Pyloris produce large amounts of enzyme urease -> it converts urea into CO2 and ammonia
- there is a protective layer around the bacterium (neutral pH)
- bacteria enters gastric mucosa away from acidic content of the lumen
Why complications (malignancy) of H Pylori occur?
This is due to constant irritation by a bacteria -> inflammation -> ulcer may form
When we eradicate the bacteria and ulcer heals -> gastric mucosa may re-generate into an intestinal type of epithelium (metaplasia)
If irritation persists -> another change in mucosa may occur -> dysplasia
Is low-grade MALT lymphoma treatable? How?
Antibiotics to eradicate H. Pylori
What’s that?
Adenocarcinoma (intramucosal)
- Normal glands -> on the right
- bizarre, crowded glands, strange nuclei -> on the left (cancer)
What’s that?
MALT lymphoma (B-cell lymphoma)
What are different types of gastritis?
- H Pylori gastritis
- reactive (chemical or reflux) gastritis
- lymphocytic gastritis (may or not be associated with H pylori)
- autoimmune gastritis
- iron pill gastritis - iron tablets may irritate gastric mucosa
- granulomatous gastritis (Crohn’s, idiopathic, foreign body, sarcoidosis, TB)
What changes occur in Barrett’soesophagus?
metaplasia of the lower oesophageal mucosa:
squamous epithelium (oesophagus) -> replaced by columnar epithelium (gastric)
What’s the management of Barrett’s oesophagus?
Management
- endoscopic surveillance with biopsies (as the risk of oesophageal cancer) -> endoscopy every 3-5 years
- high-dose proton pump inhibitor
Why we may get cancer of oesophagus if we have GORD/ Barrett’s? (pathophysiology of Ca development)
Gastric acid reflux into the oesophagus or even bile reflux possible -> acid in the oesophagus (squamous epithelium is not used to acid) -> ulcers -> repair as a different type of epithelium (e.g. gastric or intestinal, as they can resist the aid damage)
Pathophysiology of GORD
- Retrograde flow of gastric or sometimes duodenal content into the oesophagus
- This happens due to loss of lower oesophageal sphincter (LOS) pressure gradient
Management of dyspepsia in primary care
1st line:
- PPI*
- H.Pylori ‘test and treat’
2nd line:
H2 receptor antagonist (if PPI is not effective)
Simple pathophysiology of Coeliac disease
Coeliac disease is an autoimmune condition caused by sensitivity to the protein gluten -> repeated exposure to gluten -> villous atrophy -> malabsorption -> symptoms
What other diseases is Coeliac disease associated with?
- dermatitis herpetiformis
- type 1 diabetes mellitus
- autoimmune hepatitis
What symptoms should prompt investigation for Coeliac Disease?
- Chronic or intermittent diarrhoea
- Failure to thrive or faltering growth (in children)
- Persistent or unexplained gastrointestinal symptoms including nausea and vomiting
- Prolonged fatigue (‘tired all the time’)
- Recurrent abdominal pain, cramping or distension
- Sudden or unexpected weight loss
- Unexplained iron-deficiency anaemia, or other unspecified anaemia
Presence of which conditions should prompt an investigation for Coeliac Disease?
- Autoimmune thyroid disease
- Dermatitis herpetiformis
- Irritable bowel syndrome
- Type 1 diabetes
- First-degree relatives (parents, siblings or children) with coeliac disease
What genes are associated with Coeliac disease?
HLA-DQ2 (95% of patients) and HLA-DQ8 (80%).
How Coeliac Disease is investigated?
combination of immunology and jejunal biopsy
Immunology
- tissue transglutaminase (TTG) antibodies (IgA) are first-choice according to NICE
- endomyseal antibody (IgA)
- anti-casein antibodies -> found in some patients
Biopsy
