Aspergilose invasiva em pacientes com doença pulmonar obstrutiva crônica internados em unidade de terapia intensiva

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2011

RESUMO

Recent data have suggested that chronic obstructive pulmonary disease (COPD) may be an important risk factor for invasive aspergillosis (IA), particularly in the context of mechanical ventilation (MV) and therapy with corticosteroids. Here we present the results of a prospective multicentric study (2009-2010) conducted in three intensive care units (ICUs) in Southern Brazil. COPD patients on steroids showing a new lung infiltrate while on mechanical ventilation were included and the following tests were performed in respiratory samples (mostly tracheal aspirates): microscopy, quantitative fungal culture, galactomannan (GM) (Platelia Aspergillus EIA) and real-time PCR to detect Aspergillus DNA. DNA was extracted using MycXtra kit (Myconostica, UK) and amplification was performed using two q-PCR commercial kits: Aspergillus spp q-PCR Alert kit (Nanogen, Italy) and MycAssayTM Aspergillus kit (Myconostica, UK). Serum was also obtained and tested for Aspergillus precipitins, GM and total IgE levels. Ethical approval was obtained in each of the participant hospitals. A total of 47 patients were enrolled in the study (male 59.6%). Mean age was 68.6 years-old (± 9.9). Most patients had severe COPD (GOLD stages III/IV in 72.8%). Steroid dosage (prednisone equivalent) ranged from 100-4125 mg (median 900 mg). Microscopy and culture were positive for Aspergillus section Fumigatti in only 2 patients (4.2%). Other fungi included H. capsulatum (n=1) and S. apiospermum (n=1). Aspergillus precipitins were positive for three patients, at low titers (<1:2). IgE levels ranged from 2 to >3,000 IU/ml (median 74 IU/ml). All serum GM indexes were <0.5 and respiratory samples, GM indexes of >0.5, >1.0 and >1.5 were observed in 74.5%, 40.5%, and 21.3%, respectively. Myconostica PCR was positive in 10 patients, while Nanogen PCR detected only one patient. Overall mortality was 53.2%. This prospective multicenter study showed a low incidence (4.2%) of IA in critically ill patients with COPD. High optical indices were observed when GM was tested in respiratory samples (50% of the results showed indices of >1.3). Therefore, the test did not discriminate IA and a a higher cutoff would be needed to exclude false-positive results. The combination of PCR and GM for the diagnosis of IA in respiratory samples deserves further investigation due to the low diagnostic sensitivity of the classical mycology methods.

ASSUNTO(S)

invasive aspergillosis aspergilose pulmonar invasiva doença pulmonar obstrutiva crônica aspergillus fumigatus copd reação em cadeia da polimerase galactomannan

ACESSO AO ARTIGO

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