1. The extraordinary spectrum of diseases caused by Aspergillus
David W. Denning
Wythenshawe Hospital
University of Manchester

2. The genus Aspergillus - importance to humanity
on the negative side:
cause invasive and allergic disease
in humans and other animals:
A. fumigatus
cause plant and food spoilage and
produce mycotoxins:
A. flavus and A. parasiticus
Several species of Aspergillus can cause disease in humans and animals particularly when the host is immunosuppressed, eg in cancer patients, transplant patients and AIDS patients. Aspergillus spores are airborne and occur naturally in the environment, but are often more abundant around building sites. Near compost or where damp conditions prevail. Invasive disease usually only occurs in immunosuppressed patients with inhalation being the primary route of infection. Allergic aspergillosis occurs in patients with asthma, atopy or cystic fibrosis.
In many underdeveloped countries contamination of crops such as maize, groundnuts etc has lead to loss of crops and severe illness in both humans and farm stock where contaminated food is ingested (due to mycotoxins which harm the body).

3. The genus Aspergillus - importance to humanity
on the positive side:
composting
well-established model organism in cell biology and genetics:
A. nidulans
food production:
enzymes and organic acids: A. niger
East Asian foods: A. oryzae and A. sojae
1) Fungi play an essential role in both the Nitrogen and Carbon cycle by breaking down dead organic material.
2) The detailed genetic study of A.nidulans has lead to some important discoveries, such as the parasexual cycle in fungi, and the genetic defect causing alkaptonuria
3) Most of us use fungi every day without knowing it. We eat mushrooms and Quorn™ (a vegetarian fungal protein made from Fusarium graminarium), but we also prepare many other foods using fungi. The yeast Saccharomyces cerevisiae is used to ferment sugar to alcohol and carbon dioxide – the process used to make beer and wine and also to make bread rise. All citric acid is produced by Apergillus niger. The fungi Aspergillus oryzae and Aspergillus sojae are used in the production of the oriental foods soy sauce and miso. We also use fungi to produce flavourings, vitamins and enzymes and to mature many cheeses. 4) Apart from penicillin, the most important antibiotics from fungi are the cephalosporins (beta-lactams with similar mode of action to penicillin, but with less allergenicity) and griseofulvin (from Penicillium griseofulvum and related species) which is used to treat athlete's foot and related fungal infections of the skin. The echinocandins anidulafungin and aminocandin (HMR 327) are semi-synthetic antifungals originally derived from fermentation of A. nidulans var restrictus and A. sydowi respectively.
Lovastatin a cholesterol lowering drug is produced by Aspergillus terreus. And the group of antifungal drugs called echinocandins have been produced using A nidulans and A sydowi.
Fumagillin is a secondary metabolite that inhibits angiogenesis and antibiotic properties, especially against protozoa such as Entamoeba histolytica. LD50 in mice 800 mg/kg body-weight subcutaneously although as much as 2 mg/kg body-weight could be tolerated orally. Fumigillin or analogue TNP-470 have been used in the treatment of microsporidiosis, usually caused by the microscopic fungus Enterocytozoon bieneusi (Fumagillin treatment of intestinal microsporidiosis. New Engl J Med 2002;346: ).
pharmaceuticals:
echinocandins: A. nidulans and A. sydowi
lovastatin: A. terreus
fumagillin: A. fumigatus

4. Aspergillus Life-cycle
Germination
Spores inhaled
Hyphal elongation and branching
Mass of hyphae (plateau phase)
Short movie clips showing germination of spores and growth of hyphae can be viewed on this website at the following link:

5. The genus Aspergillus – ~180 species,
38 have caused disease (able to grow at 37C)
Common in the environment
Aspergillus fumigatus conidial head
A. terreus – resistant to AmB
A. nidulans – may be amphotericin B resistant
A. niger
A. flavus -sometimes amphotericin B resistant
A. fumigatus low frequency of azole resistance
The relative frequency of species associated with acute invasive aspergillosis is 85-90% A. fumigatus, 5-10% A. flavus, 3-7% A. niger and 1% A. nidulans. There are approximately other species of Aspergillus which have caused disease in humans.. ( see view the species section within the image bank). The few species which cause disease in man and animals are also known to have some resistance to antifungal drugs.

