title: In vivo molecular microimaging of pulmonary aspergillosis.
abstract: The early diagnosis of invasive pulmonary aspergillosis (IPA) is challenging. Fibered confocal fluorescence microscopy (FCFM) is a new technique that allows in vivo imaging of the lung microstructure during bronchoscopy. In this study, we investigated the ability of FCFM to detect a fluorescent peptide-tracer bound to Aspergillus fumigatus in experimental IPA in 13 immunosuppressed, non-neutropenic rats. Subpleural IPA microabscesses were imaged through a transthoracic window using FCFM in vivo after i.v. injection of the c(CGGRLGPFC)-NH2([FITC]) peptide (n = 7) or saline. Results were compared to 10 immunosuppressed, non-infected rats and to six immunosuppressed Geosmithia argillacea-infected rats with and without i.v. injection of the peptide. The peptide in vitro specifically labeled A. fumigatus grown under biofilm growth conditions but not G. argillacea. In vivo, FCFM showed a local infiltration of fluorescent host cells in both Aspergillus and Geosmithia infections. Lung/inner thoracic wall fluorescence intensity ratio (FI) did not differ before and after peptide administration on healthy lung areas, on non-specific inflammatory areas, or on Geosmithia micro-abscesses. In contrast, FI increased from 1.05 without peptide to 1.83 after peptide injection on Aspergillus micro-abscesses (p < 0.0001). In peptide-injected rats, FI from IPA foci was higher than from non-specific inflammation or from Geosmithia abscesses (p ≤ 0.002). Using c(CGGRLFPC)-NH2([FITC]) peptide, FCFM allows the in vivo specific imaging of pulmonary aspergillosis. These data provide the basis for the in vivo diagnosis of human pulmonary aspergillosis using alveolar confocal endomicroscopy.
authors.affiliation: Laboratoire Quant.I.F-LITIS EA 4108, Rouen University, Rouen, France.
authors.forename: Helene
authors.initials: H
authors.lastname: Morisse
authors.forename: Loraine
authors.initials: L
authors.lastname: Heyman
authors.forename: Mathieu
authors.initials: M
authors.lastname: Salaün
authors.forename: Loïc
authors.initials: L
authors.lastname: Favennec
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Picquenot
authors.forename: Pierre
authors.initials: P
authors.lastname: Bohn
authors.forename: Luc
authors.initials: L
authors.lastname: Thiberville
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000302:isolation & purification / Q000502:physiology; D001232:Aspergillus fumigatus / Q000302:isolation & purification* / Q000502:physiology; D018441:Biofilms; D001999:Bronchoscopy / Q000379:methods; D004195:Disease Models, Animal; D016650:Fluorescein-5-isothiocyanate; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D055744:Invasive Pulmonary Aspergillosis / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology; D008168:Lung / Q000473:pathology; D016676:Macrophages, Alveolar / Q000276:immunology; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D010456:Peptides, Cyclic; D057786:Peptidomimetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D010456:Peptides, Cyclic; D057786:Peptidomimetics; D016650:Fluorescein-5-isothiocyanate