gastro Flashcards
Alpha-1-antitrypsin deficiency: pathophysiology:
alpha-1-antitrypsin is a gene for a protease inhibitor
Elastase is an enzyme secreted by neutrophils. This enzyme digests connective tissues. Alpha-1-antitrypsin (A1AT) is mainly produced in the liver, travels around the body and offers protection by inhibiting the neutrophil elastase enzyme. A1AT is coded for on chromosome 14. In A1AT deficiency, there is an autosomal recessive defect in the gene for A1AT.
which organs does A1AT deficiency effect?
lungs and liver
- cirrhosis (50yos)
- bronchiectasis and emphysema (30yos)
cx of A1AT deficiency in liver over time?
hepatocellular carcinoma
which condition are all new T1DM’s investigated for as they are linked?
coeliac disease
what 2 findings will endoscopy and biopsy show in coeliac disease? (duodenal biopsy)
villous atrophy
crypt hypertrophy
how do you test for coeliac antibodies in a patient with IgA deficiency?
so anti-TTG and anti-EMA are both IgA - when these are tested for its important to test for total IgA abs too - if deficient they can be false negative
–> test for the IgG version of anti-TTG or anti-EMA antibodies or simply do an endoscopy with biopsies.
name some cx of untreated coeliac disease? (5)
vitamin deficiency anaemia OP ulcerative jejunitis EATL of the intestine NHL adenocarcinoma of small bowel
rare neurological presentation of coeliac?
peripheral neuropathy
cerebellar ataxia
epilepsy
what rash may be seen in coeliac disease - describe?
Dermatitis herpetiformis (an itchy blistering skin rash typically on the abdomen)
type of anaemia seen in coeliac?
anaemia secondary to iron, B12 or folate deficiency
could be either micro or macrocytic
Crohn’s (crows NESTS) mnemonic:
N – No blood or mucus (less common)
E – Entire GI tract
S – “Skip lesions” on endoscopy
T – Terminal ileum most affected and Transmural (full thickness) inflammation
S – Smoking is a risk factor (don’t set the nest on fire)
Crohn’s is also associated with weight loss, strictures and fistulas, gallstones, increased goblet cells
Ulcerative Colitis (remember U – C – CLOSEUP):
C – Continuous inflammation L – Limited to colon and rectum (rectum commonest) O – Only superficial mucosa affected S – Smoking is protective E – Excrete blood and mucus U – Use aminosalicylates P – Primary Sclerosing Cholangitis
what is a useful investigation for IBD?
faecal calprotectin (90% cases)
diagnostic test for IBD?
endoscopy + biopsy
what type of condition is proctitis?
type of ulcerative collitis
should you start someone on suspected UC on anti-diarrhoea drugs?
no - can precipitate life threatening cx toxic megacolon
what cardiac cx of carcinoid syndrome ca?
pulmonary stenosis and tricuspid insufficiency
affects right side of heart
ix carcinoid syndrome?
urinary 5-HIAA
tx carcinoid syndrome?
somatostatin analogue - octreotide - sx relief
diarrhoea - cryptoheptadine
mild normocytic anaemia and raised urea on U&Es indicates:
GI bleed - especially in context of long term NSAID use with no PPI prescription
If ? GI bleed - ix?
endoscopy within 24 hours
tx for c diff 1st line?
oral metronidazole 10-14/7
2nd is PO vanc alone
c diff - what should happen to pt other than abx treatmetn?
isolated for 48 hours and barrier nursed
other than abx, main risk factor drug for c diff?
PPI