ISBB Flashcards
From the following, identify a specific component of the adaptive immune system that is formed in response to antigenic stimulation:
A. Lysozyme
B. Complement
C. Commensal organisms
D. Immunoglobulin
D. Immunoglobulin
Which two organs are considered the primary lymphoid organs in which immunocompetent cells originate and mature?
A. Thyroid and Peyer’s patches
B. Thymus and bone marrow
C. Spleen and mucosal-associated lymphoid tissue (MALT)
D. Lymph nodes and thoracic duct
B. Thymus and bone marrow
What type of B cells are formed after antigen stimulation?
A. Plasma cells and memory B cells
B. Mature B cells
C. Antigen-dependent B cells
D. Receptor-activated B cells
A. Plasma cells and memory B cells
T cells travel from the bone marrow to the thymus for maturation. What is the correct order of the maturation sequence for T cells in the thymus?
A. Bone marrow to the cortex; after thymic education, released back to peripheral circulation
B. Maturation and selection occur in the cortex; migration to the medulla; release of mature T cells to secondary lymphoid organs
C. Storage in either the cortex or medulla; release of
T cells into the peripheral circulation
D. Activation and selection occur in the medulla; mature T cells are stored in the cortex until activated by antigen
B. Maturation and selection occur in the cortex; migration to the medulla; release of mature T cells to secondary lymphoid organs
Which cluster of differentiation (CD) marker appears during the first stage of T-cell development and remains present as an identifying marker for T cells?
A. CD1
B. CD2
C. CD3
D. CD4 or CD8
B. CD2
Which markers are found on mature, peripheral helper T cells?
A. CD1, CD2, CD4
B. CD2, CD3, CD8
C. CD1, CD3, CD4
D. CD2, CD3, CD4
D. CD2, CD3, CD4
Which T cell expresses the CD8 marker and acts specifically to kill tumors or virally infected cells?
A. Helper T
B. T suppressor
C. T cytotoxic
D. T inducer/suppressor
C. T cytotoxic
How are cytotoxic T cells (TC cells) and natural killer (NK) cells similar?
A. Require antibody to be present
B. Effective against virally infected cells
C. Recognize antigen in association with HLA class II markers
D. Do not bind to infected cells
B. Effective against virally infected cells
What is the name of the process by which phagocytic cells are attracted to a substance such as a bacterial peptide?
A. Diapedesis
B. Degranulation
C. Chemotaxis
D. Phagotaxis
C. Chemotaxis
All of the following are immunologic functions of complement except:
A. Induction of an antiviral state
B. Opsonization
C. Chemotaxis
D. Anaphylatoxin formation
A. Induction of an antiviral state
Which complement component is found in both the classic and alternative pathways?
A. C1
B. C4
C. Factor D
D. C3
D. C3
Which immunoglobulin(s) help(s) initiate the classic complement pathway?
A. IgA and IgD
B. IgM only
C. IgG and IgM
D. IgG only
C. IgG and IgM
How is complement activity destroyed in vitro?
A. Heating serum at 56°C for 30 min
B. Keeping serum at room temperature of 22°C for 1 hour
C. Heating serum at 37°C for 45 min
D. Freezing serum at 0°C for 24 hours
A. Heating serum at 56°C for 30 min
What is the purpose of C3a, C4a, and C5a, the split products of the complement cascade?
A. To bind with specific membrane receptors of lymphocytes and cause release of cytotoxic substances
B. To cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils
C. To bind with membrane receptors of macrophages to facilitate phagocytosis and the removal of debris and foreign substances
D. To regulate and degrade membrane cofactor protein after activation by C3 convertase
B. To cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils
Which region of the immunoglobulin molecule can bind antigen?
A. Fab
B. Fc
C. CL
D. CH
A. Fab
Which region determines whether an immunoglobulin molecule can fix complement?
A. VH
B. CH
C. VL
D. CL
B. CH
Which immunoglobulin class(es) has (have) a J chain?
A. IgM
B. IgE and IgD
C. IgM and sIgA
D. IgG3 and IgA
C. IgM and sIgA
Which immunoglobulin appears first in the primary immune response?
A. IgG
B. IgM
C. IgA
D. IgE
B. IgM
Which immunoglobulin appears in highest titer in the secondary response?
A. IgG
B. IgM
C. IgA
D. IgE
A. IgG
Which immunoglobulin can cross the placenta?
A. IgG
B. IgM
C. IgA
D. IgE
A. IgG
Which immunoglobulin cross links mast cells to release histamine?
A. IgG
B. IgM
C. IgA
D. IgE
D. IgE
All of the following are functions of
immunoglobulins except:
A. Neutralizing toxic substances
B. Facilitating phagocytosis through opsonization
C. Interacting with TC cells to lyse viruses
D. Combining with complement to destroy cellular antigens
C. Interacting with TC cells to lyse viruses
Which of the following cell surface molecules is classified as an MHC class II antigen?
