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
Changes found on biopsy in Coeliac Disease
Duodenal biopsy (occasionally also jejunal)
- villous atrophy
- crypt hyperplasia
- increase in intraepithelial lymphocytes
- lamina propria infiltration with lymphocytes
Management of Coeliac Disease
- a gluten-free diet
Tissue transglutaminase antibodies may be checked to check compliance with a gluten free diet
- functional hyposplenism (often in patient’s with Coeliac Disease) -> pneumococcal vaccine and possibly influenza vaccine
Diet in Coeliac disease
- examples of foods that contain gluten
- what does not contain gluten
- can a patient drink whisky?
Gluten containing cereals include:
- wheat: bread, pasta, pastry
- barley*: beer
- rye
- oats (some patients may tolerate them)
Some notable foods which are gluten-free include:
- rice
- potatoes
- corn (maize)
*whisky is made using malted barley. Proteins such as gluten are however removed during the distillation process making it safe to drink for patients with coeliac disease
Other diseases where histological changes that are similar to Coeliac disease
- other food intolerances
- autoimmune enteropathy
- tropical sprue
- post-infectious gastroenteritis
- H. Pylori (affects gastric mucosa but may cause changes in duodenum)
- bacterial overgrowth
- Kwashiorkor
