Pathology of Inflammatory Bowel Disease Flashcards
What is the definition of Inflammatory Bowel Disease (IBD)
Spectrum of chronic intestinal inflammation with episodic symptoms and exacerbation
spectrumL
CD - Indeterminate colitis - UC
Where is IBD most more common?
well-developed areas
urban areas
higher socioeconomic classes
What pathology is NOD2/CARD-15 associated with?
Crohn’s
gene product binds to bacterial peptidoglycans
What pathology is IL23R gene associated with?
IL-23 receptor
inc risk for both CD and US
What pathology is HNFA gene associated with? What other gene is it associated with?
reduce barrier function (tight junction defects)
Crohn’s
associated with MODY (maturity onset diabetes of the young)
What characteristic of the gut flora is associated with IBD?
anti-flagellin antibodies - Crohn’s
What are the mucosal immune responses in CD and UC?
- CD: TH1 cells that produce INF-gamma (chronic delayed type sensitivity rxn)
- US: excessive activation of TH2 cells
What are characteristics of Crohn’s Disease?
- Mouth to anus (skip lesions) - spares rectum
- cobblestoning, creeping fat
- Radiology: STRING SIGN
- NONCASEATING GRANULOMAS W MULTINUCLEATED GIANT CELLS (pathognomonic)
- Transmural inflammation
- Paneth cell metaplasia (left colon)
- mucosal aphthous ulcers (ulcers run parallel to length of bowel
What are histological features of Crohn’s?
Noncaseating Granulomas
Multinucleated Giant Cells
Paneth Cell metaplasia
What are characteristics of Ulcerative Colitis?
- Continuous lesions (starts at rectum, extends prox)
- Mucosa + submucosa (not full thickness)
- Friable + hemorrhagic
- Flattened mucosa = radiography = lead pipe
- chronic = inflammatory pseudopolyps
- crypt abscesses
What are pseudopolyps comprised of? what do they look like?
mononuclear inflammation polypoid appearance (rug like)
How does smoking affect risk of UC and CD?
CD: increased risk
UC: decreased risk
What is the clinical presentation, extranintestinal features, and complications of Crohn’s?
clinical presentation: RLQ colicky pain, aphthous ulcers
Extraintestinal features: Erythema nodosum, iritis/uveitis, pyodermagrangrenosum, spondyloarthropathy, nephrolithiasis
Complications: Fistulas, calcium oxalate stones
What is the clinical presentation, extranintestinal features, and complications of Ulcerative Colitis?
presentation: Left sided pain, bloody/mucus diarrhea
Extraintestinal features: PSC, pyoderma grangrenosum, spondyloarthropathy
Complications: Epithelial dysplasia, adenocarcinoma, toxic megacolon
What are the two types of Microscopic colitis what are shared features of the two?
- Colagenous colitis
- Lymphocytic colitis
Idiopathic, chronic, watery diarrhea w/o blood or weight loss
radiographically: normal bowel