Inflammatory Bowel Disease Flashcards
Definition of IBD?
An immune-mediated, chronic inflammatory response to intestinal bacteria in a genetically susceptible individual
(which would otherwise result in acute, controlled inflammation in a normal person)
Which has a greater genetic influence: Crohn’s Disease or Ulcerative Colitis?
Crohn’s Disease, which also has specific phenotype/location similarities amongst affected family members
(although both have 15-20% chance of having an affected relative)
T or F?
w/out resident bacteria in lumen, Crohn’s Disease & Ulcerative Colitis would be asymptomatic
True
Colitis = Macrophage & Th1 immune activation
Normal = no immune activation
NOD-2 : genetic mutation “buzzword” for what diagnosis?
Crohn’s Disease
Mucosal Barrier cells that have:
Tight junctions?
Epithelial cells
Mucosal Barrier cells that contribute:
mucous layer
Goblet cells
Mucosal Barrier cells that contribute:
Defensins
Paneth cells
Mucosal Barrier cells that contribute:
Ability to regenerate & repair cells
Epithelial cells
Mucosal Barrier cells that contribute:
IgA secretion
B cells
Naive T-cells can differentiate into at least 3 distinct subsets when faced w/ antigen presenting cells (APCs).
What is the route that mediates granulomatous & cell-mediated inflammation?
(ex: Crohn’s or Celiac’s Disease)
- APCs release IL-12
- IL-12 stimulates Th0 cells to differentiate into Th1 cells
- Th1 cells produce IFN-gamma, IL-2, & TNF
Naive T-cells can differentiate into at least 3 distinct subsets when faced w/ antigen presenting cells (APCs).
What is the route that mediates hypersensitivity reactions?
(ex: food allergy, helminthic infections, & possible Ulcerative Colitis)
- Th0 cells differentiate into Th2 cells
- Th2 cells produce IL-4, IL-5, & IL-10
Naive T-cells can differentiate into at least 3 distinct subsets when faced w/ antigen presenting cells (APCs).
What is the route that mediates tolerance?
(ex: normal response to commensal bacteria & dietary antigens)
- APCs release IL-10
- IL-10 stimulate Th0 differentiation into regulatory T-cells (TR1) & Th3-cells
- TR1-cells secrete IL-10
- Th3 cells secrete TGF-beta
Name some pro-inflammatory cytokines
- TNF
- IFN-gamma
- IL-4, IL-5, IL-13, IL-17, IL-21, IL-22, IL-26
What are some effects of TNF-alpha?
- Activation of T-helper cells
- inc’d production of pro-inflammatory cytokines
- PMN & Mononuclear cell adherence to intestinal wall capillaries
- Release of chemokines
- Release of toxic metabolites from PMNs & Mononuclear cells
Crohn’s Disease- typical anatomic locations of involvement?
- 50% include both small & large bowels (Ileocolitis)
- ⅓ confined to small bowel (regional enteritis) –usually involving the Ileum (ileitis)
- 20% confined to colon alone (colitis)
(50% have perianal lesions, but infrequently alone or as first presenting sign
Inflammation, Obstruction, Microperforation, & Fistulization are typical clinical patterns of what?
Crohn’s Disease
Drug therapy classes involved in potential Tx for Crohn’s Disease?
- Antibiotics (ex: metronidazole, quinolones)
- Immunomodulators
- Corticosteroids
- Aminosalicylates
- Supportive agents (i.e. antidiarrheal, bile sequestrants, bulk formers, antidepressants, pain-killers, anti-spasmodics)
What 2 characteristics about Crohn’s Disease seen on Barium enema are best at distinguishing it from Ulcerative Colitis?
- Skip Lesions
- Relative Rectal Sparing
Crohn’s Disease vs. Ulcerative Colitis:
Malabsorption?
CD - Yes
UC - No
Crohn’s Disease vs. Ulcerative Colitis:
Malignant potential?
CD - Only w/ colonic involvement
UC - Yes
Crohn’s Disease vs. Ulcerative Colitis:
Recurrence after surgery?
CD - Common
UC - No
Crohn’s Disease vs. Ulcerative Colitis:
Toxic Megacolon?
CD - No
UC - Yes
Crohn’s Disease vs. Ulcerative Colitis:
Stricture?
CD - Yes
UC - Rare
Crohn’s Disease vs. Ulcerative Colitis:
Wall thickness?
CD - Thick
UC - Thin
Crohn’s Disease vs. Ulcerative Colitis:
Pseudopolyps?
CD - Moderate
UC - Marked (more common)
Crohn’s Disease vs. Ulcerative Colitis:
Ulcers?
CD - Deep, fissuring ulcers
UC - Broad-based, superficial
Crohn’s Disease vs. Ulcerative Colitis:
Lymphoid reaction?
CD - Marked (full-thickness infiltrate)
UC - Moderate
Crohn’s Disease vs. Ulcerative Colitis:
Serositis?
CD - Marked
UC - Moderate
Crohn’s Disease vs. Ulcerative Colitis:
Granulomas?
CD - Yes (~35%)
UC - No
