Immunology Review HCMC
A male infant had been well until about 5 months of age, at which time he was diagnosed as having otitis media and bronchitis cuased by H. influenza. Over the next several months he presented with streptococcal phenymonia and giardiasis. At 10 months of age a serum protein ELP showd a virtual lack of gamma globulins. Quantitative serum levels were: 75 mg/dL IgG and undetectable levels of IgM, IgA, IgE, and IgD. There were a normal number of T cells and they exhibited normal mitogen simulation. What disease does this child most likely suffer from? A. Multiple myeloma B. Combined immunodeficiency C. Iatrogenic immunodeficiency D. X-lined agammaglobulinemia E. DiGeorge's syndrome
D. DiGeorge's sydrome -The case history is typical of a child with X-linked agammaglobulinemia. He presented with chronic and recurrent infections beginning at 5 months of age, when transplancentally acquired IgG had declines. -Normal IgG serum level is about 300-1200 mg/dL. -Theinfact had normal T cell function, which rules out combined ummunodeficiency and DiGeorge syndrome. -Iatrogenic immunodeficiency reers to an immunodeficiency following therapy prescribed by a physician.
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 person read the slide D. Dilute the sample and repeat
D. Dilute the same and retest -An unexpected patter may indicate the presence of more than one aby - diluting may help to clearly show to aby specificities, if they are found in different titers -If the pattern is still atypical, a new sample should be collected and the test repeated
In testing for DiGeorge's syndrome, what type of lab analysis would be most helpful in determining the number of mature T cells? A. CBC B. Nitroblue tetrazolium (NBT) test C. T-cell enzyme assays D. Flow cytometry
D. Flow cytometry -DiGeorge's syndrome is caused by a developmental failure or hypoplasia of the thymus, and results in a deficiency of T lymphs and cell-mediate immune function. -The T-cell count is low, but the level of immunoglobulins is usually normal.
Which is classified as an MHC class II ag? A. HLA-A B. HLA-B C. HLA-C D. HLA-DR
D. HLA-DR -Expressed on B cells
All of the following tests measure phagocyte function except: A. Leukocyte adhesion molecule analysis B. Hydrogen peroxide production C. NBT test D. IL-2 assay
D. IL-2 assay
Which of the following methods is least likely to give a definitive result for the diagnosis of RA? A. Nephelometric measurement of anti-IgG B. Agglutination testing for rheumatoid factor C. ELISA of anti-IgG D. Immunofluourscence testing for antinucler abys
D. Immunofluourscence testing for antinuclear abys -Patients with RA usually show a homogenous pattern of fluorescence in tests for antinuclear abys. However, this patter is seen in a wide range of systemic autoimmune disease andin manh normal persons at a titer below 10.
What is the predominant type of aby found in the serum of neonates?
D. Maternal IgG (can cross the placenta)
24. You are evaluating an ELISA assay as a replacement for your immunoflourescent antinuclear aby test. You test 50 specimens in duplicate on each assay. The ELISA assay used a HEp-2 extract as its ag source. The correlation between the ELISA and the IFA tests is only 60% (30 of 50 specimens agree). Which of the following is the next best course of action? A. Test another 50 samples B. Perform a compentency check on the technologist who performed the tests C. Order a new lot of both kits and then retest on the new lots D. Refer the discrepant specimens for testing by another method
D. Refer the discrepant specimens for testing by another method
A transplant patient began to show signs of rejection 8 days after receipt of the transplanted organ, and the organ was removed. What immune elements might by found in the rejected organ? A. antibody and complement B. Primarily antibody C. Mfs D. T cells
D. T cells -Acute rejection occurs within 3 weeks of transplantation. -The immune elements most likely to be involved in an acute rejection are T cells in a type IV, DTH (cell-mediated) rection. -Preformed aby, and ossibly complement, is usually involved in hyperacute (immediate) rejection and crhonic rejection.