6. CLASSIFICATION OF ASPERGILLOSIS
Invasive aspergillosis
Acute (<1 month course)
Subacute/chronic necrotising (1-3 months)
Airways/nasal exposure to airborne Aspergillus
Chronic aspergillosis (>3 months)
Chronic cavitary pulmonary
Aspergilloma of lung
Chronic fibrosing pulmonary
Chronic invasive sinusitis
Maxillary (sinus) aspergilloma
Persistence without disease - colonisation of the airways or nose/sinuses
Allergic
Allergic bronchopulmonary (ABPA)
Extrinsic allergic (broncho)alveolitis (EAA)
Asthma with fungal sensitisation
Allergic Aspergillus sinusitis (eosinophilic fungal rhinosinusitis)
Exposure to individual Aspergillus spores or conidia is almost constant. If eradicated immediately, as is usual in normal people, no disease results. If colonisation occurs, it may be short or long term. The pattern of disease is mostly determined by the host group (see slide 8), with probably a component of the inoculum size contributing to invasive disease.
Acute and subacute disease is usually associated with immunocompromised patients eg AIDS, chemotherapy, transplant etc. and these will be discussed first.

7. Immunosuppression and infection
Inhalation of aspergillus spores is a common daily occurrence. A healthy immune system would normally remove the spores and no symptoms or infection would occur.
In individuals whose immune system may be suppressed either because of illness eg AIDS, cancer patients or drugs, spores may germinate and resulting tissue or systemic aspergillus invasion can result.
Individuals with allergies such as asthma, can also be vulnerable to aspergillus disease.

8. Normal immune function
Interaction of Aspergillus with the host A unique microbial-host interaction
Acute IA
ABPA
Allergic sinusitis
Subacute IA
Frequency of aspergillosis
Frequency of aspergillosis
Tracheobronchitis
Aspergilloma
Chronic cavitary
Chronic fibrosing
Objective: The risk of developing invasive aspergillosis increases with increasing levels of immune deficiency. In contrast the risk of allergic aspergillosis is enhanced in individuals whose immune system is hyper-reactive (atopic).
Immune dysfunction
Normal immune function
Immune hyperactivity .

9. Changing incidence of fatal invasive mycoses in non-HIV patients in USA
Rate per 100,000 population
Candidiasis
Aspergillosis
This slide contrasts the reduction in mortality related to candidaemia and invasive candidiasis with invasive aspergillosis in the US. Other figures from Europe indicate 4% of patients dying in teaching hospitals have invasive aspergillosis, including medical intensive care in patients not normally considered susceptible.
McNeil et al, Clin Infect Dis 2001;33:641

10. Invasive pulmonary aspergillosis
IPA
Normal lung
IPA occurs in ~7% of acute leukaemia patients, 10-15% allogeneic BMT patients
Chest X ray showing large lesion due to invasive pulmonary aspergillosis.
Chest radiograph with ‘classical’ appearance of a pulmonary infarction – a wedge-shaped lesion peripherally set against the pleura. This patient was receiving chemotherapy including corticosteroids, who had had a splenectomy previously presented with fever and right-sided pleuritic chest pain. Blood cultures grew Aspergillus fumigatus and he responded to amphotericin B and flucytosine. (Case published in Denning DW, Williams A H. Invasive pulmonary aspergillosis diagnosed by blood culture and successfully treated. Br J Dis Chest 1987, 81: 300. See also case 38 in the case history section

