Flashcards in Tumor markers and Major Proteins Deck (28)
most plasma proteins are synthesized in the
What plasma proteins are NOT synthesized in the liver?
immunoglobulins, made in plasma cells
ref ranges of total protein and albumin
T: 6.5 to 8 g/dL; A: 3.5 to 5
what are some ions transported by albumin?
calcium and magnesium
what transports unconjugated bilirubin?
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?
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
the 3 major a2 proteins:
haptoglobin, ceruloplasmin, a2-macroglobulin
what type of major protein classification is haptoglobin and what are its two main functions?
alpha-2; is an acute phase reactant that binds free hemoglobin
when would haptoglobin be elevated and when decreased?
elevated: inflammatory conditions, burns and trauma
decreased: during intravascular hemolysis, bc complexes with the released Hgb and goes to liver
what is ceruloplasmin?
an acute phase reactant a2 protein that binds `90% of serum copper; it has enzymatic properties
when is ceruloplasmin increased and decreased?
Increased in pregnancy and with oral contraceptive use, inflammation, malignancy
decreased in Wilson's disease, malnutrition, malabsorption, severe liver disease
This proteolytic a2 globulin inhibits thrombin, trypsin, and pepsin; WHen is increased and decreased?
a2 macroglobulin; increases in nephrotic syndrome and with pregnancy and estrogen therapy
decreases markedly in acute pancreatitis
Name 2 major B-globulin major proteins
Transferrin and CRP
what is transferrin and when increases or decreases?
a B-globulin that transports iron
decreases in infections, liver disease, nephrotic syndrome
increases in iron deficiency anemia and pregnancy
when is the B-globulin acute phase reactant protein CRP elevated?
tissue necrosis, rheumatic fever, infection, MI, RA, gout
what is the value of measuring fibronectin in cervicovaginal secretions?
can help predict risk of premature birth because may leak from placenta during stress, infection or hemorrhage
What is the biuret method? give it's purpose, components of reagent, and color of product
to determine presence of peptide bonds and thus protein concentration; reagent contains alkaline agent (NaOH), copper sulfate (for cupric ions), and potassium sodium tartrate
Do serum proteins have a net negative or positive charge? to what end do they migrate on electrophoresis, and what charge is that end?
neg; they migrate to the anode which is positively charged in this case
how are globulin concentrations determined? (all globulins not individual)
subtracting albumin from total protein
reference range for urine total protein, and limit should be present for one 24 hour period
1 to 14 mg/dL; Less than 100 mg
what kind of proteins may be found in the urine of multiple myeloma patients? What are they?
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
what forms of PSA are detectable on immunoassay? Is PSA specific for prostate cancer? AT what level should biopsy be performed?
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
Is lower or higher % free PSA associated with increased cancer risk?
men with prostate cancer tend to have LOWER % FREE PSA (out of total)
most tumor markers are not actually useful for diagnosis. What ARE they useful for?
monitoring treatment and surveillance for relapse, as well as staging and prognosis
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?
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)
what is CA 15-3?
a mucin glycoprotein antigen useful for monitoring the response and recurrence of previously treated breast cancer
ALSO elevated in chronic hepatitis, TB, and SLE
what is CA 125
a marker for ovarian and endometrial cancer, used for monitoring progress