*IBD 1 - Lecture 1 Flashcards
What is the name of the overlap condition between Crohn’s disease and ulcerative colitis?
Indeterminate colitis
How does Crohn’s disease tend to present? (2)
How does ulcerative colitis tend to present? (2)
Crohn’s:
-abdo pain
peri-anal disease
UC:
- diarrhoea
- bleeding
What are the 3 overlapping factors why people tend to develop IBD?
Genetic predisposition
Mucosal immune system problem
Environmental triggers
What is the best established risk factor for IBD development?
Positive family history
What mutations lead to a higher risk of developing Crohns disease?
Mutation in NOD2 (on chromosome 16) - also called CARD15 or IBD-1
Encodes a protein involved in bacterial recognition
Amount of bacteria present in Crohn’s?
Amount of bacteria present in UC?
Crohn's = too much UC = too little
What are 4 pieces of evidence regarding the role of gut flora in IBD?
- gut flora is indispensable to the development of animal models of colitis
- antibiotics effective in the treatment of peri-anal Crohn’s disease
- diverting faecal stream helps Crohn’s
- altered bacterial flora in colons with UC
What are the 4 theories of IBD pathogenesis?
Pathogenic bacteria
Abnormal microbial composition
Defective host containment of commensal bacteria
Defective host immunoregulation
Which IBD does smoking aggregate and which does it protect against?
Aggravates Crohns and protects against UC
Which pain relief should you not take when you have IBD?
NSAIDs
What is ulcerative colitis?
Inflammation of the colon of unknown aetiology
Peak age incidence?
20 - 30s
What type of course does UC follow?
A relapsing corse
What part of the gut does UC affect?
Affects rectum extending proximally to the caecum
What are the names of the 3 different UC extents and what part of the bowel does each affect?
Proctitis = just rectum
Left sided colitis = to splenic flexure
Pan-colitis = to ileocaecal valve
What is the natural history of UC 1 year after diagnosis?
10% = colectomy 52% = active disease 38% = remission
UC symtoms?
Diarrhoea + bleeding (main) increased bowel frequency urgency tenesmus incontinence night rising lower abdominal pain (esp. LIF) (practice can cause constipation due to inflammation in the rectum preventing them from passing stool)
What is the Truelove and Witt criteria for severe ulcerative colitis?
What does meeting this criteria mean in terms of clinical outcomes?
passing greater than 6 bloody stool in a 24 hour period 1 or more of: fever (greater than 37.8) Tachycardia Anaemia elevated ESR/ CRP
30% risk of colectomy
Further assessment of UC?
Bloods (CRP and albumin (a negative acute phase reactant which decreases in sepsis or inflammation)
Plain AXR
Endoscopy
Histology
What are you looking for on a plain AXR in a UC patient? (3)
Stool distribution (none in inflamed colon) Mucosal oedema = thumbprining Toxic megacolon
What is toxic megacolon? Widths?
an acute toxic colitis with dilatation of the colon
Transverse greater than 5.5cm
Caecum greater than 9cm
What would be seen in endoscopy of a patient with UC? (5)
Confluent inflammation/ ulceration extending proximally from anal margin to "transition zone" Loss of vessel pattern Loss of hausfrau Granular mucosa Contact bleeding Pseudopolyps sometimes (endoscopy used to define extent)
Histology:
what layers of the colon does ulcerative colitis affect?
What cells are absent in histology of UC?
What happens to the crypts in UC?
Mucosal layer only
Goblet cells are absent
Crypts can become distorted and enlarged and accesses can form
Long term complication of UC?
Increased risk of colorectal cancer
What is the risk of developing colorectal cancer from UC determined by?
Severity of inflammation
Duration of disease
Disease extent
(patients who have extensive colitis (to beyond splenic flexure) for over 10 years should have regular colonoscopy)
Extra-intestinal manifestations of IBD?
Skin (erythema nodosum)
Joints (spondylitis, sarcolitis, peripheral arthritis)
Eyes (uveitis)
deranged LFTS (steatosis of liver, gallstones, sclerosing cholangitis)
Renal stones
Primary sclerosing cholangitis?
Symptoms?
Progressive cholestasis with bile duct inflammation and fibrosing stricture formation
80% of patients with this have associated IBD (UC more common cause than Crohns)
Most asymptomatic or itch and rigours
Median time to death or liver transplant is 10 years
15% get cholangiocarcinoma
Mean age of diagnosis of Crohns disease?
27 (90% onset before age of 40)
Where along the gut does IBD affect?
Can affect any region pf the GI tract from the most to naus
Does Crohns occur as skip lesions or does it affect the GI tract continually?
Skip lesions
How deep into the GI tract does crohns affect histologically?
Transmural inflammation
How does peri-anal Crohns disease present? (4)
Recurrent abscess formation
pain
Can lead to fistula with persistent leakage
Damaged sphincters
What % of crohns patient require surgery within 8-10 years?
75%
Why do we try to minimise resection in Crohns disease?
It is non-curative (having short bowel causes major malabsorption problems)
What are the 3 disease phenotypes of Crohns disease?
Stenosis (50%) - need to establish whether this is fibrotic or inflammatory
Inflammation (30%)
Fistula (20%)
What determine the Crohns disease symptoms?
Site of disease
Symptoms of Crohns disease of the small intestine?
Abdominal cramps (peri-umbilical) Diarrhoea, weight loss
Symptoms of Crohn’s disease of the colon?
Abdominal cramps (lower abdomen)
Diarrhoea with blood
Wt loss
Symptoms of Crohn’s disease of the mouth?
Painful ulcers
Swollen lips
angular chielitis
Symptoms of Crohn’s disease of the anus?
Peri-anal pain
Abscess
Further assessment of Crohns disease?
Clinical exam (evidence of wt loss, RIF mass, peri-anal signs) Bloods (CRP, albumin, platelets, B12 (if affecting t. ileum), ferritin) Stage disease extent using endoscopy
Where is vitamin B12 absorbed?
Ileum
What may you seen on endoscopy of a patient with Crohn’s disease?
Cobblestonning
Fissures
Ulceration
What creates the “cobble-stoning” seen in crohns disease?
Longitudinal and circumferential fissures and ulcers separate islands of mucosa, giving it an appearance reminiscent of cobblestones.
What would histology of crohns disease look like?
Patchy
Granuloma (30-50%)
What can be used to assess the small bowel for Crohns disease? (3)
Barium follow-through
Small bowel MRI
Technetium-labelled white cell scan?
