ch. 13 & 14
Analysis of flow cytometer data of cells can be filtered in many ways by using a method of a. "gating" in a dot plot. b. banding of a histogram. c. single-parameter histogram monitoring. d. automatic sampling.
a. "gating" in a dot plot.
To determine if a patient is allergic to rye grass, the best test to perform is the a. total IgE test. b. skin prick test. c. DAT. d. complement fixation.
b. skin prick test.
If an analyzer consistently indicates a positive test when the analyte in question is not present, this represents a problem with a. sensitivity. b. specificity. c. reportable range. d. precision
b. specificity.
T cell-dependent hypersensitivity occurs: A) 24 to 72 hours after exposure to the antigen. B) immediately after exposure to the antigen. C) 5 to 7 days after contact with antigen. D) 1 to 4 hours after contact with antigen.
A) 24 to 72 hours after exposure to the antigen.
What immune phenomenon is responsible for the muscle weakness associated with myasthenia gravis? A) Binding of antibody to a receptor on muscle cells B) Muscle cell destruction by cytotoxic T cells C) Deposition of immune complexes in the muscles D) Release of histamine from mast cells in the muscles
A) Binding of antibody to a receptor on muscle cells
Anaphylaxis is characterized by which of the following? A) Degranulation of mast cells B) Production of IgG C) T-cell mediators D! All of the above
A) Degranulation of mast cells
Preformed mediators that are released during the activation phase of a type I hypersensitivity response include which of the following? A) Histamine B) Cyclooxygenase C) Leukotriene D) Prostaglandin
A) Histamine
Which isotype of immunoglobulin is involved in a type I hypersensitivity? A) IgE B) IgA C) IgG D) IgM
A) IgE
Type I hypersensitivity involves: A) IgE binding to mast cells and basophils. B) phagocytic cell degranulation and proteolytic enzyme activity. C) a kidney membrane antigen and specific antibody. D) natural killer cell activation.
A) IgE binding to mast cells and basophils.
The normal activity of a type I hypersensitivity response is protection primarily against which of the following? A) Parasites B) Viruses C) Bacteria D) Fungi
A) Parasites
Which description best describes the reportable range? A) Span of test result values over which the laboratory can establish or verify the accuracy of an instrument or test system B) Range of test values found in a healthy population of people C) Variation observed in repeated measurements of the same sample D) Difference in concentration between the highest and lowest standards used in the standard curve
A) Span of test result values over which the laboratory can establish or verify the accuracy of an instrument or test system
How close a measured value is to the actual (true)value is called: A) accuracy. B) precision. C) analytic sensitivity. D) analytic specificity.
A) accuracy.
To determine if a patient is allergic to peanuts,the best test to perform is: A) allergen-specific IgE. B) total serum IgE. C) serum protein electrophoresis. D) RID to measure IgG.
A) allergen-specific IgE.
A test system is producing many false-positive results. You suspect this is a problem involving: A) analytic specificity. B) precision. C) analytic sensitivity. D) a sampling error.
A) analytic specificity.
Compared with percutaneous (prick)tests,intradermal skin tests: A) are more sensitive. B) require less antigen. C) carry less risk. D) are better for diagnosing food allergies.
A) are more sensitive.
A positive direct antiglobulin test might indicate: A) autoimmune hemolytic anemia. B) an allergic reaction. C) a mismatch of a transplant. D) rheumatoid arthritis.
A) autoimmune hemolytic anemia.
In flow cytometry, forward scatter provides a measure of: A) cell size. B) cell granularity. C) membrane receptor expression.
A) cell size.
A single cell parameter acquired by flow cytometry is presented graphically as a: A) histogram. B) dot plot. C) vector plot. D) quadrant analysis.
A) histogram.
A direct antiglobulin test is ordered on a patient sample. This test detects: A) in vivo attachment of antibodies to red blood cells. B) allergic reaction. C) passive agglutination. D) naturally occurring antibodies.
A) in vivo attachment of antibodies to red blood cells.
As measured in flow cytometry, cells that are the smallest and have the least granules would be identified as: A) lymphocytes. B) granulocytes. C) monocytes. D) erythrocytes.
A) lymphocytes.
Anaphylactic reactions are mediated by: A) mast cells. B) lymphocytes. C) macrophages. D) natural killer cells.
A) mast cells.
