The extraordinary spectrum of diseases caused by Aspergillus David W. Denning Wythenshawe Hospital University of Manchester
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 www.aspergillus.man.ac.uk
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 pharmaceuticals: echinocandins: A. nidulans and A. sydowi lovastatin: A. terreus fumagillin: A. fumigatus www.aspergillus.man.ac.uk
Aspergillus Life-cycleSpores inhaled GerminationMass of hyphae Hyphal elongation(plateau phase) and branching www.aspergillus.man.ac.uk
The genus Aspergillus – ~180 species,38 have caused disease (able to grow at 37C)Common in the environment Aspergillus A. nidulans – may be amphotericin B resistant fumigatus conidial head A. niger A. flavus -sometimes to AmB of azole resistance A. fumigatus low frequency A. terreus – resistant amphotericin B resistant www.aspergillus.man.ac.uk
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.
Interaction of Aspergillus with the host A unique microbial-host interaction Frequency of aspergillosisFrequency of aspergillosis Acute IA ABPA Allergic sinusitis Subacute IA Tracheobronchitis Aspergilloma Chronic cavitary Chronic fibrosing Immune dysfunction Normal Immune hyperactivity immune function . www.aspergillus.man.ac.uk
Changing incidence of fatal invasivemycoses in non-HIV patients in USA 0.8 Rate per 100,000 population 0.2 0.4 0.6 Candidiasis Aspergillosis 0.0 1981 1986 1991 1996 McNeil et al, Clin Infect Dis 2001;33:641
Invasive pulmonary aspergillosis IPA Normal lungIPA occurs in ~7%of acute leukaemia patients, 10-15% allogeneic BMT patients www.aspergillus.man.ac.uk
Unequivocal ‘Halo sign’ surrounding a noduleHalo sign Herbrecht, Denning et al, NEJM 2002;347:408-15.
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? Gillies & Campbell, www.aspergillus.man.ac.uk
How does Aspergillus fumigatus cause thrombosis (clotting of vessels) and also bleeding?Interaction of conidia andendothelial cell Internalisation of projections conidia (and hyphae) by endothelial cells with injury apparent at 4 hours Filler et al, Blood 2004;103:2134; Paris et al, Infect Immun 1997;65:1510.
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 www.aspergillus.man.ac.uk
Early diagnosis of invasive aspergillosis is importantTreatment started <10d >11dMortality 40% 90% Von Eiff et al, Respiration 1995;62:241-7.
Sputum Cultures for FungusBacteriological 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.
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 Herbrecht et al, J Clin Microbiol 2002;20:1898-906; and others
Outcome from invasive aspergillosis – amphotericin B therapy Survival Functions by Site of Infection1.0 .9 .8 Sinusitis (n =17) .7 .6 Multi-site (n =11) .5 Aspe rgilloma (n =10) .4 .3 .2 Pu lmonary (n =83) .1 CNS o r Dissemin ated (n =35)0.0 0 30 60 90 120 150 180 210 240 270 300 330 360 Days Lin et al, Clin Infect Dis 2001;32:358
Sub-acute invasive aspergillosis in AIDS www.aspergillus.man.ac.uk
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 www.aspergillus.man.ac.uk
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.
Chronic necrotising pulmonary aspergillosis Right upper lobe showing circular Right lobe shows huge cavity shadow partly filled by a mass. PT MS containing some debris, with 1996 +ve aspergillus precipitins.Pt MS 1999 Right upper lobe. Patient has Same lobe shows expansion of diabetes and pulmonary the shadow, still partially filledmycobacterium avium- shows small with a mass. Pt MS 1998 cavitary lesion PT MS 1995. Denning, Clin Microbiol Infect 2001;7(Suppl 2):25-31.
