Pathology of IBD

Question 1

What is IBD?

Answer 1

inflammatory bowel disease - UC and CD
idiopathic and chronic
episodic and follows a course of flares and remission

Question 2

causes of IBD?

Answer 2

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

Question 3

what are some differences b.w UC and CD

Answer 3

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

Question 4

Investigations?

Answer 4

family and social history
full blood count
- platelets will tell us if patient is immunosuppressed
- if CRP > 5 sign of inflammation
imaging - sigmoidoscopy/colonoscopy

Question 5

clinical features of UC?

Answer 5

severe diarrhoea with blood and mucus
dehydration + fever
anaemia
left sided pain

Question 6

Clinical features of CD?

Answer 6

abdominal pain, weight loss
sometimes diarrhoea
malabsorption, anorexia
frequent perianal disease - fistula

Question 7

Complications of UC and CD?

Answer 7

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

Question 8

what are some differences in appearance with a normal ileum/small intestine and in CD and UC?

Answer 8

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

Question 9

What are strictures and fistulae

Answer 9

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