Which two organs are considered the primary lymphoid Organs where immunocompetent cells Originate and mature?
Thymus and bone marrow
What is the name of the process by which phagocytic cells are attracted toward a substance such as a bacterial peptide?
which of the following are functions of immunoglobulins except?
Interact with Tc cells to lyse viruses
Affinity between individual antigen and antibody molecules depends upon several types of bonds such as ionic bonds, hydrophobic bonds, hydrogen bonds, and van der Waals forces. How is the strength of this attraction characterized?
The detection of precipitation reactions depends upon the presence of maximal proportions of antigen and antibody. A patient's sample contains a large amount of antibody but the reaction in a test system containing antigen is negative. What has happened?
Why is radioimmunoassay (RIA) or enzyme immunoassay (EIA) the method of choice for detection of certain analytes such as hormones, normally found in low concentrations?
Because of high sensitivity
what comprises the reaction system in an enzyme-linked immunosorbent assay (ELISA)?
Enzyme-conjugate + substrate + chromogen
Which type of nephelometry is used to measure immune complex formation almost immediately after reagent has been added?
All of the statements below regarding agglutination reactions used for serodiagnosis are true except?
Most agglutination reactions are direct reactions .
what has happened in a titer.if tubes numbered 5 - 7 show stronqer reaction than tube in 1 - 4?
The directions for a slide agglutination test instruct that after mixing the patient's serum and latex particles the slide must be rotated for 2 minutes. What would happen if the slide were rotated for 10 minutes?
Which serum antibody response usually characterizes the primary (early) stage of syphilis?
Detected 1-3 weeks after appearance of the primary chancre
What substance is detected by the rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) tests for syphilis?
A biological false-positive reaction is least likely with which test for syphilis?
Flourescent T. pallidum antibody absorption test (FTA-ASS)
A RPR card test performed on a spinal fluid sample was nonreactive. The physician was skeptical and asked for a repeat test of the spinal fluid. The RPR result was reactive 1:1 dilution. The result?
Is unreportable; the RPR card test should not be performed on spinal fluid
Interpret the following quantitative RPR test results: RPR titer: weakly reactive 1:8; reactive 1:8-1:64?
Excess antibody, prozone effect
Which tests are considered confirmatory test for HIV?
Immunofluorescence assay (IFA), Western blot; and radioimmunoprecipitation assays (RIPA)
what criteria constitute the classification system for HIV infection?
CD4-posititve T-cell count and clinical symptoms
Which T helper to T suppressor ratio is most likely in a patient with acquired immunodeficiency syndrome (AIDS)?
What constitutes a diagnosis of viral hepatitis?
Abnormal test results for liver enzyme. Clinical signs and symptoms. Positive results for hepatitis markers. All of the above
All of the following hepatitis viruses are spread through blood or blood products except?
Interpret the following results for EBV infection: IgG and IgM antibodies to viral capsid antigen (VCA) are positive?
Infection in the past
What is the endpoint for the antistreptolysin a (ASO) test?
Lowest-serum dilution that shows hemolysis
A streptozyme test was performed but the result was negative, even though the patient showed clinical signs of a streptococcal throat infection. What should be done next?
Another streptozyme test using diluted serum
All positive cold agglutinin tubes remain positive after 37 degree incubation except the positive control. What is the most likely explanation for this situation?
Antibody other than cold agglutinins
Which of the following positive antibody tests may be an indication of recent vaccination or early primary infection for rubella in a patient with no clinical symptoms?
Only IgM antibodies positive
why is laboratory diagnosis difficult in cases of Lyme disease?
Clinical response may not be apparent upon initial infection; IgM antibody may not be detected until 3-6 weeks after the infection
Which of the following is not an explanation for the development of autoimmune diseases?
Suppression of anti-idiotypic antibodies
Which disease is likely to show a rim (peripheral) pattem in an immunofluorescence (IF) microscopy test for ANA?
What type of antibodies are represented by the solid or homogenous pattern in the immunofluorescence test for antinuclear antibodies?
Anti histone antibodies
Which disease is least likely when a nucleolar pattern occurs in an immunofluorescence test for antinuclear antibodies?
When an antinuclear antibody test result does not fit a definite pattern what should be done next?
Repeat the test
An antinuclear antibody screen exhibits diffuse peripheral, and coarse-speckled fluorescence. All of the controls are acceptable. NO other samples tested in the same run exhibit multiple patterns of fluorescence. What should be done next?
Dilute the sample in question and reassay
Which of the following is used in rapid slide tests for detection of rheumatoid factors?
Fc portion of the IgG molecule
Which of the following methods is least likely to give a definitive result for the diagnosis of RA?
Immunofluorescence testing for antinuclear antibodies
What is the main use of laboratory tests to detect antibodies to islet cells and insulin in cases of insulin-dependent diabetes mellitus (IDDM)?
To screen susceptible individuals prior to destruction of B cells
which of the following is a description of type I hypersensitivity reaction?
Ragweed antigen cross-links with IgE on the surface of mast cells causing release of preformed mediators and resulting in symptoms of an allergic reaction
Why is skin testing the most widely used method to test for a type I hypersensitivity reaction?
It has greater sensitivity than in vitro measurements
Which in vitro test measures IgE levels against a specific allergen?
Radioallergosorbent test (RAST)
A patient who is blood group 0 is accidentally transfused with group A blood. What antibody is involved in this type II reaction?
Which test would measure the coating of red cells by antibody as occurs in hemolytic transfusion reactions?
Direct antiglobulin test (DAT)
Which test detects antibodies that have attached to tissues what type of laboratory analysis would be most helpful in determining the number of mature T cells?
resulting in a type II cytotoxic reaction?,Direct IF
Which of the following symptoms in a young child may indicate an immunodeficiency syndrome?
Recurrent bacterial, fungal, and viral Infections
What screening test should be performed first in a young patient suspected of having an immune dysfunction disorder?
Complete blood count (CBC) and white cell differential
Which disease may be expected to show an IgM spike on an electrophoretic pattern?
In testing for DiGeorge's syndrome what type of laboratory analysis would be most helpful in determining the number of mature T cells?
What is an advantage of performing a prostate-specific (PSA) test for prostate cancer?
PSA is stable in serum and not affected by digital-rectal exam
Inflammation involves a variety of biochemical and cellular mediators. Which of the following may be increased within 72 hours after an initial infection?
Neutrophils, macrophages, complement, fibrinogen, C-reactive protein
Which of the following statements is true regarding C-reactive protein (CRP)?
It can be elevated in postoperative patients
Which of the following is most likely to be associated with a false-negative urine pregnancy test performed by latex-particle agglutination immunoassay?
Specific gravity <1.010
Which of the following is characteristic of the Laurell or rocket technique of one-dimensional electroimmunoassay?
Antigen is moved by electrophoresis rather than by diffusion
In an immunoassay serum is added to a microtiter well coated with specific antibody. After incubation and washing, enzyme-labeled specific antibody is added. This procedure is?
A sandwich immunoassay
which of the following is true of the antihyaluronidase test?
The antibody in the patient's serum neutralizes the hyaluronidase activity