IS xx Flashcards by hehe gege

A 10-month-old girl presented with fever of 39°C and with diarrhea. Stool was (+) for fecal leukocytes. Her history was
remarkable for recurrent bronchitis, pneumonia, and enterocolitis. Her serum IgA level is 15 mg/dL (normal is 50 mg/dL). What is the role of IgA? * 1/1

opsonization
release of antihelminthic enzymes by eosinophils
activation of the classical complement pathway
inhibition of microbial adhesion

inhibition of microbial adhesion

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A 34-year old woman awoke from a nap in her mobile home at the smell of gas. She went to the kitchen and it her propane stove, causing an explosion. She sustained severe burns over most of her body surface. She managed to get out to be pulled away from the trailer by her neighbor. by the time the paramedics arrived, she was in extreme pain and had the following vital signs: pulse 120
beats/min, blood pressure 110/60 mm Hg, respiratory rate 25/min, and temperature 36.8°C. She received IV fluids, an intravenous bolus of morphine sulfate, and oxygen mask. What was disrupted most significantly in this patient?

first line of defense
second line of defense
phagocytosis
Ab production

first line of defense

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A 14-year old girl was referred to radiology because of abdominal pain and vague respiratory symptoms. An abdominal x-ray with barium swallow revealed an approximately 20-cm long train track-line filling defect. The patient’s stool was (+) for ova of a common parasite. Chest x-ray interferon-gamma - mediated killing of phagocytosed pathogen by natural killer showed pulmonary infiltrates. what is the likely to be elevated in this patient?

basophils 
neutrophils 
platelets 
eosinophils 
lymphocytes

eosinophils

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A 25-year old woman in the 32nd week of gestation develops sepsis and gives birth to a stillborn infant. She lives on a farm, where she milks cows and often she drinks unpasteurized milk. An
intracellular bacterium, Listeria monocytogenes is recovered from the mother’s blood and all of the autopsy samples obtained from the infant. What is important in the early control of L. monocytogenes infection?

cells
Ab-mediated killing of L. monocytogenes
eosinophilic infiltration
granuloma formation

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A 20-year old woman injured in a car accident while driving without a seat belt fastened is brought to the ER department. Internal bleeding is suspected, and an emergency laparotomy is performed, which reveals a ruptured spleen necessitating splenectomy. The patient is at risk for developing:

B cell immunodeficiency 
T cell immunodeficiency 
HIV/AIDS 
infections with encapsulated organisms
malabsorption

infections with encapsulated organisms

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A researcher working in Immunology has 
developed an antibody that reacts with a 
protein that is expressed on developing 
immune cells. if the researcher decides to 
stain various lymphoid tissues to look for 
expression of this protein using the Ab 
that he developed, what tissue would 
most likely give a strong reaction?
1/1 
tonsils spleen 
lymph nodes 
Peyer's patches 
thymus

thymus

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Ag-presentation is an important aspect of 
immune function. Several cell types are 
capable of presenting the Ag to immune 
cells. What cell type is least likely to be 
called as a professional Ag presenting 
cell? 
1/1
B lymphocyte
T lymphocyte 
macrophage 
dendritic cell 
Langerhans cells

T lymphocyte

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A 40-year old man was treated for an 
upper respiratory tract infection with an 
antibiotic. After administration of the 
drug, the patient developed fever, 
pruritus, and rashes. A complete blood 
count was done. Apart from the anemia 
and mild lymphocytosis, the rest of the 
complete blood count was within normal 
limits. Direct Coombs' test was positive. 
The most likely reason for the 
autoimmune hemolytic anemia after 
therapy in this patient was due to the 
drug being a: 
1/1 
superantigen 
hapten 
polysaccharide Ag 
mitogen ionophore

hapten

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A 16-year old boy is injured while
playing football. He does not remember
the last time he had a tetanus shot, so the
attending physician administers a tetanus
toxoid vaccine. this kind of immunity
would be best classified as:

natural active natural 
passive artificial 
active artificial 
passive acquired 
passive

active artificial

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A child with recurrent pyogenic
sinopulmonary infections comes to the
clinic with fever and sinusitis. on workup
of this patient, it is discovered that the
neutrophils of the child do not show the
oxidative burst phenomenon. A
diagnosis of chronic granulomatous
disease is made. Because neutrophils are
part of the innate immune response, the
characteristic that most likely
corresponds to cells of the innate
immune system is:
1/1
memory response
specificity lag time for primary response
present at birth
acquired response to Ags

present at birth

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present at birth

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Digestion of an Ig with pepsin yields F(ab’)2 fragments. Several clinical trials using F(ab’)2 are being conducted for their use as blocking molecules. What is the immune phenomenon that is most likely to be seen with an F(ab’)2 fragment?
1/1
complement fixation
opsonization
Ag neutralization
Ig polymerization react with the Fc receptor

