Assays for Immune Function

Question 1

CBC with diff

Answer 1

• number of cells

- check morphology of cells

Question 2

general markers of inflammation

Answer 2

• ESR; erythrocyte sedimentation rate (sed rate)

- CRP; c-reactive protein

Question 3

chemistry panel

Answer 3

• check organ systems

- can include urinalysis

Question 4

first step in eval of antibody deficiency/defects

Answer 4

• measure total IgG, IgA, IgM

- check normal range

Question 5

pattern of abnormality important for

Answer 5

• specific immune deficiency

Question 6

measurement of IgG subclasses and/or IgE subclasses

Answer 6

• may be useful depending on presentation

Question 7

when do you check IgD?

Answer 7

• only if periodic fever

- not immune deficiency

Question 8

next step if any antibody deficiency is confirmed

Answer 8

• consider B cell quantitation

Question 9

most common immune deficiency

Answer 9

• selective IgA deficiency

Question 10

normal quantity does not always equal

Answer 10

• normal function

Question 11

assays for antibody function

Answer 11

• antibody titers to specific pathogens

Question 12

titer to vaccine

Answer 12

• known exposure

- diphtheria/tetanus titer

Question 13

response to polysaccharides

Answer 13

• pneumococcal titers in older children given the polysaccharide vaccine

Question 14

isohemagglutinins

Answer 14

• antibodies generated in response to polysaccharides of glut flora
• cross react with A or B blood group erythrocyte antigens

Question 15

low IgG levels - something to consider

Answer 15

• protein loss as cause

Question 16

what is always the first step

Answer 16

• CBC with differential

Question 17

what do you need to check if you have lymphopenia?

Answer 17

• primary versus secondary

- which lymphocytes are low

Question 18

use of flow cytometry important for?

Answer 18

• quantitating lymphocytes

- can also tell what lymphocytes are present

Question 19

CD3 marker for which cell type

Answer 19

• T cells

Question 20

CD4 marker for which cell type

Answer 20

• helper T cells

Question 21

CD8 marker for which cell type

Answer 21

• Cytotoxic T cells

- also 1/3 NK cells

Question 22

CD19 marker for which cell type

Answer 22

• B cells

Question 23

CD16/56 marker for which cell type

Answer 23

• NK cells

Question 24

limited lymphocyte markers testing

Answer 24

• CD 3, 4, 8

Question 25

complete lymphocyte markers testing

Answer 25

• all

Question 26

T cell function assays

Answer 26

• in vitro assay of T cell function

Question 27

T cell function assays measure

Answer 27

• peripheral T cell proliferation in response to varied types of stimuli

Question 28

T cell function assays use what proteins?

Answer 28

• mitogens such as phytohemagglutinin, concanavalin A, and pokeweed mitogen

Question 29

extent of proliferation

Answer 29

• measure the radioactivity taken up by cells

Question 30

cutaneous delayed type hypersensitivity test

Answer 30

• class in vivo test of cellular immunity

Question 31

cutaneous delayed type hypersensitivity test - how it works

Answer 31

• intradermal injection of antigen to which the individual has been exposed

Question 32

cutaneous delayed type hypersensitivity test - positive response requires

Answer 32

• uptake and processing of antigen by antigen presenting cells
• interaction with CD4 cells
• cytokine production
• recruitment and activation of monocytes and macrophages

Question 33

cutaneous delayed type hypersensitivity test example

Answer 33

• PPD

Question 34

neutrophil defects initial test

Answer 34

• CBC with differential

Question 35

neutrophil defects initial test - if neutrophils numbers are normal and a neutrophil defect is suspected

Answer 35

• tests of function should be ordered

Question 36

how to measure neutrophil oxidative burst

Answer 36

• nitroblue tetrazolium test (NBT)

- flow cytometry

Question 37

serum IgE

Answer 37

• hyper IgE syndrome

Question 38

giant azurophilic granules are seen in granocytes of persons with

Answer 38

• Chediak-Higashi syndrome

Question 39

complement defects - initial screening test

Answer 39

• total hemolytic complement (CD50)

Question 40

total hemolytic complement measures

Answer 40

• assessment of classical pathway

Question 41

if total hemolytic complement test significantly reduced

Answer 41

• specific complement components can be assessed

Question 42

if total hemolytic complement test is normal but a complement deficiency is still suspected, what test do you run?

Answer 42

• tests for AH50 - screening test for alternative pathway defects

Question 43

alternative complement deficiencies include

Answer 43

• properdin and factor D deficiencies

- exclude mannose-binding lectin defect