11. Unequivocal ‘Halo sign’ surrounding a nodule
CT scan showing characteristic halo sign - in a cavity with fungus ball there is a crescent shaped semi-translucent space along the upper portion, of a density giving the appearance of a halo.
Angioinvasion is the pathological hallmark of acute IPA in the neutropenic setting. Two patterns of pathology are discernable: invasion of major proximal pulmonary arteries with resultant thrombosis and distal tissue infarction and a well circumscribed spherical nodule with a vessel in the centre of the lesion invaded by hyphae. Such nodules have a pale centre of coagulative necrosis with extensive permeation of tissue by hyphal elements but few inflammatory cells or haemorrhage. Surrounding this necrotic centre is haemorrhagic parenchyma. In the former, the radiological appearance is one of a wedge shaped lesion with the base abutting the visceral pleura. [Fraser]. The latter lesion is seen on CT as a nodule with or without an associated halo sign [Fraser, Meziane]. If the lesion cavitates, the area of central necrosis (sequestrum) contracts with replacement by an air-cap, and an air-crescent sign may be visible.
Fraser RS. Pulmonary aspergillosis: pathologic and pathogenetic features. Pathol Annu 1993; 28 Pt 1:
Meziane MA, Hruban RH, Zerhouni EA, et al. High resolution CT of the lung parenchyma with pathological correlation. Radiographics 1988; 8:
Halo sign
Herbrecht, Denning et al, NEJM 2002;347:

12. Recent examples of the frequency of invasive aspergillosis
Underlying condition
Incidence
Reference/year
Acute myeloid leukaemia 8%
Cornet, 2002
Acute lymphatic leukaemia
6.3%
Allogeneic HSCT
11-15%
Grow, 2002;
Marr, 2002
Lung transplantation %
Minari, 2002; Singh,2003
Heart-lung transplantation
11%
Duchini, 2002
Small bowel tranplantation
AIDS
2.9%
Libanore, 2002
Recent examples of the incidence of IA in different at risk groups. Actual numbers are unit dependant and diagnostic criteria dependent.

13. Bleeding as an aspect of disseminated invasive aspergillosis
Fumagillin is anti-angiogenic
A haemolysin described from Aspergillus fumigatus
Other factors that contribute to thrombosis or a coagulopathy?
Fumagillin -  a product of Aspergillus fumigatus is an inhibitor of endothelial cell proliferation and angiogenesis. Yet angiogenesis is a hallmark for invasive aspergillosis. (see previous slide). Certain proteases are probably important in contributing to a coagulation disorder.
Gillies & Campbell,

14. Interaction of conidia and endothelial cell projections
How does Aspergillus fumigatus cause thrombosis (clotting of vessels) and also bleeding?
Interaction of conidia and endothelial cell projections
Internalisation of conidia (and hyphae) by endothelial cells with injury apparent at 4 hours
These images show the interaction of swollen Aspergillus fumigatus conidia interacting with endothelial cells (the innermost layer of cells in blood vessels). The images direct interaction of conidia with the cells, phagocytosis by the endothelial cell, and then cellular damage, all in a 4 hour time-frame. The precise mechanisms are not clear.
Filler et al, Blood 2004;103:2134; Paris et al, Infect Immun 1997;65:1510.

15. Cerebral aspergillosis (abscess) in chronic lymphocytic leukaemia
Dissemination via the blood stream to the brain occurs in ~5% of cases of invasive aspergillosis, and in ~40% of allogeneic bone marrow (HSCT) recipients
Patient diagnosed with Stage C Chronic Lymphocytic Leukaemia, treated in the MRC CLL4 study, with prednisolone for 4 weeks followed by oral chlorambucil for 7 days. Patient developed severe pneumonia due to pseudomonas and staphylococcus. Following treatment with broad spectrum antibiotics and 1 week of Abelcet, patient was readmitted with headache, disorientation and fever. CT brain scans showed 3 ring enhancing lesions, aspirated material showed neutrophils but grew aspergillus. Patient now improved on Abelcet (4 mg/kg) and oral itrconazole suspension 200mg b.d.

