Ciulla Review Questions Flashcards
Color Plate 21B depicts a monomeric immunoglobulin molecule. The portion of the molecule indicated by the dotted red circle and the red arrow is called the
Fab fragment
A hapten is
A determinant capable of stimulating
an immune response only when bound to a carrier
Which of the following is characteristic of B cells?
Contain surface immunoglobulins
A lymphokine is
A soluble mediator produced by
lymphocytes
Monocytes and macrophages play a major role in the mononuclear phagocytic system. For an antibody-coated antigen to be phagocytized, what part of the antibody molecule fits into a receptor on the phagocytic cell?
Fc region
Cell-mediated immunity is primarily mediated by
T helper cells
The HLA complex is located primarily on
Chromosome 6
HLA antigens are found on
All nucleated cells
Which of the following is more likely to be diagnostic of an acute infection?
A total acute antibody liter of 2
followed by a convalescent titer of 16
A young woman shows increased susceptibility to pyogenic infections. Upon assay, she shows a low level of C3. Which of the following statements is probably true?
She has decreased production of C3.
What is the predominant type of antibody found in the serum of neonates born after full-term gestation?
Maternal IgG
An important part of the nonspecific immune response is(are)
Complement cascade
The major class of immunoglobulin found in adult human serum is
IgG
Which class of immunoglobulin possesses delta heavy chains?
IgD
Which class of immunoglobulin possesses 10 antigenic binding sites?
IgM
Color Plate 22 • represents a dimericIgA molecule. The structure printed in red and indicated by the red arrow is called the
J-piece
Which class of immunoglobulin binds to basophils and mast cells to mediate immediate hypersensitivityreactions?
IgE
Type I hypersensitivity is
An immediate allergic reaction
When performing the enzyme-multiplied immunoassay technique (EMIT), how is the ligand in the patient’s serum detected?
Competes with enzyme-labeled
antigen for binding to a specific
antibody
Severe combined immunodeficiency (SCID) is an
Immunodeficiency with decreased or dysfunctional T and B cells
An example of immune injury due to the deposition of antigen-antibody complexes is
Acute glomerulonephritis
The serologically detectable antibody produced in rheumatoid arthritis (RA) is primarily of the class
IgM
In bone marrow transplantation, immuno- competent cells in the donor marrow may recognize antigens in the recipient and respond to those antigens. This phenome- non is an example of
Graft-versus-host disease
Multiple myeloma is a
Cancer of plasma cells characterized
by increased antibody concentration
Which one of the following describes a direct immunofluorescence assay?
Conjugated reagent antibody reacts with antigen to form antigen-antibody complexes
Inindividuals allergic to pollen, hyposensitization protocols may be initiated. These individuals receive injections of
Allergen
After exposure to antigen, the first antibodies that can be detected belong to the class
IgM
Corneal tissue may be transplanted successfully from one patient to another because
The cornea occupies a privileged site
not usually seen by the immune system
A kidney transplant from one identical twin to another is an example of a(n)
Isograft
In Bruton disease, measurement of serum immunoglobulins would show
The absence of all immunoglobulins
Diagnosis of group A streptococci (Streptococcus pyogenes) infection is indicated by the presence of
Anti-DNase B
A molecule found in human serum sometimes used as a tumor marker is
a-Fetoprotein
Which cell is the principal source of interleukin 2?
T cell
Diagnostic reagents useful for detecting antigen by the coagglutination reaction may be prepared by binding antibody to killed staphylococcal cells via the Fc receptor of staphylococcal protein A. The class of antibody bound by this protein is
IgG
A major advantage of passive immunization compared to active immunization is that
Antibody is available more quickly
The strength with which a multivalent antibody binds a multivalent antigen is termed the
Avidity
How does the secondary humoral immune response differ from the primary response?
The antibody levels produced are higher in the secondary immune response.
