Immunologic Lung Disease

Question 0

If you had to associate Allergic Bronchopulmonary Aspergillosis with one branch of the adaptive immune system, which one would it be?

Answer 0

Th2 - Type 2 T helper cells

Question 1

If you had to associate Hypersensitivity Pneumonitis with one branch of the adaptive immune system, what would it be?

Answer 1

Th1 - Type 1 T helper cells

Question 2

Symptoms of Hypersenstivity Pneumonitis?

Answer 2

Cough, dyspnea, and fever. Notably, with exposure to antigen.

Question 3

How can you test for IgG against an allergen?

Why not use an ELISA?

Answer 3

Ouchterlony test - in a gel, 3 wells. Patient’s serum in center well. Allergen in side well. Control antigen (or anti-IgG in another well). If patient has antibodies against the allergen, a line of precipitate will form between the allergen well and the serum well.

(this allows you to test for Abs against any allergen you can isolate - not just antigens for which you already have antibodies/ELISAs developed)

Question 4

3 stages of hypersensitivity pneumonitis?

HRCT findings of each?

Answer 4

Acute - ground glass infiltrates (showing inflammation).
Subacute - nodules and air-trapping.
Chronic - fibrosis, honeycombing, emphysema.

Question 5

What’s the predominate immunopathological finding in acute, subacute, and chronic hypersensitivity pneumonitis?

Answer 5

Acute: Th1 lymphocyte response, immune complexes.
Subacute: Granulomas.
Chronic: Fibrosis.

Question 6

PFTs in hypersensitivity pneumonitis?

How about bronchiolar lavage?

Answer 6

Typically restrictive, but can be normal.

Bronchiolar lavage increased total cells, increased T cells, CD4/CD8 >1

Question 7

6 diagnostic criteria for hypersensitivity pneumonitis?

the first 2 are most important

Answer 7

1. Exposure to antigen.
2. Precipitating antibodies to known antigen. (Ouchterlony test).
3. Recurrent episodes.
4. Inspiratory crackles on PE.
5. Symptoms occur 4-8 hours after exposure.
6. Weight loss.

Question 8

Management of hypersensitivity pneumonitis? (most important points)

Answer 8

Stop exposure to antigen.
Treat acute phase with glucocorticoids.
(if subacute phase, more / longer steroid treatment..)
Fix it before there’s permanent damage.

Question 9

4 symptoms / findings of allergic bronchopulmonary asperigillosis (ABPA) - or more broadly, allergic bronchopulmonary mycosis?

Answer 9

Asthma.
Pulmonary infiltrates.
Mucus plugging.
Proximal bronchiectasis.

Question 10

5 diagnostic criteria for ABPA?

Answer 10

Asthma.
Central bronchiectasis. (important!)
Immediate cutaneous reactivity to Aspergillus.
Elevated total serum IgE.
Elevates IgE or IgG to Aspergillus.

Question 11

PFT findings in ABPA?

Answer 11

Obstructive (it’s considered asthma..).
1/2 of patients respond to bronchodilators.
Air-trapping.
Reduced DLCO (uncommon).

Question 12

More specific treatments for ABPA? (i.e. other than normal asthma treatment)

Answer 12

Antifungals.
Anti-IgE (omulizumab - Zolair).
-though it’s unclear how effective these are.

Question 13

What are some features of the histology of vasculitis?

Answer 13

Fibrinoid necrosis.

Lymphocytic infiltrate.

Question 14

Several skin manifestations of vasculitis?

Answer 14

Palpable purpura - hemorrhages.

Ulcers, gangrene, saddle nose deformity - secondary to ischemia.

Question 15

Granulomatous polyangitis (GPA, no longer aka Wegener’s vasculitis) can affect many organs. Which does it most commonly affect?

Answer 15

Lungs - upper airways (73%) more so than lower airways (48%).
Joints (32%).
Kidneys (20%).
Eyes, skin, nerves less commonly.

Question 16

4 upper airway manifestations of GPA?

Answer 16

Sinus disease.
Epistaxis.
Septal perforation.
Subglottic stenosis -> dyspnea, stridor, voice change, cough.

Question 17

How can GPA affect the lungs?

Answer 17

With cavities, hemorrhage, inflammation, stenosis, and endobronchial disease.

Question 18

Which ANCA (anti-neutrophil cytoplasmic antibody) is GPA associated with?

Answer 18

C-ANCA (cytoplasmic).

As opposed to P-ANCA, perinuclear.

Question 19

4 clinical aspects of the diagnosis of GPA?

1 helpful lab value?

Answer 19

Nasal inflammation.
Abnormal chest CT - nodules, fixed infiltrate, cavities.
Abnormal urinary sediment.
Granulomatous inflammation of biopsied blood vessel.

Positive C-ANCA points toward GPA.
(also positive anti-Proteinase-3)

Question 21

T cell subtype associated with GPA inflammation?

Answer 21

Th1 - with IFNgamma, TNFalpha, etc.

Question 22

Immune cells involved in GPA?

Answer 22

CD4s, B cells, PMNs

Question 23

What do PFTs show in a patient with GPA?

Answer 23

Restrictive lung disease with reduced D(L)CO.