A. HLA-A
B. HLA-B
C. HLA-C
D. HLA-DR
D. HLA-DR
Which MHC class of molecule is necessary for antigen recognition by CD4-positive T cells?
A. Class I
B. Class II
C. Class III
D. No MHC molecule is necessary for antigen recognition
B. Class II
Which of the following are products of HLA class III genes?
A. T-cell immune receptors
B. HLA-D antigens on immune cells
C. Complement proteins C2, C4, and Factor B
D. Immunoglobulin VL regions
C. Complement proteins C2, C4, and Factor B
What molecule on the surface of most T cells recognizes antigen?
A. IgT, a four-chain molecule that includes the tau heavy chain
B. MHC protein, a two-chain molecule encoded by the HLA region
C. CD3, consisting of six different chains
D. TcR, consisting of two chains, alpha and beta
D. TcR, consisting of two chains, alpha and beta
The T-cell antigen receptor is similar to immunoglobulin molecules in that it:
A. Remains bound to the cell surface and is never secreted
B. Contains V and C regions on each of its chains
C. Binds complement
D. Can cross the placenta and provide protection to a fetus
B. Contains V and C regions on each of its chains
Toll-like receptors are found on which cells?
A. T cells
B. Dendritic cells
C. B cells
D. Large granular lymphocytes
B. Dendritic cells
Macrophages produce which of the following proteins during antigen processing?
A. IL-1 and IL-6
B. γ-Interferon
C. IL-4, IL-5, and IL-10
D. Complement components C1 and C3
A. IL-1 and IL-6
A superantigen, such as toxic shock syndrome toxin-1 (TSST-1), bypasses the normal antigen processing stage by binding to and cross linking:
A. A portion of an immunoglobulin molecule and complement component C1
B. Toll-like receptors and an MHC class 1 molecule
C. A portion of an immunoglobulin and a portion of a T-cell receptor
D. A portion of a T-cell receptor and an MHC class II molecule
D. A portion of a T-cell receptor and an MHC class II molecule
T regulator cells, responsible for controlling autoimmune antibody production, express which of the following phenotypes?
A. CD3, CD4, CD8
B. CD3, CD8, CD25
C. CD3, CD4, CD25
D. CD8, CD25, CD56
C. CD3, CD4, CD25
The interaction between an individual antigen and antibody molecule depends upon several
types of bonds such as ionic bonds, hydrogen bonds, hydrophobic bonds, and van der Waals forces. How is the strength of this attraction
characterized?
A. Avidity
B. Affinity
C. Reactivity
D. Valency
B. Affinity
A laboratory is evaluating an enzyme-linked immunosorbent assay (ELISA) for detecting an antibody to cyclic citrullinated peptide (CCP), which is a marker for rheumatoid arthritis. The laboratory includes serum from healthy volunteers
and patients with other connective tissue diseases in the evaluation. These specimens determine which factor of the assay?
A. Sensitivity
B. Precision
C. Bias
D. Specificity
D. Specificity
The detection of precipitation reactions depends on the presence of optimal proportions of antigen
and antibody. A patient’s sample contains a large amount of antibody, but the reaction in a test system
containing antigen is negative. What has happened?
A. Performance error
B. Low specificity
C. A shift in the zone of equivalence
D. Prozone phenomenon
D. Prozone phenomenon
Which part of the radial immunodiffusion (RID) test system contains the antisera?
A. Center well
B. Outer wells
C. Gel
D. Antisera may be added to any well
C. Gel
What is the interpretation when an Ouchterlony plate shows crossed lines between wells 1 and 2
(antigen is placed in the center well and antisera in wells 1 and 2)?
A. No reaction between wells 1 and 2
B. Partial identity between wells 1 and 2
C. Nonidentity between wells 1 and 2
D. Identity between wells 1 and 2
C. Nonidentity between wells 1 and 2
Why is a chemiluminescent immunoassay (CIA) or enzyme immunoassay (EIA) the method of choice for detection of certain analytes, such as hormones, normally found in low concentrations?
A. Because of low cross reactivity
B. Because of high specificity
C. Because of high sensitivity
D. Because test systems may be designed as both competitive and noncompetitive assays
C. Because of high sensitivity
What comprises the indicator system in an indirect ELISA for detecting antibody?
A. Enzyme-conjugated antibody + chromogenic substrate
B. Enzyme conjugated antigen + chromogenic substrate
C. Enzyme + antigen
D. Substrate + antigen
A. Enzyme-conjugated antibody + chromogenic substrate
What outcome results from improper washing of a tube or well after adding the enzyme–antibody
conjugate in an ELISA system?
A. Result will be falsely decreased
B. Result will be falsely increased
C. Result will be unaffected
D. Result is impossible to determine
B. Result will be falsely increased
What would happen if the color reaction phase is prolonged in one tube or well of an ELISA test?
A. Result will be falsely decreased
B. Result will be falsely increased
C. Result will be unaffected
D. Impossible to determine
B. Result will be falsely increased
The absorbance of a sample measured by ELISA is greater than the highest standard. What corrective action should be taken?
