Diagnosis of autoimmune diseases (core immunology)

Question 1

What is the definition of sensitivity and specificity?

Answer 1

SENSITIVITY:
-measure of how good the test is in identifying people with the disease.

SPECIFICITY:
-measure of how good the test is at correctly identifying people without the disease.

Question 2

What is a positive predictive value?

Answer 2

The proportion of people with a positive test who have the target disorder.

Question 3

What is a negative prediction value?

Answer 3

the proportion of people with a negative test who do not have the target disorder

Question 4

Give examples of non specific markers of systemic inflammation?

Answer 4

1) ferretin
2) CRP (C-reactive protein)
3) ESR (erythrocyte sedimentation rate)
4) fibrinogen
5) Haptoglobin
6) Albumin
7) complement

Question 5

What is Rheumatoid factor?

Answer 5

Search Results
Rheumatoid factors are proteins produced by immune system, can attack healthy tissue. High levels of rheumatoid factor in the blood are associated with autoimmune diseases, eg.rheumatoid arthritis.

-usually antibodies (IgM, IgG or IgA)

Question 6

What marker is 95% specific for Rheumatoid arthritis than Rheumatoid factor?

Answer 6

Anti-CCP (ACPA)

ACPA positive patients tend to have more sever and erosive disease,

Question 7

Anti-neutrophilic cytoplasmic antibodies (ANCA) were first described as an autoantibody specific for what disease?

Answer 7

Wegeners granulomatosis

(AKA Granulomatosis with polyangiitis)

Also associated with:
Microscopic polyangiitis and churg-strauss syndrome

Question 8

What ANCA associated systemic vascultidies causes alveoral haemorrhage?

Answer 8

All 3 :
Wegener’s granulomatosis
Microscopic polyangiitis
Churg-Strauss syndrome

Question 9

How useful is ANCA testing ?

Answer 9

• a positive ANCA is useful in suggesting the diagnosis

- a negative ANCA does not exclude AASV (ANCA associated systemic vasculitidies)

Question 10

What antibody is specific for primary biliary sclerosis?

Answer 10

Anti-mitochondrial antibody

Question 11

In what disease is anti smooth muscle and anti liver/kidney antibodies found in?

Answer 11

Autoimmune hepatitis

Question 12

What types of autoantibodies are present in type 1 diabetes?

Answer 12

1) Islet cell antibodies
2) Anti-GAD65 and Anti-GAD67
3) insulin autoantibodies (IAAs)
4) Anti-insulinoma antigen