Basic principles of immunology

Identify a specific component of the adaptive immune system tha is formed in response to antigenic stimulation:

Immunoglobulin

compliment , losozyme, and commensal organisms all act nonspecifically

Basic principles of immunology

Which two areas are considered the primary lymphoid organs in which immunocompetent cells originate and mature.?

Basic principles of immunology

What types of B cells are formed after antien stimulation?

Basic principles of immunology

T cells travel from the bone marrow to the thymus for maturation. What is the correct order of maturation sequence for T cells in the Thymus?

Basic principles of immunology

Which cluster of differentiation (CD) marker appeares during the first stage of T cell development and remains present as an identifying marker for T cells?

CD2

Basic principles of immunology

Which markers are found on mature, peripheral helper T cells?

Basic principles of immunology

Which T cell expresses the CD8 marker and acts specifically to kill tumors or virally infected cells?

Basic principles of immunology

How are cytotoxic T cells (T_c cells) and natural killer (NK)cells similar?

Effective aginst virally infected cells.

and neither requires antibody to be present to to infected cells

Basic principles of immunology

What is the name of the process by which phagocytic cells are attracted to substance such as a bacterial peptide?

Chemotaxis

They detect a disturbance in the normal functions of boby tissue.

Basic principles of immunology

What are the immunological functions of complement?

Opsonizaton

 Chemotaxis

Anaphylaoxin

what isnt "Induction of antiviral state."

Basic principles of immunology

What complement component is found in both the classic and alternative pathways?

C3

In the classic pathway C3b forms a complex on the cell with C4b2a that enzymatically cleaves C5, In the alternative pathway , C3b binds to an activator on the cell surface, it forms a complex with factor  B called C3bBb which, like C42a3b, can split C5.

Basic principles of immunology

Which immunoglobulins help initiate the classic complement pathway?

Basic principles of immunology

How is complement actively destroyed in-vitro?

Basic principles of immunology

What is the purpose of C3a, C4a, and C5a, the split products of the complement cascade?

Basic principles of immunology

Which region of the immunoglobulin molecule can bind antigen?

Fab

Two Fab fragments are formed from hydrolysis of the immunoglobulin molecule by papain

Basic principles of immunology

Which region determines wether an immunoglobulin can fix complement?

C_H

The composition and structure of the constant region of the heavy chain determine wether that immunoglobulin will fix complement

Basic principles of immunology

Which immunoglobulin classes has a j chain?

IgM and sIgA

the J chain in IgM joins 5 molecules and the J chain in sIgA joins two molecules. 

Basic principles of immunology

Which immunoglobulin appears first in the primary immune response?

IgM

Basic principles of immunology

Which immunoglobulin appears in the higest titer in the secondary response?

Basic principles of immunology

What immunoglobulin can cross the placenta?

Basic principles of immunology

Which immunoglobulin cross-links mast cells to release histamine?

Basic principles of immunology

the following are functions of immunoglobulins:

Nutralizing toxic substances

Facilitating phagocytosis through opsonization

Combining with complement to destroy cellualar antigens

but NOT Interacting with T cells to lyse viruses

Cytitoxic T cells lyse virally infected cells directly, without requirement for specific antibody.

Basic principles of immunology

Which is classified as an MHC class II antigen?

HLA DR

The MHC region is located on the short arm of chromozome 6 and codes for antigens expressed on the surface  of leukocytes and tissues. The MHC region genes control immune recognition; their products include the antigens that determine transplantaton rejection . HLA DR antigens are expressed on B cells . HLA-DR2, DR3, DR4 and DR5 antigens show linkage with a wide range of autoimmune diseases.

Basic principles of immunology

Which MHC class of antigens is necessary for antigen recognition by CD4 positive T cells?

Class II

Helper T cells (CD4 positive T cells) recognize only in the context of a class II molecule.

(Class II molecules are expressed on macrophages)

Basic principles of immunology

Which are the products of HLA class III genes?

Basic principles of immunology

What molocule on the surface of most T cells recognizes antigen?

Basic principles of immunology

The T cellantigen receptor is similar to immunoglobulin molecules in that it:

Contains V and C regions on each of its chains.

