Tumor markers and Major Proteins

Question 1

most plasma proteins are synthesized in the

Answer 1

liver

Question 2

What plasma proteins are NOT synthesized in the liver?

Answer 2

immunoglobulins, made in plasma cells

Question 3

ref ranges of total protein and albumin

Answer 3

T: 6.5 to 8 g/dL; A: 3.5 to 5

Question 4

what are some ions transported by albumin?

Answer 4

calcium and magnesium

Question 5

what transports unconjugated bilirubin?

Answer 5

albumin

Question 6

name the 3 major a1 proteins; which are acute phase reactants? Which is increased in liver cell and gonadal tumors as well as maternal serum?

Answer 6

a1: a1-antitrypsin, a1-fetoprotein, a1-acid glycoprotein
- > a1 antitrypsin and acid glycoprotein are acute phase reaactants;
- > fetoprotein is elevated in maternal serum when neural tube defects/spina bifida/ fetal distress AS WELL as possibly in adult liver or gonadal tumors, and decreased in Down syndrome or trisomy 18

Question 7

the 3 major a2 proteins:

Answer 7

haptoglobin, ceruloplasmin, a2-macroglobulin

Question 8

what type of major protein classification is haptoglobin and what are its two main functions?

Answer 8

alpha-2; is an acute phase reactant that binds free hemoglobin

Question 9

when would haptoglobin be elevated and when decreased?

Answer 9

elevated: inflammatory conditions, burns and trauma
decreased: during intravascular hemolysis, bc complexes with the released Hgb and goes to liver

Question 10

what is ceruloplasmin?

Answer 10

an acute phase reactant a2 protein that binds `90% of serum copper; it has enzymatic properties

Question 11

when is ceruloplasmin increased and decreased?

Answer 11

Increased in pregnancy and with oral contraceptive use, inflammation, malignancy
decreased in Wilson’s disease, malnutrition, malabsorption, severe liver disease

Question 12

This proteolytic a2 globulin inhibits thrombin, trypsin, and pepsin; WHen is increased and decreased?

Answer 12

a2 macroglobulin; increases in nephrotic syndrome and with pregnancy and estrogen therapy
decreases markedly in acute pancreatitis

Question 13

Name 2 major B-globulin major proteins

Answer 13

Transferrin and CRP

Question 14

what is transferrin and when increases or decreases?

Answer 14

a B-globulin that transports iron
decreases in infections, liver disease, nephrotic syndrome
increases in iron deficiency anemia and pregnancy

Question 15

when is the B-globulin acute phase reactant protein CRP elevated?

Answer 15

tissue necrosis, rheumatic fever, infection, MI, RA, gout

Question 16

what is the value of measuring fibronectin in cervicovaginal secretions?

Answer 16

can help predict risk of premature birth because may leak from placenta during stress, infection or hemorrhage

Question 17

What is the biuret method? give it’s purpose, components of reagent, and color of product

Answer 17

to determine presence of peptide bonds and thus protein concentration; reagent contains alkaline agent (NaOH), copper sulfate (for cupric ions), and potassium sodium tartrate

Question 18

Do serum proteins have a net negative or positive charge? to what end do they migrate on electrophoresis, and what charge is that end?

Answer 18

neg; they migrate to the anode which is positively charged in this case

Question 19

how are globulin concentrations determined? (all globulins not individual)

Answer 19

subtracting albumin from total protein

Question 20

reference range for urine total protein, and limit should be present for one 24 hour period

Answer 20

1 to 14 mg/dL; Less than 100 mg

Question 21

what kind of proteins may be found in the urine of multiple myeloma patients? What are they?

Answer 21

Bence-Jones; they are light chains either kappa or lambda, produced in excess in the disease, and thus exceed the renal threshold and are excreted in urine

Question 22

what forms of PSA are detectable on immunoassay? Is PSA specific for prostate cancer? AT what level should biopsy be performed?

Answer 22

the free PSA and the form that is complexed to a1-antichymotrypsin (a protease inhibitor), but enveloped PSA is not detectable; PSA can be elevated in hypertrophy that is noncancerous as wel as in cancer; >2.5 ng/mL

Question 23

Is lower or higher % free PSA associated with increased cancer risk?

Answer 23

men with prostate cancer tend to have LOWER % FREE PSA (out of total)

Question 24

most tumor markers are not actually useful for diagnosis. What ARE they useful for?

Answer 24

monitoring treatment and surveillance for relapse, as well as staging and prognosis

Question 25

hCG is a glycoprotein of how many subunits and which is unique to this molecule alone? where is it found and how is it useful?

Answer 25

2 subunits, alpha and beta; Only the beta subunit is unique to hCG, the alpha is common to other hormones. It is normally secreted by the placenta, but is found increased in testicular and ovarian tumors, choriocarcinoma (uterine)

Question 26

what is CA 15-3?

Answer 26

a mucin glycoprotein antigen useful for monitoring the response and recurrence of previously treated breast cancer
ALSO elevated in chronic hepatitis, TB, and SLE

Question 27

what is CA 125

Answer 27

a marker for ovarian and endometrial cancer, used for monitoring progress

Question 28

This marker is a sialylated derivative of the Lewis blood group system; Name it and also what it is a marker for (give 3 or 4)

Answer 28

CA 19-9; pancreatic/ colorectal, lung and gastric carcinomas