chemistry externship - immunology 3.7-3.8 Flashcards
a patient had surgery for colorectal cancer, after which he received chemotherapy for 6 months. The test for carcinoembryonic antigen (CEA) was normal this time. One year later, the bimonthly level of CEA was elevated (above 10 ng/mL). An examination and biopsy revealed recurrence of a small tumor. What was the value of the results provided by the CEA test in this clinical situation
A. diagnostic information
B. information for further treatment
C. information on the immunologic response of the patient
D. no useful clinical information in this case
B. information for further treatment
- CEA sensitivity is ,ow but elevated after treatment can be used as evidence of tumor recurrence
a carbohydrate antigen 125 assay (CA-125) was performed on a woman with ovarian cancer. After treatment the levels fell significantly. An examination performed later revealed recurrence of the tumor, but the CA-125 levels remained low. How is this explained
A. test error
B. CA-125 was the wrong lab test; AFP is a better test to monitor overian cancer
C. CA-125 may not be sensitive enough when used alone to monitor tumor development
D. CA-125 is not specific enough to detect only one type of tumor
C. CA-125 may not be sensitive enough when used alone
- associated mostly with ovarian cancer but minorly in pancreatic cancer
what is the correct procedure upon recipt of a test request of hCG on the serum of a 60 yro man
A. return the request; hCG us not performed on men
B. perform qualitative hCG to see if hCG is present
C. perform the test; hCG may be increased in testicular tumors
D. perform the test; but use different standards and controls
C. perform the test; hCG may be increased in testicular tumors
would an hCG test using a monoclonal antibody against the beta-subunit of hCG likely be affected by an increased level of FSH
A. yes, the beta-subunit of FSH is identical to that of hCG
B. no, the test would be spp for the beta-subunit of hCG
C. yes, a cross reaction would occur because of structural similarities
D. no, the structure of FSH and hCG are not at all similar
B. no, the test would be spp for the beta-subunit of hCG
- LH, FSH and hCG have common alpha unit but different beta unit
which of the following substances, sometimes used as a tumor marker, is increased in two or threefold in a normal pregnancy
A. ALP
B. calcitonin
C. ACTH
D. neuron specific enolase
A. ALP
- isoenzymes of ALP can be used as tumor markers
what is an advantage of performing a prostate specific antigen (PSA) test for prostate cancer
A. PSA is stable in serum and not affected by digital rectal examination
B. PSA is increased only in prostatic malignancy
C. a normal serum level rules out malignant prostatic disease
D. the percentage of free PSA is elevated in persons with malignant disease
A. PSA is stable in serum and not affected by digital rectal examination
- PSA is specific for prostate gland but is unaffected by rectal exam
which method is the most sensitive for quantitation of AFP
A. double immunodiffusion
B. electrophoresis
C. enzyme immunoassay
D. particle agglutination
C. enzyme immunoassay
- produced in hepatoma and in other tunmors
- EIA is sensitive or chemiluminescent to detect reduced AFP in maternal serum and spinal bifida
how is HLA typing used in the investigation of genetic disease
A. for prediction of severity of disease
B. genetic linkage studies
C. direct diagnosis of disease
D. not useful
B. genetic linkage
- HLA typing can predict some genetic diseases
- example: ankylosing spondylitis = HLA-B27
select the best donor for a man, blood type AB in need of a kidney transplant
A. his brother, AB, HLA matches for class II antigens
B, his mother, type B, HLA matched for class I
C. his cousin, type O, HLA matched for major class II antigens
D. deceased donor, type O, HLA matched for some class I and II antigens
A. his brother
- siblings of same blood type matched for class II are best donors since class II determine ability of transplant recipe to recognize the graft
- same II are more likely to inherit same type I genes
interpret the following microctyotoxicity targect cell results
- A9 and B12 cells: damaged
- A1 and Aw19 cells: intact
A. pos for A1 and Aw19; neg for A9 and b12
B. neg for A1 and Aw19; pos for A9 and B12
C. error in test system
D. impossible to determin
B. neg for A1 and Aw19; pos for A9 and B12
- based on reaction of spp antisera and HLA antigens on test cells
- cells damaged by binding of antibody and comp that is detected with supravital dye
which method, classically used for HLA-D typing, is often used to determine the compatibility between a living organ donor and a recipe
A. flow
B. mixed lymphocyte culture (MLC)
C. primed lymphocyte test
D. RLFP
B. MLC
- flow = type serologically defined HLA antigens
SITUATION: cells type neg for all HLA antigens in a complement dependent cytotoxicity assay. what is the most likely cause
A. oo much supravital dye was added
B. rabbit complement is inactive
C. all leukocytes are dead
D. antisera is too concentrated
B. rabbit complement is inactivated
- may not become fixed to Abs that have bound test leumocytes = no lysis
what method may be used for tissue typing instead of serological HLA typing
A. PCR
B. southern blotting
C. RLFP
D. all of these
D. all
- usually PCR is the routine determination of HLA type
