RT Journal Article
SR Electronic
T1 More airway smooth muscle in preschool children increases risk of future asthma
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1407
VO 38
IS Suppl 55
A1 Ruth O'Reilly
A1 Tim Oates
A1 Jie Zhu
A1 Peter Jeffery
A1 Andrew Bush
A1 Sejal Saglani
YR 2011
UL http://erj.ersjournals.com/content/38/Suppl_55/1407.abstract
AB Introduction: Accurate prediction of future asthma in preschool wheezers is not possible. Reticular basement membrane (RBM) thickness and airway smooth muscle (ASM) are increased in school-aged asthmatic children [Regamey AJRCCM 2008], but nothing is known about ASM changes in preschool wheezers, or the relationship of early airway pathology to future asthma.Aims: 1)To measure RBM thickness and ASM in severe preschool wheezers and age-matched controls; 2)To relate preschool RBM thickness and ASM to school age asthmaMethods: Endobronchial biopsies (EBx) were obtained from preschool wheezers (n=47, median age 26 months) and non-wheezers (n=21, median age 15 months) undergoing clinically indicated bronchoscopy between 2002-2005 [Saglani AJRCCM 2007]. 5μm sections were stained with haematoxylin & eosin. ASM was expressed as a proportion of the subepithelial area. ASM and RBM thickness were quantified using computer analysis. Children were followed up age 6-11 years to determine asthma status.Results: At preschool age, RBM thickness was increased in wheezers (n=37, median 4.3μm) compared to controls (n=16, median 3.6μm), p=0.01. ASM was similar between preschool wheezers (n=28, median 0.08) and controls (n=14, median 0.077), p=0.97. 51/68 (75%) children were followed up at school age. School age children with and without asthma had similar RBM thickness in their preschool EBx, p=0.23. However, children with asthma (n=8, median age 9.1 years) had increased preschool ASM (median 0.12) compared to those without asthma (n=24, median age 7.3 years, median ASM 0.066), p=0.007.Conclusion: Preschool children whose EBx had a higher proportion (>10%) of ASM had a 10 fold increased risk of asthma at school age.