A mature cytotoxic T cell expresses which markers? A) CD3, CD4, and CD8 B) CD4, CD3, and CD5 C) CD5, CD8, and CD3 D) CD8, CD3, and CD2
D) CD8, CD3, and CD2
A hypersensitivity reaction characterized by the presence of IgG that reacts with soluble antigen best describes: A) type III hypersensitivity. B) contact dermatitis. C) type II hypersensitivity. D) asthma.
A) type III hypersensitivity.
Reaction to poison ivy is which type of hypersensitivity? A) I B) II C) III D) IV
D) IV
The precipitation of immune complexes in small blood vessels under the skin that occurs when antigen is injected in an animal with large amounts of circulating antibody describes which of the following? A) Serum sickness B) Arthus reaction C) Anaphylaxis D) Delayed hypersensitivity
B) Arthus reaction
All of the hypersensitivity responses have which of the following in common? A) Involvement of antibody B) Asymptomatic sensitization phase C) Release of histamine D) Activation of macrophage against a pathogen.
B) Asymptomatic sensitization phase
The expression of cell surface markers is determined in the flow cytometer by which of the following? A) Chemiluminescence B) Fluorescence C) Optical density D) Radioactivity E) Scatter
B) Fluorescence
In flow cytometry, if there are two light detectors, what does the amount of side scatter indicate? A) Size of the cell B) Granularity of the cell C) Surface markers D) Shape of the cell
B) Granularity of the cell
Which newly synthesized mediator has a mode of action similar to that of histamine? A) LTB4 B) Heparin C) ECF-A D) PGD
B) Heparin
What is a disadvantage of automated testing in a clinical immunology laboratory? A) Decreases potential for manual errors B) Increases dependence on a single machine C) Cannot be used within the preanalytical stage of testing D) Cannot perform combined chemistry and immunoassay testing on a single platform
B) Increases dependence on a single machine
Which of the following diseases is an example of a type II hypersensitivity? A) Anaphylaxis B) Myasthenia gravis C) Post-streptococcal glomerulonephritis D) Bruton's agammaglobulinemia
B) Myasthenia gravis
Which light signal in flow cytometry could be used to provide information about the expression of a protein on the outer surface of a cell membrane? A) Forward-angle light scatter B) Red light emitted by phycoerythrin C) Polarized light D) Right-angle light scatter
B) Red light emitted by phycoerythrin
What are the advantages of automated testing in a clinical immunology laboratory? A) Requires minimal investment and maintenance B) Reduces turnaround time C) Increases hands-on time by staff D) Does not require validation
B) Reduces turnaround time
Which of the following occurs in hemolytic disease of the newborn? A) IgE builds up on the mother's cells. B) The Rh- mother is exposed to Rh+ baby cells. C) The Rh+ mother is exposed to Rh- baby cells. D) The baby must be Rh-.
B) The Rh- mother is exposed to Rh+ baby cells.
Cold autoimmune hemolytic anemia is an example of which type of hypersensitivity? A) Type I B) Type II C) Type III D) Type IV
B) Type II
Complement is responsible for tissue damage in which of the following reactions? A) Immediate hypersensitivity B) Type III hypersensitivity C) Delayed hypersensitivity D) Anaphylaxis
B) Type III hypersensitivity
In flow cytometry, the sheath fluid: A) contains a dye required for cell identification. B) draws the suspended cells into a laminar flow. C) filters out extraneous wavelengths of light. D) provides nutrients necessary to maintain cellular metabolism.
B) draws the suspended cells into a laminar flow.
In flow cytometry, fluorescence is usually used to determine: A) intrinsic cell parameters. B) extrinsic cell parameters.
B) extrinsic cell parameters
An intrinsic parameter that can be measured by a flow cytometer is: A) surface expression of CD3. B) granularity. C) cytoplasmic protein content. D) RNA content.
B) granularity.
An exaggerated reaction directed against an antigen that is harmless is called: A) atopy. B) hypersensitivity. C) immune complex disease. D) passive cutaneous anaphylaxis.
B) hypersensitivity.
The reference interval is determined by: A) using a standardized reagent to establish the highest and lowest concentrations that can be measured by an instrument or test system. B) measuring an analyte in samples from a large number of healthy people, using the same instrument or test system. C) the period of time between the acquisition and testing of a sample. D) the difference in concentration between the highest and lowest standards used in the standard curve.
B) measuring an analyte in samples from a large number of healthy people, using the same instrument or test system.
The ability to consistently reproduce the same result on repeated testing of the same sample is called: A) accuracy. B) precision. C) analytic sensitivity. D) analytic specificity.
B) precision.