Aspergillus and airwaysTypes 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
Aspergillus tracheobronchitisAutopsy drawing of a‘normal’ 3 year oldwho died over 10 days Wheaton, Path Trans 1890; 41:34-37
Aspergillus tracheobronchitisReview of 58 patients in literature for normal and immuno compromised patients - risk factors %None (ie normal) 25Heart / Lung transplant 18Solid tumour 15BMT 13Leukaemia 13HIV/AIDS 8Other 8 Kemper et al, Clin Infect Dis 1993; 17: 344
Aspergilloma Fungus ball Patient RT December 2002
Chronic pulmonary aspergillosis – pre-existingdiseaseAll 18 patients had prior pulmonarydisease 9 TB, 5 with atypical mycobacteria 13 smokers or ex-smokers All 18 non-immunocompromised 3 excess alcohol Denning DW et al, Clin Infect Dis 2003; 37:S265
Chronic pulmonary aspergillosis - serologyAll 18 patients had positive Aspergillus precipitins (1+ - 4+)All 18 patients had elevated inflammatory markers, CRP, PV and / or ESR14 of 18 (78%) had elevated total IgE (>20), 13 >200 and 7 >4009 of 14 (67%) had Aspergillus specific IgE (RAST) Denning DW et al, Clin Infect Dis 2003; 37:S265
Chronic cavitary pulmonary aspergillosis (CCPA) Patient RWPatient RW September 1992December 1991 Relapse in normal lungPre surgical resection www.aspergillus.man.ac.uk
Chronic cavitary pulmonary aspergillosis Patient RW July 1993 www.aspergillus.man.ac.uk
Chronic Cavitary Pulmonary Aspergillosis Patient JA Jan 2001
Chronic Cavitary Pulmonary Aspergillosis Patient JA Feb 2002
Chronic Cavitary Pulmonary Aspergillosis Patient JA April 2003
Chronic Cavitary Pulmonary Aspergillosis Patient JA July 2003
Chronic cavitary pulmonary aspergillosis Patient JP June 1999 Denning DW et al, Clin Infect Dis 2003; 37:S265
Chronic Cavitary Pulmonary Aspergillosis, with aspergilloma Patient JP July 2001 Denning DW et al, Clin Infect Dis 2003; 37:S265
Chronic Fibrosing Pulmonary Aspergillosis Patient JP April 2002 Denning DW et al, Clin Infect Dis 2003; 37:S265
Mannose Binding Lectin (MBL)- a key partof the innate immune system Di b il dn sh o u ed p I ri w nt i tc t eo h an cc e o oi c r l tr p l n t e e E x on 1 I ri w nt i tc t eo h an MA SP E x on 2 C R D E x on 3 2n t + ne C di aii s bg E x on 4 Crosdale et al J Infect Dis 2001;184:653
Mannose Binding Protein Mutations5 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
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) Crosdale et al J Infect Dis 2001;184:653; Vaid et al, unpublished.
ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS – Key diagnostic criteria ABPA possible• Asthma ABPA possible• Blood eosinophilia (>1,000 / cu mm) ABPA probable• History of pulmonary infiltrates ABPA almost certain• Central bronchiectasis• Precipitins against A. fumigatus positive If 3 tests +ve,• Aspergillus IgE antibody >2x asthma control then ABPA very• Aspergillus IgG antibody >2x asthma control likely, If all 4 +ve the• Total serum IgE concentration, >1000 iu/mL diagnosis established Rickett et al. Arch Intern Med 1983; 143: 1553; Patterson, Chest 2000;118:7
ABPA After bronchoscopyBefore bronchoscopy www.aspergillus.man.ac.uk
ABPA - CT showing central bronchiectasis www.aspergillus.man.ac.uk
ABPA and surfactant5 surfactant proteins in man, SPA1, SPA2, SPB, SPC and SPD– all ‘collectin’ family Mason et al, Am J Physiol 1998;275:L1-13.
ABPA – surfactant defects2 exonic polymorphisms, and 2 intronic polymorphisms in SP-A2 associated with ABPAA1660G = OR of 4.78; or if combined with G1649C = OR 10.4Also associated with higher peripheral eosinophilia Saxena et al, J Allergy Clin Immunol 2003;111:1001-7.
Eosinophilic fungal rhinosinusitis or allergic fungal sinusitisPatient with chronic symptomsof nasal obstruction, loss of smelland nasal polyps Ponikau et al, Mayo Clinic Proc 1999;74:877 & WWW.aspergillus.man.ac.uk
Eosinophilic fungal rhinosinusitis(link with airborne fungi - ?which most important = Myelin basic protein, highly toxic to local epithelium Ponikau et al, Mayo Clinic Proc 1999;74:877
Fungal-associated asthma – evidence Severe asthma linked with fungal sensitisation Frequency of fungal sensitisation ABPA Fungal-associated asthma Treatment of ABPA High spore counts and and pilot data asthmatic attacks
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)OHollaren, N Engl J Med 1991; 324: 359; Newson, Occup Environ Med 2000; 57: 786-92.
Fungus at homeEnvironmental 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.
Mild asthma – 564 (50%) Moderate asthma – 333 (29%)Severe asthma and moulds Severe asthma – 235 (21%) – linked with fungus skin test positivity Zureik et al, Br Med J 2002;325:411