ANCA Antibodies

Question 1

What are ANCAs?

Answer 1

Anti-neutrophil cytoplasmic antibodies

Autoantibodies produced against neutrophil components

Question 2

How are ANCAs detected?

Answer 2

Indirect immunofluorescence

Question 3

What are the three different types of ANCAs?

Answer 3

C-ANCA (cytoplasmic_
P-ANCA (perinuclear)
X-ANCA (atypical)

Question 4

Why are ANCAs investigated?
(3)

Answer 4

These are autoantibodies found in several different necrotising systemic vasculitides such as Granulomatosis with polyangiitis

ANCAs are sensitive and specific for these vasculitides

ANCA is useful in establishing the diagnosis before the damage to the kidneys and lungs has become irreversible

Question 5

What might rising titres of ANCAs mean?

Answer 5

Disease relapse

Question 6

What might stable or falling ANCAs mean?

Answer 6

Disease remission

Question 7

What are vasculitides?

Answer 7

Vasculitis describes a group of rare conditions, also called angiitis, that damage blood vessels by causing inflammation , or swelling

The vasculitides are defined by the presence of inflammatory leukocytes in vessel walls with reactive damage to mural structures. Both loss of vessel integrity leading to bleeding, and compromise of the lumen may result in downstream tissue ischemia and necrosis

Question 8

What are vasculitides in your own words
(5)

Answer 8

A group of rare disorders which cause inflammation in the blood vessels

They cause damage to blood vessels which can cause swelling and bruising

This can cause downstream tissue ischemia and necrosis

Areas of the body most affected are the lungs and kidneys

These diseases are caused by the presence of leucocytes - neutrophils in the blood vessel walls which have reactive damage to the structures surrounding

Question 9

Give two examples of vasculitides

Answer 9

Granulomatosis with polyangiitis -> Wegner’s Granulomatosis

Microscopic polyangiitis

Question 10

Write about C-ANCAs

Answer 10

Cytoplasmic anti-neutrophil cytoplasmic antibodies

Antibodies produced mostly against proteinase-3 (90% of the time)

Involved in respiratory tract vasculitides

Question 11

Write about P-ANCAs

Answer 11

Perinuclear anti-neutrophil cytoplasmic antibodies

Antibodies produced mostly against myeloperoxidase (80% of the time)

Involved in kidney diseases -> glomerulonephritis

Question 12

Write about X-ANCAs

Answer 12

Atypical P-ANCA

Thought to be an antibody against Cathepsin G

Associated with inflammatory bowel disease

Question 13

Write about Granulomatosis with polyangiitis/Wegner’s Granulomatosis

Answer 13

Vasculitide affecting the small arteries, capillaries and veins

More common in elderly

Typically C-ANCA positive 95%

Mostly proteinase-3 antibodies 95%

Different presentations can occur but most acute is deteriorating kidney function

Question 14

Write about microscopic polyangiitis

Answer 14

Systemic vasculitic disease of the small arteries

More common in elderly

Rare

Patients may present with general symptoms e.g. fatigue and weight loss

Shortness of breath common

Kidney may not be involved but can cause deterioration

Typically P-ANCA positive (95%) which tend to be antibodies against myeloperoxidase (80%)