title: The characteristics of different diagnostic tests in adult mild asthmatic patients: comparison with patients with asthma-like symptoms by gastro-oesophageal reflux.
abstract: BACKGROUND
  Diagnosing asthma cannot be always easy. It is important to consider the validity of the diagnostic tests, and/or how much more commonly they are positive in patients with asthma compared to healthy subjects and, particularly, to patients with asthma-like symptoms.
  
  
  OBJECTIVE
  To evaluate the validity of diagnostic tests for asthma, in terms of sensitivity, specificity, positive and negative predictive values, in patients with bronchial asthma compared to patients affected by gastro-oesophageal reflux disease (GERD) with asthma-like symptoms, and healthy control subjects without asthma and gastro-oesophageal reflux (GER).
  
  
  METHODS
  Single-center, cross-sectional, observational study.
  
  
  METHODS
  We studied 60 patients with mild asthma, 30 patients with GERD and asthma-like symptoms and 25 healthy control subjects.
  
  
  METHODS
  We measured provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in 1s (MCh PC(20)/FEV(1)), the amplitude percent mean of peak expiratory flow (A%M of PEF), derived from twice-daily readings for >2 weeks, the FEV(1)/forced vital capacity (FEV(1)/FVC) ratio, the eosinophil count in blood and in induced sputum and the serum eosinophil cationic protein (ECP) levels.
  
  
  RESULTS
  FEV(1)/FVC ratio, A%M of PEF, blood eosinophils counts and serum ECP levels were less sensitive and specific when the reference population was composed of patients with asthma-like symptoms by GER. While, MCh PC(20)/FEV(1) and induced sputum eosinophils count were the most sensitive (both 90%) and specific (89% and 92%, respectively) tests.
  
  
  CONCLUSIONS
  Our findings demonstrate that MCh PC(20)/FEV(1) and the induced sputum eosinophil count are the most useful objective tests in patients with mild asthma. All patients with asthma presented both an MCh PC(20)/FEV(1) <1500 microg and eosinophils count in the induced sputum >1%.
authors.affiliation: Dipartimento di Medicina Clinica e delle Patologie Emergenti, Università degli Studi di Palermo, Via del Vespro no. 141, 90127 Palermo, Italy. dilo601@unipa.it
authors.forename: Gabriele
authors.initials: G
authors.lastname: Di Lorenzo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Mansueto
authors.forename: Maria
authors.initials: M
authors.lastname: Esposito-Pellitteri
authors.forename: Vito
authors.initials: V
authors.lastname: Ditta
authors.forename: Francesco
authors.initials: F
authors.lastname: Castello
authors.forename: Claudia
authors.initials: C
authors.lastname: Lo Bianco
authors.forename: Maria Stefania
authors.initials: MS
authors.lastname: Leto-Barone
authors.forename: Gaetana
authors.initials: G
authors.lastname: Di Fede
authors.forename: Marcello
authors.initials: M
authors.lastname: Traverso
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rotolo
authors.forename: Sergio
authors.initials: S
authors.lastname: Vigneri
authors.forename: Giovambattista
authors.initials: G
authors.lastname: Rini
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D001985:Bronchial Provocation Tests / Q000379:methods; D016085:Bronchoconstrictor Agents; D003937:Diagnosis, Differential; D047150:Eosinophil Cationic Protein / Q000097:blood; D004804:Eosinophils / Q000473:pathology; D004812:Epidemiologic Methods; D005260:Female; D005541:Forced Expiratory Volume; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D013147:Spirometry / Q000379:methods; D013183:Sputum / Q000166:cytology; D014797:Vital Capacity
chemical_list: D015415:Biomarkers; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride; D047150:Eosinophil Cationic Protein; C479220:RNASE3 protein, human