(Variable and Constant)

Basic principles of immunology

Toll like receptors are found on which cells?

Dendritic cells

Toll-like receptors (TLR) are the primary antigen recognitin protein  of the innate immune system. They are found om the antigen presenting cells such as dendritic cells and macrophages.

Basic principles of immunology

Macrophages produce which proteins?

IL1 and IL6

Interlukin 1 and 6 are proinflammatory macrophage -produced cytokines.

they activate T cells

Basic principles of immunology

A superantigen, such as toxic shock syndrome toxin -1 (TSST1), bypass the the normal antigen processing stage by binding to and cross linking:

IMMUNOLOGICAL PROCEDURES

The interactin between an individual antigen and antibody molecule depends upon several types of bonds such as ionic bonds , hydrogen bonds, hydrophobic bonds, and vander Walls forces How is the strength of this attraction characterized?

Affinity

Affinity refers to the strength of a single antigen- antibody reaction.

IMMUNOLOGICAL PROCEDURES

A laboratory is evaluating anenzyme-linked immunosorbent assay (ELISA) for detecting an antibody to cyclic citrullinated peptide (CCP), which is a marker for rheumatoid arthritis. The laboatory includes serum from healthy volunteers and patients with other connective tissue diseases in the evaluation. These specimens determine which factor of the assay?

Specificity.

Specificity is defined as the negative result in the absence of the disease.

IMMUNOLOGICAL PROCEDURES

The detection of preciptation reaction depends on the presence of maximal proportions of antigen and antibody. A patient's sample contains a large amount of antibody, but the reaction in the test system containing the antigen is negative. What has happened?

IMMUNOLOGICAL PROCEDURES

Which part of the radial immunodiffusion (RID) test system contains the antisera?

Gel

the gel contains the antibody

IMMUNOLOGICAL PROCEDURES

What is the interpretation when an Ouchterlony plate shows crossed lines between wells one and two (antigen is placed in the center welland antisera in wells one and two)

Nonidenty between well one and two.

The antibody form well 1 recognozes a different antigenic determinant than the antibody from well 2

IMMUNOLOGICAL PROCEDURES

Why is radioimmunoassay (RIA) or enzyme immunoassay (EIA) the method of choice for detection of certian analytes, such as hormones, normally found in low concentrations.

IMMUNOLOGICAL PROCEDURES

What comprises the indicator system in an ELISA for detecting antibody?

Enzyme-conjuated antibody + chromogenic substrate.

IMMUNOLOGICAL PROCEDURES

What outcome results from improper washing of a tube or well after adding adding the enzyme antibody conjugate in an ELISA system?

lt will be falsey increased.

If unbound enzyme-conjuate is not washed away, it will catalyze conversion of substrate to colored product , yealding a falsely elevated result.

IMMUNOLOGICAL PROCEDURES

What would happen if the color reaction phase is prolonged in one tube or well of an elisa TEST?

Result would be falsley increased.

If the color reaction is not stopped within the time limits specified by the proceedure, the enzyme will contnue to act on the substrate, producing a falsely evevated test result.

IMMUNOLOGICAL PROCEDURES

A patient was suspected of having a lymphoprolifrative disorder. After several laboratory test were completed , the patient was found to have an IgM_k paraprotein. In what squence should the laboratory test leading to this diagnosis have been preformed.

Serum and urine protein electrophoresis followed by immunofixation electrophoresis (IFE) on the positives.

IMMUNOLOGICAL PROCEDURES

An IFE performed on a serum sample showed a narrow dark band in the lanes containing anti-γ and anti-λ. How should this result be interpreted?

Abnormal test results demonstrating monoclonal IgGλ.

IMMUNOLOGICAL PROCEDURES

Which type of nephelometry is used to measure immune complex formation almost immediately after reagent has been added?

Rate.

Rate nephelometry is used to measure formatin of small immune complexes as they are formed under conditions of antibody excess. The rate of the increase in photodetector output is measured within seconds or minutes and increases with increasing antigen concentration.Antigen concentration is determined by compareing the rate for the sample to that for standards using an algorythm that compensates for linearity.

