Infection, Inflammation and the Gut Flashcards
Infective causes in the Gut
Giardiasis
Whipples disease
Psuedomembrane colitis
Giardisis
Protozoa
Waterbourne infection
Rare in Glasgow
Usually a chronic infection
Symptoms- diarrhoea, malabsorption, weight loss but often asymptomatic
RFs- immunodeficiency
Tbx - metronidazole
Whipples disease
Tropheryma whipplei
Patients have lack of immmunity to ogansim . Absorption of digested food in the intestine is reduced.
Rfs- Middle aged men
Symptoms- Abdominal pain, skin pigmentation, arthrlagia (joint pain), diarrhoea
Diagnosis - Biopsy of dudoenum - PAS positive macrophages
Tbx- antibiotics
Psuedomembrane colitis
Clostridium difficile
Overgrowth with toxin producing clostridium difficile after abx therapy with clindimycin
Symptoms- Feverm abdominal pain, diarrhoea, necrosis
Diagnosis - toxin in stool
Treatment - Vancomycin
Non infective causes of gut inflammation
Acute appendicitis
Coeliac disease
Coeliac disease Definition
A condition where there is inflammation of the jejunum mucosa that improves when the patient is treated with a glten free diet and relapses when gluten is introduced
Clinical featues of coeliac
- fatty diarrhoea: bulky, pale, greasy and offensive
- Weight loss
- Reduced bone density with increased risk of fracture (osteomalacia)
- iron deficiency aneamia (can digest but not absorb)
- oral apthous ulcers
- Dermatitis herpetiforms
Investigations for coeliac disease
a. Duodenal/jejunual biopsy
b. Endomysial (EMA) Ab
c. Haematology
d. Biochemistry
Risk factors of coeliac disease
RFs - genetic predispostiion (HLA-Dq)
Epidemiology of coeliac
Epideimiology - commonest cause of villous atrophy in UK (1in 200)
Pathophysiology of coeliac disease
Cause - triggered by ingestion of gluten
- Prolamins (gliadin from wheat, Hordeins from barley, seclans from rye) are damaging factors
- Gluten is fractioned to give alpha, beta and gamma-gliadin peptides (alpha-gliagin is main damaging factor)
- gliadin peptides pass through the epithelium
- deaminated by tissue transglutamase
- Gliadin peptides then bind to APC and presented to CD4 T cells in lamina propria via HLA Dq2/8
- T cells produce pro-inflammatory cytokines
- T cells also interact with B cells to produce autoantibodies (transglutaminase + antiendomysial autoantibodies) against self tissue
- Leads to:
a. Villous atrophy - normally cells created at the pit of tge crypt and regenerate
b. Crypt hyperplasisa - proliferative component increased
Classification used in coeliac
Marsh classification
0- Normal mucosa
1- Increase number of intra-epithelial lymphocytes >20 per 100 enterocytes)
2- Proliferation of the crypts of liberkuhn
3 - Variable villous atrophy
3a- Partial villous atrophy
3b- Subtotal villous atrophy
3c - total villous atrophy
4. hypoplasia of the small bowel architecture
Treatment of coeliac disease
Treatments with gluten free diet - recovery of villous atrophy in three months
Complications of coeliac disease
-TTG antibodies are a good measure of compliance. If the diet is good they will stay low.
They are at risk of enteropathy associated T cell lymphoma
They are prone to osteoporosis – therefore bone should be screened regularly. Would not use bisphosphonates at such a young age – save them for later in life.
Can have side effect of causing spontaneous mid shaft femur fractures.
Use regular biopsies to monitor bowel
Acute appendicitis
Bacterial infection of blocked appendix
Right iliac fossa pain!!!
