inflammation of GI tract W7 Flashcards
which layer of the GI tract is most commonly damaged
mucosal layer
causes of mucosal injury?
GI tract secretions (acid, pepsin, biliary/pancreatic secretions)
ischaemia
drugs (NSAIDs, antibiotics, steroids, chemotherapy)
coeliac disease
infections
radiation
trauma
idiopathic (ulcerative colitis, Crohn’s)
common infections involving the GI tract?
helicobacter
salmonella
shigella
E. coli
C. difficile
CMV
manifestations of mucosal injury?
inflammation
necrosis/apoptosis
erosion and ulceration
hypoplasia and atrophy
hyperplasia
metaplasia (Barrett’s secondary to GORT)
dysplasia +/- neoplasia
prominent apoptosis in the mucosa indicated what?
certain drugs
graft vs host disease (bone marrow transplantation)
HIV infection
gastritis classification?
acute gastritis
chronic gastritis
special forms of chronic gastritis
acute gastritis types/features?
acute erosive/haemorrhagic gastritis - ingestion of irritant chemicals
acute H. pylori infection - usually no/minor symptoms, seldom seen in biopsies
chronic gastritis types/features?
non-atrophic gastritis - chronic H. pylori infection
atrophic gastritis - autoimmune gastritis, chronic H. pylori infection
special forms of chronic gastritis?
chemical gastritis (bile reflux, NSAIDs)
radiation gastritis
lymphocytic gastritis
non-infectious granulomatous gastritis (eg Crohn’s disease, sarcoidosis)
eosinophilic gastritis (eg food sensitivities)
other infectious gastritides (non h. pylori)
H. pylori infection histology?
chronic inflammation within lamina propria
ongoing acute inflammation in form of neutrophil infiltration of gastric pits.
chemical gastritis/gastropathy histology?
hyperplasia of epithelium, elongated corkscrew glands
intestinal metaplasia histology?
presence of goblet cells - large pale staining cells
what is coeliac disease characterised by
hypersensitivity reaction to glutamine rich proteins in wheat/barley/rye (leads to malabsorption due to injury to mucosa of small intestine)
coeliac disease features
strong link to certain HLA class genes
diagnosis of coeliac disease?
typical histological changes in biopsy from small intestine
detection of autoantibodies in blood
demonstration of improvement of symptoms following gluten free diet
how is asymptomatic coeliac disease often picked up?
routine haematology (iron deficiency anaemia)
what conditions out with the intestine can coeliac disease be associated with?
other autoimmune diseases
disorders of the liver/skin
neuro
cardiac
common for dermatitis herpetiformis to be the initial presentation
what can untreated coeliac disease increase your risk of
certain types of malignancy (particularly small bowel adenocarcinoma)
typical histological features seen in a duodenal biopsy in a patient with coeliac disease?
loss of normal villous architecture
chronic inflammation in lamina propria
increased number of T lymphocytes within surface epithelium
epithelial damage
crypt hyperplasia (attempt at regeneration and repair)
GI tract bacterial infections types? visible in biopsy?
helicobacter pylori (visible in biopsy)
shigella, salmonella
campylobacter jejuni
clostridium difficile
vibrio cholera
mycobacterium tuberculosis (visible in biopsy)
atypical mycobacteria (eg MAI)
yersinia enterocolitica
bacterial infections with characteristic pattern of injury on biopsy?
clostridium difficile - pseudomembranous colitis
yersinia enterocolitica - neutrophil rich granulomas
GI tract viral infection types?
rotaviruses
enteric adenoviruses
herpes viruses (HSV)
cytomegalovirus (CMV)
HIV
GI tract fungal infection types?
candida
histoplasmosis
mucormycosis
GI tract protozoal infection types?
giardia lamblia
(entamoeba histolytica
cryptosporidia
microsporidia)
GI tract helminths infections?
worms!!
enterobius
ascaris
tapeworms
amoebic colitis biopsy features
flask shaped ulcers
pseudomembranous colitis (antibiotic-associated colitis) infection appearance? what is this caused by?
mucosa covered by yellow material (mixture of fibrin and pus, erupting from dilated crypts). organism involved is C difficile.