The purified protein derivative reaction to determine exposure to tuberculosis is based on which of the following? A) Formation of antigen-antibody complexes B) An immediate hypersensitivity reaction C) A sensitized T-cell response D) A type II hypersensitivity reaction
C) A sensitized T-cell response
What is meant by "gating" in flow cytometry? A) The chromatic arrangement of cellular populations B) The process by which one cell population adheres to another population C) An electronic window separating subpopulations of cells D) An electronic device measuring all populations of cells
C) An electronic window separating subpopulations of cells
Identify the difference between batch and random-access analyzers. A) Batch analyzers are not automated. B) Random-access analyzers only analyze one sample at a time. C) Batch analyzers only do one type of analysis at a time. D) Random-access analyzers cannot be used for stat samples.
C) Batch analyzers only do one type of analysis at a time.
Immune injury resulting from the localization of immune complexes in blood vessels and tissues describes which hypersensitivity reaction? A) I B) II C) III D) IV
C) III
Contact dermatitis can be characterized by: A) formation of antigen-antibody complexes. B) immediate sensitization of Th1 cells. C) Langerhans cells acting as antigen-presenting cells. D) decreased cytokine production.
C) Langerhans cells acting as antigen-presenting cells.
Which of the following is characteristic of autoimmune hemolytic anemia caused by cold agglutinins? A) It is a type I hypersensitivity reaction. B) It is the most common cause of autoimmune hemolytic anemia. C) The IgM antibodies are specific to Ii blood groups. D) The reaction is irreversible.
C) The IgM antibodies are specific to Ii blood groups.
The lowest measurable amount of an analyte is called: A) accuracy. B) precision. C) analytic sensitivity. D) analytic specificity.
C) analytic sensitivity.
Type I hypersensitivity can be treated by injecting a specific recombinant humanized IgG called omalizumab.This antibody: A) binds allergens, preventing them from binding patient IgE. B) occupies Fc receptors on mast cells, preventing binding by patient IgE. C) binds to a heavy-chain domain on patient IgE, preventing the IgE from binding to mast cells. D) inhibits Th2 cells that would otherwise promote excess IgE production.
C) binds to a heavy-chain domain on patient IgE, preventing the IgE from binding to mast cells.
Flow cytometry is commonly used to: A) measure serum protein concentrations. B) identify microbes. C) determine the stage of leukocyte differentiation. D) measure complement activation.
C) determine the stage of leukocyte differentiation.
A fluorescent signal in flow cytometry is generated by: A) light reflected off cells passing through a laser beam. B) light scattered by fluorochromes. C) fluorochromes that absorb energy from a laser beam and then release the energy as longer-wavelength light. D) cell metabolism.
C) fluorochromes that absorb energy from a laser beam and then release the energy as longer-wavelength light.
By gradually increasing doses of an allergen over time,allergy immunotherapy is thought to: A) inhibit Th1 response. B) induce Th2 cell development. C) induce Treg cell development. D) block allergen-specific IgG.
C) induce Treg cell development.
Fluorescently labeled antibodies are used in flow cytometry to determine: A) the size of a cell. B) the granularity of a cell. C) proteins associated with a cell. D) the shape of the nucleus.
C) proteins associated with a cell.
In most flow cytometers,labeled cells: A) scatter the light and absorb fluorescence. B) absorb fluorescence and emit electronic impulses. C) scatter the light and emit fluorescence. D) absorb both fluorescence and light.
C) scatter the light and emit fluorescence.
In flow cytometry, it is possible to detect the expression of 10 different cell membrane proteins simultaneously by: A) using 10 different lasers that produce light at different wavelengths. B) measuring the amount of light scattered at 10 different angles. C) staining the cells with 10 different labeled probes that fluoresce at different wavelengths. D) measuring mass as well as fluorescent intensity.
C) staining the cells with 10 different labeled probes that fluoresce at different wavelengths.
The principal difference between type II and type III hypersensitivity reactions is: A) the isotype of the antibody involved. B) complement-mediated lysis of host cells. C) whether the antigen is cellular or soluble. D) involvement of helper T cells and macrophages.
C) whether the antigen is cellular or soluble.
Which light signal in flow cytometry provides information about a cell's intrinsic physical characteristics? A) Green light emitted by fluorescein isothiocyanate (FITC) B) Red light emitted by phycoerythrin C) Polarized light D) Scattered light
D) Scattered light
Which immune mechanism is involved in contact dermatitis? A) Presence of circulating IgE B) Deposition of immune complexes C) Activation of complement D) Sensitization of cytotoxic T cells
D) Sensitization of cytotoxic T cells
Hydrodynamic focusing in flow cytometry refers to the: A) diameter of the laser beam. B) refractive properties of the assay buffer. C) orientation of the photomultiplier tubes. D) alignment of the cells flowing past the laser beam.
