exam 4: diagnostics, cancer immunology Flashcards
describe the difference between a product that used polyclonal Ab and one that uses a monoclonal Ab
polyclonal Ab has high affinity, low specificity
monoclonal Ab better for specificity
nonspecific absorption, nonpathologic Ab rxn, binding to FcR, contamination, internally bound Ig detected, inappropriate cut off or recent transfusion can all lead to what type of test?
false positive
low reactivity, low affinity Ab, inappropriate Ab:Ag ratio, steric hindrance, inappropriate cut off, cell-mediated cytopenia, Ab vs precursor not cell, drug dependant or steroid administration can all lead to what type of test
false negative
Radioimmunoassay (RIA)
detects serum antigens, good for low concentrations
(+) if serum is infected, decreased radioactivity
(-) if serum is not infected, increased radioactivity
Direct Coombs Test
detects IgG, IgM or C3 bound to RBC
tests of immune-mediated hemolytic anemia (IMHA)
ELISAs
enzyme-linked immunosorbent assay
test for complement, Ab, or Ag
indirect: primary Ab that detects Ag, then a secondary enzyme conjugated Ab that detects primary Ab
direct: an enzyme conjugated antibody that detects patient antibody
immunochemistry
can localize antigen to area of tissue damage
species specific
detects Ag in situ
deparaffinize & Ag retrieval with block, primary Ab and secondary Ab
immunohistochemistry
antigens on tissue sections rather than single cell suspensions
immunofluorescent assay (IFA)
small quanities of antigen or antibody easier to detect
flow cytometry
detects cell-specific antigens & can indicate cell state
cellular antigens, cellular products, cell cycle analysis, cell types, cellular viability & vitality
side scatter = complexity of cell
forward scatter = size of cell
immunoelectrophoresis
differentiation between groups of plasma proteins
albumin (smallest)
acute phase proteins (alpha & beta globulins)
immunoglobulins (gamma globulins)
what are a couple important beta-globulins in non-domestic species
fibrinogen
amyloid A
C-reactive proteins
immunofixation
separates isotypes of immunoglobulins
detects Ig light chains (kappa/lambda)
immunofixation
separates isotypes of immunoglobulins
detects Ig light chains (kappa/lambda)
acute serum vs convalescent serum
acute serum: initial sample, usually will show IgM with acute infection
convalescent serum: later sample, IgG would increase with the active disease process and you would see a 4-fold increase in Ab titers
how do you determine if an antibody titer has a strong reaction/many antibodies present
the greater the dilution the better (e.g. 1:64)
define premunition
an antibody is present but may not completely clear an infection
is hyperplasia reversible
yes
types of cancers
epitheial tumors are ___
mesenchymal tumors are ___
round cell tumors are ____
adenomas, carcinomas
sarcomas
lymphoma, plasma cell tumor, histiocytoma, mast cell tumor, transmissible venereal tumor
proto-oncogens
mutation enhances function
(e.g. growth factors, growth factor receptors, signal transduction proteins, gene transcription proteins)
tumor suppressor gene
example: P53 or Rb
mutation leads to loss of function
what causes neoplastic transformation of cells
break down in DNA repair processes
uncontrolled growth
inhibition of apoptosis
alteration in tumor microenvironment (e.g. angiogenesis which allows cancer to receive blood supply)
immune evasion
how does slow initial growth of cancer evade the immune system
cancer cells are not detected