What is the main use of lab tesets to detect antibodies to islet cells and insulin in cases of insulin-dependent diabetes mellitus (IDDM)? A. To regulate levels of injected insulin B. To diagnose IDDM C. To rule out the presence of other autoimmune diseases D. To screen susceptible individuals prior to destruction of beta cells
D. To screen susceptible individuals prior to destruction of beta cells
What hypersensitivty reactions is the C3 complement component involved in? A. Type I and IV hypersensistivity response B. Type II and IV hypersensitivity response C. Type I and III hypersensisvity response D. Type II and III hypersensitivity response
D. Type II and III -If a person was deficient in C3 the responses would be deficient or 'normal'
What abys are represented by the nucleolar pattern in the immunofluorescence test for antinuclear abys? A. Antihistone antibodies B. Anti-dsDNA abys C. Anti-ENA (anti-Sm and anti-RNP) abys D. Anti-RNA abys
D. anti-RNA abys -The pattern may be seen in most systemic autoimmune disease and is especially common in patients with scleroderma
Which of the following is true about the test of CRP? A. It is diagnostic for rheumatic fever B. It measures patient antibody C. The antigen used is particulate D. The aby used may be absorbed to latex beads E. All of the above
D. the aby used may be absorbed to latex beads
How does the secondary immune response differ from the primary immunes response? A. IgG is the predominant aby class produced B. Shorter lag phase C. Higher aby levels formed D. Steeper log phase of aby formation E. All of the above
E. All of the above
The alternate pathway for complement activation A. Does not require aby for activation B. Bypasses steps C1-C4 C. Can be activated by bacterial capsule polysaccharides D. Can by activated by properdin E. All of the above
E. All of the above
Which are true about immunoglobulin light chains? A. There are two types: kappa and lambda B. They form part of the Fab structure C. They contain a constant and variable region D. Each immunoglobulin molecule has either one kappa or one lambda chain E. All of the above
E. All of the above
Which are true about monoclonal abys of the same clone? A. They are produced by a hybrid cell in tissue culture B They are produced by a malignant cell C. They are highly specific D. They have the same idiotype E. All of the above
E. All of the above
Which of the following have been identified as B cell surface markers? A. Immunoglobulin B. Fc receptor C. C3 receptor D. MHC class II ags E. All of the above
E. All of the above -Surface Igs on B cells usually have mu and delta heavy chains (IgM and IgD). -They also contain receptors to bind the Fc portion of igs. -Receptors for C3 are on about 75%. -B cells have MHC class II ags, which are involved in T and B cell cooperation.
Which of the following is characteristic of contact hypersensistivity reactions? A. Usually due to a hapten B. Casued by T-cell activity C. Frequently initiated by metals such as nickel D. Primarily an epidermal reaction E. All of the above
E. All of the above Contact sensitivity reactions are common with metal ions or plant contact. Binding of these haptens to skin proteins results in a T-cell sensitivity.The epidermal reaction can be distinguished from a bacterial inflammatory reaction by the lack of neutrophils
A 5-year old boy siffering from fever, inflamed cervical lymph nodes, multiple skin abcesses, and granulomes was admitted to the hospital. Lab results: WBC: 15,000/mm Diff: 72% PMN 20% lymphs 5% monos 2% eos 1% basos Tota immunoglobulins: elevated CH50: Normal Serum protein ELP: Normal Skin test against Candida ags: positive Nitroblue tetrazolium (NBT): Negative T cell conA stimulation: Normal Which describes his immune deficiency? A. B cell deficiency B. T cell deficiency C. Neutropenia E. Defective neutrophil function
E. Defective neutrophil function -Most reslts of immune function were normal, complement (CH50), B cells (immunoglobulin assay), and T cell (Con-A stimulation and Candida skin test). -An abnormal NBT test indicates defective netrophil functions, which is supported by the granulomatous disease.
Contact dermatitis is mediated by: A. IgA B. IgD C. IgE D. Polymorphonuclear cells E. T lymphocytes
E. T lymphocytes (cell-mediated hypersensitivity reaction)
Which of the following is not a charcteristic of B cells? A. Differentiate in to plasma cells B. Contain surface immunoglobulins C. Become memory cells D. Form rosettes with unsensitized sheep red blood cells E. all are characteristics are true
E. all characteristics are true
In the enzyme-linked immunosorbent assay (ELISA) system, the visible reaction is due to a reaction between what?
Enzyme and substrate
What outcome results from improper washing of a tube or well after adding the ezyme=aby conjugate in an ELISA system? A. Result with be falsely decreased B. Result will bu falsely increased C. Result with be unaffected D. Result is impossible to determine
B. Result will be falsely increased - If unbound enzyme-conjugated anti-immunoglobulin is not washed away, it will catalyze conversion of substrate to colored product, yeilding a falsely elevated result
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. Reuslt will be falsely incrased -If the color reaction of not stopped within the time limits, the enzyme will continue to act on the substrate, producing a falsely elevated result.