D) alignment of the cells flowing past the laser beam.
Hypersensitivities to poison ivy and nickel are: A) mediated by IgG and IgM antibodies. B) immunodeficiency diseases. C) IgE responses to a hapten. D) macrophage and T-cell responses to a hapten.
D) macrophage and T-cell responses to a hapten.
An example of a condition that involves type III hypersensitivity is: A) myasthenia gravis. B) allergic rhinitis. C) contact sensitivity. D) rheumatoid arthritis.
D) rheumatoid arthritis.
Reactions to antigens in natural rubber (latex)can trigger: A) type I and type II hypersensitivity. B) type II and type III hypersensitivity. C) type III and type IV hypersensitivity. D) type I and type IV hypersensitivity.
D) type I and type IV hypersensitivity.
Which of the following is associated with anaphylaxis? a. Buildup of IgE on mast cells b. Activation of complement c. Increase in cytotoxic T cells d. Large amount of circulating IgG
a. Buildup of IgE on mast cells
Which of the following cell surface markers would be present on a population of T helper (Th) cells? a. CD3 and CD4 b. CD3 and CD8 c. CD3 only d. CD4 only
a. CD3 and CD4
Flow cytometry characterizes cells on the basis of which of the following? a. Forward and 90-degree side scatter of an interrupted beam of light b. Front-angle scatter only of an interrupted light beam c. Absorbance of light by different types of cells d. Transmittance of light by cells in solution
a. Forward and 90-degree side scatter of an interrupted beam of light
Which of the following explains the difference between type II and type III hypersensitivity reactions? a. Type II involves cellular antigens. b. Type III involves IgE. c. IgG is involved only in type III reactions. d. Type II reactions involve no antibod
a. Type II involves cellular antigens.
Which of the following is associated with an increase in IgE production? a. Transfusion reaction b. Activation of Th2 cells c. Reaction to poison ivy d. HDN
b. Activation of Th2 cells
What is the single most important requirement for samples to be analyzed on a flow cytometer? a. Whole blood is collected into a serum-separator tube. b. Cells must be in a single-cell suspension. c. Samples must be fixed in formaldehyde before processing. d. Blood must be kept refrigerated while processing
b. Cells must be in a single-cell suspension.
What is the immune mechanism involved in type III hypersensitivity reactions? a. Cellular antigens are involved. b. Deposition of immune complexes occurs in antibody excess. c. Only heterologous antigens are involved. d. Tissue damage results from exocytosis.
b. Deposition of immune complexes occurs in antibody excess.
Which type of analyzer allows one to measure multiple analytes from numerous samples, loaded at any time? a. Batch analyzer b. Random access analyzer c. Front-end loaded analyzer d. Sequential access analyzer
b. Random access analyzer
All of the following are associated with type I hypersensitivity except a. release of preformed mediators from mast cells. b. activation of complement. c. cell-bound antibody bridged by antigen. d. an inherited tendency to respond to allergens.
b. activation of complement.
Two days after administration of the PPD test, a female health-care worker developed an area of redness and induration 12 mm in size at the injection site. This result means that she has a. an active case of tuberculosis. b. been exposed to M tuberculosis. c. developed protective immunity against tuberculosis. d. a result in the normal range for her risk group.
b. been exposed to M tuberculosis.
All of the following are benefits of automation except a. greater accuracy. b. increased turnaround time. c. savings on controls. d. less disposal of outdated reagents.
b. increased turnaround time.
Analyzers use different methods for mixing, including magnetic stirring, rotation paddles, forceful dispensing, and vigorous lateral shaking. Whichever method used, it is imperative that a. reagents always be kept refrigerated. b. there is no splashing or carry-over between samples. c. samples are kept at room temperature. d. multiple methods are not used simultaneously
b. there is no splashing or carry-over between samples.
Which of the following is a general characteristic of hypersensitivity reactions? a. The immune responsiveness is depressed. b. Antibodies are involved in all reactions. c. An exaggerated immune response to an antigen occurs. d. The antigen triggering the reaction is a harmful one
c. An exaggerated immune response to an antigen occurs.
