Diffuse parenchymal lung disorders / interstitial lung diseases

Question 1

What are interstitial lung diseases?

Answer 1

Group of diseases with bilateral diffuse lung injury and inflammation that can progress to lung fibrosis
Involves interstitial space, alveoli, bronchioles and blood vessels

Question 2

What is the common presentation?

Answer 2

Dyspnoea
Persistant non productive cough
Abnormal CXR- bilateral diffuse pulmonary infiltrates
Pulmonary symptoms

Question 3

What is sarcoidosis?

Answer 3

Multi-system granulomatous disorder affecting any organ system, but predominantly the lymph nodes and lung

Question 4

What genes mutations are associated with sarcoidosis?

Answer 4

HLA-DRB1 and DQB1 alleles

Question 5

What type of granuloma is present in sarcoidosis?

Answer 5

non-caseating sarcoid granuloma: focal accumulation of epithelial cells, macrophages and lymphocytes.

Question 6

Describe the pathophysiology of sarcoidosis?

Answer 6

T cells are removed in the lung and trapped in granulomas
–>
Depressed cell mediated reactivity to antigens such as tuberculin and candida albicans + overall lymphopenia with low circulating T cells

Increased number of cells (esp. CD4 helper) in bronchoalveolar lavage

Question 7

Describe epidemiology of sarcoidosis

Answer 7

age = 20-40
F>M
Afro Caribbean > Caucasian

Question 8

How does sarcoidosis usually present

Answer 8

Often incidental finding on CXR

Acute sarcoidosis presents with erythema nodosum, and polyarthralgia

Question 9

What is erythema nodosum?

Answer 9

red lumps caused by inflammation of fat cells

Question 10

What is polyarthralgia?

Answer 10

Multiple achy joints

Question 11

What pulmonary features are present in sarcoidosis?

Answer 11

CXR – bilateral hilar lymphadenopathy ± pulmonary infiltrates or fibrosis

Progressive dyspnoea
Dry cough
decreased exercise tolerance
Chest pain

Question 12

What non pulmonary signs are there?

Answer 12

Literally everything man

But most commonly: Lymphadenopathy, Hepatomegaly, Splenomegaly, Uveitis

Question 13

What is the differential diagnosis of Bi-hilar lymphadenopathy?

Answer 13

Sarcoidosis
Infection e.g. TB, mycoplasma
Malignancy e.g. lymphoma, carcinoma, mediastinal tumours
Organic dust disease e.g. silicosis, berylliosis
Extrinsic allergic alveolitis (hypersensitivity pneumonitis)
Histocytosis X

Question 14

What different types of granulomatous disease are there?

Answer 14

Infections 
Autoimmune
Vasculitis 
Organic dust disease
Idiopathic 
Hypersensitivity pneumonitis
Histiocytosis X

Question 15

What blood test results are typical for a patient with sarcoidosis?

Answer 15

Raised ESR
Lymphopenia 
Raised serum ACE in 60% (non specific) 
Raised LFTs, 
Raised calcium 
Raised IGs

Question 16

What will urine analysis show for a patient with sarcoidosis?

Answer 16

Raised calcium

Question 17

Chest Xray is abnormal in 90% what are stages 0-4 for sarcoidosis

Answer 17

0- normal 
1- Bi-hilar lymphadenopathy 
2- BHL + pulmonary infiltrate 
3- pulmonary infiltrate alone 
4- Pulmonary fibrosis with honey combing and pleural involvement

Question 18

What do lung function tests show for patients with sarcoidosis?

Answer 18

generally show restriction and reduced volume

Question 19

What spirometry results would indicate restrictive lung disease

Answer 19

FVC <0.8 of expected value

FEV1 >0.8 of FVC

Question 20

A positive tissue biopsy in sarcoidosis is diagnostic. What would a tissue biopsy show?

Answer 20

shows non-caseating granuloma – lung, liver, lymph nodes, skin nodules

Question 21

What does broncheoalveolar lavage show in patients with sarcoidosis?