What immune elements are involved in a positive skin test for TB? A. IgE abys B. T cells and mfs C. NK cells and IgG aby D. B cells and IgM aby
B. T cells and mfs -Localized typ IV cell-mediated hypersensitivity. May take 72 hrs to peak.
Tests to ID infection with HIV fall into which three geneneral classification types of tests? A. Tissue culture, ag, and aby B. Tests for ags, abys, and nucleic acid C. DNA probe, DNA amplification, and Western blot D. ELISA, Western blot, and Southern blot tests
B. Tests are ags, abys, and nucleic acid
Which region determined whether an immunoglobulin molecule can fix complement? A. The variable region of the heavy chain B. The constant region of the heavy chain C. The variable region of the light chain D. The constant region of the light chain
B. The constant region of the heavy chain
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 mfs 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 uscle, and release of histamine from basos
Why is skin testing the most widely used method to test for a type I hypersensitivity reaction? A. it causes less trauma and is more cost-effective than other methods B. It has greater sensitivity than in vitro measurements C. It is more liley to be positive for IgE-specific allergens than other methods D. It maybe used to predict the development of further allergen sensitivity
B. it has greater sensitivity than in vitro measurements -In vitro measurements = measure total or ag-sepcific IgE
A kidney transplant from on identical twin to another is an example of a(n) A. allograft B. autograft C. isograft D. xenograft
C
An important part of the nonspecific immune response is(are) A. B cells B. Basophils C. complement cascade D. Cytotoxic T lymphocytes
C
In bone marrow transplantation, immunocompetent cells in the donor marrow may recognize antigens in the recipient and respond to those antigens. The phenomenon is an example of: A. acute rejection B. Chronic rejection C. Graft versus host disease D. Hyperacture rejection
C
Severe combined immunodeficiency (SCID) is an 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
When performing the enzyme-multiplied immunoassay technique (EMIT), how is the ligand in the patient's serum detected? A. agglutinates by binding to antibody-coated latex beads B. binds to enzyme-labeled antibody C. competes with enzyme-labeled antigen for binding to a specific antibody D. Forms antibody-antigen complex and precipitates
C
Which of the following tests is used to detect circulating immune complexes in the serum of some patients with systemic autoimmune diseases such as rheumatoid arthritis? A. direct immunofluorescence B. Enzyme immunoassay C. Assay of cryoglobulins D. Indirect antiglobulin test
C. Assay of cryoglobulins
The strength with which a multivalent aby binds to a multivalent ag is termed the: A. Specificity B. Affinity C. Avidity D. Valence E. Reactivity
C. Avidity
Which is characteristic of B cells? A. phagocytic B. Participate in antibody-dependent cellular cytotoxicity (ADCC) reactions C. Contain surface immunoglobulins D. Secrete the C5 component of complement
C. B cells carry surface immunoglobulins that react to a specific ag. The ag can then be internalized and presented to an appropriate T helper cell
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. Both IgG and IgM -Both help to initiate, but IgM is the more potent activator
A young woman showed increased susceptibility to pyogenic infections. Upon assay, she showed low level of C3. Which of the following statements is probably true: A. She has an autoimmune disease within continual antigen-antibody activity causing consumption of C3 B. She has DiGeorge Syndrome C. She had decreased production of C3 D. She may produce an inactive form of C2, a precursor of C3
C. C3 may be decreased due to a genetic defect that causes deficient production
What is measured in the CH50 assay? A. RBC quanitity needed to agglutinate 50% of aby B. Complement needed to lyse 50% of RBCs C. Compelment needed to lyse 50% of aby-sensitized RBCs D. Abys and complement needed to sensitize 50% of RBCs
C. Compelment needed to lyse 50% of aby-sensitized RBCs -Low levels are associated with deficiency of some complement components and active systemic autoimmune disease in which complement is being consumed.
What is the main difficultly associated with the development of an HIV vaccine? A. The virus has been hard to culture; ag extraction and concentration are extremely laborious B. Human trials cannot be performed C. Different strains of the virus are genetically diverse D. Anti-idiotype abys cannot be developed
C. Different strains of the virus are genetically diverse -New strains are constantly emerging
Which in vitro test measures IgE levels against a spcific allergen? A. Histamine release assay B. Radioimmunosorbent est (RIST) C. Fluorescent allergosorbent test (FAST) D. Precipitin radioimmunosorbent test (PRIST)
C. FAST - this has replaced RAST
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
Which region of the immunoglobulin molecule can bind ag?
Fab
Monos and mfs play a big 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
Which outcome indicates a negative result in a compelment fixation test? A. Hemagglutination B. Absence of hemagglutination C. Hemolysis D. Absence of hemolysis
C. Hemolysis -The absence of hemolysis indicates that compelment was fixed in an ag-aby reaction and therefore, that the specific complement binding aby was present in the patient's serum. Consequently it was not avaialable to react in the indicator system.
