Immuno Final Flashcards
Lupis Erythematosus is best diagnosed by
antinuclear antibodies
Sera tested for IFA-ANA is best stored at what temperature?
5°C ± 2°C
Rim patern in the IFA-ANA test is most commonly associated with what
antibodies directed at native DNA
If a technologist observes a homogenous staining of the nucleus of interphase cells during an IFA-ANA test, combined with chromosome staining of the mitotic cells, this result is?
Expected of anti-DNA antibodies
An anti-dsDNA titer 1:80 and a higher titer of antibodies to Sm are best correlated with
an anti-nuclear antibody test with a titer of 1:320 for a peripheral pattern
High titers of DNA antibody are common test realists in what patients?
systemic lupus erythematosus
If a patient has these test results: ANA- +1:320, ASO- Todd Units, Complement- Decreased, RA- +,
What does the patient have?
lupus erythematosus
Nephelometry is
the most sensitive and appropriate method for the derection of rheumatoid factor
Gamma globulin-coated particles can react with
the rheumatoid factor
Consistent and repetitive negative IFA-ANA is a sign of what
Strong evidence against untreated SLE
Hyperglobulinemia is associated with
positive rheumatoid factor
A positive test for the detection of IgM class antibodies may be false when
rheumatoid factor is present in a patient’s serum
Autoantibodies with the specificity for the Fc portion of the immunoglobulin (IgG) molecule is the definition of?
Rheumatoid factor
Thyroid disease most often results in high titers of what?
antimicrosomal antibodies
High titers of anti-smooth muscle are seen in
chronic active hepatitis
Nucleolar immunofluorescent patterns are seen in individuals that have
anti-RNA antibodies
Speckled immunofluorescent patterns are often associated with what?
Anti-extractable nuclear antigens
When given an anti-nuclear antibody indirect immunofluorescent test, a patient exhibits a positive speckled pattern. What other test is necessary to perform?
Screen for Sm and RNP antibodies
Goat anti-human immunoglobulin is an antibody that…
has an indirect immunofluoresecent method of antibody detection in patient serum.
Antigen-antibody reactions are the same as what?
Chemical reactions
Fluorescein isothiocyanate is a common label for
direct fluorescent antibody technique (DFA)
Describe the Indirect fluorescence procedure
a substrate is first exposed into a patient’s serum and then after washing an anti-human immunoglobulin labeled with fluorochrome is added
Strength of a reacting antbody is the definition for?
Avidity
A rise in titer of the patient’s serum is most important in
the interpretation of agglutination tests for febrile diseases.
To increase sensitivity of the antigen, what is added in flocculation tests for Syphilis?
cholesterol.
Avidity is defined as
the strength of a visible reaction
When precipitin lines cross and form a double spur, what type of antigen-antibody precipitation reaction is identified?
reaction of non-identity
The test that has the highest sensitivity for antigen detection is?
ELISA
When excess antigen is present in precipitation gel reactions, what is expected to happen to the gel?
it will dissolve the precipitate after formation
The condition of antigen excess is formed under what complexes?
soluble immune complexes
Precipitation is described as
the visible serological reaction between soluble antigen and its specific antibody.
The enzyme control tube in an ASO hemolytic assay exhibits no cell lysis. What is the most likely
explanation for this?
oxidation of the enzyme
In a positive anti-streptolysin “0” enzyme inhibition test, the patient’s:
anti-streptolysin “0” inhibits the reagent streptolysin “O”’s, resulting in no hemolysis
Blood is drawn from a patient for serological tests for a viral disease at the time of onset and again
4 weeks later. The results of the tests are considered diagnostic if the:
second antibody titer is at least 4x the first
Which of the following is most useful in establishing a diagnosis in the convalescence phase of
a viral infection?
serological techniques
The best method to detect infections due to rubella, Epstein-Barr and human immunodeficiency
viruses is:
antibody detection by EIA
Immunoassays are based on the principle of:
antibody recognition of homologous antigen
A DPT vaccination is an example of:
active humoral-mediated immunity
Cells known to be actively phagocytic include:
neutrophils, eosinophils, monocytes
The presence of HbsAg, anti-HBc and often HbeAg is characteristic of:
early acute phase HBV hepatitis
When testing a patient for HIV antibody, which of the following is used to confirm a positive
screening test?
