Immunology labs

Question 1

four types

Answer 1

drugs (latex)
food
inhalants
venom

Question 2

type II

Answer 2

graves
good pastures
haemolytic disease

Question 3

type I

Answer 3

IgE mediated

1. exposure to the allergen
2. specific IgE production (plasma cells, memory cells)
3. sensitisation of IgE onto mast cells
4. re-exposure

Question 4

testing in allergy

Answer 4

specific IgE (sensitised- can have a positive IgE) (could be that there are not many mast cells, high levels of IgE so the test is a false atopic triad)
*only request IgE to a specific implicated

mast cell tryptase (acute phase test)

clinical-

1. skin prick testing
   * patch testing is more helpful in the context of a delayed (prolonged exposure)
2. intradermal testing
3. graded challenge

control - saline test (control positive) (interpret the positive control)

histamine (control neg)
see how the skin responds to histamine
advised not to take antihistamines so if they have forgotten then you should check (helps interpret the test)

Question 5

graded challenge

Answer 5

gold standard
can give someone what they allergic to and watch if symptoms develop
e.g. medication

food (peanut, cashew) in someone vegan or army

Question 6

measuring specific IgE in the lab

Answer 6

red patches contain peanut proteins
take the serum from the patient. if they have the specific IgE for the peanut it will bind and stick.

enzyme labelled antibodies specific for IgE is added.
secondary put commercial antibodies. add a chemical which causes the enzyme to elicit a colour change

more IgE-change colour (fluroscence)

Question 7

mast cell tryptase

Answer 7

enzyme released from mast cells when they degranulate.

30 mins and peak around 2 hours.

NICE guidance three measurements

1. within an hour of triggering event
2. repeat around 2-3 levels to capture peak
3. post 24 hours (baseline level)

antibodies stuck int he sponge that will capture the mast cell tryptase. add pt serum if contains mast cell trytpase will bind. add commercial antibodies= fluroscence colour change

Question 8

protein chemistry

Answer 8

IgG= opsonin in the complement system. binds to the pathogen (bacteria)

IgM= first to be made whilst B cells is making memory cells IgG/IgA

IgE= allergy (designed to protect against parasites) (rhinitis- runny nose, vomiting, diarrhoea) (these are mechanisms the immune system has set up to rid parasites)

IgD= B cell receptors. no known purpose or function.

IgA= found in breast milk

Question 9

immunoglobulin analysis

Answer 9

light chain
heavy chain
antigen binding sight
fc region (constant region)
fab fragment

Question 10

how to count immunoglobulins

Answer 10

human IgG
given to goat/rabbit which makes anti human IgG
then you mix it and it forms a complex

put it in a glass and there’s a light beam shining through

when there’s no sample or complex= sample detect picks up a clear signal

when there’s complex= scatter the light= detectors picks up less. sinks down because it’s very heavy and now the light can come through.

absorbance of the light correlates with the amount of IgG present

Question 11

serum electrophoresis

Answer 11

separates proteins
serum is plasma without clotting factors

serum separates size/charts

gel is made up of polymers. (cheese with holes in)
you put pt serum in and apply a charge
the smallest particles most attracted will migrate furthest

electro is given to the protein, gammaglobulins,
immunoglobulins and antibodies are all the same

Question 12

hypergammaglobulinaemia

Answer 12

immune system has been chronically stimulated

sjogren’s syndrome- constantly stimulates your b cells to make antibodies.

high IgG- think HIV (immunodeficiency of T cells so B increases because they’re not regulated)

Question 13

monoclonal band / protein (paraprotein)

Answer 13

the gamma spike is narrow (wide so only one antibody whereas the broad was lots of the Ig’s)

for example- plasma cell malignancy in multiple myeloma

Question 14

hypogammaglobulinaemia

Answer 14

primary / secondary

SCID
malignancy / disease
nephrotic syndrome
malnutrition
chemotherapy
RT
rituximab
antiepileptics

Question 15

pneumococcal serotypes

Answer 15

isolate 13 serotypes of pneumococcal

can detect if there are protective antibodies in the pt serum

give pneumovaccine  (polysacharide) vaccination which has the 13 serotypes
the immune system should process and mount an immune response

should have 12-13/13 of these

need for seroconversion to make the antibodies is 4-6 weeks

if not immune-competent can’t make these
prevanar also tests T cells