Monoclonal abys are produced by A. cultured T cells B. Mouse plasma cells C. Human plasma cells D. Hybridomas E. None of the above
C. Human plasma cells
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 ags
C. Interacting with Tc cells to lyse viruses -Tc cells lyse virally infected cells direction, without requirement for specific abys. -The Tc cell is activated by viral ag that is associated with MHC class I molecules on the surface of the infected cell. -The activated Tc cell secretes several toxins, such as tumor necrosis factor, with destroys the infected cell and virions.
Inflammation involves a variety of biochemical and cellular mediators. Which of the following may be increased within 72 hours after an initial infection? A. Neutrophils, macrophages, aby, complement, alpha1-antitrypson B. Mfs, T cells, aby, haptoglobin, fibrinogen C. Neutrophils, mfs, complement, fibrinogen, CRP D. Mfs, T cells, B cells, ceruloplasmin, complement
C. Neutrophils, mfs, complement, fibrinogen, CRP - all mediators are involved in an inflammatory response within 72 hours after initial infections.
The type of immunity that follows the injection of an aby is A. adaptive B. active C. Passive D. Innate E. Complementary
C. Passive
An antinuclear aby test is perfomed on a specimen from a 55 yr old woman with unexplained joint pain. The IFA result is a titer of 40 and a homogenous pattern. The appropriate follow-up for thsi patient is: A. Anti-DNA assay B. ENA testing C. Retest ANA in 3-6 months D. CH50 complement assay
C. Retest ANA in 3-6 months About 25% of women in this age range may have low titer positive ANA assays with no demonstratable disease.
Which disease is liley to show a rim (peripheral) pattern in an immunofluourescnce (IF) micrscopy test for ANA? A. Mixed connective tissue disease (MCTD) B. Rheumatoid arthritis C. Systemic lupus erythematosis D. Scleroderma
C. SLE -The responsible autoaby is highly correlated to anti-dble stranded DNA (anti-dsDNA)
In Bruton's disease, serum ELP would show: A. and elevated albumin peak B. A reduced ablumin peak C. The absence of a gamma globulin peak D. a "church spire" gamma globulin peak E. A broad-based gamma globulin peak
C. The absence of a gamma globulin peak (agammaglobulinemia)
In the enzyme-linked immunosorbent assay (ELISA) A. the enzyme system is attached to patient aby B. A radioactive label is required C. The end point must be determined by a spectrophotometer D. The system may be adapted to detect ag E. All of the above
C. The end point must be determined by a spectrophotometer ELISA system is a method in which an aby that has been complexed to an enzyme system reacts with an initial ag-aby reaction.
Which disease may be expected to show an IgM spike on an elxtrophoretic pattern? A. Hypogammaglobulinemia B. Multicystic kidney disease C. Waldentrom's macroglobulinemia D. Wiskott-Aldrich syndrome
C. Waldenstrom's macrogolbulinemia -Is a malignancy of plasmacytoid lymphs involving both the BM and lymph nodes. The malignant cells secrete monoclonal IgM and are in transition from B cells and plasma cells. -In contrast to multiple myeloma, osteolytic bone lesions are not found.
What is the name of the process by which phagocytic cells are attracted to a substance such as a bacterial peptide?
Chemotaxis
When chromosome is the HLA complex primarily located on?
Chomosome 6
Which MHC class of antigens is necessary for ag recognition by CD4-positive T cells?
Class II -Helper T cells recognize ags only in the context of a class II molecule, -Because vlass II ags are expressed on mfs, monos, and B cells, the helper T-cell response is mediated by interaction with processed ag on the surface of these cells.
A hapten is: A. Half of an immunoglobulin molecule B. A carrier 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
Corneal tissue may be transplanted successfully from one patient to another because A. the cornea is nonantigenic B. Corneal ags do not activate T cells C. Anticorneal abys are easily suppressed D. The cornea occupies a privileged site not usually seen by the immune system
D
Type I hypersensitivity is A. associated with complement-mediated cell lysis B. Due to immune complex deposition C. Mediated by activated macrophages D. An immediate allergic reaction
D
What is the predominant type of antibody found in the serum of neonates born after full-term gestation?
D
Which describes a direct immunofluorescence assay? A. conjugated reagent ag reacts with abys to form ag-aby complexes B. Ags regact with unlabeled aby forming ag-aby complexes that attach to labeled abys C. A dye is attached to a molecule and it reacts with an immune complex to produce a color D. Conjugated reagent aby reacts with ag to form ag-aby complexes
D
In Brutons disease, measurement of serum immunoglobulins would show: A. Elevated levels of IgE B. Elevated levels of IgG C. Normal levels of IgG and IgM, but reduced levels of IgA D. The absence of all immunoglobulins
D- Burtons disease is a congenital form of agammaglobulinemia. It is a sex-linked phenomenon that affects males. B cells are not produced, affected males have levels of IgA, D, E and M undetectable by routine assay. IgG may be absent or present at very low levels.
