Faecal testing

Question 1

What is calprotectin?

Answer 1

Calcium and zinc binding protein produced by neutrophils. A marker of neutrophil count (ie inflammation) in body fluids.

Question 2

Causes of high faecal calprotectin

Answer 2

1. Inflammatory bowel disease
2. Blood in stool (nosebleed, menstrual blood)
3. NSAID/aspirin enteropathy
4. Bacterial inflammation
5. Extremes of age
6. CRC
7. Diverticular disease

Question 3

Utility of faecal calprotectin

Answer 3

1. Distinguish IBD from IBS
2. Early detection of relapse in IBD
3. Prediction of relapse in IBD
4. Prediction of response to treatment

Question 4

Your lab’s method for calprotectin

Answer 4

Diasorin Liaison. Two-step, 2 site chemiluminscent immunoassay utilising paramagentic particles coated with capture antibody and isoluminol labelled signal antibody.

Question 5

What is faecal elastase?

Answer 5

Pancreatic protease that passes unchanged through GIT

Question 6

Utility of faecal elastase?

Answer 6

1. Identify pancreatic exocrine insufficiency (replaces faecal trypsin/chymotrypsin)
2. Investigate diarrhoea unknown cause
3. Assess pts with CF

Question 7

Causes of falsely low faecal elastase?

Answer 7

Watery diarrhoea (dilutes concentration) - however a normal result in this scenario therefore can exclude pancreatic insufficiency.

Question 8

Is porcine elastase in supplements detected by faecal elastase test?

Answer 8

NO

Question 9

Your lab’s method for faecal elastase

Answer 9

Diasorin Liaison. 2 step 2 site chemiluminescent immunoassay with capture antibody bound to paramagnetic particles and isoluminol-labelled signal antibody.

Question 10

Decision limits for faecal elastase

Answer 10

< 100 ug/g = severe pancreatic exocrine insufficiency
100-200ug/g = mild to mod exocrine pancreatic insufficiency
>/= 200 ug/g = normal