title: Induced sputum in adolescents with severe stable asthma. Safety and the relationship of cell counts and eosinophil cationic protein to clinical severity.
abstract: This study examined the safety of sputum induction and the relation between sputum cell counts and clinical parameters in adolescents with severe persistent asthma. Within 5 days, induced sputum and reversibility in forced expiratory volume in one second (FEV1), quality of life, provocative concentration causing a 20% fall in FEV1 (PC20) of adenosine monophosphate and histamine, exercise-induced bronchoconstriction, overall asthma severity index, and blood eosinophils were collected in 20 atopic adolescents with moderate-to-severe persistent asthma (12-18 yrs of age, FEV1 65-110% of predicted, on 500-2,000 microg inhaled steroids daily). FEV1 was reversible by 13.3-2.3% pred. After sputum induction, FEV1 was still increased by 9.0+/-2.6% pred as compared to the pre-salbutamol baseline. Sputum contained, median (range): 12.4 (0.4-59.5)% squamous cells, 47.3 (6.8-84.0)% macrophages, 39.0 (4.6-84.8)% neutrophils, 4.8 (1.0-12.4)% lymphocytes, 0.4 (0-10.8)% eosinophils and 3.6 (0-23.4)% bronchial epithelial cells. Sputum eosinophils showed a trend towards a significant association with the overall asthma severity index (r=0.46, p=0.06) and correlated inversely with baseline FEV1 (r=-0.51, p=0.03). In conclusion, sputum can be induced safely in adolescents with moderate-to-severe persistent asthma, if pretreated with beta2-agonists. Despite relatively low sputum eosinophil counts in these patients on inhaled steroids, the association of eosinophil numbers with baseline forced expiratory volume in one second and asthma severity index favours a role of induced sputum in monitoring adolescents with severe asthma.
authors.affiliation: Dutch Asthma Centre, Davos, Switzerland.
authors.forename: D C
authors.initials: DC
authors.lastname: Grootendorst
authors.forename: J W
authors.initials: JW
authors.lastname: van den Bos
authors.forename: J J
authors.initials: JJ
authors.lastname: Romeijn
authors.forename: M
authors.initials: M
authors.lastname: Veselic-Charvat
authors.forename: E J
authors.initials: EJ
authors.lastname: Duiverman
authors.forename: E J
authors.initials: EJ
authors.lastname: Vrijlandt
authors.forename: P J
authors.initials: PJ
authors.lastname: Sterk
authors.forename: A C
authors.initials: AC
authors.lastname: Roldaan
mesh_terms: D000293:Adolescent; D000420:Albuterol; D001249:Asthma / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis*; D001985:Bronchial Provocation Tests; D002452:Cell Count; D003430:Cross-Sectional Studies; D019937:Diagnostic Techniques and Procedures / Q000009:adverse effects; D047091:Eosinophil Granule Proteins; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis*; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D011379:Prognosis; D011788:Quality of Life; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D012260:Ribonucleases; D013183:Sputum / Q000737:chemistry / Q000166:cytology*
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D012260:Ribonucleases; D000420:Albuterol