16. Early diagnosis of invasive aspergillosis is important
Treatment started <10d >11d
Mortality % 90%
Von Eiff et al, Respiration 1995;62:241-7.

17. Sputum Cultures for Fungus
Bacteriological media inferior to fungal media – 32% higher yield on fungal media
A four day A. fumigatus culture on malt extract agar (above). Light microscopy pictures are taken at 1000x, stained with lacto-phenol cotton blue.
At least 3 sputum specimens should be submitted for fungal culture whenever fungal infection is suspected. On a survey of routine bacterial culture versus fungal culture, many positive cultures for Aspergillus were found on the routine cultures, but 32% of instances of Aspergillus were only seen in the fungal culture medium. Horvath & Dummer, Am J Med 1996;100:171-8.

18. Aspergillus Antigen Test
Diagnosis or surveillance?
Only blood, or BAL, CSF etc
Best OD cut-off - 0.7
False positives in kids / antibiotics
False negative with antifungal
prophylaxis
Not as useful for non-hematology
Not useful if pre-existing antibody
There are substantial data on aspergillus antigen (galactomannan) using the commercial ELISA format published. Essentially, it can be detected in blood in most patients with acute invasive aspergillosis. False positives arise because of intestinal absorption of galactomannan which is found in many foods (see (oldest article), and contamination of some antibiotics batches with antigen. Most Aspergillus species are detected, as all the common pathogenic species produce galactomannan. False negatives do arise, probably partly because of complexing by antibody. If the absolute incidence of IA is high (ie >6%) the balance of argument is to use a screening approach, if less frequent than this, a diagnostic approach. However, anti-aspergillus prophylaxis (such as itraconazole solution) probably reduces the test’s utility. Once positive, rising titres on treatment predict failure, and usually death. CSF antigen is useful for diagnosing cerebral aspergillosis, and BAL antigen is probably useful for pulmonary aspergillosis, but the assay cut-off and performance is not yet clear.
Herbrecht et al, J Clin Microbiol 2002;20: ; and others

19. Outcome from invasive aspergillosis – amphotericin B therapy
Note 60% death rate in 30 days from acute invasive pulmonary aspergillosis treated with amphotericin B.
Lin et al, Clin Infect Dis 2001;32:358

20. Sub-acute invasive aspergillosis in AIDS
This patient, thought initially to have pulmonary tuberculosis in AIDS, has bilateral upper-lobe cavities, more marked on the left. He presented with fever, non-productive cough and dyspnoea. Bronchoscopy yielded Aspergillus fumigatus. He refused therapy and died with progressive disease. He is reported as patient 8 in (Denning DW, Follansbee S, Scolaro M, Norris S, Edelstein D, Stevens DA. Pulmonary aspergillosis in AIDS. N Engl J Med 1991; 324: )

21. Sub-acute invasive aspergillosis
Less immunocompromised patients
Slower progression of disease (> 1 month)
Cavitary or nodular pulmonary disease typical
Vascular invasion less common
Dissemination less common
Antigen testing less useful
Antibody testing may be helpful in diagnosis

22. Chronic necrotizing aspergillosis (CNPA)
Chronic necrotizing pulmonary aspergillosis (CNPA) is a subacute process usually found in patients with some degree of immunosuppression.
Usually it is associated with underlying lung disease, alcoholism, or chronic corticosteroid therapy. Because it is uncommon, CNPA often remains unrecognized for weeks or months and causes a progressive cavitary pulmonary infiltrate.