Ag neutralization

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Which type of cells is known to be 
involved in the initial presentation of 
antigen to T lymphocytes? 
1/1 
A Dendritic cells 
B Plasma cells 
C Neutrophil polymorphonuclear 
leucocytes 
D Erythrocytes 
E Platelets

A Dendritic cells

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Which of the following cells are thought 
NOT to be of monocyte-macrophage 
lineage? 
1/1 
A Neutrophils 
B Follicular dendritic cells of lymph nodes 
C Kupffer cells in liver 
D Histiocytes in tissues 
E Monocytes in blood

A Neutrophils

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Which of the following types of cell 
produce IgE? 
1/1 
A Mast cells 
B Eosinophils 
C Basophils 
D T lymphocytes
E Plasma cells

E Plasma cells

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Helper CD4+ T lymphocytes recognize 
which one of the following types of 
molecules on dendritic cells? 
1/1 
A HLA class I antigen 
B HLA class III antigen 
C Processed peptides from antigen
D CD8 antigen 
E Surface immunoglobulin

C Processed peptides from antigen

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Which one of the following statements
about the alternate pathway is FALSE?
1/1
A Properdin forms part of the C5 convertase.
B The alternate pathway isphylogenetically older than the classical pathway.
C The alternate pathway can be activated by bacterial cell walls.
D There is a positive feedback loop.
E Activity in vivo is best estimated by C4 levels.

E Activity in vivo is best estimated by C4 levels.

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Which of the following cell types is 
phagocytic? 
1/1 
A Hepatocytes 
B Lymphocytes 
C Monocytes 
D Erythrocytes 
E Plasma cells

C Monocytes

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Type I hypersensitivity classically 
involves which one of the following?
1/1 
A IgM 
B IgD 
C Macrophages 
D IgE 
E Enterocytes

D IgE

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Which one of the following cytokines act 
as a chemo-attractant for eosinophils: 
1/1 
A IL-5 
B IL-10 
C IFN-gamma 
D IL-2 
E IL-7

A IL-5

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Which one of the following statements 
about isotype switching by B cells is 
true? 
1/1 
A Isotype switching by B cells is dependent on the interaction between CD40 on the Bcell surface and its ligand on activated T cells, CD40L.

B B-cell switching involves switching from IgG to IgM isotypes

C Specific recognition of the antigenic peptide is not required D CD28 on the B cell recognizes CD86 on the T cell to allow augmentation of the activation process

A Isotype switching by B cells is dependent on the interaction between CD40 on the Bcell surface and its ligand on activated T cells, CD40L.

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When either CD40 or CD40 ligand are
missing (as in CD40 Ligand or CD40
deficiency), no switching occurs. Which
one of the following statements about
antibody production is true?
1/1
A B cells cannot produce specific antibody without T-cell help.
B Tregs can produce antibodies to regulate autoantibody production
C The BCR of B cells is a member of the immunoglobulin superfamily

C The BCR of B cells is a member of the immunoglobulin superfamily

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Which one of the following statements about genes for immunoglobulin production is true?
1/1
A Heavy and light chains of immunoglobulin molecules are coded for by genes on the same chromosome
B Kappa chains are coded on chromosome 14
C Lambda chains are coded on chromosome 14
D Heavy chains are coded on chromosome 14

D Heavy chains are coded on chromosome 14

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Where do B lymphocytes develop? 
1/1 
spleen 
thymus 
MALT 
tonsils 
none of the choices

none of the choices

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``` What is the normal CD4: CD8 ratio? 1/1 10:1 2:1 5:1 4:2 ```

