Lecture 10

Question 1

What does the bone marrow do for the immune system

Answer 1

lymphocytes develop from stem cells into B and T cells

Question 2

What does the thymus do for the immune system

Answer 2

site where T lymphocytes develop

Question 3

What does the lymph nodes do for the immune system

Answer 3

site where antigens are presented to B lymphocytes

Question 4

What does the spleen do for the immune system

Answer 4

B–cells and T–cells meet antigen presenting cells

Question 5

The Immune response:

Answer 5

 antibodies bind to antigens (foreign bodies) and mark them for destruction
 antibodies are proteins that are produced in response to foreign substances (antigens)

always write anti A/ Anit B

Question 6

Immune Reaction properties

Specific

Answer 6

recognize and remembers different Ag

Question 7

Immune Reaction properties:

 recognition

Answer 7

can distinguish between self and foreign substances

Question 8

Immune Reaction properties:

 memory

Answer 8

once antibodies develop, they are formed for life-remembers long after initial exposure

Question 9

IgM

Answer 9

large molecule; cannot cross into the placenta

• 5 IgM monomers bound together by a protein
• a mother’s IgM cannot attack the RBCs of her foetus having a different ABO group
• antibody to blood group antigens A and B

Question 10

IgG

Answer 10

(gamma globulin or immune globulin)

• small antibody that can cross the placental barrier and provides protection to the fetus
• highest concentration in the blood
• gdevelops after exposure to antigens including blood antigens other than A and B

Question 11

Antibody production after exposure to an antigen

1º response:

Answer 11

IgM is produced first

Question 12

Antibody production after exposure to an antigen

2º response:

Answer 12

IgG at an increased level due to memory response

look at picture on slide

Question 13

IgA

Answer 13

found in tears ,saliva, breast milk

Question 14

IgD

Answer 14

found in blood in small amounts

Question 15

IgE-

Answer 15

least found in blood. Involved in allergies such a Hey fever and food allergies

Question 16

Serology is

Answer 16

use of Ab:Ag reaction to diagnose a disease
o identify blood group
o identify cell markers

Question 17

General procedure of serology

Answer 17

combine a source of Ag with a source of Ab

Question 18

Agglutination, Precipitation:

Answer 18

antibody mixed with antigen causes clumping(insoluble)

Question 19

Florescent Ab stain

Answer 19

• bacterial smear is prepared

- smear is stained with a fluorescent dye fixed to an antibody to the target organism ex VDRL for syphilis

Question 20

Enzyme Linked Immunoassay (EIA or ELISA)

Answer 20

1. antibody to target antigen is fixed to a microtitre plate
2. sample is added -> antigens bind to antibody
3. non-specific unbound antigen is removed by rinsing
4. antibody linked to an enzyme is added -> antibody binds to the antigen
5. unbound antibody-enzyme is removed by rinsing
6. a colourless substrate is added -> a coloured product is formed indicating a positive test

Question 21

Radioimmunoassay (RIA)

Answer 21

uses antibodies that are labelled with a radioactive isotope

Question 22

Antibody Titre:

Answer 22

Titre is inverse of highest dilution at which test is still positive; result = 1/dilution

Question 23

Tests include: EBV

Answer 23

Heterophil antibody screen (Monospot test)
-detect heterophile Ab in the patients’ blood

Heterophil antibody titre (Paul Bunnell)
Sample: serum or plasma

Question 24

Newer Rapid Testing Systems

Answer 24

• Can detect the IgM heterophile antibodies in serum, plasma or whole blood
• Color ImmunoChromatographic Assay
• Have built in control
• Fast
• Positive test- blue line
• Negative test – no blue line

Question 25

QC: Newer Rapid Testing Systems

Answer 25

store reagents at 2-8ºC, - do not mix reagents from different kits, - warm to RT before use

Question 26

Arthritis:

Answer 26

caused by autoimmune antibodies - Rheumatoid factor is an antibody to human IgG. - serum containing RF( auto antibodies) is mixed with IgG coated particles - RF’s bind to IgG causing agglutination

Question 27

``` Arthritis: Tests: - Sample: - Controls QC: Other tests: ```

Answer 27

- RF Latex, RF Slide - serum - positive and negative - store reagents at 2-8ºC; warm up to RT before using - CRP (C-reactive protein), ESR

Question 28

SLE:

Answer 28

an autoimmune disease that causes inflammation | Systemic Lupus Erythematosis

Question 29

``` For SLE Test Method: Sample: Other tests: ```

Answer 29

- antinuclear antibody (ANA) - tissue slide flooded with serum; then stained with anti human globulin bound to fluorescent dye *** - SST, spin and separate immediately - ANA panel ( anti-DNA, anti-Sm, anti-RNP, anti-Ro, anti-La); LE Prep (uses heparinized sample, must process immediately) **

Question 30

Hypothyroidism and Tests:

Answer 30

- may be due to antibodies to thyroid gland or to thyroid hormones - anti-Thyroglobulin Ab: cause thyroid cell destruction ** - anti- Microsomal Ab: destroy microsomal component of thyroid cells**

Question 31

Hepatitis -Test method:

Answer 31

ELISA Hepatitis A: anti-HAV Hepatitis B HBs Ag, HBe Ag , anti-HBc, anti-HBs, anti-HBe Hepatitis C: anti-HCV

Question 32

Syphillis Tests Sample

Answer 32

-Venereal disease caused by Treponema pallidum -VDRL and RPR are nonspecific tests with false positives FTA and MHA are specific test and are used to confirm positives -serum,sent to MOH with standard MOH form; positive results are reported looking for antibody

Question 33

HIV Laboratory Testing POCT: Specimen

Answer 33

-ELISA test, repeated if positive, confirmed by a second method -rapid test kits using ELISA; positives sent to lab to confirm -serum sent to MOH with standard MOH forms specimen and MOH form can be identified with a coded number to ensure no identifying information on the label

Question 34

Cold Agglutinins

Answer 34

Antibodies to Mycoplasma (atypical pneumonia) causes RBCs to agglutinate at cold temperatures

Question 35

Specimen for Cold Agglutinins | Method

Answer 35

- blood is allowed to clot in 37ºC water incubator, centrifuged and separated immediately - serum mixed with RBCs, incubated at 4ºC and examined for agglutination - repeat using diluted sample to determine titre need cells and serum