Aspergillus lung disease

Question 1

Define Aspergillus lung disease

Answer 1

Aspergillus lung disease = lung disease associated with Aspergillus fungal infection
• Clinical spectrum: colonisation -> allergy -> asthma -> aspergilloma (fungal ball) -> invasive disease

Question 2

Explain the aetiology of Atopic asthma and Aspergilloma

Answer 2

Inhalation of the ubiquitous (found everywhere) Aspergillus spores
o Usually Aspergillus fumigates (50-70%)
o The spores are 2-10 micrometres diameter and are routinely inhaled, but promptly eliminated

Atopic asthma - Type-1 hypersensitivity reaction through inhalation of fungal spores

Aspergilloma - Growth of an A. fumigatus mycetoma ball in a pre-existing lung cavity – e.g. post TB, old infarct, abscess

Question 3

What is the aetiology of Allergic bronchopulmonary aspergillosis (ABPA)?

Answer 3

Colonisation of the airways leads to an IgE and IgG mediated immune response – type 3 hypersensitivity reaction (Usually in asthmatics)

Ultimately causes airway damage and central bronchiectasis as Proteolytic enzymes and mycotoxins released by fungi, Th2 cells producing IL4/5 and mediating eosinophilic cause inflammation, and IL8 mediated neutrophilic inflammation

Question 4

What is the aetiology of Invasive aspergillosis?

Answer 4

Aspergillus invasion into lung tissue and fungal dissemination

Secondary to
Immunosuppression - Neutropenia, steroids, transplantation, AIDS
SLE
Burns
Broad spectrum antibiotics

Question 5

Explain the risk factors of Aspergillus lung disease

Answer 5

Immunocompromise: 
Neutropenia
Compromised T-cell/macrophage function
Allogeneic transplantation
CGD
Acute leukaemia 
Immunosuppressive therapy

Pre-existing cavity

Asthma/CF

Question 6

Summarise the epidemiology of Aspergillus lung disease

Answer 6

Uncommon (Usually in immunocompromised, e.g. cancer, transplant patients)

Question 7

Recognise the presenting symptoms of Aspergillus lung disease

Answer 7

Aspergilloma
o Asymptomatic
o Haemoptysis

ABPA
o Difficult to control asthma
o Recurrent pneumonia with wheeze/cough/fever
o History of atopy

Invasive aspergillosis
o	Non-productive cough
o	Headache
o	Septic picture - Fever
o	Dyspnoea
o	Pleuritic chest pain

Question 8

Recognise the signs of Aspergillus lung disease on physical examination

Answer 8

Aspergillomas
o Tracheal deviation (if large)

ABPA
o Dullness in affected lung
o Decreased breath sounds
o Wheeze

Invasive aspergillosis
o Cyanosis

Question 9

What are investigations for Aspergilloma?

Answer 9

o CXR
Round opacity with crescent of air surrounding
Usually upper lobe

o CT/MRI

o Sputum cultures
May be negative if no connection between cavity and bronchial tree

Question 10

What are investigations for ABPA?

Answer 10

o Skin prick test for sensitivity
Immediate reaction to Aspergillus antigens – positive wheal and flare reaction

o Bloods - Eosinophilia, Serum total IgE = raised
Serum specific IgE/IgG to Aspergillus fumigatus = raised

o CXR - Transient patchy shadows, Collapse
Distended mucus-filled bronchi producing tubular shadows (‘gloved fingers’ appearance)

Signs of complications - Upper lobe fibrosis, Parallel-line shadows and rings (bronchiectasis)

o CT - Lung infiltrates, Central bronchiectasis

o Spirometry - Reversible airflow limitation

Question 11

What are investigations for Invasive aspergillosis?

Answer 11

Blood cultures, sputum MC+S, bronchoalveolar lavage

• Detected of Aspergillus
• Evidence of septate hyphae

Chest CT
- Nodules surrounding ground-glass appearance