A superantigen, such as toxic shock syndrome toxin-1 (TSST-1), bypasses the normal ag processing stage by binding and cross-linking: A. A portion of an immunoglobulin molecule and compelment component C1 B. Toll-like receptors and an MHC class I 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 - A super ag binds to the variable beta portion of the TCR and an MHC class II molecule. -This binding can activate T cells without the involvement of an APC.
All immunoglobulins have the same basic structure which consists of
2 heavy chains, 4 light chains
A major advantage of passive immunization compared to active immunization is that: A. Antibody is available more quickly B. Antibody persists for the life of the recipient C. IgM is the predominant antibody class provided D. Oral administration can be used
A
A molecule found in human serum sometimes used as a tumor marker is A. alpha fetoprotein B. HBsAg C. Biotin D. CD1
A
An example of immune injury dye to the deposition of antigen-antibody complexes is A. Acute glomerulonephritis B. Bee-sting allergy C. Contact dermatitis D. Penicillin allergy
A
HLA antigens are found on: A. All nucleated cells B. red blood cells only C. solid tissue only D. WBCs only
A
In individuals allergic to pollen, hyposensitization protocols may be initiated. These individuals receive injections of A. allergen B. Pooled human antisera C. Monoclonal aby directed against human T cells D. Monoclonal aby directed against human B cells
A
Mfs produce which of the following proteins during ag processing: A. IL-1 and IL-6 B. Interferon-gamma C. IL-4, IL-5, and IL-10 D. Compelement components C1 and C3
A IL-1 and IL-6 are proinflammatory mf-produced cytokins. -They also activate T-helper cells during ag presentation. -Il-4,5,10 are all produced by T cells. -Complement components are produced by a variety of cells but are not part of the mf ag presentation process.
Describe a syngeneic graft
A kidney transplantation from one identical twin to another
The type of immunity following the transfer of lymphocytes from an immune host to a non-immune host is A. Adaptive B. Active C. Passive D. Innate E. Complementary
A. Adaptive
Which of the following substances, sometimes used as a tumor marker, is increased two-or threefold in a normal pregnancy? A. Alkaline phosphatase (ALP) B. Calcitonin C. Adrenocortocotropic hormone (ACTH) D. Neruon-specific enolase
A. Alkaline phasophatase -Isoenzymes of ALP are sometimes used as tumor markers but have a low specificity becuase they are also increased in nonmalignant dieases.
What type of abys are represented by the solid or homogeneous patter in the immunofluorescence test for antinuclear abys? A. Antihistone B. Antocentromere C. Anti-ENA (anti-Sm and anti-RNP) abys D. Anti-RNA abys
A. Anti-histone (an also anti-DNA antibodies) cuase the solid or homogeneous pattern, which is commonly found in patients with SLE, RA, MCTD, and Sjogren's syndrome.
What type of disorders would show a decrease in C3, C4, and Ch50? A. Autoimmune disoderssuch as SLE and RA B. Immunodeficiency disorders such as common variable immunodeficiency C. Tumors D. Bacterial, viral, fungal, or parasitic infections
A. Autoimmune disorders such as SLE and RA -The pattern of decreased C3, C4, and CH50 indicates classic pathway activation, which results in consumption of complement.
For a substance to be antigenic it must A. Be recognized as non-self B. Be less than 5000 molecular weight C. Be a linear molecule D. Be a lipid E. All of the above
A. Be recognized as non-self
Which of the following methods used for HIV ID is considered a signal amplification technique? A. Branched chain DNA analysis B. DNA PCR C. Reverse transciptase PCR D. Nucleic acid sequenced based assay (NASBA)
A. Branched chain DNA analysis -It is a signal amplification technique - no gene amplification -The detection reagent is amplified
Which of the folllowing complement proteins is not part of the membrane attack complex? A. C4 B. C5 C. C6 D. C7 E. C9
A. C4 The membrane attack complex follows the binding of C5 to a biologic memrane. The complex is formed by the sequential addition of C6, C7, C8, ad C9. When C5-C8 complexes with C9, a tubule is formed that bridges the cell membrane.
