Flashcards in Clinical Lab in GI Disease Deck (44)
What are the diagnostic criteria for acute pancreatitis?
Need two of three:
Abdominal pain characteristic of disease
amylase and/or lipase at least 3x the ULN
characteristic imaging findings
Which is better for pancreatitis and why: amylase or lipase?
lipase because it is more sensitive and more specific
also remains elevated longer than amylase
IN FACT: CURRENT REC IS FOR LIPASE ALONE
What are some other causes for elevated pancreatic enzymes?
peptic ulcer disease
diabetes (esp lipase)
parotid/salivary gland (amylase only)
What are the two most common causes of acute pancreatitis?
gallstones and alcohol
What are some other less common causes of acute pancreatitis?
Genetic - like CF mutations
Drugs (azathioprine, sulfonamides, NSAIDs, steroids, tetracycline)
Viral infections (mumps, rubella, EBV, CMV, hepatitis)
What are the first tier LFT labs?
What is the general pattern of liver labs in hepatocellular injury/necrosis?
ALT and AST significantly elevated, moreso than alk phos
What is the general pattern of liver labs in cholestatic disease?
alk phos elevated higher than ALT/AST
What is the general pattern of liver labs in infiltrative liver disease?
elevated AP with either normal or just slightly elevated AST/ALT
Which transaminase is more specific for liver disease?
AST is also found in muscle and red cells, so with extensive muscle breakdown, both ALT and AST will rise
Which transaminase has a longer half-life?
(So Liver and Longer)
Where on the cell is alk phos located?
on the hepatocyte membrane bordering the bile canaliculi, which is why it elevated in obstructive disease
Where in the body are other alk phos isoemzymes located?
bone and placenta
also elevated in other GI and kidney diseases
What can you use to confirm a liver course of an elevated alk phos?
GGT - there are few reasons to order a GGT other than this!
What are the main causes of acute rises in transaminases?
Ishcemic "shock liver"
acute ductal obstruction
ALT is often in the thousands with acute hepatitis. If it's over 5,000 U/L, though, what should you consider?
unusual viruses like HSV
What are the four main causes of chronic hepatitis?
Alcoholic liver disease
What is the time cutoff for hepatitis to be called chronic?
over 3 months
What are some common causes of cholestasis?
Primary biliary cholangitis
primary sclerosing cholangitis
Which suggests liver disease: elevated unconjugated bilir (indirect) or elevated conjugated bili (direct)?
elevations in unconjugated (indirect) suggest hemolysis
Jaundice will become visible at what bili level?
Can bilirubin help you determine whether liver disease is hepatocellular, cholestatic or infiltrative?
What are some causes for unconjugated hyperbilirubinemia besides hemolysis?
resorption of large hematoma
ineffective erythropoiesis (like B12 def)
neonatal physiologic hyperbilirubinemia
What is the typical pattern of LFTs in alcoholic hepatitis?
AST > 2 x ALT
but AST less than 400 UL
What are the two main autoantibodies seen in autoimmune hepatitis?
type 1 with anti-smooth muscle and antinuclear
type 2 with liver-kidney microsome type 1
Who gets PBC and how do they present?
middle aged women
presenting with fatigue and pruritus
What will labs look like in PBC?
increased alk phos
Fal soluble bitamin deficiencyes
later increased Bili
If you did a biopsy of a liver with PBC, what would you see?
granulomatous infiltration of the septal bile ducts
What is the main antibody seen in PBC?