L3: Liver Tests and Hepatic Serology

Question 1

What are the tests involved in the liver panel?

Answer 1

ALT
AST
Total bilirubin
Albumin
Alk phosph
GGT
Total protein
PT/INR
Lactate dehydrogenase

Question 2

What are the 3 types of liver disease categories?

Answer 2

1. Hepatocellular (injury to hepatocytes)
2. Cholestatic (injury of bile ducts or bile flow obstruction)
3. Infiltrative (liver invaded by non-hepatic substances)

Question 3

Which 3 of the liver tests assess liver function?

Answer 3

PT/INR
Total bilirubin
Albumin

Question 4

What 2 tests will be elevated if there is damage to the hepatocytes?

Answer 4

ALT

AST

Question 5

What 3 tests will be affected with a cholestatic process?

Answer 5

Total bili
Alk phosph
GGT

Question 6

What does elevated alk phosph suggest?

Answer 6

Cholestasis

• ALP isoenzymes (bone vs. liver disease)
• 5NP (enzyme elevated if problem in biliary tree, distinguishes liver as the origin)
• GGT when simultaneously elevated can confirm liver origin

Question 7

What is the “equation” for total bilirubin?

Answer 7

Total = sum of direct + indirect

If direct elevated = inside liver
If indirect elevated= outside liver

Question 8

What is the equation of fractionated bilirubin

Answer 8

Fraction of total bilirubin that is direct vs indirect

*useful when standard liver tests are normal and total bilirubin is elevated

Question 9

Elevated direct bilirubin, elevated or normal indirect bilirubin, + an elevated AST/ALT is indicative of

Answer 9

liver disease

Question 10

Describe direct, indirect, and other labs affected by liver disease

Answer 10

Elevated direct bilirubin, elevated or normal indirect bilirubin, + an elevated AST/ALT

Question 11

Elevated (90% of total bili) indirect bili + anemia and normal AST/ALT is indicative of

Answer 11

hemolysis

Question 12

Describe the direct, indirect, and other labs affected with hemolysis

Answer 12

Direct: normal
Indirect: elevated
Other: Anemia, increased retic count, abnormal peripheral smear, normal AST and ALT

Question 13

Elevated (>90% of total bili), normal AST and ALT, with no anemia is indicative of

Answer 13

Gilbert’s syndrome

Question 14

What is Gilbert’s syndrome?

Answer 14

Inherited decrease in ability to conjugate bili

Question 15

true/false: elevated liver tests mean liver is normal

Answer 15

False

Pts with normal ALT and AST can have significant liver disease chronically

Question 16

The first step in eval of a patient with elevated liver tests but no sxs is:

Answer 16

repeat the test (fasting)

Question 17

Is AST or ALT more specific to the liver?

Answer 17

ALT

highest level found in kidney, AST found other places, ALT gender specific

Question 18

GGT is present in:

Answer 18

hepatocytes and epithelial cells

Question 19

GGT is useful when:

Answer 19

1) ALP IS ELEVATED = confers liver specificity
2) When AST/ALT >2 it further supports alcoholic liver disease

Know these!

Question 20

What is a nonhepatic source of an elevated bilirubin?

Answer 20

RBC (hemolysis, etc.)

Question 21

What is a nonhepatic source of an elevated AST?

Answer 21

SM, cardiac muscle, kidney, and brain

Question 22

What is a nonhepatic source of an elevated ALT?

Answer 22

SM, cardiac muscle, kidneys

Question 23

What is a nonhepatic source of an elevated LDH?

Answer 23

Enzyme present in tissues all throughout the body

Question 24

What is a nonhepatic source of an elevated ALP?

Answer 24

Bone, 1st trimester placenta, intestines

Question 25

List 4 herbals/vitamins that can cause DILI.

Answer 25

Ephedra Kava Vit A Garcinia cambogia

Question 26

List some meds that can cause DILI

Answer 26

``` Acetaminophen Statins Antifungals/azoles Abx Anti-tb drugs NSAIDs ```

Question 27

What is the best way to see if a med is responsible for DILI

Answer 27

Stop tx and see if lab values return to normal

Question 28

What are some non-liver causes of elevated liver tests (5)

Answer 28

- Muscle (cardiac, skeletal) - Cholethiasis - Masses (tumors) - Hemodynamic disorders (CHF) - Celiac, hypothyroidism, adrenal insufficiency

Question 29

List a primary cause of mildly elevated AST and ALT

Answer 29

Fatty liver (chronic rather than acute condition)

Question 30

What condition can cause an elevated AST > ALT

Answer 30

Alcoholic hepatitis

Question 31

A pt with an AST:ALT ratio of >/= 2 is suggestive of

Answer 31

alcoholic liver disease (present in both mild and severe cases)

Question 32

A pt with an AST:ALT ratio of <2 is suggestive of

Answer 32

Acute or chronic viral hepatitis (AST:ALT <1)

Question 33

If AST, ALT higher than ALP, think

Answer 33

hepatocellular

Question 34

If ALP higher than AST, ALT, think

Answer 34

cholestasis

Question 35

If elevated ALP with AST, ALT nearly normal think

Answer 35

cholestasis or infiltrative (differentiate with imaging)

Question 36

There is ______ cause for fat accumulation in the liver.

Answer 36

NO secondary

Question 37

What is non-alcoholic fatty liver disease?

Answer 37

Fatty liver WITHOUT INFLAMMATION | Low risk of developing significant fibrosis

Question 38

What is non-alcoholic steatohepatitis (NASH)?

Answer 38

Fatty liver + inflammation of hepatocyte injury +/- fibrosis | -HIGH RISK DEVELOPING SIGNIFICANT FIBROSIS, cirrhosis, liver failure, and liver cancer

Question 39

What are risk factors for NAFLD?

Answer 39

``` Abdominal obesity DM Hyperlipidemia Metabolic syndrome ***strongest precursor for NASH! Polycystic ovarian syndrome ```

Question 40

Are patients with NASH usually symptomatic?

Answer 40

No, majority asymptomatic (will have RUQ pain if sx)

Question 41

What will be elevated with NASH?

Answer 41

Mildly elevated AST (2-4 x ULN)

Question 42

What will imaging show in a patient with NASH?

Answer 42

Fatty infiltration on imaging or biospy

Question 43

What will a liver biopsy show in a patient with NASH

Answer 43

- steatosis (fat accumulation) - inflammation +/- fibrosis - Liver bx w/ metabolic syndrome helps with dx and prognosis

Question 44

What are 4 lifestyle recommendations for NASH tx?

Answer 44

Caloric intake reduction Weight loss Exercise No heavy alcohol consumption

Question 45

When would you consider liver transplant in a pt with NASH?

Answer 45

If it progresses to cirrhossi

Question 46

What is hereditary hemochromatosis?

Answer 46

Hereditary disorder of iron metabolism (increased intestinal absorption of Fe = too much iron)

Question 47

Hereditary hemochromatosis can lead to what 2 disorders?

Answer 47

Fibrosis/cirrhosis | Hepatocellular carcinoma

Question 48

What are the typical signs and sxs of hereditary hemochromatosis?

Answer 48

- Usually asymptomatic - If symptomatic: fatigue/malaise, arthralgia, loss of libido - Late manifestations: hepatomegaly, cirrhosis, DM, impotence, bronze skin, cardiomegaly +/- CHF

Question 49

What are the lab findings of hereditary hemochromatosis?

Answer 49

- Elevated AST and ALT | - slide 37....