Amylase, Lipase and Spec cPL

Re: Amylase, Lipase and Spec cPL

Andrew Kent — Mon, 14 Dec 2009 20:51:22 GMT

PLI should be very specific for pancreatic inflammation but I have also seen some cases which have made me doubt this.

My reasoning for this currently is that the pancreas is showing inflammation secondary to other conditions, for example I've had positive PLI snap tests on both hypo and hyperadrenocorticism cases, GI foreign bodies etc. Equally dogs with EPI often have an elevated PLI, the guys from texas suggest this is related to inflammation in remaining pancreatic tissue.

Andy

Re: Amylase, Lipase and Spec cPL

Hanna Bennett — Sun, 13 Dec 2009 21:15:04 GMT

We had a Boxer which came in for something completely unrelated, think it was a lump off. White Boxer, with, unsurprisingly, allergic skin disease. Bloods showed lipase to be off the scale, and while I know this is not specific we ran a Spec PL at a certain reference lab, and the result was off the scale high (>1000!). No assoc clinical signs, so discussed it with lab who assured me it was specific for pancreatiis. Client and i agreed to monitor, still no clinical signs a year later. Also had a Rottie with acute pain, impossible to tell if musculoskeletal or abdominal, but nothing on rads, again lipase was very high and so ran SpecPL which was high. Responded well to tramadol + lypex.

Experience suggests it is not as specific as they would like us to believe, some other focus of inflammation may play a part, but many of these do seem to respond to pain relief... Not the best medicine i'm sure!

Re: Amylase, Lipase and Spec cPL

sophia guymer — Sun, 13 Dec 2009 21:03:32 GMT

[quote user="Trident"]I have seen a dog with normal cPLI that had pancreatitis and a dog with high cPLI that didn't. I think that false positives are more common than false negatives though. [/quote]

Hmmm, am I alone in thinking, it sounds like cPLI is not as much help than as I thought it was??

I had a dog come in as a behavioural case few weeks ago. Used to be friendly, no prob, recently gotten unpredictable, aggressive etc. Clinical examination showed cran abdominal pain. Did have occ vomiting and chronic diarr. cPLI pos.(cobalamine was also low, treated with injections) That to me was enough to diagnose him with (chronic) pancreatits. Put on painrelief, chappie (owners financially challenged) etc and the dog was much better, behaviour also improved significantly (in conjunct with some behavioural therapy). Still, should I have not diagnosed it so soon?? Could it have been something completely diff?

I also had a dog with increased TLI(tested as at the time I suspected poss EPI), normal amylase lipase and normal cPLI so I ruled out pancreatits, wrongly??

Hmm, food for thought (for me)

Re: Amylase, Lipase and Spec cPL

Laurence Webb — Sat, 12 Dec 2009 10:04:02 GMT

As Trident said, extrapancreatitis enzyme production of amylase and lipase limits their use markedly although I tend to feel that reduced renal excretion due to renal pathology or dehydration is a more significant cause of elevated lipase. Not hugely helpful if you're presented with a vomiting dehydrated dog. I think their main advantage is the ability to perform amylase/lipase cheaply in-house, although IDEXX have developed a SNAP cPLI test.

Acute pancreatitis on top of chronic pancreatitis can result in normal cPLI - if there's insufficient pancreatic tissue left it doesn't matter how inflamed it gets as it won't leak enough enzymes into the blood to give you a rise. I had this demonstrated recently (in a cat, but I'd expect the principle is the same) when fPL was normal. Ex-lap showed a firm shrunken pancreas whch histologically consisted of lots of scar tissue with a small amount of inflamed functional tissue. You can't rule out pancreatitis on the basis of normal PLI although a normal result makes it less likley. I suppose a TLI would be nice to run in these cases.

Re: Amylase, Lipase and Spec cPL

Trident — Fri, 11 Dec 2009 23:50:20 GMT

For acute pancreatitis, amylase has a sensitivity of approx. 60% and specificity of about 55% whereas the sensitivity of lipase is 75% and its specificity is 55%. The salivary glands, muscles, liver and gut all produce amylase in addition to the pancreas and so can affect the values. Lipase also originates from other sources like the stomach muscosa. Amylase and lipase therefore can be altered sue to lots of diseases like gastritis, liver disease, DKA, kidney failure/clearance, tumours, drugs e.g. dexamethasone. As a result, the values can be elevated for many reasons not just pancreatitis.

cPL is only produced by the pancreas and its sensitivity for acute pancreatitis is assumed to be around 80% but I remember seeing one study showing that its sensitivity was lower than both serum amylase and lipase. This lower value may have been because of the cases being both chronic and acute pancreatitis.

I agree with you about clinical signs - these tests are only an adjunct to our diagnosis. I have seen a dog with normal cPLI that had pancreatitis and a dog with high cPLI that didn't. I think that false positives are more common than false negatives though. If the clinical signs and history are suggestive, together with a suspicious looking ultrasound image, then cPLI may help to confirm but I certainly wouldn't make the diagnosis on cPLI alone.