What screening test should be performed first in a young patient suspected of having an immune disfunction disorder? A. CBC B. Chemotaxis assay C. Complement levels D. BM biopsy
A. CBC
Which is the the only complement receptor on rbcs? A. CR1 B CR2 C. CR3 D. CR4 E. None of the above
A. CR1 - it enhances phagocytosis and is the only complement receptor found on rbcs. It is also found on granulocytes, monos and B cells. It serves as a cofactor in the cleavage of C3b to iC3b by Factor I.
What comproses the indicator system in an ELISA for detecting aby? A. Enzyme-conjugated aby + chromogenic substrate B. Ag-conjugate + chromogenic substrate C. Enzyme + ag D. Substrate + ag
A. Enzyme-conjugated aby + chromogenic substrate -The ELISA test measures aby using immobilized reagent ag.
Select the best donor for a man, blood type AB, in need of a kidney transplant A. His brother type AB, HLA matched for class II ags B. His mother, type B, HLA matched for class I ags C. His cousin, type O HLA matched for major class II ags D. Cadaver donor, type O, HLA matched for some class I and II ags
A. His brother, type AB, HLA matched for class II ags -Class II ags (HLA-D, DR, DQ, DP) deermine the ability of the transplant reipient to recognize the graft.
Which test should be performed when a patient has a reaction to transfused plamsa products? A. Immunoglobulin levels B. T-cell count C. Hemoglobin levels D. Red cell enzymes
A. Immunoglobulin levels -A reaction to plasma products may be found in an IgA-deficient person who has formed anti-IgA abys
All are immunological unctions of complement except: A. Induction of an antiviral state B. Opsonization C. Chemotaxis D. Anaphylatoxin formation
A. Induction of an antiviral state This is performed by interferons.
The cytokine most important for increased NK cell activity and decreased viral replications is A. Interferon gamma B. Interleukin 3 C. Interleukin 4 D. Interleukin 5 E. Interleukin 6
A. Interferon gamma
Which statement best describes immunophenotyping? A. Lineage determination by detecting ags on the surface of the gated cells using fluorescent abys B. ID of cell maturity using abys to detect ags within the nucleus C. ID and sorting of cells by front and side-scatter light from a laser D. Analysis of cells collected by flow cytometry using traditional agglutination reactions
A. Lineage determination by detecting ags on the surface of the gated cells using fluorescent abys
Which disease is least likely when a nucleolar pattern occurs in an immunofluorescence test for antinuclear abys? A. MCTD B. Sjogren's sundrome C. SLE D. Sceroderma
A. MCTD
Which of the following is more likely to be diagnostic of an acute infection? A. a total acute aby titer of 2 follow by a convalescent titer of 16 B. a total acute aby titer of 80 followed by a convalescent tier of 40 C. A total aby titer of 80 D. An IgG titer of 80
A. The most significant indicator of acute or recent infection is the presence of a rising antibody titer. A fourfold or greater rise in titer from 2 to 16, is significant.
The idiotype of an immunoglobulin aby A. Is the variation of an immunoglobulin aby B. Defines the light chain C. Defines the heavy chain D. Determines the subclass E. Is constant for all immunoglobulins of an individual
A. is the variation of an immunoglobulin aby - the idiotype refers to the variable region of an immunoglobulin molecule. The region is the portion of immunoglobulin that binds ag. Each clone of immunoglobulin usually has a unique idiotype.
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? A. Fc region B. Fab region C. Hinge region D. Variable region
A. the Fc region of an IgG molecule fits into an Fc receptor (FcR) on macrophages and monocytes. The Fc receptor bind to specific amino acid residues in the Fc region of the immunoglobulin. The variable region of immunoglobulin binds to the antigen.
Which test would best distinguish between SLE and MCTD? A. Ouchterlony or ELISA test for anti-Sm and anti-RNP B. Immunofluourescence testing with Crithidia and substrate C. Slide agglutination D. Lab tests can't distinguish between these disorders
A.Ouchterlony (double) or ELISA -Anti-Sm with or without anti-RNP is found in about one third of SLE patients. -Anti-RNP in the absence of anti-Sm is found in over 95% of MCTD patients.
What is the type of immunty that results from the injection of ag?
Active
What method may be used for tissue typing instead of serological HLA typing? A. PCR B. Southern blotting C. RFLP D. All of the above
D. All of the above -Many labs use PCR technology for the routine detmination of HLA type
HLA ags are foun don what cells?