23. Chronic necrotising pulmonary aspergillosis
Right upper lobe showing circular shadow partly filled by a mass. PT MS 1996
Right lobe shows huge cavity containing some debris, with +ve aspergillus precipitins.Pt MS 1999
Same lobe shows expansion of the shadow, still partially filled with a mass. Pt MS 1998
Right upper lobe. Patient has diabetes and pulmonary mycobacterium avium- shows small cavitary lesion PT MS 1995.
This man was an insulin dependent diabetic, otherwise well. The first panel (chest X-ray) shows the original infection with mycobacterial infection (M. avium intracellulare (atypical)). The second shows a much larger cavity, with a fungal mass in it. An isolated film would allow a diagnosis of aspergilloma, but later X-rays show progression. The third chest X-ray shows an expanding cavity, with a larger fungal ball in it. The final X-ray shows a very large thin-walled cavity containing fluid. Aspiration of the fluid grew Staphylococcus aureus.
Denning, Clin Microbiol Infect 2001;7(Suppl 2):25-31.

24. CLASSIFICATION OF ASPERGILLOSIS
Invasive aspergillosis
Acute (<1 month course)
Subacute/chronic necrotising (1-3 months)
Airways/nasal exposure to airborne Aspergillus
Chronic aspergillosis (>3 months)
Chronic cavitary pulmonary
Aspergilloma of lung
Chronic fibrosing pulmonary
Chronic invasive sinusitis
Maxillary (sinus) aspergilloma
Persistence without disease - colonisation of the airways or nose/sinuses
Allergic
Allergic bronchopulmonary (ABPA)
Extrinsic allergic (broncho)alveolitis (EAA)
Asthma with fungal sensitisation
Allergic Aspergillus sinusitis (eosinophilic fungal rhinosinusitis)
Exposure to individual Aspergillus spores or conidia is almost constant. If eradicated immediately, as is usual in normal people, no disease results. If colonisation occurs, it may be short or long term. The pattern of disease is mostly determined by the host group (see next slide), with probably a component of the inoculum size contributing to invasive disease.
However chronic disease if usually seen in patients with apparently normal immune systems.

25. Aspergillus and airways
Types of aspergillosis of the airways
Colonisation (no disease – could be at risk)
Obstructing Aspergillus tracheobronchitis /Mucus impaction (non-invasive)
Aspergillus bronchitis/tracheobronchitis (superficially invasive only)
Ulcerative Aspergillus tracheobroncitis (locally invasive) (lung transplants – at anastomosis)
Pseudomembranous Aspergillus tracheobronchitis (Extensive disease, locally invasive, associated with IPA and may disseminate)
Langley, ATS 2004
The categories of invasive aspergillosis of the the airways and whether the disease is likely to be invasive or not, is described.

26. Aspergillus tracheobronchitis
Autopsy drawing of a
‘normal’ 3 year old
who died over 10 days
This drawing shows the appearance of the tracheobronchial tree at autopsy. It shows white plaques of fungal growth on the trachea and main bronchi. This is the first case of Aspergillus tracheobronchitis reported, and emphasises that some cases are in ‘normal’ patients, ie no immunosuppression.
Wheaton, Path Trans 1890; 41:34-37

27. Aspergillus tracheobronchitis
Review of 58 patients in literature for normal and immuno compromised patients - risk factors %
None (ie normal) 25
Heart / Lung transplant 18
Solid tumour 15
BMT
Leukaemia 13
HIV/AIDS 8
Other
Kemper et al, Clin Infect Dis 1993; 17: 344

28. Aspergilloma Patient RT December 2002 Fungus ball
Pulmonary aspergilloma is a mass caused by a fungal infection that usually grows in pre-existing lung cavities. An aspergilloma can also form in the maxillary sinus, often related to dental work on the upper teeth. In the lung, it must be distinguished from chronic cavitary pulmonary aspergillosis (complex aspergilloma), characterised by multicavity disease. Aspergillomas are single, and always have substantial pleural thickening over them, and these patients have positive serum aspergillus precipitins.
Patient RT
December 2002

