ClinPath

Question 1

list 3 catalytic assays used in the diagnosis of pancreatitis

Answer 1

• amylase
• lipase
• DGGR lipase

Question 2

advantages of amylase in the diagnosis of pancreatitis

Answer 2

• widely available
• steroids do not elevate it; so useful in dogs with HAC

Question 3

disadvantages of amylase in the diagnosis of pancreatitis

Answer 3

• low sensitivity and specificity because of high background level from other sources, including small intestine

Question 4

advantages of lipase assay in diagnosis of pancreatitis

Answer 4

• widely available
• more sensitive than amylase
• new DGGR lipase assay has higher sensitivity and specificity than previous *correlates well with PLI

Question 5

disadvantages of liapse assay in pancreatitis dx.

Answer 5

• extrapancreatic sources - so high background level
• steroids elevate up to 5 times

Question 6

what is the MOA of an catalytic assay

Answer 6

A catalytic assay relies on the abilty of a molecule to catalyse a reaction in vivo and thus rely on the presence of active enzyme. Tend to be species non-specific.

Question 7

how does an immunoassay work

Answer 7

Uses an antibody against a part of the enzyme molecule distance from the active site and thus will also measure inactive precursors (eg. trypsinogen)
tend to be species-specific

Question 8

adv. of canine TLI in diagnosis of pancreatitis

Answer 8

• if elevated has high specificity for pancreatitis

Question 9

disadvantages of cTLI in dx. of pancreatitis

Answer 9

• low sensitivity for diagnosis of pancreatitis (high for EPI)
• renally excreted so elevates 2-3 times in azotemia
• may be inappropriately low in severe/chronic cases due to pancreatitic depletion/loss of tissue mass

Question 10

disadvantages of fTLI in dx. of pancreatitis

Answer 10

• lower sensitivity and specificity than canine TLI - better used for EPI
• renally excreted so increases w/ azotaemia

Question 11

adv of fTLI in dx. of pancreatitis

Answer 11

no advantages for diagnosis of pancreatitis - reserve for diagnosis of EPI

Question 12

adv of cPLI in dx. of pancreatitis

Answer 12

• most sensitive and specific test for canine pancreatitis together with DGGR lipase
• organ-specific so no interference from extrapancreatic sources

Question 13

adv of fPLI in dx. of pancreatitis

Answer 13

• most sensitive and specific test available for feline pancreatitis toegether with DGGR lipase

Question 14

disadvantages of cPLI in dx. of pancreatitis

Answer 14

• increased in renal disease

Question 15

disadvantages of fPLI in dx. of pancreatitis

Answer 15

little is published

Question 16

how does pancreatitis cause azotaemia?

Answer 16

usually pre-renal due to dehydration
+ can also be intrinsic renal failure (sepsis and immune complexes)

Question 17

how does pancreatitis cause potassium changes?

Answer 17

decreased due to
- loss in vomiting and renal loss with fluid therapy
- reduced intake
- aldosterone release 2nd to hypovolaemia