Proteins and Tumor Markers Flashcards
Total protein reference range:
Albumin reference range:
TP = 6.5-8.3 g/dL Albumin = 3.5-5.0 g/dL
Prealbumin (transthyretin)
Indicates nutritional status, transports thyroid hormones
Decreased: liver disorder, inflammation, malignancy, poor nutrition
Increased: steroids, renal failure, alcoholism
Albumin
Highest conc. of all plasma proteins
Transports many things, significantly contributes to osmotic pressure
Decreased: liver disorders, GI malabsorption, muscle-wasting diseases, burns, renal disease, starvation/nutrition
Increased: dehydration
alpha1-Antitrypsin
Neutralizes trypsin-type enzymes
Decreased: emphysema related pulmonary disease, juvenile hepatic disorders
Increased: inflammatory disorders
alpha1-Fetoprotein
Synthesized in gestation, peak at 13 weeks and decline at 34 weeks
Increased: neural tube defects, spina bifida, fetal distress
Decreased: Down syndrome, trisomy 18
In adults, increased: hepatocellular carcinoma and gonadal tumors
alpha1-Acid glycoprotein (orosomucoid)
Binds to basic drugs
Increased: inflammatory, RA, pneumonia, conditions with cell proliferation
Decreased: nephrotic syndrome
Haptoglobin
Binds free hemoglobin
Increased: inflammatory, burns, trauma
Decreased: intravascular hemolysis (liver removes haptoglobin-hemoglobin complex)
Ceruloplasmin
Binds copper
Increased: pregnancy, inflammatory, malignancy, oral estrogen/contraceptives
Decreased: Wilson disease, malnutrition, liver disease
alpha2-Macroglobulin
Inhibits thrombin, trypsin, and pepsin
Increased: nephrotic syndrome, contraceptives, pregnancy, estrogen therapy
Decreased: acute inflammatory disorders, prostatic cancer, acute pancreatitis
Transferrin
Transports iron
Decreased: infections, liver disease, nephrotic syndrome
Increased: iron-deficiency anemia, pregnancy
C-reactive protein
Increased: tissue necrosis, rheumatic fever, infections, MI, RA, gout
< 1 mg/L = low risk
1-3 mg/L = average risk
> 3 mg/L = high risk
IgG
Can cross placenta
Increased: liver disorders, infection, collagen disease
Decreased: increased susceptibility to infection
IgA
Increases after birth
Increased: liver disorders, infections, autoimmune diseases
Decreased: inhibited protein synthesis, hereditary immune disorders
IgM
Made by fetus
Increased: bacterial/viral/fungal infections, Waldenstrom macroglobulinemia
Decreased: protein loss in renal disorders, immunodeficiency disorders
IgD
Increased in liver disorders, infection, and connective tissue disorders
IgE
Increased in allergies, asthma, hay fever, parasitic infections
Fetal fibronectin
Predict risk of premature birth (leakage from placenta into cervicovaginal secretions
Biuret method
Cupric ions bind to peptide bonds, produce purple complex, amount of purple directly proportional to amount of protein
Kjeldahl method
Quantify nitrogen content of protein
Albumin dye binding
Use bromcresol green and bromcresol purple
Calculation for globulins
Total protein - albumin = globulins
Urine protein
Test with sulfosalicylic acid, trichloroacetic acid, benzethonium chloride, and Coomassie brilliant blue
Ref. range = 1-14 mg/dL, < 100 mg/day
Increased: multiple myeloma, nephrotic syndrome, tubular/glomerular dysfunction
CSF protein
Test with sulfosalicylic acid, trichloroacetic acid, benzethonium chloride, and Coomassie brilliant blue
Ref. range = 15-45 mg/dL
Increased: meningitis, traumatic tap, MS, herniated disk, cerebral infarction
Decreased: hyperthyroidism, CNS leakage of CSF
Prostate-specific antigen (PSA)
Produced in prostate, function in liquefaction of seminal coagulum
Tissue specific but not tumor specific
PSA > 2.5 ng/mL = perform biopsy
Men with prostate cancer tend to have low free % PSA compared to benign disease