29. Chronic pulmonary aspergillosis – pre-existing disease
All 18 patients had prior pulmonary disease
9 TB, 5 with atypical mycobacteria
13 smokers or ex-smokers
All 18 non-immunocompromised
3 excess alcohol
Studied symptoms in 18 patients .Chronic cavitary pulmonary aspergillosis (complex aspergilloma),is characterised by multicavity disease.
Denning DW et al, Clin Infect Dis 2003; 37:S265

30. Chronic pulmonary aspergillosis - presentation
Weight loss / 18 (89%)
Cough / 18 (83%)
Shortness of breath 9 / 18 (50%)
Haemoptysis / 18 (50%)
Fatigue / malaise 5 / 18 (28%)
Chest pain / 18 (17%)
Sputum production / 18 (17%)
Fever / 18 (11%)
Denning DW et al, Clin Infect Dis 2003; 37:S265

31. Chronic pulmonary aspergillosis - serology
All 18 patients had positive Aspergillus precipitins ( )
All 18 patients had elevated inflammatory markers, CRP, PV and / or ESR
14 of 18 (78%) had elevated total IgE (>20), 13 >200 and 7 >400
9 of 14 (67%) had Aspergillus specific IgE (RAST)
Denning DW et al, Clin Infect Dis 2003; 37:S265

32. Chronic cavitary pulmonary aspergillosis (CCPA)
Close up view of right upper-lobe of the lung in a 45 year old man who smoked cigarettes showing an ill-defined shadow behind the clavicle and additional abnormalities inferior to this in the right upper-lobe. The lesions were considered to be possibly malignant and surgically resected. The specimen revealed a 2cm cavity with necrotic contents associated with local bronchiectasis and thickening of the parietal pleura. The lung specimen showed severe emphysema with fibrosis. Microscopically, the cavity was in an area of cystic bronchiectasis with erosion of the mucosa. The cavity contents were purulent and contained a fungus ball without apparent invasion or tissue eosinophilia. A fibrosing (necrotising) granuloma was seen superior to the cavity. Stains for acid fast organisms and cultures for TB were negative and fungal cultures were not done.. B. June 1992 Recurrence of disease. Chest radiograph demonstrating cavitary invasive aspergillosis. Despite resection of part of the right upper-lobe, invasive aspergillosis recurred six months later. Sputum cultures grew A. fumigatus and Aspergillus antibodies were detected in serum. He responded to itraconazole but subsequently progressed.  
Patient RW
September 1992
Relapse in normal lung
Patient RW
December 1991
Pre surgical resection

33. Chronic cavitary pulmonary aspergillosis
This CT scan of the thorax illustrates the formation of multiple cavities, without any fungal ball formation (aspergilloma) developing in ‘normal’ (emphysematous) lung a non immunocompromised patient. The appearances are reminiscent of tuberculosis and coccidioidomycosis. Pleural involvement is seen as well.
Patient RW
July 1993

34. Chronic Cavitary Pulmonary Aspergillosis
Young 33 year-old female smoker (no other risk factors) spontaneously developed these bilateral pulmonary shadows that then cavitated, and the cavities expanded in size of the next 3 years.
Patient JA
Jan 2001

35. Chronic Cavitary Pulmonary Aspergillosis
Patient JA
Feb 2002

36. Chronic Cavitary Pulmonary Aspergillosis
Patient JA
April 2003

37. Chronic Cavitary Pulmonary Aspergillosis
Patient JA
July 2003

38. Chronic cavitary pulmonary aspergillosis
Case 004 (also published) in case histories section.
Patient JP
June 1999
Denning DW et al, Clin Infect Dis 2003; 37:S265

39. Chronic Cavitary Pulmonary Aspergillosis, with aspergilloma
Case 004 (also published) in case histories section.
Patient JP
July 2001
Denning DW et al, Clin Infect Dis 2003; 37:S265

40. Chronic Fibrosing Pulmonary Aspergillosis
Case 004 (also published) in case histories section.
Patient JP
April 2002
Denning DW et al, Clin Infect Dis 2003; 37:S265

