Immunological and Molecular Diagnostics Flashcards Preview

Vet - notes > Immunological and Molecular Diagnostics > Flashcards

Flashcards in Immunological and Molecular Diagnostics Deck (28):
1

function of serology

Evaluation of immune status / function
Exposure of animal to infection
Response to vaccination
Diagnosis of immune-mediated disease

2

function of immunoassay

Using labelled antibodies as detection reagents
Presence of pathogen in a biological sample
Measurement of a biomarker
Immunophenotyping

3

blood sample for serum

clotted sample

4

blood sample for cells

citrate/heparin

5

acute phase proteins

C-reactive protein, Serum amyloid A, fibrinogen,
haptoglobin
provide evidence of infl in horses

6

Serological markers of adaptive immunity

antibodies
cytokines

7

measuring total immunoglobulin can be useful in

Failure of passive transfer in foals
Specific Ig deficiency syndromes
Monoclonal / polyclonal gammopathy

8

antigen-specific immunoglobulin useful for

Exposure to pathogen
Response to vaccination
diagnosis of antibody-mediated hypersensitivity - Allergy, Autoimmunity

9

Diagnosis of FPT in foals

blood test 15 – 18 hours of age

10

ELISA can be used to detect either ___ or ____

antigen or antibodies

11

ELISA test early on in an infection vs later on

early test for antigen as antibodies in lag phase
later on test for antibodies as the body is responding to the disease

12

immunofluorescence assay (IFA)

same principle as ELISA exept detection antibody marked with fluorescent marker not enzyme

13

virus neutralization (VN) assay

cultured cells infected with the virus +/- serum from patient
if antibody absent - cells infected

14

VN assay advantage over ELISA or IFA

indicates presence of biologically active antibody
presence of antibody in ELISA does not necessarily mean that it is protective

15

virus neutralising titre

greatest dilation of serum that prevents cell from becoming infected

16

Evaluation of T cell responses

CD4+ T cell
measure cytokine release following stimulation with specific antigen

17

Bovine TB gamma-IFN test

Heparinised blood sample to AHVLA
Culture cells in vitro with mycobacterial antigens (PPD)
Measure IFN-gamma production by ELISA
More sensitive but less specific than tuberculin “skin test”

18

Intradermal skin tesing

Used a lot for diagnosis of small animal allergic skin disease
Immediate-type (IgE-mediated) hypersensitivity

19

Tuberculin test for TB in cattle

Clip hair
Measure skin thickness
Inject PPD (avian & bovine)
Measure skin thickness 72 hrs later

20

Immunodiagnostics for Autoimmunity

coombs test for IMHA
ANA for SLE
measurement of specific autoantibodies

21

detection of pathogen in a sample

sandwich ELISA
IFA
immunohistochemistry

22

immunophenotyping

antibodies against cell-surface markers can tell which cell types are in a sample
can be done on cells in suspension by flow cytometry

23

Identification of pathogen’s nucleic acid in a biological sample

Usually using PCR or qPCR (quantitative PCR)
Pathogen-specific primers / probes tell if sample is +/-ve
16S rRNA sequencing can also be used

24

Genotyping pathogen

Influenza virus H + N genes
Virulence factors

25

disease susceptibility genes

Monogenic vs complex genetic disorder
Autosomal vs sex-linked
Dominant vs recessive
Complete vs incomplete penetrance
PCR based test

26

use of DNA genotyping

parentage
Diagnosis of disease – SOD1 mutation in degenerative myelopathy of GSD, KIT mutations in mast cell tumours
Establishing potential risk of disease in later life
Screening for carrier animals in a breeding population

27

Mast cells and KIT

Tissue mast cell viability is dependent upon the presence of stem cell factor (SCF)
SCF acts through the KIT (c-kit) receptor, which has tyrosine kinase activity.
KIT gene mutations are found in 30-50% of mast cell tumours
The presence of a KIT mutation seems to be associated with more aggressive disease.

28

acute phase proteins serological markers of innate or adaptive immunity?

innate