Chi;dren
Histo- acute inflammation followed by ulceration and trasnmural inflammation
Complications - transmural gangrene leading to perforation, generalised peritonitis
Chronic inflammatory bowel disease consists of
Ulcerative collitis
Crohns disease
Ulcerative collitis vs Crohns
Position, incidence and age of onset
Ulcerative collitis:
- rectum and extends confluently into to colon only
- 10-20/100,000
- Age of onset 35
- Not common in non-smokers -Smoking protective
Crohns
- affects any part of the gastrointestinal wall from mouth to anus (usually terminal ileum)
- 5-10/100,000
- 26
- common in smokers
Ulcerative collitis vs crohns
Endoscopic findings
Ulcerative collitis
- con fluent inflammation
- pseudo polyps
- thin bowel wall
- erythema, odema, abnormal vascular pattern
Crohns
- skip lesions (normal mucosa between affected areas)!
- coblblestoning
- aphthous and linear ulcerations
- strictures
- thickened bowel wall
Ulcerative collitis vs crohns
Clinical features
Ulcerative collitis
- L sided abdominal cramping
- Diarrhoea, often with blood and mucus (haemotochezia)
- Tenesmus (a continual or recurrent inclination to evacuate the bowels)
Crohns
- RLQ colicy pain
- Diarrhoea + blood PR (less blood)
- Fistula (communication between one lumen to another)
- apothlous ulcers - canker sores-
- Crohns ileitus -inflammation/ulceration of terminal ileum )
- anaemia
General inflammatory bowel disease (IBD) extra-colonic manifestations
Msk: arthritis - ankylosis get spondylitis, clubbing
Dermo and oral -
reactive lesions: pyoderma gangrenosa, aphthous ulcers
Specific: fissures, fistulas and oral Crohns
Hepatobilary: PSC, chronic acute hepatitis
Ocular: iritis
Renal: calcium - oxalate stones
Ulcerative colitis vs inflammatory bowel disease
Serological markers
ulcerative collitis
- ANCA (anti cytoplasmic antibodies)
Crohns
-ASCA (anti- saccharides cerevisae)
Complications of inflammatory bowel disease
- colon cancer
- Toxic megacolon
- strictures
4/ fistula
Diverticular disease
“mucosal outpouchings through muscle coat of colon”
Common-
>40
Sigmoid colon
causes - low roughage diet causes constipation and high sigmoid luminal pressure-herniation of mucosal through wekaness in muscle coat of sigmoid
-Left iliac fossa pain
Complicaitions:
- perforation
- fistula –> bladder or bowel
- bleed
- obstruct bowel
Microscopic colitis
Middle aged persons with profuse watery diarrhoea- 10 motions per fay
Colonscopy entirely norma
Abnormal histology
Two types:
lymphocytic –> increased lymphocytes
Collagenous –> increased collage
Tbx - eliminate drug cause then treat with 5aminosalicyclic acid
Ichaemic gut
Acute- sudden onset abdominal pain with blood per rectum
Chronic- abdominal angina
pain assoc with eating -weight loss (reduced absorption)
Causes- -mesenteric artery or vein thrombosis. -Mesenteric artery embolus. Hypotension(causing watershed infarction) (splenic flexure). - strangulated hernia. Volvulus
Pathology: Mucosa and transmural infacrtion. Coagulative necrosis. Gangrene. Surgical resection may be needed if severe.
Ulcerative colitis definition
A relapsing and remitting inflammatory disease of the colon, arising in the anus and spreading proximally, not beyond ileocecal valve
Crohn’s disease definition
Chronic relapsing non-cheating granulomatous transmural inflammatory condition can affect any part of GI tract from mouth to Anus
Investigations of IBD
FBC - macrocytic or microcytic WCC - increases infection and chronic inflammation U&es may be dehydrated in diarrhoea LFTs primary sclerosising cholangitis ESR and CRP raised Stool culture - to exclude C.DIFF
Radio - abdo ultrasound -AXR - obstruction mucosal thickening Contrast studies (barium meal, barium follow through, barium enema)
CXR- air under diaphragm
PR for blood
