exam 2 Flashcards
what is the best temperature range for cold agglutinatinins to react?
0-5C
give 3 examples of infections that may cause cold agglutinins to develop
mycoplasma pneumoniae
infectious mononucleosis
primary atypical pneumonia
explain desensitization
a hypersensitive animal that is given very small subcutaneous injection of Ag at closely spaced intervals may be able to tolerate an ordinarily shocking dose without severe rxc.
can be used clinically for pt. with intense allergic rxc to penicillin or horse antiserum
briefly explain Graves’ disease
hyperthyroidism
increased T3 and T4
decreased/absent TSH
goiter, wt. loss, tachycardia
explain what the reactions mean in hemagglutination inhibition test
negative for agglutination = there was agglutination
+ = no agglutination
within which organ is it thought that potentially self-reactive lymphocytes are removed?
thymus
the Nichols strain of T. pallidum is used in what type of testing?
FTA-ABS
when do serum tests for syphilis usually become reactive?
week 1-3 following appearance of primary lesions
in secondary syphilis what would the serological tests look like, result wise.
positive
how long after treatment does the serological test become nonreactive in secondary syphilis?
12-18 months
the secondary stage of syphilis occurs how many weeks after the appearance of the primary chancre?
6-8 weeks
name three pharmacologically active mediators of anaphylaxis
ECFA triptase chimase neutrophils chemotaxis
which of the following is true about the late latent stage of syphilis: it is highly contagious, usually noncontagious, not detectable by serological tests, or not communicable between mother and fetus?
usually noncontagious
P24 is a viral antigen that is the first to be detected in which potentially deadly virus?
HIV
name three means of transmission of the HIV virus
intimate sexual contact
contact with blood or bodily fluids
perinatally from infected mother to infant (transplacental)
needles that dispense antigen for the VDRL test must be calibrated to deliver how much?
1/60 mL
the VDRL needles- how often should they be QC’d
every new batch
T. pallidum crosses the placenta in which week of gestation?
18
what does the FTA-ABS test identify in the patient’s serum?
specific trepnonemal
FTA-ABS; what does the fluorescein labeled antihuman globulin do for the purposes of interpreting this test?
makes Ag-Ab rxc visible
in the direct fluorescent antibody test, the ____ is “labeled” with fluorescent dye
Ab
the serum is inactivated to destroy complement in the VDRL or the RPR?
VDRL
give 5 examples of an autoimmune disease and describe wether it is organ-specific and, if so, which organs are affected etc
hoshimotos thyroiditis- OS- thyroid gland
Graves disease- OS-thyroid gland
Rheumatoid Arthritis- OS- synovial lining of joints
Systemic Lupus Erythematosis-SYS- body tissues
Good Pasteurs Syndrome- OS- glomerulus
a flat-bottomed bottle is required in the VDRL or the RPR?
VDRL
explain a flocculation test and give examples of this type of testing
a very specific type of precipitation that occurs over a narrow range of Ag concentration
ex. RPR
the VDRL or the RPR is always read macroscopically?
RPR
a modified VDRL antigen is used in what type of testing?
RPR
name some synonyms for Type B viral hepatitis
Hepatitis B
HBV
serum hepatitis
what is chancre?
lesions that occur in the peripheral region that occur in syphilis
what speed should the rotator be set at for the RPR test
100 rpm
what speed should the rotator be set for the VDRL
180 rpm
why do you get false negative results with a postzone reaction?
because of the excess Ag present that may be obscuring a small amount of Ab
the antibody to tissue lipids is called?
reagin
why would you get a false negative results with a prozone reaction?
excess Ab over Ag
explain the zone of equivalence
in the precipitation curve this is where the optimal proportions of Ab and Ag are reached
stable lattice structures are formed and precipitate out, allowing visual
what is tannic acid used for in serologic testing?
allows proteins to complex with RBC as antigen carriers
what is serum sickness?
a benign and self limiting disease that results from passive sensitization with animal serum used to treat infections such as tetanus, diphtheria, and gangrene
how does the Western Blot test differ from ELISA test?
