Histopathology and antibody

Question 1

What is the difference between Histopathologist and cytopathologists?

Answer 1

Histopathologist-interested in tissues-biopsies, specimens, frozen sections, post-mortems
Cytopathologists-interested in CELLS-smears, needle aspirates

Question 2

What is the main role of histopathologist?

Answer 2

Diagnosis based on tissue

Assess cancer spread (stage)+monitor disease and treatment (in stuff like IBS/UC)

Question 3

What are the 4 main samples hisotpathologist use?

Answer 3

Biopsies, resection specimens (from removal surgeries), frozen section, post mortems

Question 4

What are the main information gathered from biopsies?

Answer 4

is it normal or not
Is it inflammed-and why
Is it a tumour
if yes-what type of tumour

Question 5

What is a resection specimen? What do you check in them?

Answer 5

usually a large specimen-usually done after diagnosis
Always check the margins of specimen (see if all cancer has been removed, its stage etc)-if its not cancer-also important

Question 6

What is a frozen section? What is the use?

Answer 6

Done during the surgery-and usually for cancer
Often margin check to see if its all out
and check if its the right cancer-and treatment is appropriate

Question 7

How are tissue sections obtained and treated?

Answer 7

Labelled and placed in box with formallin-sets the tissue to watch
Then embed in parafin was and cut section-then microscope

Stains are the main use-gram, ZN, etc
But can also use AB to specific antibody
some molecular tests too

Question 8

How are cytopathology samples obtained?

Answer 8

Looking for cells-not tissue (might be easier to get if organ hard to reach)
Use fine needle aspirations-

Question 9

How are ABs made for therapeutic/diagnostic purposes?

Answer 9

Can attatch enzymes, probs, dyes, magnetic beads (to purifiy different cell types), Drugs (like BC-anti-her2)
Main reason to use them is specificity

Either-produced by patient
Or manufactures (Immunised animals-take from (but multiclonal-and limited supply) (monoclonal Ab-can make tons) (and now make them from the gene directly + genetic engineering

Question 10

What are the different therapeutic uses of ABs?

Answer 10

1) prophylactic against microbial infertion (in immunocompromised patients)
2) Anti Cancer therapy (the Anti-Her2)
3) Removal of T cells from BM grafts (Anti CD3 Ab)
4) Block cytokine activity-anti TNF for Rhumathoid arthiritis
5) Anti-calcitonin gene related peptide for migrane
6) -and more coming every months

main issue is their price and volatility

Question 11

What are the different diagnostic uses of ABs?

Answer 11

Determine blood groups
Quantitative immunoassays (hormoones, AB, Ag)
Immunogiagnostics (disease, AID, allergy, Malignancy)

Question 12

What is indirect labelling using Anti-anti-body?

Answer 12

Ab binds the AG-and a secondary Ab (anti-antibody) with a reporter that identifies the first one (or bring drug etc)

Question 13

how do you produce monoclonal Ab?

Answer 13

Mouse is challenged with Antigen-take spleen cells to produce the Ab to that
Fuse them with B-cell cancers (myeloma)-create hybdridoma that produce the Ab but are immortal like cancer cells
select the right cell-and then have infinite supply

Question 14

How do you produce Ab using DNA technology?

Answer 14

Isolate the genes encoding the variable region-and then fuse with a bacteriophage coat protein-cloning a random population gives rise to mix of bacteriophages-PHAGE DISPLAY LIBRARY
then just select the right one

Question 15

How are AB used in quantitative tests?

Answer 15

Using ELISA test-has a capture Ab on plastic-then it binds the AG
Then another Ab binds the AG as well-and its linked with a dye that generates a colour easy to measure-and directly proportional to Ag present

Question 16

How can ABs be used for rapid testing?

Answer 16

Sample is mixed with Abs-flow (Ab binds Ag)-and in the first strip Ab to Ag again that will bind the AB-AG complex and send signal
AFter-second line has Anti AB-binds those that didnt bind AG

Question 17

What are immune complexes?

Answer 17

Usually signs as vagues pain and aches-immune complexes-being deposited in various parts of body
Size matters the most-and once membrane bound activate complement very well

causes
Inflammation/complement activations
Serum sickess
Immune complex glomerulonephritis
Immuni complex at other sites (skin, joints, lungs)

Question 18

What are the 3 main things measured in an immunology lab?

Answer 18

Serum IG levels-ELISA, Serum electrophoresis, etc-check if compromised
Specific ABs or AGs-ELISA
Lymphocyte subsets-CD3/4/5 etc

Question 19

How does serum electrophoresis measure Ab activity?

Answer 19

like normal electrophoresis
Has an albumin band at bottom (very abundant) and then several bands along the way in which different Abs will stop-measureing the size of each bands tells us which one is most abundant
In infected patients-large thick band in gamma bands-not compromised
In some-thin by very dark gamma band-moloclonal

Question 20

How does flow cytometetry use Ab to identify the cells?

Answer 20

use AB with specific dyes that binds the Ags in the cells-they will bind the cells with their Ag-and then single cells passed by and their dye colour is measured-tells you what cells have one AG, another, or both