Which of the following conclusions can be drawn about a patient whose total IgE level was determined to be 150 IU/mL? a. The patient definitely has allergic tendencies. b. The patient may be subject to anaphylactic shock. c. Antigen-specific testing should be done. d. The patient will never have an allergic reaction
c. Antigen-specific testing should be done.
Which cell surface marker is present on cells seen in hairy cell leukemia? a. CD138 b. CD33 c. CD103 d. CD34
c. CD103
What is the immune phenomenon associated with the Arthus reaction? a. Tissue destruction by cytotoxic T cells b. Removal of antibody-coated RBCs c. Deposition of immune complexes in blood vessels d. Release of histamine from mast cells
c. Deposition of immune complexes in blood vessels
Many flow cytometry laboratories now use the CD45 marker in combination with SSC in differentiating various populations of WBCs to replace which of the following combinations? a. CD4 + SSC b. CD4 + FSC c. FSC + SSC d. FSC + CD45
c. FSC + SSC
Which statement represents the best explanation for a flow cytometer's ability to detect several cell surface markers at the same time? a. The forward scatter can separate out cells on the basis of complexity. b. One detector can be used to detect many different wavelengths. c. For each marker, a specific fluorochrome-antibody combination is used. d. Intrinsic parameters are separated out on the basis of the amount of side scatter.
c. For each marker, a specific fluorochrome-antibody combination is used.
CD45 is a pan-leukocyte marker expressed on WBCs in varying levels or amounts of expression, based on a. size of a cell. b. granularity of a cell. c. maturity and lineage of a cell. d. malignancy of a cell.
c. maturity and lineage of a cell.
To determine a cold agglutinin titer a. patient serum should be separated from whole blood at 4°C and tested at 4°C. b. patient serum should be separated from whole blood at 4°C and tested at 37°C. c. patient serum should be separated from whole blood at 37°C and tested at 4°C. d. patient serum should be separated from whole blood at 37°C and tested at 37°C.
c. patient serum should be separated from whole blood at 37°C and tested at 4°C.
The various signals generated by cells intersecting with a flow cytometry laser are captured by a. bandwidth waves. b. wave channels. c. photomultiplier tubes. d. flow cells.
c. photomultiplier tubes.
Forward-angle light scatter is an indicator of cell a. granularity. b. density. c. size. d. number.
c. size.
How many fluorochromes (colors) are current clinical flow cytometers capable of detecting? a. 2 b. 6 c. 8 d. 10
d. 10
Which of the following statements best describes a single-parameter histogram? a. Each event is represented by a dot. b. Data is distributed in four quadrants. c. Positive and negative events are plotted on the x and y axis. d. A chosen parameter is plotted versus the number of events
d. A chosen parameter is plotted versus the number of events
Which of the following would cause a positive DAT test? a. Presence of IgG on RBCs b. Presence of C3b or C3d on RBCs c. A transfusion reaction caused by preformed antibody d. Any of the above
d. Any of the above
If an analyzer gets different results each time the same sample is tested, what type of problem does this represent? a. Sensitivity b. Specificity c. Accuracy d. Precision
d. Precision
Which condition would result in HDN? a. Buildup of IgE on mother's cells b. Sensitization of cytotoxic T cells c. Exposure to antigen found on both mother and baby RBCs d. Prior exposure to foreign RBC antigen
d. Prior exposure to foreign RBC antigen
Reactions to latex are caused by a. type I hypersensitivity. b. type IV hypersensitivity. c. skin irritation. d. all of the above
d. all of the above
A young woman developed red, itchy papules on her wrist 2 days after wearing a new bracelet. This reaction was caused by a. IgE-sensitized mast cells in the skin. b. antigen-antibody complexes in the skin. c. damage to the skin cells by antibodies and complement. d. an inflammatory response induced by cytokines released from Th1 cells.
d. an inflammatory response induced by cytokines released from Th1 cells.
A newer flow cytometry technology that has the potential to detect over 500 analytes from one sample of blood is called a/an a. RBC fragmentation assay. b. Dihydrorhodamine 123. c. sucrose test. d. cytometric bead array
d. cytometric bead array
All of the following are clinical applications for flow cytometry except a. fetal hemoglobin. b. immunophenotyping of lymphocyte subpopulations. c. HIV viral load analysis. d. enumeration of stem cells in a peripheral blood mononuclear cell product.
d. enumeration of stem cells in a peripheral blood mononuclear cell product.
Operational considerations when selecting automated analyzers for your laboratory include all of the following except a. reagent stability. b. test menu. c. STAT capability. d. purchase cost.
d. purchase cost.