2:1

Which of the following is false? 1/1 The anamnestic response is an accelerated response. IgM is produced first in a primary response. IgG is the predominant Ab in the secondary response. the primary and the secondary response are similar

the primary and the secondary response are similar

``` Which part of the immunoglobulin molecule determines the Ig class? 1/1 light chains heavy chains Fc Fab none of the choice ```

heavy chains

``` Injection of an attenuated Ag should result in the development of which type of immunity? 1/1 active passive innate ```

active

An Ab-mediated immunity involving B lymphocytes and plasma cells and provides defenses against extracellular pathogens. cell mediated humoral innate T lymphocyte-mediated immunity

humoral

``` Are the sites of Ag independent differentiation of lymphocytes. 1/1 peripheral lymphoid organs primary lymphoid tissues GALT spleen lymph nodes ```

primary lymphoid tissues

``` What is the name of the region of the Ig molecule that creates the Ag-binding site? 1/1 Fc CH region CV region Fab CL region ```

Fab (fragment Ag-binding)

``` Which Ig is a pentamer and is the first immunoglobulin developed during human fetal development at 20 weeks? 1/1 IgM IgG IgA IgD IgE ```

IgM

``` Which Ig is present on mucosal surfacesand serves as the first line of defense against Ags? 1/1 IgG IgM IgD IgE IgA ```

IgA

Which of these Ab can bind to complement? IgA and IgE IgG and IgM

IgG and IgM

``` Where does the complement attach to the Ig molecule? 1/1 IgG and IgD IgG and IgA to the TCR to the BCR to the Fab region to the Fc region none of the choices ```

to the Fc region

``` Which cells have surface receptors to the Fc portion of IgE? 1/1 neutrophils and basophils basophils and macrophages mast cells and basophils eosinophils and neutrophils ```

mast cells and basophils

``` Which ions are required in the complement cascade? 1/1 chromium (III) Cr3+ and hydrogen H+ calcium Ca2+ and magnesium Mg2+ potassium K+ and aluminum Al3+ cadmium Cd2+ and iron (II) Fe2+ none of the choices ```

calcium Ca2+ and magnesium Mg2+

What is the end point of complement activation? ``` opsonization chemotaxis phagocytosis cellular lysis none of the choice ```

cellular lysis

``` Are cytokines produced by T cells and other cells that inhibit viral synthesis or act as immune regulators 1/1 interferons interleukins TGF beta ```

interferons

``` Which cells do not possess HLA Ags? 1/1 neutrophils chemokines TNF alpha macrophages erythrocytes megakaryocytes hepatocytes melanocytes ```

erythrocytes

``` The chemokine receptors ____ and ____ function as coreceptors for HIV-1 entry into CD4+ cells. 1/1 CCR6 and CXCR 8 CXCR4 and CCR5 C1 AND CXC10 CX3C and XC4 ```

CXCR4 and CCR5

The chemokine receptors CXCR4 and CCR5 function as coreceptors for HIV-1 entry into CD4+ cells. During the early stages of HIV infection, viral isolates tend to use CCR5 for viral entry, while later isolates tend to use CXCR4. B lymphocytes and T lymphocytes are derived from A. Hematopoietic stem cells B. Macrophages or monocytes C. Mucosa-associated lymphoid tissue D. The fetal liver

A. Hematopoietic stem cells

``` In patients with human immunodeficiency virus infection, immune status can be monitored by measuring the ratio of. 1/1 A. CD3+ cells to CD8+ cells B. CD4+ cells to CD8+ cells C. Lymphocytes to monocytes D. T cells to B cells ```

B. CD4+ cells to CD8+ cells

``` Cells that can act as antigen-presenting cells for exogenous antigens include 1/1 A. All nucleated cells B. Endothelial cells C. B lymphocytes D. T lymphocytes ```

C. B lymphocytes

The isotype of an immunoglobulin antibody 1/1 A. Is defined by the heavy chain B. Is defined as different alleles of the same antibody type (e.g., IgG) C. Is constant for all immunoglobulins of an individual D. Is the variation within the variable region

A. Is defined by the heavy chain

What is the indicator system used in the complement fixation test? 1/1 A. Sensitized sheep red blood cells B. Fluorescent-labeled antihuman globulin C. Enzyme-labeled antihuman globulin D. Guinea pig complement