All nucleated cells
A lymphokine is: 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
Cell-mediated immunity is primarily mediated by A. B cells B. T helper cells C. Plasma cells D. Dendritic cells
B
Diagnosis of grp A strep infection is indicated by the presence of: A. Anti-protein A B. Anti-DNase B C. Anti-bet-toxin D. C-reactive protein
B
Multiple myeloma is a A. lymphoproliferative disease of T cells B. Cancer of plasma cells characterized by increased kappa lambda chain synthesis C. lymphoproliferative disease resulting in a decrease in antibody production D. Cancer of monocytes characterized by increased kappa and lambda chain synthesis
B
The HLA complex is located primarily on Chromosome: A. 3 B. 6 C. 9 D. 17
B
Which cell is the principal source of interleukin 2? A. B cells B. T cell C. Monocyte D. Plasma cell
B IL2 is a lympokine produced by activated T helper cells. IL-2 principally affects T cells, including the cell that released IL-2, acting on its target cells via the IL-2 receptor. This receptor is not present on resting cells.
What type of cell predominates in the germinal centers of lymph nodes?
B cells - The germinal centers of lymph nodes are where B cells undergo transformation after ag stimulation.
What is the titer in tube No. 8 if tube No. 1 is undiluted and dilutions are doubled? A. 64 B. 128 C. 256 D. 512
B. 128 -The aby titer is reciprocal of the highest dilution of serum giving a positive reaction. -For dbling dilutions, each tube has 1/2 the amount of serum as the previous tube.
Which is NOT a characteristic of T cells? A. protection against intracellular parasites B. Aby synthesis C. Possess OKT1 (CD1) ag D. Able to bind ag E. Possess receptors for interleukin 2
B. Aby synthesis
An 18-yr old female presented with fever, sore throat, lethargy, and tender cervicallymphadenopathy. Relevant findings included splenomegaly and lymphocytosis wihth many large atypical lymphs. Additionally, monospot and heterophile aby tests were negative. IgG Titer IgM Titer CMV 1:20 0 EBV 0 1:80 Toxoplasma 0 0 What conclusion can be made concerning the diagnosis? A. Acute CMV infection B. Acute EBV infection C. Acute toxoplasmosis D. Acute hepaitits B infection E. Autoimmune disease
B. Acute EBV infection
Which 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
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. Dc cells C. B cells D. Large granular lymphocytes
B. Dc cells -TLRs are the primary ag recognition protein of the innate immune system. -They are found on ag-presenting cells like dc cels and mfs. -11 are known -TLRs recognize certain structural motifs common to infecting organisms.
A 19-year old girl came to her physician complaining of a sore throat and fatigue. Upon physical exam, lymphadenopathy was noted. Reactive lymps were noted of the diff, but a rapid test for IM abys was neg. Liver enzymes were only slightly elevated. What test(s) shold be ordered next? A. Hepatitis testing B. EBV serological panel C. HIV confirmatory testing D. BM biopsy
B. EBV serological panel -It would give a more accurate assessment than a rapid slide IM test. The time of appearance of the various antibiodes to the viral antigens differ according to the clinical course of the inection.
How are Tc cells and NK cells similar? A. Require aby to be present B. Effective against virally infected cells C. Recognize ag in association with HLA class II markers D. Do not bind to infected cells
B. Effective against virally infected cells NK cells don't exhibit MHC class restriction, whereas the activation of Tc cells required the presence of MHC class I moleculas in association with the viral ag.
Which is the most likely positive western blot result for infection with HIV? A. Band at p24 B. Band at gp60 C. Bands at p24 and p31 D. Bands t p24 and gp120
D. Bands at p24 and gp120 -To be considered pos by Western blot testing, bands must be found for at least 2 of the following three HIV proteins: gp41, p24, and gp120 or 160
Which complement component is foud in both the classic and alternate pathways? A. C1 B. C4 C. Factor D D. C3
D. C3
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 -Gating is the step to select the proper clls to be counted
In the classic pathway of complement activation A. C1q is activated by the presence of one Fab region B. C1q is bound to C9 in its inactive form C. the sequence of ctivation is C1,2,3,4 D. C3 is split into C3a and C3b E. C3 is activated by binding C-reactive protein
D. C3 is split into C3a and C3b
How is HLA typing used in the investigation of genetic diseases? A. For prediction of the severity of the disease B. For genetic linkage studies C. For direct diagnosis of disease D. Is not useful in this situation
B. For genetic linkage studies -HLA typing is useful in predicting some genetic disease and for genetic counseling becuase certain HLA types show strong linkage to seom diseases. -HLA typing is not specifically used to diagnose a disease or assess its severity.
What cell is the principle source of interleukin 2? A. B cells B. T cells C. Monos D. Plasma E. Fibroblast
B. IL 2 is a lymphokine produced exclusively by activated T cells. The only known targets of IL2 are T, B and NK cells. IL2 acts on its target cells via the IL2 receptor. This receptor is not present on resting cells.