Western blot
What kind of antigen-antibody reaction would be expected if soluble antigen is added to
homologous antibody?
precipitation
The Rapid Plasma Reagin test:
is useful in screening for syphilis
Flocculation tests for syphilis detect the presence of:
reagin antibody
In the cold agglutinin test, the tubes containing the serum and erythrocytes are allowed to
stand overnight in the refrigerator, and the results are read the next morning. If a disk of the
erythrocytes floats up from the bottom of the tube with only the flick of finger, this is read as a:
4+ reaction
Flocculation tests for syphilis use antigen composed of:
cardiolipin and lecithin
A VDRL serum sample is heat inactivated, then placed in a refrigerator for overnight storage. Before being tested, the serum must be:
reheated to 56°C for 10 minutes
Substancesthat are antigenic only when coupled to a protein carrier are:
haptens
.A serological test for syphilis that depends upon the detection of cardiolipin-lecithin-cholesterol antigen is:
RPR
The serological test for syphilis recommended for detecting antibody in cerebrospinal fluid is:
a nontreponemal antibody
CSF-VDRL
What assay would confirm the immune status to hepatitis B virus?
anti-HBs
The following procedure has been routinely used for detection of hepatitis B surface antigen (HBsAg) because of its high level of sensitivity:
ELISA
In an indirect ELISA method designed to detect antibody to the rubella virus in patient serum, the conjugate used should be:
anti-human IgG conjugated to an enzyme
Which of the following is the best indicator of an acute infection with the hepatitis A virus?
the presence of IgM antibodies to hepatitis A virus
Biological false-positive VDRL reactions are frequently encountered in patients with:
lupus erythematosus
Which serological marker of HBV (hepatitis B virus) infection indicates recovery immunity?
anti-HBs
For diagnosis of late latent or tertiary syphilis, the most appropriate assay is:
FTA-ABS
A 26-year-old nurse developed fatigue, a low-grade fever, polyarthritis and urticaria. Two months earlier she had cared for a patient with hepatitis. Which of the following findings are likely to be observed in this nurse?
elevated AST and ALT levels
The classic antibody response pattern following infection with hepatitis A is:
increase in IgM antibody; decrease in IgM antibody; increase in IgG antibody
The enzyme-linked immunosorbent assay (ELISA) technique for the detection of HBsAg:
uses anti-HBs linked to horseradish peroxidase
The antigen marker most closely associated with transmissibility of HBV infection is:
HBeAg
Chronic carriers ofHBV:
continue to carryHBV
The initial immune response following fetal infection with rubeEa is the production of which class(es) of antibodies?
IgM
A maternal serum rubella titer that is equal to or greater than 1:8 indicates:
probable immunity to rubella
Which of the following is a treponemal test?
FTA-ABS
The air temperature throughout the serology laboratory is 20°C. How will this affect VDRL and RPR test results?
weaken reactions so that false negatives occur
Which laboratory technique is most frequently used to diagnose and follow the course of therapy of a patient with secondary syphilis?
flocculation
The most commonly used serological indicator of recent streptococcal infection is the antibody to:
streptolysin O
Antibodies composed of IgG immunoglobulin:
can cross the placenta from mother to fetus
Measurement of serum levels of which of the following immunoglobulins can serve as a screening
test for multiple allergies?
a IgA b IgE c IgG d IgM
Cells that are precursors of plasma cells and also produce immunoglobulins are:
B lymphocytes
IgM antibodies are frequently hemolytic because of:
their efficient ability to fix complement
To which of the following classes do the antibodies that cause hemolytic disease of the newborn belong?
IgG
It is important to note that when an infant is born, levels of specific antibody of the following class are used to indicate neonatal infection:
IgG
Antibodies are produced by:
B cells
Antibody class and antibody subclass are determined by major physiochemical differences and antigenic variation found primarily in the:
constant region of heavy chain
Which of the following immunoglobulin classes is associated with a secretory component (transport piece)?
IgA
The immunoglobulin class typically found to be present in saliva, tears and other secretions is
IgA
Treatment of IgG with papain results in how many fragments from each immunoglobulin molecule?
3
The immunoglobulin class associated with immediate hypersensitivity or atopic reactions is:
IgE
Which of the following immunoglobulins is the most efficient at agglutination?
IgM
The key structural difference that distinguishes immunoglobulin subclasses is the:
the sequence of the constant regions
The IgM molecule is a:
pentamer
Which of the following immunoglobuHns is present in the highest concentration in normal human serum?
IgG
Which of the following statements about immunoglobuHns is true?
