The clinical relevance of Aspergillus isolation from respiratory tract samples & detection of Aspergillus galactomannan antigen in serum of patients with acute exacerbation of COPD

Ref ID: 19473

Author:

MS Fathi1*, LA Azzam1, AM El Maraghy2

Author address:

1Medical Microbiology & Immunology, Faculty of Medicine/Ain Shams University, Cairo, Egypt
2Chest, Faculty of Medicine/Ain Shams University, Cairo, Egypt

Full conference title:

6th Advances Against Aspergillosis 2014

Abstract:

Purpose:
This study aimed at finding an approximate incidence of IPA in patients with acute exacerbation
of COPD and whether a combination of two tests, serological detection and mycological culture
yielded a more specific diagnosis of IPA.
Methods:
This study included 30 COPD patients with the criteria of acute exacerbation according to the GOLD
guidelines who were admitted at the Chest Department, Ain Shams University Hospital.
All patients were subjected to the following: full history taking, thorough clinical examination,
chest-X-ray, arterial blood gases, ECG, routine laboratory investigations, fibrooptic bronchoscopy
to obtain samples of bronchial lavage, blood samples to obtain serum samples.
’Probable’ Aspergillus infection of the lower respiratory tract was diagnosed in the COPD patient,
who had severe disease (stage III or IV) according to GOLD criteria, with recent exacerbation
of dyspnea resistant to appropriate treatment (including antibiotics), accompanied by one of the
following: i) positive culture for Aspergillus from LRT, ii) positive serum antibody test for Aspergillus
fumigatus, iii) positive serum Galactomannan (GM) antigen test (Gao et al., 2010). Colonization
with Aspergillus was diagnosed if culture was positive for Aspergillus with no other evidence of
fungal infection. Culture was performed on Sabouraud Dextrose agar, incubated for 7 days at both
25oC and 37oC. Colonies were identified according to McClenny, 2005.
Galactomannan (GM) antigen of Aspergillus was detected in serum specimens by Platelia Aspergillus
Ag Enzyme immunoassay (EIA) kit supplied by Bio-Rad, Marnes la Coquette, France.
Results:
Of the 30 specimens, 7 (24%) yielded a positive culture of Aspergillus fumigatus. 23 (76%) serum
specimens were positive for Aspergillus antigen by EIA testing. The 7 positive culture specimens
were also positive for Aspergillus antigen, giving a diagnosis of ’Probable’ Aspergillus infection
of the lower respiratory tract with 2 criteria in 24% of patients, whereas the remaining 16 patients
(54%) were diagnosed as ’Probable’ Aspergillus infection with only 1 criterion.
Conclusions:
A highly significant statistical correlation between the severity of COPD and the presence of
Aspergillus galactomannan antigen in serum. We propose that IPA should be thought of in all patients
with severe exacerbations of COPD, especially those refractory to antibiotic therapy. The sensitivity
and specificity of the GM antigen test obtained in this study, warrants its use, in combination with
culture from BAL, as an early indicator of probable IPA. The only drawback of the antigen detection
test is its cost, which could be a limitation to its use in facilities with limited resources.

Abstract Number: 1

Conference Year: 2014

Link to conference website: http://www.AAA2014.org

New link: NULL

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