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Flashcards in Immunodiagnosis (complete) Deck (20):
1

Describe the procedure used in serum protein electrophoresis. What are the underlaying principles?

- Serum (urine, CSF) is placed on a gel
- Turn on voltage
- Measure peaks of albumin, alpha1, alpha2, beta, and gamma

2

What does no gamma peak indicate in an electrophoresis?

Agammaglobulinemia

- No IgG

3

What does a high, broad gamma peak indicate in an electrophoresis?

Polyclonal hypergammaglobulinemia

or severe pyogenic (pus-producing) infections

4

What does a high, single gamma peak indicate in an electrophoresis?

Monoclonal hypergammaglobulinemia

5

What does a normal serum protein electrophoretic pattern look like?

- Large albumin peak
- Baby peaks for alpha1&2, beta, gamma

Go google it NOW!

6

What does a serum protein electrophoretic pattern look like for a person with selective IgA deficiency?

Same as a normal peak

You can't pick up this deficiency with serum electrophoresis

7

What does a serum protein electrophoretic pattern look like for a person with multiple myeloma?

Large spike in gamma region (AKA M spike) --- remember the M protein in MM?

Not as sharp as the monoclonal hypergammaglobulinemia

8

What is single radial immunodiffusion?

Measures individual immunoglobulin (sub)classes --- or just Ag

9

What are the types of Ag that can be quantified in single radial immunodiffusion?

Multivalent Ag

- Can form a precipitate w/ an appropriate Ab

10

How is the quantization done in single radial immunodiffusion?

You compare patient's serum to the controls

11

What are the advantages of passive agglutination over precipitation?

A lot quicker and more sensitive

12

Describe passive agglutination test

- Couple small Ags to RBCs or latex beads
- Add dilutions of pt serum
- Look for agglutination

The agglutination titer is the reciprocal of the highest dilution that produces agglutination

13

What is the difference between direct and indirect immunofluorescence techniques?

Direct:
pt swab smeared on slide, fluorescent-labelled Abs added --- a test for ANTIGEN

Indirect:
Known bacteria on slide, add pt's serum, wash and added fluorescent-labelled anti-human Ig --- a test for ANTIBODY

14

Describe the reactions involved when the ELISA is used to measure Ag

Enzyme-linked immunosorbent assay

- works well if Ag is at least divalent
- Need 2 monoAbs
- Put one on the bottom => add pt's serum
- Wash, then add 2nd monoAb (will stick to other epitope)
- 2nd Ab has enzyme coupled to it (peroxidase)
- Add colorless peroxidase substate => produces color if peroxidase bound to 2nd Ab

15

Describe the reactions involved when the ELISA is used to measure Ab

- Ag is at bottom of plate, sticks there
- Put on pt's serum
- Wash everything that doesn't stick
- Add anti-Ab Ig (has enzyme on the end)
- Add enzyme substrate => produces color if testing Ab is present

16

Describe a test which can be used to evaluate T cell immunocompetence in a clinic or on the ward

Think of a TB test

1) Ag is endocytosed by DCs
2) Ag digested w/in endosomes by lysosomal enzymes
3) Ag loaded onto MHC Class II
4) MHC Class II cycles to the DCs surface
5) Th1 anti-TB cells come by
6) Th1 anti-TB cells recognize Ag + MHC Class II.
7) Th1 cells are activated and secrete IFNγ
8) Macrophages are attracted
9) Macrophages are activated and become M1

17

What are tests used to evaluate T cell numbers and function in the lab?

You can stain for CD3, CD4, or CD8 in serum

18

Describe flow cytometry

- Light scattered according to CD markers
- Increasing intensity of CD8 on y-axis
- Increasing intensity of CD4 on x-axis

19

Where would you find both CD4 and CD8 cells?

Only the thymus

- This is where double positives are weeded out

20

Where would you find cells without CD4 or CD8 markers?

Lymph nodes

- Primarily B cells
- These have no CD4 or 8 markers