41. Mannose Binding Lectin (MBL)- a key part of the innate immune system
Mannose-binding lectin (MBL) is a serum protein of hepatic origin belonging to a family of Ca2+-dependent collagenous lectins, most of which are components of the innate immune system). MBL is able to bind through multiple sites to various carbohydrate structures and, on binding to its ligands, is able to activate complement in an antibody- and C1q-independent manner using MBL-associated serine protease 1 (MASP-1) and MASP-2).
In humans, low levels of MBL are caused by one of three structural mutations found within exon 1 of the MBL gene. One - M54 - effects 16% of caucasians.
Crosdale et al J Infect Dis 2001;184:653

42. Mannose Binding Protein
Mutations
5 mutations described
2 in promoter region (less important)
3 in open reading frame (M52, M54, M57)
Codon 54 mutation present in 16% of Caucasian homozygous in 2%
Defects associated with bacterial infections in children and hepatitis B carriage
Eisen & Minchinton Clin Infect Dis 2003;37:1496

43. CCPA and human gene defects
8 of 11 (72%) had low MBL genotypes p=<0.05
(compared to normal controls)
8 of 17 (47%) had low MBL genotypes p=0.0002
32% and 21.5% frequency of 2 SPA2 mutations, compared with normals (18% and 11%) (p=0.021 and p=0.044)
not related to coeliac disease (<1 in 30)
Mannose binding protein genetic defects are common in CCPA patients (47-72%). Less common are defects in superfactant A2 protein, one of the 5 main surfactants found in the lung. Cytokine defects are also likely.
Crosdale et al J Infect Dis 2001;184:653; Vaid et al, unpublished.

44. CLASSIFICATION OF ASPERGILLOSIS
Invasive aspergillosis
Acute (<1 month course)
Subacute/chronic necrotising (1-3 months)
Airways/nasal exposure to airborne Aspergillus
Chronic aspergillosis (>3 months)
Chronic cavitary pulmonary
Aspergilloma of lung
Chronic fibrosing pulmonary
Chronic invasive sinusitis
Maxillary (sinus) aspergilloma
Persistence without disease - colonisation of the airways or nose/sinuses
Allergic
Allergic bronchopulmonary (ABPA)
Extrinsic allergic (broncho)alveolitis (EAA)
Asthma with fungal sensitisation
Allergic Aspergillus sinusitis (eosinophilic fungal rhinosinusitis)
Exposure to individual Aspergillus spores or conidia is almost constant. If eradicated immediately, as is usual in normal people, no disease results. If colonisation occurs, it may be short or long term. The pattern of disease is mostly determined by the host group (see next slide), with probably a component of the inoculum size contributing to invasive disease.

45. ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS – Key diagnostic criteria
ABPA possible
ABPA probable
ABPA almost certain
Asthma
Blood eosinophilia (>1,000 / cu mm)
History of pulmonary infiltrates
Central bronchiectasis
Precipitins against A. fumigatus positive
Aspergillus IgE antibody >2x asthma control
Aspergillus IgG antibody >2x asthma control
Total serum IgE concentration, >1000 iu/mL
If 3 tests +ve, then ABPA very likely,
If all 4 +ve the diagnosis established
Key criteria for the diagnosis of ABPA
Rickett et al. Arch Intern Med 1983; 143: 1553; Patterson, Chest 2000;118:7

46. ABPA After bronchoscopy Before bronchoscopy www.aspergillus.org.uk
Remarkably oedematous bronchial mucosa, as seen in ABPA. Before and after image shows remarkable obstruction by a mucus plug, subsequently removed by bronchoscopy.

47. ABPA mucous plugging www.aspergillus.org.uk
There was a long mucous plug in the anterior segment of the RUL. Half of this was aspirated and sent for microscopy and culture. The second half "fell into" the bronchus intermedius (which feeds the right middle lobe) and was only partially aspirated.

