Diagnosis of Autoimmune Disease

Question 1

Define: Sensitivity

Answer 1

How good the test is at identifying people with the disease

Question 2

Define: Specificity

Answer 2

How good the test is at defining people without the disease.

Question 3

What is the positive predictive value?

Answer 3

The proportion of people with a positive result that have the disease.

Question 4

What is the negative predictive value?

Answer 4

The proportion of people with a negative result that don’t have the disorder.

Question 5

What is a non-specific diagnostic test?

Answer 5

Inflammatory marker

Question 6

What is a specific diagnostic test?

Answer 6

HLA typing, autoantibody testing.

Question 7

What are ESR and CRP ? (not what they are abbreviations of)

Answer 7

Non- specific markers of systemic inflammation.

Question 8

What does ESR stand for?

Answer 8

Erythrocyte sedimentation response.

Question 9

What makes both ESR and CRP?

Answer 9

Liver

Question 10

Why is ESR measured? (Inflam agents)

Answer 10

Inflammatory agents released by liver –> plasma thicker = Inflammatory level.

Question 11

Why is CRP measured?

Answer 11

It is like complement, rapidly used up. Can use that to check inflammatory level.

Question 12

What other markers rise with systemic inflammation?

Answer 12

Ferritin and Fibrinogen.

Question 13

What are the other markers of systemic inflammation?

Answer 13

Haptoglobin, Albumin, Complement.

Question 14

What do anti-nuclear antibodies do?

Answer 14

Engulf own leukocyte nuclei.

Question 15

Examples of Extractable Nuclear Antigens include?

Answer 15

> Ro and La = Proteins involved in transcription of DNA.
dsDNA
Ribonuclear Protein = Involved in transcription and translation.

Question 16

What can ANA detection diagnose?

Answer 16

Lupus

Question 17

What type of cell is used in ANA detecting?

Answer 17

Fibrocyte type cells - prominent nuclei

Question 18

What are the steps of ANA detection?

Answer 18

> Fibrocyte cells onto slide
Serum from pt, if auto-antibodies present –> bind to nuclei
To see binding, use flourescent marker - binds to Fc portion of IgG.

Question 19

What is Rheumatoid Factor (RF) ?

Answer 19

An autoantibody directed against Fc portion of IgG.

Question 20

What disease is RF commonly found?

Answer 20

Rheumatoid Arthritis

Question 21

What other disease is RF found in?

Answer 21

Polyclonal stimulation of B cells (chronic infection).

Question 22

What is ACPA (Anti-citrullination protein antibody) a useful prognostic marker for?

Answer 22

RA

Question 23

What do pt’s with +ACPA have?

Answer 23

More severe and erosive disease

Question 24

In ANCA (Anti-neutrophilic cytoplasmic testing) what is used as a ANA substrate?

Answer 24

Granulocytes.

Question 25

What glows up with cytoplasmic ANCA?

Answer 25

Cytoplasm

Question 26

What glows with peri-nuclear ANCA?

Answer 26

Nucleus

Question 27

What is a disease flare?

Answer 27

+ve ANCA in a ANCA -ve pt.

Question 28

What autoantibody is found in primary biliary sclerosis?

Answer 28

Anti-mitochondria antibody

Question 29

What autoantibody is found in autoimmune hepatitis?

Answer 29

Anti smooth-muscle and anti-liver/kidney/microsomal antib’s.

Question 30

Are Type 1 diabetes autoantibodies pathogenic or non?

Answer 30

Non - mostly.

Question 31

In later Type 1 diabetes what happens to the autoantibodies?

Answer 31

Disappear as the disease progresses

Question 32

In early Type 1 what happens to the autoantibodies?

Answer 32

Increases as the disease progresses

Question 33

What is destroyed in Type 1 diabetes?

Answer 33

B islet cells