A. Sensitized sheep red blood cells

``` A cut on a person's finger becomes contaminated with the bacterium Staphylococcus aureus. The first response by the immune system consists of activity of 1/1 A. B cells B. Monocytes C. Neutrophils D. T cells ```

C. Neutrophils

``` The alternative complement pathway 1/1 A. Can be activated by bacterial capsule polysaccharides B. Uses C5b as a C3 convertase C. Bypasses steps C3 through C5 D. Is inactivated by properdin ```

A. Can be activated by bacterial capsule polysaccharides

In the classical pathway of complement activation, 1/1 A. C3 is activated by binding C-reactive protein B. The sequence of activation is Cl, C2, C3,C4 C. Clq is activated by the presence of a single Fab region D. Activation by antibody requires one IgM or two IgG molecules

D. Activation by antibody requires one IgM or two IgG molecules

``` Which of the following complement proteins is part of the membrane attack complex? 1/1 A. Cl B. C3 C. C4 D. C5 ```

D. C5

Which of the following is a characteristic of T cells? * 1/1 A. Synthesize antibody B. Mature in the thymus C. Able to bind unprocessed antigen D. Primarily protect against extracellular parasites

B. Mature in the thymus

The activity of natural killer (NK) cells * 1/1 A. Does not require previous exposure to an antigen B. Involves phagocytosis and killing of bacteria C. Requires interaction with cytotoxic T cells D. Requires interaction with B cells

A. Does not require previous exposure to an antigen

``` Antibodies that bind to the same epitope are of the same * 1/1 A. Allotype B. Autotype C. Idiotype D. Isotype ```

C. Idiotype

``` Monoclonal antibodies are produced by 1/1 A. Cultured T cells B. Human plasma cells C. Mouse plasma cells D. Hybridomas ```

D. Hybridomas

Which of the following statements applies to the Fc fragment of an immunoglobulin molecule? 1/1 A. It consists of the entire heavy chain. B. It contains the variable region of the heavy chain. C. It contains the antigen binding sites of the molecule. D. It is the region of the molecule that binds to receptors on various white blood cells.

D. It is the region of the molecule that binds to receptors on various white blood cells.

Which of the following statements about immunoglobulin light chains is true ? 1/1 A. Each immunoglobulin monomer has either one kappa or one lambda chain. B. There are two types: kappa and lambda. C. They consist of constant regions only. D. They form part of the Fc fragment.

B. There are two types: kappa and lambda.

``` A human cell with CDS on its surface is most likely a 1/1 A. B cell B. Monocyte C. T helper cell D. Cytotoxic T cell ```

D. Cytotoxic T cell

``` Identical antibodies produced from a single clone of plasma cells describes * 1/1 A. Reagin B. Cold agglutinins C. Heterophile antibodies D. Monoclonal antibodies ```

D. Monoclonal antibodies

``` The portion of an antigen that binds to an antibody or T cell receptor is called a(n) * 1/1 A. Allergin B. Avidin C. Epitope D. Valence ```

C. Epitope

``` Innate immunity includes 1/1 A. Anamnestic response B. Antibody production C. Cytotoxic T cell activity D. Phagocytosis by polymorphonuclear cells ```

D. Phagocytosis by polymorphonuclear cells

``` The type of immunity that follows the injection of antibodies synthesized by another individual or animal is termed 1/1 A. Artificial active B. Natural adaptive C. Artificial passive D. Natural passive ```

C. Artificial passive

``` The type of immunity that follows the injection of an immunogen is termed 1/1 A. Artificial active B. Natural active C. Artificial passive ```

A. Artificial active

``` After activation of the complement system, leukocytes and macrophages are attracted to the site of complement activation by 1/1 A. C1 B. C5a C. C8 D. IgM ```

B. C5a

How does the secondary humoral differ from the primary response? * 1/1 A. The lag phase (the time between exposure to immunogen and production of antibody) is longer in the secondary immune response. B. IgM is the predominant antibody class produced in the secondary immune response. C. The antibody levels produced are higher in the secondary immune response. D. Cytotoxic T lymphocytes play an important role in the secondary response

C. The antibody levels produced are higher in the secondary immune response.

A major advantage of passive immunization compared to active immunization is that 1/1 A. Antibody is available more quickly B. Antibody persists for the life of the

