Restrictive: Sarcoidosis

Question 1

What is sarcoidosis?

Answer 1

Systematic disease

Characterised by immune mediated widespread noncaseating granulomas in multiple organs

Question 2

What is the aetiology and who does is normally affect?

Answer 2

• Aetiology is unknown, likely due to CD4+ helper T cell response to unknown antigen

Classically seen in African American females

Commonly involved organs are the lung and hilar lymph nodes

Question 3

Explain the pathophysiology of sarcoidosis

Answer 3

Unknown antigen triggers cell-mediated immune response

Characterized by accumulation of T cells and macrophages

Release cytokines and chemokines

And organize responding cells into granulomas.

Inflammatory process leads to formation of noncaseating granulomas - hallmark of sarcoidosis

Granulomas are collections of mononuclear cells and macrophages that differentiate into epithelioid and multinucleated giant cells and are surrounded by lymphocytes, plasma cells, fibroblasts, and collagen

Question 4

Explain the histological findings

Answer 4

Pink region = epithelioid histocytes – defining cell of a granuloma

Giant cells

Non-caseating – meaning all cells present are alive, there is no necrosis

Asteroid bodies seen – configuration of granuloma – characteristic of sarcoidosis

Question 5

Explain the pathological findings

Answer 5

Granulomas most commonly in hilar lymph nodes and lung

• Leads to restrictive lung disease
• Lung becomes less compliant due to the granulomas present in interstitium

Question 6

Explain the clinical features/signs

Answer 6

• Dyspnoea
• Cough
• Fatigue
• Malaise
• Weight loss/anorexia
• Erythema Nodosum
• Fever/night sweats
• Elevated serum ACE (angiotensin converting enzyme)
• Elevated CD4/CD8 ratio in bronchoalveolar lavage fluid
• Hypercalcemia (because granulomas have one alpha-1 hydroxylase activity and they can activate vitamin D – BUT in any disease with non-caseating granulomas will have activity of alpha-1 hydroxylase resulting in overproduction of hypercalcemia i.e beryllium

Question 7

What are the other important commonly involved tissues in sarcoidosis?

Answer 7

• Uvea (uveitis)
• Skin (cutaneous nodules or erythema nodosum)
• Salivary and lacrimal glands (mimics Sjogren syndrome – AI – body attacks the salivary lacrimal glands causing dry mouth and eyes – HY)
• Almost any tissue can be involved

Question 8

Name a way to remember the associations with this disease

Answer 8

A facial droop is UGLIER:

Facial droop: Bells Palsy

U - veitis
G - ranulomas (noncaseating epithelioid, Shaumann/asteroid bodies)
L - upus pernio (facial skin lesions resembling lupus)
I - nterstitial fibrosis
E - rythema Nodosum (skin inflammation, red painful lumps)
R - heumatoid arthritis-like arthropathy

Question 9

Diagnosis of sarcoidosis?

Answer 9

CXR:

• Bilateral hilar lymphadenopathy
• Course reticular opacities

Chest CT
Better shows extensive hilar and mediastinal adenopathy’s

Main diagnosis is exclusion
- Biopsy shows characteristic features ie: Non-caseating granulomas
Schaumann bodies: dystrophic calcifications inside of langhan cells as part of granuloma and asteroid bodies

Question 10

Treatment of sarcoidosis?

Answer 10

Steroids – often resolves spontaneously without treatment

(NSAIDs
Corticosteroids
Occasionally immunosuppressants)