Inflammatory Bowel Disease Flashcards
What part of the bowel is involved in UC?
always involves rectum, extends proximally but is limited to the colon
What are the histological findings of UC?
mucosal/submucosal involved, lymphocytic infiltrate, crypt distortion, no granulomas
What part of the GIT is involved in crohn’s disease?
may affect any part, may have skip lesions
What are the histological findings of crohn’s disease?
transmural, granulomas in 50% of cases
What are some of the bowel complications of crohn’s disease?
fistulisation, obstruction, microperforation, strictures
What are the clinical features of the NOD2/CARD15 variant of crohn’s disease?
younger age of onset, small bowel involvement, stricturing phenotype, early initial surgery/surgical recurrence
Which medications may trigger flares of UC?
aspirin, NSAIDs, OCP
What protects against UC/
smoking, appendicectomy
What is faecal calprotectin?
a protein released by inflammatory cells in the gut, not usually present in the stool, elevated in bowel inflammation
What is a positive ASCA and negative ANCA suggestive of?
crohn’s disease
What is a positive ANCA and negative ASCA suggestive of?
UC
What is perianal disease suggestive of?
crohn’s disease
What is sparing of the rectum suggestive of?
crohn’s disease
What are the extraintestinal manifesations of IBD associated with active disease?
oral ulcers, erythema nodosum, large joint arthritis, episcleritis
What are the extraintestinal manifesations of IBD independent of GI disease?
PSC, ank spond, uveitis, pyoderma gangreonsum, kidney stones, gall stones
What is the role of sulfasalazine/5-aminosalicylates?
used in the treatment of mild to moderate UC to induce and maintain remission
What is the effect of sulfsalazine/5-aminosalicylates on colorectal cancer?
reduces risk in UC patients
Do steroids maintain remission in IBD?
no
What is entocort and when is it useful?
budesonide with extensive first-pass metabolism so it is delivered specifically to the terminal ileum and proximal colon -> effective in ileocaecal crohn’s
Whay is cortiment and when is it useful?
budeonside attached to a matrix so it has colonic release -> effective in UC
What is the mechanism of action of azathioprine/6-mercaptopurine?
metabolised to 6-thioguanine which inhibit purine synthesis, inhibits T and B cell proliferation and induces T cell apoptosis
What is TPMT?
An enzyme (thiopurine methyltransferase) - if patient’s have poor enzyme activity can be at risk of severe neutropaenia on azathioprine
What is measured for therapeutic drug monitoring of azathioprine?
6-MMP (inactive metabolite) and 6-TGN (active metabolite)
What does it mean if patients have low 6-TGN and low 6-MMP?
either non adherance or underdosing
What does it mean if patients have high 6-TGN and high 6-MMP?
refractory -> need to use another drug
What does it mean if patients have low 6-TGN and high 6-MMP?
they are thiopurine resistant ‘shunters’ -> can use allopurinol in addition to stop shunting of the pathway (and reduce dose of thioprine)
What are the side effects of thiopurines?
allergic reactions, leukopaenia, hepatitis, pancreatitis, infections, non hodgkins lymphoma, non melanoma skin cancer
What is the mechanism of action of cyclosporine?
calcineurin antagonist
What is the use of cyclosporine?
used as rescue therapy for severe steroid refractory UC to avoid surgery - > can’t be used long term or in crohn’s
Which anti-TNF agents are available for use in IBD?
infliximab, adalimumab, golimumab
What are the adverse effects of anti-TNF therapy?
lupus, serious infection, TB, non hodgkin’s lymphoma, melanoma, psoriadorm reactions
What is the mechanism of action of vedolizumab?
binds alpha 4 beta 7 integrin on surface of T lymphocytes -> inhibits trafficking of leukocytes to sites of inflammation
What is the mechanism of action of ustekinumab?
monoclonal antibody to p40 subunit of IL-12/IL-23
Which patients are most at risk of hepatosplenic T cell lymphoma?
young males on thiopurine and anti-TNF
What is the usual treatment plan for crohn’s?
start with corticosteroid and azathioprine/6-MP, taper steroids, if continue steroid free remission continue monotherapy, if not in steroid free remission add infliximab or adalimumab
What is the usual treatment plan for UC?
start with aminosalicylate, if ongoing disease add corticosteroid and thiopurine, if ongoing disease add anti-TNF
What are the features of acute severe colitis?
> 6 bloody stools per day plus one of HR > 90, T > 37.8, Hb < 105 or ESR > 30
What is the treatment of acute severe colitis?
IV steroids, IVT, IV abx, tranfuse to Hb >100, early surgical review
What factors increase risk of colorectal cancer in IBD?
disease duration disease extent severity of inflammation PSC FHx of CRC presence of dysplasia
