title: Diagnostic yield of specific inhalation challenge in hypersensitivity pneumonitis.
abstract: Reliable methods are needed to diagnose hypersensitivity pneumonitis. The aim of the study was to establish the diagnostic yield of specific inhalation challenge (SIC) in patients with hypersensitivity pneumonitis. All patients with suspected hypersensitivity pneumonitis in whom SIC was performed (n=113) were included. SIC was considered positive when patients showed a decrease of >15% in forced vital capacity (FVC) or >20% in diffusing capacity of the lung for carbon dioxide, or a decrease of 10% to 15% in FVC accompanied by a temperature increase of 0.5°C within 24 h of inhalation of the antigen. SIC was positive to the agents tested in 68 patients: 64 received a diagnosis of hypersensitivity pneumonitis and SIC results were considered false-positive in the remaining four patients. In the SIC-negative group (n=45), 24 patients received a diagnosis of hypersensitivity pneumonitis and SIC results were considered false-negative, and 21 patients were diagnosed with other respiratory diseases. The sensitivity and specificity of the test were 72.7% and 84%, respectively. Having hypersensitivity pneumonitis caused by an antigen other than birds or fungi predicted a false-negative result (p=0.001). In hypersensitivity pneumonitis, positive SIC testing virtually confirms the diagnosis, whereas negative testing does not rule it out, especially when the antigenic sources are not birds or fungi.
authors.affiliation: Pulmonology Service, Medicine Dept, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain CIBER Enfermedades Respiratorias (Ciberes), Spain Dept of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain xmunoz@vhebron.net.
authors.forename: Xavier
authors.initials: X
authors.lastname: Muñoz
authors.affiliation: Pulmonology Service, Medicine Dept, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain CIBER Enfermedades Respiratorias (Ciberes), Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Sánchez-Ortiz
authors.affiliation: Biostatistics and Data Management Platform, IDIBAPS, Hospital Clinic, Biostatistics Unit, School of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Torres
authors.affiliation: Pulmonology Service, Medicine Dept, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain CIBER Enfermedades Respiratorias (Ciberes), Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Villar
authors.affiliation: Pulmonology Service, Medicine Dept, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain CIBER Enfermedades Respiratorias (Ciberes), Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Morell
authors.affiliation: Pulmonology Service, Medicine Dept, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain CIBER Enfermedades Respiratorias (Ciberes), Spain.
authors.forename: María-Jesús
authors.initials: MJ
authors.lastname: Cruz
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis* / Q000503:physiopathology; D001716:Bird Fancier's Lung / Q000175:diagnosis; D001831:Body Temperature; D001985:Bronchial Provocation Tests; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011653:Pulmonary Diffusing Capacity / Q000502:physiology; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014797:Vital Capacity / Q000502:physiology