Inflammatory Bowel Disease Flashcards
What are the two main diseases that come under Inflammatory Bowel Disease?
Ulcerative Colitis
Crohn’s Disease
What is the underlying pathogenesis of IBD based on?
A defective interaction between the mucosal immune system + gut flora
List 4 key environmental risk factors associated with IBD
Diet
Smoking
Medication
Microbiome
Which T cell responses are involved in:
a. Ulcerative Colitis
b. Crohn’s Disease
UC: Th2
CD: Th1
What are the main cytokines in:
a. Ulcerative Colitis
b. Crohn’s Disease
UC: IL-13
CD: TNF-alpha
Which layers of the gut are affected in:
a. Ulcerative Colitis
b. Crohn’s Disease
UC: Mucosa + Submucosa
CD: All Layers
Describe which regions of the gut are affected in:
a. Ulcerative Colitis
b. Crohn’s Disease
UC: Starts at the rectum + spreads proximally (continuous inflammation)
CD: Any part of GI tract (mouth to anus). Patchy inflammation.
Are abscesses, fissures and fistulae common in:
a. Ulcerative Colitis
b. Crohn’s Disease
UC: No
CD: Yes
Describe the effectiveness of surgery in:
a. Ulcerative
b. Crohn’s Disease
UC: Curative
CD: Not always curative, even if the affected area is cut out, it often reoccurs
Describe 3 supportive therapies that are given for IBD
Nutritional support
Fluid/ electrolyte replacement
Blood transfusions/ oral iron
What are the three types of classic symptomatic treatment for IBD?
Aminosalicylates
Glucocorticoids
Immunosuppressants
What is the main aminosalicylate drug?
Mesalazine
AKA 5-aminosalicylic acid (5-ASA)
What is a slightly more complex aminosalicylate?
Olsalazine (= 2 x 5-ASA)
What type of drug are aminosalicylates?
Anti-inflammatory
Describe the mechanism of anti-inflammatory action of aminosalicylates.
Bind to PPAR receptors, acting as transcription modulators
Downregulate NFKB + MAPK, thus down regulating pro-inflammatory cytokines e.g. IL-1, TNF-alpha + IL-6
Downregulate expression of COX-2 + pro inflammatory prostaglandins
Describe the activation of aminosalicylates.
Mesalazine is active, absorbed in small bowel + colon
Olsalazine must be activated by colonic flora so is active in colon