A. Extrapolate an estimated value from the highest reading
B. Repeat the test using a standard of higher concentration
C. Repeat the assay using one half the volume of the sample
D. Dilute the test sample
D. Dilute the test sample
A patient was suspected of having a
lymphoproliferative disorder. After several laboratory tests were completed, the patient was found to have an IgMκ paraprotein. In what
sequence should the laboratory tests leading to this diagnosis have been performed?
A. Serum protein electrophoresis (SPE) followed by immunofixation electrophoresis (IFE)
B. Immunoglobulin levels followed by SPE
C. Total lymphocyte count followed by immunoglobulin levels
D. Immunoglobulin levels followed by urine protein electrophoresis
A. Serum protein electrophoresis (SPE) followed by immunofixation electrophoresis (IFE)
An IFE performed on a serum sample showed a narrow dark band in the lanes containing anti-γ and anti-λ. How should this result be interpreted?
A. Abnormally decreased IgG concentration
B. Abnormal test result demonstrating monoclonal IgGλ
C. Normal test result
D. Impossible to determine without densitometric quantitation
B. Abnormal test result demonstrating monoclonal IgGλ
Which type of nephelometry is used to measure immune complex formation almost immediately
after reagent has been added?
A. Rate
B. Endpoint
C. Continuous
D. One dimensional
A. Rate
An immunofluorescence microscopy assay (IFA) was performed, and a significant antibody titer was
reported. Positive and negative controls performed as expected. However, the clinical evaluation of the patient was not consistent with a positive finding. What is the most likely explanation of this situation?
A. The clinical condition of the patient changed since the sample was tested
B. The pattern of fluorescence was misinterpreted
C. The control results were misinterpreted
D. The wrong cell line was used for the test
B. The pattern of fluorescence was misinterpreted
What corrective action should be taken when an indeterminate pattern occurs in an indirect IFA?
A. Repeat the test using a larger volume of sample
B. Call the physician
C. Have another medical laboratory scientist read the slide
D. Dilute the sample and retest
D. Dilute the sample and retest
Which statement best describes passive agglutination reactions used for serodiagnosis?
A. Such agglutination reactions are more rapid because they are a single-step process
B. Reactions require the addition of a second antibody
C. Passive agglutination reactions require biphasic incubation
D. Carrier particles for antigen such as latex particles are used
D. Carrier particles for antigen such as latex particles are used
The directions for a slide agglutination testminstruct that after mixing the patient’s serum and latex particles, the slide must be rotated for 2 minutes. What would happen if the slide were rotated for 10 minutes?
A. Possible false-positive result
B. Possible false-negative result
C. No effect
D. Depends on the amount of antibody present in the sample
A. Possible false-positive result
What effect does selecting the wrong gate have on the results when cells are counted by flow cytometry?
A. No effect
B. Failure to count the desired cell population
C. Falsely elevated results
D. Impossible to determine
B. Failure to count the desired cell population
Which statement best describes
immunophenotyping?
A. Lineage determination by detecting antigens on the surface of the gated cells using fluorescent
antibodies
B. Identification of cell maturity using antibodies to detect antigens within the nucleus
C. Identification and sorting of cells by front and side-scatter of light from a laser
D. Analysis of cells collected by flow cytometry using traditional agglutination reactions
A. Lineage determination by detecting antigens on the surface of the gated cells using fluorescent
antibodies
A flow cytometry scattergram of a bone marrow sample shows a dense population of cells located in-between normal lymphoid and normal myeloid cells. What is the most likely explanation?
A. The sample was improperly collected
B. An abnormal cell population is present
C. The laser optics are out of alignment
D. The cells are most likely not leukocytes
B. An abnormal cell population is present
Which serum antibody response usually
characterizes the primary (early) stage of syphilis?
A. Antibodies against syphilis are undetectable
B. Detected 1–3 weeks after appearance of the primary chancre
C. Detected in 50% of cases before the primary chancre disappears
D. Detected within 2 weeks after infection
B. Detected 1–3 weeks after appearance of the primary chancre
What substance is detected by the rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) tests for syphilis?
A. Cardiolipin
B. Anticardiolipin antibody
C. Anti-T. pallidum antibody
D. Treponema pallidum
A. Cardiolipin
What type of antigen is used in the RPR card test?
A. Live treponemal organisms
B. Killed suspension of treponemal organisms
C. Cardiolipin
D. Tanned sheep cells
C. Cardiolipin
Which of the following is the most sensitive test to detect congenital syphilis?
A. VDRL
B. RPR
C. Microhemagglutinin test for T. pallidum (MHA-TP)
D. Polymerase chain reaction (PCR)
D. Polymerase chain reaction (PCR)
A biological false-positive reaction is least likely with which test for syphilis?
A. VDRL
B. Fluorescent T. pallidum antibody absorption test (FTA-ABS)
C. RPR
D. All are equally likely to detect a false-positive result
B. Fluorescent T. pallidum antibody absorption test (FTA-ABS)