After activation of the complement system, leukocytes and macrophages are attracted to the site of complement activation by
C5a
The type of immunity that follows the injection of an immunogen is termed
Artificial active
The type of immunity that follows the injection of antibodies synthesized by another individual or animal is termed
Artificial passive
Innate immunity includes
Phagocytosis by PMNs
The agglutination pattern shown in Color Plate 23• was observed while performing an antibody titration. This agglutination pattern is an example of
A prozone reaction
The antibody most frequently present in systemic lupus erythematosus is directed against
Nuclear antigen
The rapid plasma reagin assay for syphilis does not need to be read microscopically because the antigen is
Complexed with charcoal
The Venereal Disease Research Laboratory (VDRL) test for syphilis is classified as a(n)
Flocculation reaction
One cause of a false-positive VDRL test is
SLE
The portion of an antigen that binds to an antibody or T cell receptor is called a(n)
Epitope
Identical antibodies produced from a single clone of plasma cells describes
Monoclonal antibodies
IgM antibodies react well in complement fixation (CF) tests. Because of this, CF tests for antibodies should
Be positive early in the course of the
disease
Which of the following serologic tests is commonly performed by an immunofluo- rescence method?
ANA
The Fab portion of an antibody
Contains the hypervariable reagion
In the enzyme-linked immunosorbent assay (ELISA), the visible reaction is due to a reaction between
Enzyme and substrate
Elevated IgE levels are typically found in
Type I hypersensitivity reactions
Loss of self-tolerance results in
Autoimmune disease
A human cell with CDS on its surface is most likely a
Cytotoxic T cell
Which of the following statements about immunoglobulin light chains is true?
There are two types: kappa and
lambda.
Which of the following statements applies to the Fc fragment of an immunoglobulin molecule?
It is the region of the molecule that binds to receptors on various white blood cells.
Monoclonal antibodies are produced by
Hybridomas
Antibodies that bind to the same epitope are of the same
Idiotype
Skin testing is a useful diagnostic tool in a number of disorders, such as tuberculosis. Which of the following statements about skin testing is true?
Reactivity to a particular antigen may be transferred from one individual to another by sensitized lymphocytes.
The activity of natural killer (NK) cells
Does not require previous exposure to
an antigen
Interaction between B and T helper cells involves
Foreign antigen on B cell binding to T cell receptor
Which of the following is a characteristic of T cells?
Mature in the thymus
The primary mechanism responsible for pathology in systemic lupus erythematosus is
Antibodies directed against self
antigens
Which complement protein is present in the greatest concentration in human serum?
C3
An autoimmune disease causing destruction of pancreatic cells can result in
Type 1 diabetes
An Ouchterlony gel diffusion plate is depicted in Color Plate 24B. The center well contains antibody, and the peripheral wells contain antigens labeled 1 through 4. What is the relationship between the antigens in wells 2 and 3?
They are unrelated.
An Ouchterlony gel diffusion plate is depicted in Color Plate 24B. The center well contains antibody, and the peripheral wells contain antigens labeled 1 through 4. What is the relationship between the antigens in wells 2 and 4?
They are identical.
Which of the following complement proteins is part of the membrane attack complex?
C5
Which of the following is characteristic of contact hypersensitivity reactions?
Usually due to a hapten
Which of the following statements about the test for C-reactive protein (CRP) is true?
It is an indicator of ongoing inflammation.
In the classical pathway of complement activation,
Activation by antibody requires one IgM or two IgG molecules
The alternative complement pathway
Can be activated by bacterial capsule
polysaccharides
Acutonaperson’sfingerbecomes contaminated with the bacterium Staphylococcus aureus. The first response by the immune system consists of activity of
Neutrophils
Incompatible blood transfusions are examples of
Type II hypersensitivity reactions
A soluble antigen and soluble antibody reacting to form an insoluble product describes
Precipitation reactions
Which of the following is an example of a treponemal antigen test used for the diagnosis of syphilis?
FTA-ABS
A serum sample is positive for HBsAg. This result indicates that the person from whom the serum was taken
Has either active or chronic hepatitis B
infection
What is the indicator system used in the complement fixation test?
Sensitized sheep red blood cells
The isotype of an immunoglobulin antibody
Is defined by the heavy chain
A patient report states the presence of serum antibodies to OspC. What disease does the patient most likely have?
