Lecture 25 Inflammatory Bowel Disease Flashcards
What is the definition of IBD
• Chronic, relapsing, remitting inflammation of gastrointestinal tract
What are the 2 main IBDs
Crohn’s and Ulcerative colitis
What group is microscopic colitis found in and how is it diagnosed
Middle aged woman
Histology
What type of inheritance is IBD
Multi-factorial
Not-medelian
• Genetic susceptibility – SNPs (single nucleotide polymorphisms)- 1bp switch in genetic sequence- which may affect the function of the gene
What does increase permeability in the epithelium barrier lead to
Dysbosis and chronic inflammation
Microbiota metabolic function
Production of vitamins
Digestion of dietary carcinogens
Fermentation of non-degradable substrates
Production of SCFAs- energy source
Microbiota structural function
sIgA production
Intestinal villi and crypts
Mucous Layer
TJs
Microbiota protective function
Colonisation resistance
Innate and adaptive immunity
Inflammatory cytokine oversite
Extra-intestinal manifestation of IBD
- Erythema nodusom
- Ulcers on leg- PG (Crohn’s disease)
- Arthritis in large joints
- Sacroiliitis
- Associated liver disease- sclerosing cholangitis
- Gall stones and renal stones
Symptoms of Ulcerative colitis
o Bloody diarrhoea
o Abdominal pain
o Weight loss
o Fatigue
Whats a distinctive feature of UC
only colon
• Begins rectum and works proximally
Investigations for UC
- Bloods for markers of inflammation (normocytic anaemia, increased CRP/platelets, low albumin)
- Stool culture to rule out infection
- Faecal Calprotectin-non-invasive marker of inflammation in GI mucosa
Mild UC
Less than 4 stools a day +/-blood
Normal ESR
No signs of toxicity
Moderate UC
4-6 stools/day
Occasional blood
Minimal signs od toxicity
CRP<= 30mg/L
Severe UC
More than 6 stills a day and: Temp over 37.8 Tachycardia Anaemia ESR>30mm/h CRP>30mg/L
Filmiant UC
10 stools a day, continuous bleeding Toxicity Abdominal tenderness or distention Transfusion requirement Colonic dilatation (Xray)
What is proctitis
UC confined to the rectum
What are the features of proctitis
- Frequency, urgency, incontinence- constant stimulation of pressure receptors, tenesmus
- Small volume mucus and blood
- Proximal faecal stasis (constipation)
What is the treatment for proctitis
topical therapy via depository
Interventions for acute severe colitis
- Stool chart
- 3-4 serial stool cultures for C. difficile- conditions increases susceptibility to infection
- IV glucocorticoids- dampen down inflammation
- LMWH- 3X increased risk of thromboembolism (anticoagulants)
- Avoid/Stop non-steroidal analgesics, opiates, anti-diarrhoeals, anti-cholinergic
- IV hydration, careful correction of electrolytes low potassium or magnesium can precipitate toxic megacolon
- AXR – toxic dilatation, extent of disease – mucosal odema, lead pipe, proximal faecal loading
Toxic megacolon
Dilated colon filled with air >5.5cm
Clinical features of Crohn’s disease
• Patchy disease – mouth to anus – skip lesions – clinical features depend on regions involved
Clinical Features of CD
• Diarrhoea • Abdominal pain • Weight loss. • Malaise, lethargy, anorexia, N&V, low-grade fever • Malabsorption – Anaemia, vitamin deficiency
Investigations for CD
- Bloods for markers of inflammation
- Stool culture to rule out infection if diarrhoea
- Faecal Calprotectin (0-50ug/g stool=normal, 50-200=equivocal, >200 elevated) – may not be high if just small bowel disease
- Colonoscopy with terminal ileum intubation and colon/TI mucosal biopsies
- MRI small bowel study
- Capsule endoscopy- tablet with camera within it
- Occasionally CT scan if acutely unwell and want to rule out complication eg abscess
Different in histology of UC and CD
– CD granulomas – Goblet cells depleted in UC – Crypt abscesses: UC > CD – Transmural inflammation in CD – Mucosal in UC
Symptoms of perianal Crohn’s disease
Perianal pain
Pus secretion
Unable to sit down
Investigation of Perianal Crohn’s disease
MRI pelvis
Examination under anaesthetic
Treatment for perianal Crohn’s disease
Surgery to drain abscess
Medical – antibiotics and biologic therapy (anti-TNF)
Describe the step up approach for the treatment for UC
Aminosalicylates (5-ASA) Steroids-Prednisone/Budesonide Immunomodulators Biologic agents Surgery
Main Aminosalicylates (5-ASA)
Mesalazine
• Work by blocking prostaglandins and leukotrienes
• Topical to colonic mucosa can be taken orally
Can Aminosalicylates (5-ASA) work for Crohn’s
No
What is Immunomodulation
– Thiopurines used for maintenance for UC and Crohn’s disease
Significant side effects of Immunomodulation
– Leucopenia (supress bone marrow function) more susceptible to infection
– Hepatoxicity
• Requires Blood Monitoring
– Pancreatitis
– Possible long-term lymphoma risk and non-melanoma skin cancers
Name biologics used
Monoclonal Antibodies • Anti-TNF antibodies – Infliximab (Remicade) • 8 weekly IV infusion – Adulimumab (Humira) • 2 weekly SC injections • 4b7 Integrin Blockers – Vedolizumab • 8 Weekly IV Infusions • IL12/IL23 Blockers – Ustekinumab • IV loading followed by SC 8-12 weekly
UC definition of failed medical therapy
- Recurrent courses of steroid (>2 courses a year)
- Relapse prior to or shortly after stopping therapy
- Unacceptable side effects
- Acute severe colitis not responding to 72 hours high dose IV steroids +/- anti-TNF biologic ‘rescue’ therapy
Surgery for acute sever colitis
• Total colectomy o Create a rectal stump o Bring out end of small intestine in iliac fossa (end ileostomy) • Rectal preservation • Ileostomy
Surgical indicators for Crohn’s disease
- Failure of medical management
- Relief of obstructive symptoms (small bowel)- if there is development of a stricture
- Management of fistulae - e.g. bowel to bladder
- Management of intra-abdominal abscess
- Management anal conditions
- Failure to thrive