IgA class exists as serum and secretory molecules
Antibody idiotype is dictated by the:
variable regions of heavy and Hght chains
Antibody allotype is determined by the:
constant regions of heavy and light chains
Which IgG subclass is most efficient at crossing the placenta?
IgGl
The J-chain is associated with which of the following immunoglobulins?
IgA
Macrophage phagocytosis of bacteria is enhanced by which of the following:
opsonin
Which of the following is most likely to activate the alternative pathway of complement activation?
haptens
Which of the following is the larger residual split portion of C3?
C3b
Which of the following activities is associated with C3b?
opsonization
After a penicillin injection, a patient rapidly develops respiratory distress, vomiting and hives. This reaction is primarily mediated by:
IgE
Which of the following is the “recognition unit” in the classical complement pathway?
Clq
In immunofixation electrophoresis:
the antigen is electrophoresed and then monospecific antisera is reacted with it
Which of the following is the “membrane attack complex” of complement activation?
C5b, C6, C7, C8, C9
Which of the following releases histamine and other mediators from basophils?
C3a
A single, reliable screening test for detecting neonatal infection in the absence of clinical signs is:
quantitative serum IgM determination
Bence Jones proteins are:
Fab fragments of a monoclonal protein
Humoral antibodies are produced by which cells?
Blymphocytes
Initiation of the activation mechanism of the alternative complement pathway differs from that of the classical pathway in that:
antigen-antibody complexes containing IgA or IgE may initiate activation
Which of the foEowing is cleaved as a result of activation of the classical complement pathway?
C4
The component associated only with the alternative pathway of complement activation is:
properdin factor B
Potent chemotactic activity is associated with which of the following components of the complement system:
C5a
Hereditary angioedema is characterized by:
decreased activity of Cl esterase inhibitor
Which of the following has been associated with patients who have homozygous C3 deficiency?
a lifelong history of life-threatening infections
Hereditary deficiency of early complement components (Cl, C4 and C2) is associated with:
lupus erythematosus like syndrome
Hereditary deficiency of late complement components (C5, C6, C7 or C8) can be associated with which of the following conditions?
a systemic gonococcal infection if exposed
Which immunologic mechanism is usually involved in bronchial asthma?
immune complex
Antihistamines like Benadryl®:
block HI histamine receptors
A child has severe hay fever. A total IgE measurement was performed by the Ouchterlony immunodiffusion method. No lines of precipitation appeared on the immunodiffusion plate. The most likely explanation is:
IgEis in too low a concentration to be detected by this method
Which test is used to evaluate the cellular immune system in a patient?
skin test for commonly encountered antigens
T cells are incapable of:
secretion of immunoglobulins
Tlymphocytes are incapable of functioning as:
phagocyti cells
Nonspecific killing of tumor cells is carried out by:
natural killer cells
Tumor markers found in the circulation are most frequently measured by:
immunoassays
A patient with a B-cell deficiency will most likely exhibit:
increased bacterial infections
A patient with a T-cell deficiency will most likely exhibit:
increased parasitic infections
Which of the following is an important cellular mediator of immune complex tissue injury?
neutrophil
Which of the following mediators is released during T-cell activation?
cytokines
Which of the following terms describes a graft between genetically unidentical individuals belonging to the same species?
allograft
Tlymphocytes that possess the CDS surface marker mediate which of the following T-cell functions?
cytotoxic
Delayed hypersensitivity may be induced by:
contact sensitivity to inorganic chemicals
The most rapid immediate hypersensitivity reaction is associated with:
anaphylaxis
An immunofluorescence test using reagent antibody directed against the CDS surface marker would identify which of the following cell types in a sample of human peripheral blood?
all mature T lymphocytes
In flow cytometry, labeled cells:
scatter the light and emitfluorescence
A marked decrease in the CD4 lymphocytes and decrease in the CD4/CD8 ratio:
is associated with a viral induced immunodeficiency
What is the immunologic method utilized in the flow cytometer?
immunofluorescence
Given the following data: WBC: 5.0x103/L lymphs: 15% CD4: 8% Calculate the absolute CD4:
60
Given this hematologic data: WBC: 5.0x103/L!L lymphs: 15% CD4: 8% Which of the following is the correct interpretation?
consistent with a viral infection such as HIV
A patient’s abnormal lymphocytes are positive for CD2antigen, lack C3receptors, and are negative for surface immunoglobulin. This can be classified as a disorder of:
T cells