A. Antibody is available more quickly

Which cell is the principal source of interleukin 2? 1/1 B. T cell C. Monocyte

B. T cell

Which cell is the principal source of interleukin 2? 1/1 B. T cell C. Monocyte

B. T cell

``` After exposure to antigen, the first antibodies that can be detected belong to the class 1/1 A. IgA B. IgE C. IgG ```

D. IgM

``` The serologically detectable antibody produced in rheumatoid arthritis (RA) is primarily of the class 1/1 A. IgA B. IgE C. IgG D. IgM ```

D. IgM

Severe combined immunodeficiency(SCID) is an 1/1 A. Immunodeficiency with decreased B. cells and neutrophils B. Immunodeficiency with lymphocytopenia and eosinophilia C. Immunodeficiency with decreased or dysfunctional T and B cells D. Immunodeficiency with decreased lymphocytes and decreased complement concentration

C. Immunodeficiency with decreased or dysfunctional T and B cells

``` Which class of immunoglobulin possesses delta heavy chains? 1/1 C. Immunodeficiency with decreased or dysfunctional T and B cells ```

C. Immunodeficiency with decreased or dysfunctional T and B cells

``` Which class of immunoglobulin possesses 10 antigenic binding sites? 1/1 A. IgA B. IgD C. IgE D. IgG ```

B. IgD

``` The major class of immunoglobulin found in adult human serum is 1/1 A. IgA B. IgE C. IgG D. IgM ```

C. IgG

``` An important part of the nonspecific immune response is(are) 1/1 A. B cells B. Basophils C. Complement cascade D. Cytotoxic T lymphocytes ```

C. Complement cascade

``` What is the predominant type of antibody found in the serum of neonates born after full-term gestation? A. Infant IgA B. Infant IgG C. Infant IgM D. Maternal IgG ```

D. Maternal IgG

``` What is the predominant type of antibody found in the serum of neonates born after full-term gestation? A. Infant IgA B. Infant IgG C. Infant IgM D. Maternal IgG ```

D. Maternal IgG

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? 0/1 A. She has an autoimmune disease with continual antigen-antibody activity causing consumption of C3. B. She has DiGeorge syndrome. C. She has decreased production of C3. D. She may produce an inactive form of C2, a precursor of C3.

C. She has decreased production of C3.

``` HLA antigens are found on 1/1 A. All nucleated cells B. Red blood cells only C. Solid tissue only D. White blood cells only ```

A. All nucleated cells

``` HLA complex is located primarily on 1/1 A. Chromosomes B. Chromosome 6 C. Chromosome 9 D. Chromosome 17 ```

B. Chromosome 6

``` Cell-mediated immunity is primarily mediated by 1/1 A. B cells B. T helper cells C. Plasma cells D. Dendritic cells ```

B. T helper cells

``` Monocytes and macrophages play amajor role in the mononuclear phagocytic system. For an antibodycoated antigen to be phagocytized, what part of the antibody molecule fits into a receptor on the phagocytic cell? 1/1 A. Fc region B. Fab region C. Hinge region D. Variable region ```

A. Fc region

A lymphokine is 1/1 A. A soluble mediator produced by granulocytes and affecting lymphocytes B. A soluble mediator produced by lymphocytes C. A soluble mediator produced by plasma cells D. An antibody that reacts with lymphocytes

B. A soluble mediator produced by lymphocytes

Which of the following is characteristic of B cells? 1/1 A. Phagocytic B. Participate in antibody-dependent cellular cytotoxicity (ADCC) reactions C. Contain surface immunoglobulins D. Secrete the C5 component of complement

C. Contain surface immunoglobulins

A hapten is 1/1 A. Half of an immunoglobulin molecule B. A earner molecule for an antigen that is not antigenic alone C. An immunoglobulin functional only in the presence of complement D. A determinant capable of stimulating an immune response only when bound to a carrier

D. A determinant capable of stimulating an immune response only when bound to a carrier

The fundamental difference between primary and secondary organs of the lymphatic system is: 1/1 a. Antibody production occurs only in the primary lymph organs b. Complement production occurs only in the primary lymph organs c. Maturation of lymphocytes occurs in secondary organs, and activation occurs in primary organs d. Maturation of lymphocytes occurs in primary organs, and activation occurs in secondary organs

d. Maturation of lymphocytes occurs in primary organs, and activation occurs in secondary organs

``` A double-positive T cell would express which markers? 1/1 a. CD4+CD8+CD3+ b. CD4-CD8+CD3+ c. CD4-CD8-CD3- d. CD4+CD8-CD3+ ```

a. CD4+CD8+CD3+

