PT  - JOURNAL ARTICLE
AU  - Ruth O'Reilly
AU  - Tim Oates
AU  - Jie Zhu
AU  - Peter Jeffery
AU  - Andrew Bush
AU  - Sejal Saglani
TI  - More airway smooth muscle in preschool children increases risk of future asthma
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - 1407
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/1407.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/1407.full
SO  - Eur Respir J2011 Sep 01; 38
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.