48. ABPA - CT showing central bronchiectasis
Central bronchiectasis is very characteristic of ABPA. It is also seen in cystic fibrosis. It is one of the diagnostic criteria for the disease.

49. ABPA and surfactant
Structures of 2 important surfactants.
5 surfactant proteins in man, SPA1, SPA2, SPB, SPC and SPD – all ‘collectin’ family
Mason et al, Am J Physiol 1998;275:L1-13.

50. ABPA – surfactant defects
2 exonic polymorphisms, and 2 intronic polymorphisms in SP- A2 associated with ABPA
A1660G = OR of 4.78; or if combined with G1649C = OR 10.4
Also associated with higher peripheral eosinophilia
Examples of polymorphisms conferring susceptibility to ABPA in India.
Saxena et al, J Allergy Clin Immunol 2003;111:

51. Eosinophilic fungal rhinosinusitis or allergic fungal sinusitis
Patient with chronic symptoms
of nasal obstruction, loss of smell and nasal polyps
Ponikau et al, Mayo Clinic Proc 1999;74:877 &

52. Eosinophilic fungal rhinosinusitis
(link with airborne fungi - ?which most important
These panels are the same/adjacent sections stained with H&E (left) and an immunofluorescent antibody to MBP. It shows the sinus cavity full of mucus which contains substantial amount of MBP.
= Myelin basic protein, highly toxic to local epithelium
Ponikau et al, Mayo Clinic Proc 1999;74:877

53. A link between Aspergillus and asthma?

54. Fungal-associated asthma – evidence
Severe asthma linked with fungal sensitisation
Frequency of fungal sensitisation
Fungal-associated asthma
ABPA
High spore counts and asthmatic attacks
Treatment of ABPA
and pilot data

55. Spore counts and asthma attacks and admission to hospital
All circumstantial evidence
Thunderstorm asthma – linked to Alternaria
Asthma deaths (Chicago) linked to high ambient spores counts and season (summer autumn) when spore counts highest
Asthma hospital admission linked to high ambient spore counts (Derby, New Orleans, Ottawa
Asthma hospital attendance linked to high spore counts , but not pollen counts (Canada)
Asthma symptoms increased on days of high spore counts (California, Pennsylvania)
O'Hollaren, N Engl J Med 1991; 324: 359; Newson, Occup Environ Med 2000; 57:

56. Fungus at home Environmental data
Mouldy housing associated with worse asthma, with a correlation between asthma severity and degree of dampness in the home and separately with visible mould growth
In Germany bronchial reactivity in children was associated with damp housing
Mouldy and damp school associated with asthma symptoms and emergency room visits
Highest concentration of Aspergillus fumigatus is at home
Williamson, Thorax 1997;52:229. Taskinen, Acta Paediatr 1999; 88:1373.

57. Severe asthma and moulds
Mild asthma – 564 (50%)
Moderate asthma – 333 (29%)
Severe asthma – 235 (21%) – linked with fungus skin test positivity
Severe asthma and moulds
Zureik et al, Br Med J 2002;325:411

58. Asthma severity, house dust mites, cats and moulds
Allergen
No asthma
n= 111
Mild asthma FEV1 >75% <90%
n= 67
Moderate asthma FEV1 >60% <75%
n= 42
Severe asthma FEV1 >60%
House dust mite
61%
71%
45%
77%
Cats*
49%
51%
38%
35%
Moulds#
17%
19%
36%
31%
* P = 0.05
# p = 0.01
Langley, ATS 2004
This study shows a high frequency of house dust allergy irrespective of the severity of asthma, a decreasing frequency of cat allergy with worsening asthma (perhaps these people stop keeping cats at home), and a higher frequency of mould (Cladosporium, Aspergillus, Alternaria and Penicillium) allergy as asthma gets measurably worse. Asthma is assessed based on FEV1 (forced expiratory volume in 1 second) a measure how open the airways are.