``` Which cell is considered to be a bridge between the innate and adaptive immune systems? 0/1 a. NK cell b. Mast cell c. Monocyte-macrophage d. T cell ```

d. T cell

``` _______ are involved in cell-mediated immunity, whereas _______ are involved in humoral immunity. 1/1 a. T cells; B cells b. T cells; antibodies c. B cells; T cells d. A and B ```

d. A and B

``` Antigens that make very good immunogens include which of the following? 1/1 a. Carbohydrates b. Proteins c. Both a and b d. Neither a or b ```

b. Proteins

``` The function of the complement system include(s)which of the following? 1/1 a. Clearance of cellular debris b. Chemotaxis c. Lysis of bacteria d. All of the above ```

d. All of the above

When C3 is cleaved by C3 convertase, what is the result? 1/1 a. C3a is released b. C3b is used as an opsonin c. C3b is combined with other complement proteins to form C5 convertase d. All of the above

d. All of the above

``` A patient with a viral infection to the ABC virus is found to have a high antibody titer to the ABC virus’s RNA, or anti-ABCr. Which of the following is true? 1/1 a. MHC class I molecules presented antigen to CD4+ T cells b. MHC class II molecules presented antigen to CD8+ T cells c. MHC class I molecules presented antigen to CD8+ T cells d. MHC class II molecules presented antigen to CD4+ T cells ```

c. MHC class I molecules presented antigen to CD8+ T cells

Characteristics of cytokines include which of the following? 1/1 a. They can have a pleomorphic effect b. Cytokines are redundant c. Cytokines enhance cellular differentiation of lymphocytes d. All of the above

d. All of the above

``` Immunoglobulin idiotypes are antibodies with variations in the domains of which of the following? 1/1 a. CH1 and CH2 b. VH and VL c. VH and CL d. CH 1, CH 2, and CH 3 ```

b. VH and VL

``` Immunoglobulin idiotypes are antibodies with variations in the domains of which of the following? 1/1 a. CH1 and CH2 b. VH and VL c. VH and CL d. CH 1, CH 2, and CH 3 ```

b. VH and VL

``` Mannose-binding lectin is similar to which component of the classical pathway? 1/1 a. C3 b. C2 c. C1q d. C5a ```

c. C1q

``` Fixation of the C1 complement component is related to each of the following factors except: 1/1 a. Molecular weight of the antibody b. The presence of IgM antibody c. The presence of most IgG subclasses d. Spatial constraints ```

a. Molecular weight of the antibody

``` At which stage does the complement system reach its full amplitude? 1/1 a. C1q, C1r, C1s complex b. C2 c. C3 d. C4 ```

c. C3

``` Which of the following conditions can be associated with hypercomplementemia? 1/1 a. Myocardial infarction b. Systemic lupus erythematosus c. Glomerulonephritis d. Subacute bacterial endocarditis ```

a. Myocardial infarction

``` All the following are complementcontrolling proteins except: 1/1 a. C1 (INH) b. Factor I c. Factor H d. C3 ```

d. C3

All the following result from complement activation except: 1/1 a. Decreased cell susceptibility to phagocytosis b. Blood vessel dilation and increased vascular permeability c. Production of inflammatory mediators d. Cytolysis or hemolysis

a. Decreased cell susceptibility to phagocytosis

Which activity is associated with interferon? 1/1 a. Enhances phagocytosis b. Retards expression of specific genes c. Promotes complement-mediated cytolysis d. Interferes with viral replication

d. Interferes with viral replication

``` Which complement component is present in the greatest quantity in plasma? 1/1 a. 2 b. 3 c. 4 d. 8 ```

b. 3

``` Which complement component is present in the greatest quantity in plasma? 1/1 a. 2 b. 3 c. 4 d. 8 ```

b. 3

Tumor necrosis factor (TNF) differs from IL-1 in that TNF is not able to: 1/1 a. Mediate an acute inflammatory reaction b. Increase the expression of IL-2 receptors c. Enhance the proliferation and differentiation of B lymphocytes d. Stimulate T cell proliferation

d. Stimulate T cell proliferation