IMMUNOLOGICAL PROCEDURES

An immunofluorescence microscopy assay (IFA) was performed, and a significant antibody titer was reported. Positive and negative controls preformed as expected . However , the clinica evaluation of the patient was not consistant with a positive finding. What is the most likely explanation of this situation?

The pattern of the fliorescence was misinterpreted.

Both pathological and nonpatholoical antibodies can occur you must interpret with caution

IMMUNOLOGICAL PROCEDURES

What corrective action should be taken when an indeterminant pattern occurs in an indirect IFA?

Dilute the sample and retest.

An unexpected pattern may indicate the presence of more than one antibody. Diluting the sample may help to clearly show the antibody specificities.. if they are found in different titers. If the pattrn is still atypical, a new sample should be collected and the test repeated.

IMMUNOLOGICAL PROCEDURES

What best describes passive agglutination reactions used for serodiagnosis?

Carrier particles for antigen such as latex particles are used.

IMMUNOLOGICAL PROCEDURES

What has happened in a titer, if tube Nos. 5-7 show a stronger raction than tube Nos. 1-4?

IMMUNOLOGICAL PROCEDURES

What is the titer in tube No. 8 if tube No.1 is undiluted and dilutins are doubled?

IMMUNOLOGICAL PROCEDURES

The directions for a slide agglutionation test instruct that after mixing the patients serum and latex particles, the slide must be rotated for 2 minutes. What would happen if the slide were rotated for 10 minutes?

False positive result.

Drying on the slide may lead to possible erroneously positive reading.

IMMUNOLOGICAL PROCEDURES

Which outcome indicaes a negative result in a complement fixation test?

hemolysis

In Complement fixation, hemolysis indicates a negative test result. The absence of hemolysis indicated that Complement  was fixed in an antigen antbody reaction and , therefore that the specific complement  binding antibody was present in the patients serum. Consequently it was not available to react in the indicator system.

IMMUNOLOGICAL PROCEDURES

What effect does selecting the wrong gate have on the results wen cells are counted by flow cytometry?

IMMUNOLOGICAL PROCEDURES

What statement best describes immunophenotyping?

IMMUNOLOGICAL PROCEDURES

A flow cytometry scattergram of a bone marrow sample shows a dense population of cells located in between normal lymphiod and normal myeloid cells . What is the most likely explanaton.

INFECTIOUS DISEASES

Which serum antibody response usually charaterizes the primary (early) stage of syphillus?

Detected 1-3 weeks after the appearance of the primary chanche.

INFECTIOUS DISEASES

What substance is detected by the rapid plasma reagin (RPR) and Venereal Disease research laboratory (VDRL) test for syphilis? 

INFECTIOUS DISEASES

What type of antige is used in the RPR card test?

INFECTIOUS DISEASES

Which of the following is the mos sensitive test to detect congenital syphilis?

INFECTIOUS DISEASES

A biological fale positive reaction is least likely with which test for syphlis?

INFECTIOUS DISEASES

A 12 yesr old girl has symptoms of fatiue and a localized lymphadenopathy. Laboratoryntest reveal a peripheral blood lymphocytosis, a positive RPR, and a positive sot test for IM. What test should be preformed next?

MHA-TP

treponemia test for syphilis. beause of the nonspecificity of the test methods.

INFECTIOUS DISEASES

What test is most likely to be positive in the tertiary stage of syphilis?

INFECTIOUS DISEASES

What is the most likely interpretation of the following syphilis serological results?

RPR reactive

VDRL reactive

MHA-TP nonreactive

INFECTIOUS DISEASES

Which sample is the sample of choice to evaluate latent or tertiary syphilis?

CSF

INFECTIOUS DISEASES

Interpret the following RPR test results:

RPR titer weakly reactive 1:8, reactive 1:8-1:64

INFECTIOUS DISEASES

Test to identify infection with HIV fall into which three general classification types of test? 

INFECTIOUS DISEASES

Which test are considered screening test for HIV?

INFECTIOUS DISEASES

Which test are considered confirmatory for HIV?

INFECTIOUS DISEASES

What is most likely a positive Western blot result for infection with HIV.