Answer 21

Bronchoalveolar lavage (BAL) – shows increased lymphocytes in active disease, increased neutrophils in pulmonary fibrosis

Question 22

How would you treat BHL associated with sarcoidosis?

Answer 22

BHL alone doesn’t need treatment

Question 23

For acute sarcoidosis bed rest and NSAIDs are likely to induce a spontaneous recovery.
What are indications that a patient with sarcoidosis needs to be put on oral prednisolone? (corticosteroid)

Answer 23

Parenchymal lung disease
Uveitis
Hypercalcaemia
Neurological/cardiac involvement

Question 24

If sarcoidosis is not controlled by prednisolone what progressive treatment options are there?

Answer 24

Iv methylprednisolone or immunosuppressants (methotrexate, hydroxychloroquine, ciclosporin, cyclophosphamide)

Question 25

What are common dose related side effects of methotrexate?

Answer 25

Mucosal damage and bone marrow suppression

Question 26

What contraindications are there for methotrexate?

Answer 26

Teratogenic so avoid in pregnancy

Question 27

How does methotrexate act?

Answer 27

Inhibits conversion of folate into active form--> inhibits DNA production and hence cell division Should prescribe folic acid with it!!

Question 28

Idiopathic pulmonary fibrosis, what is it?

Answer 28

A type of idiopathic interstitial pneumonia. Inflammatory cell infiltrate and pulmonary fibrosis of unknown cause.

Question 29

Idiopathic pulmonary fibrosis symptoms?

Answer 29

``` Dry cough Exertional dyspnoea Malaise Weight loss Arthralgia ```

Question 30

Idiopathic pulmonary fibrosis signs?

Answer 30

Cyanosis Finger clubbing Fine end inspiratory crackles

Question 31

Idiopathic pulmonary fibrosis complications?

Answer 31

Respiratory failure | Increased risk of cancer

Question 32

Blood test results for patient with idiopathic pulmonary fibrosis

Answer 32

ABG: PaO2 low, if severe then PaCo2 is also high CRP raised Ig's raised ANA and rheumatoid factors (very unspecific but indicative of disease)

Question 33

CXR for patients with idiopathic pulmonary fibrosis

Answer 33

Lung volume decreased Bi-lateral lower zone reticulo-nodular shadows Honey comb lung CT shows the same but more sensitive

Question 34

What would spirometry show for idiopathic pulmonary fibrosis?

Answer 34

Restrictive changes FVC< 0.8 of expected value FEV1>0.8 FVC

Question 35

Lung biopsy may be required for a diagnosis what are the histological changes observed called?

Answer 35

Usual interstitial pneumonia

Question 36

Treatment for idiopathic pulmonary fibrosis?

Answer 36

``` O2 Supportive treatment Palliative care Opiates pulmonary rehab Lung transplant is feasible ```

Question 37

What is interstitial lung disease?

Answer 37

Characterized by chronic inflammation and/or progressive interstitial fibrosis

Question 38

Describe the pathology of interstitial lung disease

Answer 38

Fibrosis and remodelling of the interstitium Chronic inflammation Hyperplasia of type 2 pneumocytes

Question 39

Clinical presentation of interstitial lung disease?

Answer 39

``` Dyspnoea on exertion Non productive paroxysmal (sudden intense recurrence) cough Abnormal breathing sounds Abnormal Xray and CT Spirometry shows restriction, reduced tCO ``` (everything you would expect tbh)

Question 40

Name 4 occupational interstitial lung diseases

Answer 40

Asbestosis, berylliosis, silicosis, cotton workers lung

Question 41

What drugs can cause occupational interstitial lung disease?

Answer 41

``` Nitrofurantoin (abx for bladder infection) Bleomycin Amiodarone (anti- arrhythmic drug) Sulfasalazine (RA drug) Busulfan (chemo) ```

Question 42

What are all the different causes of interstitial lung disease?

Answer 42

Occupational (Asbestosis) Drugs (amiodarone) Hypersensitivity (Hypersensitivity pneumonitis) Infections (e.g. viral) GORD Those associated with systemic disorders (e.g. sarcoidosis, SLE) Idiopathic (idiopathic pulmonary fibrosis)