Lyme disease
Patient serum is mixed with a suspension of guinea pig antigen. When the sample is then mixed with horse red blood cells, agglutination occurs. This is suggestive of an infection caused by
Epstein-Barr virus
Hashimoto disease is an autoimmune disease primarily involving the
Thyroid gland
Rheumatic fever sometimes occurs after group A streptococcal infections. In this condition, an autoimmune response attacks the tissue of the heart valves. This phenomenon is an example of
Molecular mimicry
“Superantigens” are toxins produced by some strains of Staphylococcus aureus and group A streptococci and cause damage by
Polyclonal T cell activation
The first serologic marker to appear in patients with acute hepatitis B virus infection is
HBsAg
A living donor is being sought for a child who requires a kidney transplant. The best odds of finding an MHC-compatible donor occur between the child and
A sibling (brother or sister)
Cells that can act as antigen-presenting cells for exogenous antigens include
B lymphocytes
In patients with human immunodeficiency virus infection, immune status can be monitored by measuring the ratio of
CD4+ cells to CD8+ cells
Why does vaccination against hepatitis B virus (HBV) also prevent hepatitis D virus (HDV) infections?
HDV requires the host to be concurrently infected with HBV.
B lymphocytes and T lymphocytes are derived from
Hematopoietic stem cells
Contact dermatitis is mediated by
T lymphocytes
In a competitive radioimmunosorbent test (RIST), what does a high signal suggest?
The patient sample has a low
concentration of IgE.
An antibody titration is depicted in Color Plate 25•. In this titration, a 0.2mL aliquot of a patient’s serum sample was added to 0.8 mL of saline, and this mixture was placed into tube #1. A 0.5 mL sample was removed from tube #1 and placed into tube #2, containing 0.5 mL of saline. This procedure was repeated through tube #10. The dilutions were assayed for antibody to an infectious agent. How should the antibody titer be reported?
640
In a chemiluminescent immunologic assay, what is the signal detected?
Light
A 28-year-old female complains to her family physician of abdominal pain, loss of appetite, and low-grade fever. Physical examination reveals abdominal tenderness and a low-grade fever. Her physician orders a hepatitis profile and obtains the results below.
Which of the following is the most likely conclusion?
Chronic HBV infection
An 11-year-old female presents with fever, sore throat, lethargy, and tender cervical lymphadenopathy. Relevant findings include splenomegaly and lymphocytosis, with many large reactive (atypical) lymphocytes. A heterophile antibody test was negative. Further laboratory results were as follows:
What conclusion can be made concerning the diagnosis?
Acute EBV infection
A male infant had been well until about 5 months of age, at which time he was diagnosed as having otitis media and bronchitis caused by Haemophilus influenzae. Over the next several months he presented with streptococcal pneumonia several times. At 10 months of age a serum protein electrophoresis showed a virtual lack of gamma globulins. Quantitative serum levels were as follows: 75 mg/dL IgG and undetectable levels of IgM, IgA, and IgE. There were a normal number of T cells, and they exhibited normal mitogen stimulation. What disease does this child most likely suffer from?
X-linked agammaglobulinemia
A 25-year-old male presents to his family physician complaining of fatigue, diarrhea, and weight loss of a few months duration. On physical examination the patient is found to have a fever and abdominal discomfort. Laboratory results indicate a white blood cell count of 14.3 X 109/L (reference range 4.8-10.8 X 109/L). Assays for HBSAg and anti-HCV are negative. An ELISA test for antibodies to the human immunodeficiency virus (HIV) performed on the patient’s serum is found to be reactive. What step should be taken next?
Repeat the HIV ELISA test on the sample.
A 38-year-old woman visited her physician because of fatigue, fever, and joint pain (proximal interphalangeal, wrist, and knee joints). She also noticed sensitivity to the sun and reported having a rash following recent exposure. The physician noted a rash over her nose and cheeks. Laboratory results included white blood cell count 5.5 X 109/L (reference range 4.8-10.8 X 109/L) and red blood cell count 4.5 X 1012/L (reference range 4.0-5.4 X 1012/L). Urinalysis results were within reference ranges, except for 4+ protein and 1+ RBCs, 0-3 hyaline casts/lpf and 0-1 RBC cast/lpf on microscopic examination. Which of the following tests would be most helpful in diagnosing this patient’s condition?
Anti-nuclear antibody
