inflammation of GI tract W7

Question 1

which layer of the GI tract is most commonly damaged

Answer 1

mucosal layer

Question 2

causes of mucosal injury?

Answer 2

GI tract secretions (acid, pepsin, biliary/pancreatic secretions)
ischaemia
drugs (NSAIDs, antibiotics, steroids, chemotherapy)
coeliac disease
infections
radiation
trauma
idiopathic (ulcerative colitis, Crohn’s)

Question 3

common infections involving the GI tract?

Answer 3

helicobacter
salmonella
shigella
E. coli
C. difficile
CMV

Question 4

manifestations of mucosal injury?

Answer 4

inflammation
necrosis/apoptosis
erosion and ulceration
hypoplasia and atrophy
hyperplasia
metaplasia (Barrett’s secondary to GORT)
dysplasia +/- neoplasia

Question 5

prominent apoptosis in the mucosa indicated what?

Answer 5

certain drugs
graft vs host disease (bone marrow transplantation)
HIV infection

Question 6

gastritis classification?

Answer 6

acute gastritis
chronic gastritis
special forms of chronic gastritis

Question 7

acute gastritis types/features?

Answer 7

acute erosive/haemorrhagic gastritis - ingestion of irritant chemicals

acute H. pylori infection - usually no/minor symptoms, seldom seen in biopsies

Question 8

chronic gastritis types/features?

Answer 8

non-atrophic gastritis - chronic H. pylori infection

atrophic gastritis - autoimmune gastritis, chronic H. pylori infection

Question 9

special forms of chronic gastritis?

Answer 9

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)

Question 10

H. pylori infection histology?

Answer 10

chronic inflammation within lamina propria

ongoing acute inflammation in form of neutrophil infiltration of gastric pits.

Question 11

chemical gastritis/gastropathy histology?

Answer 11

hyperplasia of epithelium, elongated corkscrew glands

Question 12

intestinal metaplasia histology?

Answer 12

presence of goblet cells - large pale staining cells

Question 13

what is coeliac disease characterised by

Answer 13

hypersensitivity reaction to glutamine rich proteins in wheat/barley/rye (leads to malabsorption due to injury to mucosa of small intestine)

Question 14

coeliac disease features

Answer 14

strong link to certain HLA class genes

Question 15

diagnosis of coeliac disease?

Answer 15

typical histological changes in biopsy from small intestine
detection of autoantibodies in blood
demonstration of improvement of symptoms following gluten free diet

Question 16

how is asymptomatic coeliac disease often picked up?

Answer 16

routine haematology (iron deficiency anaemia)

Question 17

what conditions out with the intestine can coeliac disease be associated with?

Answer 17

other autoimmune diseases
disorders of the liver/skin
neuro
cardiac

common for dermatitis herpetiformis to be the initial presentation

Question 18

what can untreated coeliac disease increase your risk of

Answer 18

certain types of malignancy (particularly small bowel adenocarcinoma)

Question 19

typical histological features seen in a duodenal biopsy in a patient with coeliac disease?

Answer 19

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)

Question 20

GI tract bacterial infections types? visible in biopsy?

Answer 20

helicobacter pylori (visible in biopsy)
shigella, salmonella
campylobacter jejuni
clostridium difficile
vibrio cholera
mycobacterium tuberculosis (visible in biopsy)
atypical mycobacteria (eg MAI)
yersinia enterocolitica

Question 21

bacterial infections with characteristic pattern of injury on biopsy?

Answer 21

clostridium difficile - pseudomembranous colitis
yersinia enterocolitica - neutrophil rich granulomas

Question 22

GI tract viral infection types?

Answer 22

rotaviruses
enteric adenoviruses
herpes viruses (HSV)
cytomegalovirus (CMV)
HIV

Question 23

GI tract fungal infection types?

Answer 23

candida
histoplasmosis
mucormycosis

Question 24

GI tract protozoal infection types?

Answer 24

giardia lamblia
(entamoeba histolytica
cryptosporidia
microsporidia)

Question 25

GI tract helminths infections?

Answer 25

worms!!
enterobius
ascaris
tapeworms

Question 26

amoebic colitis biopsy features

Answer 26

flask shaped ulcers

Question 27

pseudomembranous colitis (antibiotic-associated colitis) infection appearance? what is this caused by?

Answer 27

mucosa covered by yellow material (mixture of fibrin and pus, erupting from dilated crypts). organism involved is C difficile.