ELISA- screening test that ID’s Ab
WB- Ag for confirmatory testing
what is an agglutinin?
the Ab involved in a agglutination reaction particulate Ag (such as cells) agglutinate with Ab
why is cholesterol added to the antigen that is used in the flocculation test for syphilis?
because it provides absorption centers for the tissue lipids so agglutinated particles can be visualized
T or F
treating a pregnant woman with syphilis does not cure the fetus
false
T/F
congenital, primary, and secondary syphilis are best treated by repeated doses of penicillin
false
T/F
treatment does not alter any tissue damage that has already occurred
true
T/F
it is necessary to get repeated blood tests for 5 years following treatment
false
T/F
tertiary syphilis cannot be treated
false
loss of self tolerance results in what type of disease?
autoimmune
explain cross reactivity and what kind of results it can lead to
Ag that are closely related in structure and get a false +
the presence of anti-double stranded DNA can distinguish RA from what other autoimmune disease
lupus
recent experience or exposure to group A hemolytic streptococci can be detected when there are high or steadily increasing concentrations of what in a patients serum?
antistreptolysin O
define anaphylaxis
“without protection” most severe type of allergic reaction, involves multiple organs and may be fatal
what is a xenograft? and what is it also known as?
heterograft
a transplant from one species to another species
transplanting from one individual to a genetically nonidentical person of the same species is called what?
homograft or allograft
define contact dermatitis
a delayed hypersensitivity reaction caused by T-cell sensitization to low molecular weight compounds that come in contact with the skin
give three examples of contact dermatitis
nickel
rubber
poison plants (ivy, oak)
which type of test is most widely used to detect HIV
ELISA
of Hep C, Hep G, Hep B, which is the most virulent?
Hep C
Why is Hep C more dangerous than Hep B?
85% of cases convert to chronic Hep.
2 out of 3 patients become carriers who can transmit
what is the first antigen to appear int he serum of a person infected with HBV?
hepatitis B surface antigen
How is hepatitis A transmitted?
fecal-oral route
Type IV hypersensitivity is the only type that involves what?
T-cells
T/F
testing for the p24 antigen would be useful as a screening test for blood products?
false
on average how long does it take (weeks) for an individual to develop HIV antibodies after exposure to HIV
6-12 weeks
what antibody appears in the serum of individuals that have recovered from Hepatitis B or who have received the Hepatitis B vaccination?
Hepatitis B surface Ab AKA
HBSAb
anti-HBSAg
which form of hepatitis is responsible for the most post-tranfusion reactions?
Hep C
if a patient has an immune response to their own IgG, they would most likely to have a positive or negative RA test?
positive
which set of antigens would be represented on a positive Western Blot?
Gp 41
Gp 120
The antigen in a precipitin reaction must be ?
soluble
what does ANA stand for?
antinuclear antibody
how is ANA useful in testing?
found in greater than 95% of lupus patients
what does HLA stand for and why is it important?
human leukocyte antigen
most important immunologic barrier for transplanted tissues
which hepatitis virus requires HBV infection?
Hep D
when discussing EBV and infectious mono, name the primary mode of transmission.
intimate contact with salivary glands
what % of lymphs would you expect to see as a typical on a peripheral blood smear in EBV and infectious mono
10%
which malignancy has been associated with EBV?
burkitt’s lymphoma
hodgkins disease
which virus have most people been exposed to by their elderly years?
cytomegalovirus (CMV)
how do antiretroviral drug therapies work?
by blocking various steps in viral replication
name some examples of antiretroviral drugs
fusion inhibitors
integrase inhibitors
core receptor antagonists
which cells are the main target of HIV virus? why?
T-helper cells
b/c of CD4 Ag serves as a receptor for the virus by binding the Gp 120 glycoprotein on the outer envelope
what is one method for determining the progression to the AIDS stage of HIV infection. how is this done?
CD4 count of < 200/ microliter
flow cytometrey
shingles is essentially a re-emergence of what virus?
varicella-zoster
regarding HIV transmission, which specimens are not considered infectious unless visibly bloody?
saliva sputum nasal secretions tears sweat urine vomit and feces
in the HIV virus what is reverse transcriptase responsible for doing?
responsible for conversion of viral RNA to complementary DNA
Name the gene that codes for the enzymes necessary for HIV replication
pol gene
briefly describe the latency period of HIV infection
decrease in viremia
subtle/absent symptoms
gradual deterioration of immune system
what is the approximate length of time for the latency period in HIV infections?
10 years
symptoms of primary infections of HIV are similar to symptoms from what other virus?
IM
what are advantages of chemiluminescent assay
excellent sensitivity
reagents are stable, relatively nontoxic
inexpensive
faster turn around time
what are the disadvantages of chemiluminescent assay
false results possible from lack of precision in injection of the hydrogen peroxide
urine and plasma may cause quenching of the light emission
briefly describe the methodology of turbidimetry
measure of cloudiness of solution
measures reduction of light intensity due to reflection, absorption and scatter
briefly describe nephlometry
measures the light that is scattered at a particular angle from the indecent beam as it passes through a suspension
the antibody that is rheumatoid factor belongs to which Ig class?
IgM
what is the test anti-CCP?
anti- cyclic citrillunated peptide
what is the anti-CCP used for?
lead marker for RA
precipitation
combining soluble Ag with soluble Ab to produce insoluble complexes that are visible
