Inflammatory Bowel Disease Flashcards
(53 cards)
What is IBD?
A chronic inflammatory disease if the GI tract of unknown aetiology
What conditions does IBD include?
Crohn’s disease
Ulcerative colitis
How is IBD characterised?
As a multi focal infarction
Pathogenic infection
Relapsing and remitting course that may lead to surgical intervention
What are the risk factors of IBD?
Thought to be a genetic predisposition
Infection
Local ischaemia
Altered immune state
Maybe Cigarette smoking
What aspects of the GI system does ulcerative colitis affect?
Confined to the mucosal and sub mucosal layers
Restricted to the large intestine
(Especially the rectum)
How is UC characterised?
Crypt abscesses and ulceration
Continuous inflammation rather than patchy
What are the symptoms of UC
Bloody diarrhoea
Abdominal tenderness
Abdominal distension
Are there any extra colonic symptoms of UC?
Reactive arthritis
(Possibly due to the proliferation and migration of activated T lymphocytes)
Anaemia
Fever
Weight loss
What is Crohn’s disease?
A transmural granulomatous condition characterised by macrophages lesions
Where does Crohn’s disease normally affect?
Can involve any section of the gut
Usually spares the rectum
How is inflammation caused by Crohn’s normally categorised?
Discontinuous and segmental inflammation
There will be inflamed portions next to healthy region of tissues
(Skipper areas)
What abnormalities can help diagnose Crohn’s?
Fistulas
(Abnormal connections between sections of the bowel)
Small bowel strictures
(Narrowing of the intestine making it hard for things to pass through)
Abscesses
Anal fissures
What are the symptoms of Crohn’s?
Diarrhoea
Abdominal pain
Fatigue
What is the molecular pathophysiology of IBD?
Poorly understood
Thought to be linked to a dysfunction in the intestinal epithelial barrier
(NOD2 gene mutation)
Or to dysregulation of innate immunity
Abnormal chemokine production
Impaired barrier repair and maintenance function
T lymphocyte migration
How does the innate immune system affect the chances of Crohn’s?
Defects in the innate immune system are associated with a predisposition to infections and autoimmune diseases
Describe how immune cell imbalances may influence IBD
T cells
Imbalances between pro inflammatory T helper 1 and T helper 2 cells and anti inflammatory T helper 3 and T regulatory cells
Disruption to this system may contribute to the pathophysiology of IBD
Molecular pathophysiology 2
Aggressive activation of adaptive immunity (cytokines)
Dysfunctional neuro immune regulation
Excessive production of nitric oxide and other radicals
Enhanced expression of matrix metalloproteinases
What is the point of therapeutic management
To induce and maintain remission
High failure rate usually results in surgery
What drugs are used in the treatment of IBD?
Corticosteroids
Aminosalicylates
Immunomodulators
TNF alpha antibodies
What are two immunomodulators used for IBD?
Thiopurines
Methotrexate
Give two examples of TNF alpha antibodies
Ciclosporin
Anti microbial agents
What do corticosteroids do?
Dampen the general inflammatory response
Reduce expression of cytokines, COX and adhesion molecules
Induce remission of active disease (particularly Crohn’s
What are some of the formulation of corticosteroids?
Oral prednisolone
Foam/ enemas for left sided distal UC
Novel drug delivery (extended controlled release)
Budesonide topically active (extensive first pass metabolism - few side effects)
IV hydrocortisone (sever disease not responding to oral therapy)
What are the side effects of using corticosteroids?
Cushing like syndrome
Metabolic disturbance
Diabetes
Fat redistribution
Bone / muscle breakdown
Growth suppression
Peptic ulcer
Hypertension
Acne
Behavioural changes