INFECTIOUS DISEASES

A woman who has had 5 pregnancies sussequently test positive for HIV by western blot. What is the most likely reason for this result?

INFECTIOUS DISEASES

Inerpret the following results for HIV infecction.

ELISA: positive

Repeat: positive

ELISA :negative

Western blot :no bands.

Negative for HIV

False positive in th first reaction or misinterpreted test.

INFECTIOUS DISEASES

Interpret the following results for HIV infection.

ELISA: positive

Western blot :indeterminant

radioimmunoprecipitaton assay (RIPA) negative

INFECTIOUS DISEASES

What is the most likely explanation when antibody test for HIV are negative but a polymerase chain reaction test preformed 1 week later is positive?

INFECTIOUS DISEASES

What criteria constitute the classification system for HIV infection?

INFECTIOUS DISEASES

What is the main difficulty associated with the development of an HIV vaccine?

INFECTIOUS DISEASES

Which T-helper to T-supressor ratio (T_h:T_s) is most likely in a patient with aquired immunedeficency syndrome (AIDS)

1:2

An inverted T_h:T_s  (less than 1.0) is a common finding in an AIDS patient.

INFECTIOUS DISEASES

What is the disadvantage of using a culture technique for diagnosis of HIV infection?

INFECTIOUS DISEASES

Which method is used to test for HIV infecton in infants who are born to HIV positive mothers?

Polymerase chain reaction.

ELISA and western blot primarily reflect the presence of the maternal antibody.

INFECTIOUS DISEASES

What is the most likely cause when a western blot or ELISA is positive for all samples and controls?

INFECTIOUS DISEASES

What constitutes a diagnosis of viral hepititis?

Abnormal test for liver enzymes, Clinical signs and symptoms, Positive results ofor hepititis markers.

(all of the above)

INFECTIOUS DISEASES

What is true about hepititis D virus?

INFECTIOUS DISEASES

All of the following hepititis viruses are spread through the blood or blood products except:

Hepititis B

Hepititis C

Hepititus D

Hepititis A is NOT

INFECTIOUS DISEASES

Which Hepititis B marker is the best indicator of early acute infection?

Hepititus B surface antigen

HBsAg

INFECTIOUS DISEASES

Which is the first antibody detected in serum after infection with Hepatitis B virus (HBV)

INFECTIOUS DISEASES

Which antibody persist in low level carriers fo hepatitis B virus?

IgG anti HBc

IgG antibodies to the Hepatitis B core antigen

INFECTIOUS DISEASES

What is the most likely explanation when a patient has clinical signs of viral hepatitis but test negative for hepatitis A IgM , hepatitis B surface antigen and hepatitis C antibody

The patient may be in the core window.

the period of hepatitis infection where both the surface antigen and surface antibody are undetectable

INFECTIOUS DISEASES

Which hepatitis B markers should be prformed on blood products?

INFECTIOUS DISEASES

Which hepatitis antibody confers immunoty aginst reinfection with with hepatitis B virus?

INFECTIOUS DISEASES

Which test, other than serological markers, is most consistantly elevated in viral hepatitis?

Alanine amino transferase

ALT

INFECTIOUS DISEASES

If only anti-HBs is positive, which of he following can be ruled out?

Chronic hepatitis B infection.

Persons with chronic HBV show a positive test result for anti HBc. (IgG or total) and HBsAg but not anti-HBs.

INFECTIOUS DISEASES

Interpret the following reults for EBV infection: IgG and IgM antibodies to viral capsid antigen (VCA) are positive

INFECTIOUS DISEASES

Which statement concerning non-Forssman antibody is true?

It is not absorbed by guine pig antigen

INFECTIOUS DISEASES

Given the heterophile antibody titer of 224, which of the results below indicate IM?

Absorption with Guine pig kidney        Absrption with beef cells

Five tube titer reduction                     Five tube titer redction

Antibodies to infectious mononucleosis (non Frossmann antibodies are not neutrilized or absorbed by guinea pig antigen (but are absorbed by beef cell antigen). A positive test is indicated by at least a four fold tube reduction in the heterophile titer.