What is the main advantage of the recovery and reinfusion of autologous stem cells? A. It slows the rate of rejection of transplanted cells B. It prevents graft-versus-host disease C. No HLA testing is required D. Engraftment occurs in a more efficient seqeunce
B. It prevents graft-versus-host disease
Which markers are found on mature, peripheral helper T cells? A. CD1,2,4 B. CD2,3,8 C. CD1,3,4 D. CD2,3,5
D. CD2,3,5
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. BM 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 lymhpoid organs C. Storage in either the cortex of 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 ag
B. Maturation and selection occur in the cortex; migration to the medulla; release of mature T cells to secondary lymphoid organs -Immature T cells travel from the BM to the thymus to mature into functional T cells. Once in the thymes, they undergo a selection and maturation sequence that begins in the cortex and moves to the medulla of the thymus. Thymic factors such as thyosin and thymopoietin and cells within the thymes such as mfs and dc cells assist in this sequence. After completion of the maturation cycle, T cells are released to secondary lymphoid organs to await ag recognition and activation.
Which class of immunoglobulin is found as dimers held together by a polypeptide called the J-Chain?
IgA - it is found in sero-mucoid secretions as a dimer stabilized by the J piece.
Which class of immunoglobulin possesses delta heavy chains?
IgD
Which class of immunoglobulin binds to basophils and mast cells to mediate immediate hypersensitivity reactions?
IgE
Which class of immunoglobulin can fix 2 homologous basophils and mediate atopic allergies?
IgE - mast cells and basos have surface receptors for the Fc portion of IgE.
In individuals allergic to bee venom, hyposensitization protocols may be initiated. These are designed to promote the formations of what class of abys?
IgG
The major class of immunoglobulin found in adult human serum is:
IgG
What is the major class if immunoglobulin found in adult human serum?
IgG (80%)
Which class of immunoglobulin has four isotypic subclasses?
IgG - based on differences in the havy chains: IgG1,2,3,4
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 aby bound by this protein is:
IgG - staphylococcal protein A binds only the IgG class (subclasses IgG1, 2 and 4)
Which class of antibody, referred to as incomplete aby, is able to agglutinate RBCs after anti-human globulin is added?
IgG - the name is given due to its decreased potential for agglutination compared to IgM.
After Exposure to antigen, the first antibodies that can be detected belong to what class?
IgM
The serologically detectable aby produced in RA is essentially always of the class:
IgM
The serologically detectable antibody produced in RA is primarily of what class?
IgM
Which class of immunoglobulins possesses 10 antigenic binding sites?
IgM
Which class of immunoglobulin possesses 10 antigenic binding sites?
IgM (pentamer)
A patient who is bood group O is accidentally trasfused with group A blood. What Aby is involved in this type II reaction?
IgM - naturally occurring anti-A in the form of IgM is present in the blood of a group O individual and would cuase an immediate transfusion reaction. -Cell destruction ocurs when abys bind to cells, causing destruction via compelment activation, therby triggering intravascular hemolysis.
How can interfering cold agglutinins be removed from a test sample?
Incubate the clot at 1-4C fro several hours then remove the serum -Cold agglutinins will attach to autologous red cells if incubated at 1-4C. The absorbed serum will be free of cold agglutinins.
How does immune injury occur in serum sickness?
Injury occurs due to the fomation of soluble circulating ag-aby complexes
What type of B cells are formed after antigen stimulation?
Plasma cells and memory B cells -Mature B cells exhibit surface immunoglobulin that may cross-link a foreign ag, thus formed the activated B cell and leading to capping and internalization of ag. -The activated B cells gives rise to plasma cells that produce and secrete immunoglobulins and memory cells that reside in lyphoid organs.
Which diease is indicated by a high titer of anti-Smith antibody?
SLE
Which T cell expresses the CD8 marker and acts specifically to kill tumors or virally infected cells?
T cytotoxic -Recognize ag in association with MHC class I complexed and act against target cells that express foreign ags. These include viral ags and the HLA ags that are the target of graft rejection.
What molecule on the surface of most T cells recognizes ag? What is the molecule made of?
The TcR -Consists of Two chains - alpha and beta
Corneal tissue can be transplanted from one patient to another because?
The cornea is a priviledged site not usually seen by the immune system
Which 2 organs are considered the primary lymphoid organs in which immunocompenent cells orignate and mature?
Thymus and Bone Marrow
Adjuvants are added to vaccine to do what?
increase the immune response
A soluble meditor produced by lymphocytes
lymphokine