Lecture 29 Flashcards
What is a hybridoma?
An antibody producing cell fused with a tumor (immortal) cell.
What is the function of hybridoma cells?
They can be cultured indefinitely bc theyre immortal
What are 3 different diagnostic tests that use monoclonal antibodies?
- enzyme-linked immunosorbent assay (ELISA)
- enzyme immunoassays (EIA)
- Fluorescent microscopy
- flow cytometry
- western blot
How can antibodies be used to determine a patients exposure to a pathogen? What are 4 outcomes of this type of testing?
Detect patient antibody in response to a pathogen by ELISA or western blot
Can determine if the patient has:
- had an immunisation (IgG)
- had the disease in the past (IgG)
- never had the disease
- or currently has the disease (IgM)
How can antibody based immunodiagnostic testing determine whether a patient has been vaccinated (not had the disease) against Hep B or been vaccinated and have the disease?
With Hep B you can distinguish between a vaccinated person and an infected person by measuring their antibody against a Hep B core antigen (HBc) which is not in the vaccine. The vaccine only contains HB surface antigen (HBsAg).
How does the Influ A&B respi-strip use antibodies to determine whether someone has the disease of interest?
Tests a patients sample to see whether they have antibodies against an influenza A or an influenza B
What T-cell based immunoassay is used to determine exposure to TB?
TB interferon gamma release assay
What diseases are you testing for when you are detecting the levels of anti-nuclear antibodies (ANA) in a patient? What % of healthy people will have the same amount of ANA as diseased people?
Testing for Lupus or Rheumatoid arthritis. ANA present in up to 15% of healthy individuals- people without lupus can have ANA but people who have lupus have ANA 100% of the time.
What are two ways of detecting allergy? How do they work?
- Skin prick testing. Allergen applied to skin using a standardised puncture device. Patient observed for wheal and redness after 15-10mins. Measures the immediate response due to IgE-mediated mast cell activation.
- Circulating allergen-specific IgE by EIA. ImmunoCAP screens for specific IgE against panels of allergens e.g. nuts. Positive samples require further testing to determine which allergens in the panel the patient is allergic to.
What is Rhesus incompatibility?
When an Rh+ve man has a baby with an Rh-ve woman and the first baby is Rh+ve, the mother produces antibodies against the Rh antigen. When the woman becomes pregnant with her second Rh+ve baby, her antibodies attack the fetus’s red blood cells. This causes haemolytic disease in new borns.
What are the two types of test to screen for Rhesus incompatibility?
Coombs test- two types
- Direct antiglobulin test- detects fetal RBC coated with maternal antibody
- Indirect antiblobulin test- detects anti-Rh antibodies in maternal serum
How do you prevent Rhesus incompatibility?
Passively immunising the mother with low dose anti-Rhesus immunoglobulin during her first incompatible pregnancy. This reduces the exposure to the antigen in the mother and production of high levels of antibody that are damaging to the fetus.
How do you treat Rhesus incompatibility?
An affected bb can be treated with a blood transfusion.
What are 3 other things (apart from Rhesus incompatibility) that the Coombs test can be used to detect?
- transfusion reaction
- autoimmune haemolytic anaemia
- drug-induced haemolytic anaemia (e.g. penicillin)
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