Pathology of IBD Flashcards
What is IBD?
inflammatory bowel disease - UC and CD
idiopathic and chronic
episodic and follows a course of flares and remission
causes of IBD?
multifactorial causes - genetic abnormalities, immune response, environmental factors
CD - genetic
- mutation of CARD 15 gene on chromosome 16 increases risk of CD upto 30%
- more likely if family member has it
UC - genetic
- mutation of HLA gene on chromosome 6
- mutation of IL-10 gene on chromosome 1
immune response
- Both CD and UC cause activated immune and adaptive immune responses - leads to increased production of pro-inflammatory cytokines
- ongoing activation of mucosal immune system + defects in bacterial clearance - results in autoimmune inflammation of intestinal tract
- difference in cytokines produced - more in CD
IL 23, 27, 17 and INF-y
environmental - smoking, diet, drugs like NSAIDs
what are some differences b.w UC and CD
UC - ulcerative colitis
- mucosal inflammation limited to colon
- divided into distal and extensive
- distal = rectum
- extensive = whole colon
CD - Crohn’s disease
- can be anywhere along the GIT
- patchy, transmural inflammation
- strictures and fistula
Investigations?
family and social history
full blood count
- platelets will tell us if patient is immunosuppressed
- if CRP > 5 sign of inflammation
imaging - sigmoidoscopy/colonoscopy
clinical features of UC?
severe diarrhoea with blood and mucus
dehydration + fever
anaemia
left sided pain
Clinical features of CD?
abdominal pain, weight loss
sometimes diarrhoea
malabsorption, anorexia
frequent perianal disease - fistula
Complications of UC and CD?
CD
- malabsorption (anaemia)
- small bowel obstructions
- strictures, fistulae, extra-intestinal disease
- fistulating disease with abscess
- osteoporosis
UC
- fluid/electrolyte imbalance
- severe bleeding + anaemia
- colorectal cancer
what are some differences in appearance with a normal ileum/small intestine and in CD and UC?
normal
- healthy, pink, wide hole
CD
- redness and swelling
- granular/cobblestone appearance = bumps of inflammation
UC
- redness and swelling
- granular appearance
- superficial in nature - inflammation on outer surface
What are strictures and fistulae
Stricture - narrowing of bowel of lumen
- bowel wall becomes thicker and lumen narrower
- treated with balloon to open the narrowing
fistula - create openings
- narrow tunnels/passage ways that link one organ to another
- need to treat inflammation so fistula can stop