Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Immunology > Lecture 18: Diagnostic Immunology Case Studies > Flashcards

Lecture 18: Diagnostic Immunology Case Studies Flashcards

1
Q

Neurological Symptoms in wild raccoons and several <1 y/o dogs with oculonasal discharge and 1 with seizures.

Differential diagnosis: rabies, toxin, canine distemper

What tests can be run

A

Rabies direct fluorescent antibody (FA) testing, submit ocular/nasal swabs for distemper FA testing, and submit blood for serology and ethylene glycol testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the steps in rabies direct FA testing

A

Requires a fresh Brain, take impression stains of tissue from brain stem, cerebellum and cerebrum

Add fluorescently- labeled rabies-specific antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the steps in submitting ocular/nasal swabs for distemper direct FA antibody testing

A

Swipe swab on slide and add fluorescently labeled distemper specific antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are direct fluorescent antibody tests looking for

A

Using patient samples and fluorescently labeled antibodies specific for a virus, we are looking for a viral antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the steps involved in submitting serology for virus/serum neutralization

A

Obtain patient serum, perform dilutions, and run tests to determine the lowest effective dilution where antibodies can fight off infection. Will determine normal healthy cells that have antigen bound to antibody and neutralized vs virus infected cells (cytopathic effect) not enough antibodies present in dilution to neutralize antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Analyzing results of neighborhood dogs tested using FA and VN:

VN: threshold > or equal to 1:80

Astro, 2yr, clinical signs include ocular discharge DFA for distemper= + and VN< 1:40

What stage is Astro at in disease

A

Astro is probably in early stages of infection so CDV antigen is present, specific immunity has not developed yet so antibody titer is low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

analyzing results of neighborhood dogs tested using FA and VN:

VN: threshold > or equal to 1:80

Barley, 4 month old, clinical signs include seizures, DFA for CDV= - and VN titer =1:320

What stage of disease is Barkley at

A

Barkley is in the very late stages of infection so viral antigens are long gone, however an immune response is present as indicated by the elevated titers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

analyzing results of neighborhood dogs tested using FA and VN:

VN: threshold > or equal to 1:80

Carlie is a 1yr, showing no clinical signs, DFA= -, VN titer= 1:640

What stage of disease is Carlie at

A

Carlie has high titers either from previous vaccination or she has recovered from an infection at young age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Tibetan Terrier in UK: 2yr/old never outside UK with 1 month progressive lethargy, pancytopenia and non-regenerative anemia, has received 2x packed RBC transfusions and steroid and antibiotic treatment

Differential diagnosis are IMHA/IMTP or tick borne disease (many agents not reported in UK)

What are some tests that can be run

A

Blood work: anti-nuclear antigen testing, Coombs/blood typing/agglutination testing

Test for tick borne disease- 4Dx SNAP and ehrlichia indirect fluorescent antibody testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the steps in Anti-nuclear antibody (ANA) testing for systemic lupus erythematosus

A

Identifies the presence of antibodies targeting dsDNa/ssDNA and histones

Take diluted patient serum add anti-dog/cat/ etc antibodies that are fluorescently labeled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does a saline agglutination test, test for and how would histology appear

A

Identifies autoantibodies in patient serum directed against RBC’s

RBC clumped together, misshaped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does an indirect Coombs test, test for

A

Identifies antibodies exogenous RBC’s in patient serum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe how IDEXX SNAP 4Dx for tick/mosquito borne disease test works

A

Obtain patient blood add enzyme linked antibody conjugate

Antigen in blood will bind to conjugate then will bind to antibody bound matrix that is pre coated on snap device

Add wash to remove any non-specific unbound conjugate (RBC’s) and then substrate will move across the matrix, react with color changing substrate and appear blue on SNAP device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does an indirect FA test for

A

Antibody against antigen is the target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the steps in ehrlichia indirect FA test

A

Take diluted patient serum and slide with ehrlichia culture, add wash and then anti-dog/cat antibodies that are fluorescently labeled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The diagnostic results for Tibetan terrier:
Saline Agglutination (+)
SNAP 4Dx (+) for Ehrlicha
Ehrlichia IFA (+)
Ehrlichia PCR (+)

Patient sent home on antibiotic and steroid then returned days later with gastrointestinal hemorrhage and hepatomgaly

What could have happened?
Why is saline agglutination (+)
If UK is Ehrlicha free how did dog become infected

A

Saline agglutination could have been positive from either improper matching with transfusions (exogenous RBC’s) or Ehrlichia antigens present on RBC’s targeting them for lysis

Ehrlichia displays similar symptoms to systemic Lupus- bone marrow suppression which can lead to non-regenerative anemia, thrombocytopenia and leukopenia (pancytopenia)

17
Q

Respiratory disease in Feedlot Cattle TX:

Hx: chronic respiratory disease in group of cattle on feedlot, ~40 deaths in 6 months

Differentials: shipping fever, BRD, Mannheimia/pasteurella, BVDV, IBR

What are some tests that can be run

A

Culture for mannheimia/pasteurella

Bovine respiratory disease panel- VN and FA

BVDV ear notch testing- ELISA, ACE

18
Q

Describe the steps in BVDV ear notch testing

A

Test with antigen capture ELISA, ACE

Need labeled anti-BVDV antibodies, wash reagents, color reagent and control

Requires FRESH tissue

Determine ELISA threshold for positive samples through graph of optical density

19
Q

Describe the steps in BVDV ear notch testing with immunohistochemistry

A

Requires fixed tissue, add labeled antibodies

20
Q

Analyze the following results for cattle

IBR VN threshold < or equal to 1:80

BVDV VN threshold < or equal to 1:80

Blue 451 IBR VN 1:1600 and BVDV 1:800, BVDV ACE test is (-)

Red 207 IBR VN 1:3200, BVDV VN: 1:1600, BVDV ACE test is (-)

Green 769 IBR VN 1:1600, BVDV VN 1:40, BVDV ACE test is (+)

What conclusions can be drawn

A

All three cattle have been sick for > 2 weeks and likely infected with both IBR and BVD

Green 769 has no antibodies against BVDV despite having positive ACE result which is because it is PERSISTENTLY INFECTED

Remove Green 769 to reduce transmission

21
Q

What samples can be used for Fluorescent assays

A

Serum, tissue, ocular/nasal swabs

22
Q

What does DFA detect

A

Antigen

23
Q

What does IFA detect

A

Antibody

24
Q

What samples can be used for virus neutralization

A

Serum

25
Q

What does virus neutralization detect and what does it indicate about disease stage (above or below threshold)

A

Lowest effective level of AB’s to neutralize antigen

If VN is below threshold and patient is experiencing symptoms, with a positive antigen test then likely in early stages of disease

If VN is above threshold could be multiple things
- above threshold with clinical signs, and negative antigen test- late stages of disease with circulating antibodies but no antigen present
- above threshold without clinical signs and negative antigen test then patient either has been recovered from disease for a while or has been vaccinated previously

26
Q

What does anti-nuclear antigen test for

A

DsDNA, ssDNA, and histones in SLE

27
Q

What does saline agglutination test for

A

Autoantibodies to RBC’s

28
Q

what does SNAP detect

A

Antigen- binds antibody and conjugate

29
Q

What samples can be used in ELISA tests

A

Fresh tissueh

30
Q

What does an ELISA (ACE) detect

A

Antigens

31
Q

What are two signs of persistent infection

A

ELISA (ACE) test is positive but BVDV is low

32
Q

What are 3 tests that target self antigens

A
  1. Saline agglutination
  2. Anti-nuclear antigen testing (ANA)
  3. Misfolding protein assays-prions

Immunology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions