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The ability to biopsy has led to studies of the early (Gonzalez,Diaz et al. 1987; Georas, Liu et
al. 1992) and late asthma reactions (Robertson, Kerigan et al. 1974; Crimi, Chiaramondia et
al. 1991) and a comparison of both (Metzger, Richerson et al. 1986; Metzger, Richerson et al.
1986; Aalbers, Kauffman et al. 1993) in response to deliberate allergy provocation. These
demonstrated an influx of neutrophils at 6-8 hours followed by an influx of eosinophils at24-
48 hours which continued more than a week but seemed to resolve by day 16. An increase in
the cellular expression of the mRNA of IL5 and GM-CSF occurred at 18 to 48 hours
(Ohnishi, Sur et al. 1993; Tang, Rolland et al. 1997) with an increase in total proteins and
ainvay permeability also in the late phase (Taylor, Hill et al.1996; Teeter and Bleecker 1996).
In assessing response to treatment in asthmatic patients treated with moderate to high doses of
IHCS (400mcg to l600mcdday beclomethasone equivalent) for between two weeks and up 5-
l0 years, most studies have reported a decrease in T-lymphocytes, eosinophils, and mast cell
numbers in the airway wall (Lundgren, Soderberg et al. 1988; Burke, Power et al. 1992;
Booth, Richmond et al. 1995; Djukanovic, Homeyard et al. 1997; Olivieri, Chetta et al. L997i
Barnes, Burke et al. 2000). As well, decreased dendritic cell number @urke, Power et al.
1992; Trigg, Manolitsas et al. 1994; Bentley, Hamid et al. 1996) and reduced inflammatory
cell activation measured as less gmnule secretory production and less cell membrane
activation markers have also been noted @entley, Hamid et al. 1996; Olivieri, Chetta et al.
1997; Barnes, Burke et al. 2000; Ward, Reid et al. 2005). The expression of mRNA for nA,
IL5 and GM-CSF within cells also decreased with steroid treatment (Sousa, Poston et al.
1993; Bentley, Hamid et al. 1996). Interestingly, the effects have been more marked in the
biopsy samples than the corresponding lavage studies (Booth, Richmond et al. 1995;
Thompson, Teschler et al. 1996: Djukanovic, Homeyard et al. 1997; Olivieri, Chetta et al.
1997). The effect of steroids on the thickness of the epithelium and basement membrane have
been less conclusive; some studies showing improvement (Olivieri, Chetta et al. 1997; Ward
and Walters 2005) that has not been demonstrated in others even after years of treatment
(Lundgren, Soderberg et al. 1988; Wenzel, Szefler et al. 1997; Wenzel, Schwartz et al. 1999;
Barnes, Burke et al. 2000).
Paediatric studies have been more recent, in keeping with the later technical bronchoscopy
development and the additional concerns regarding safety in this group. These have shown
similar findings to the adult asthma studies with eosinophilic and lymphocytic inflammation,
and an increase in the same cytokines (interleukin 4 (IL+), IL5, rantes) (de Blic, Tillie-
Irblond et al. 2OO4; Payne, Qiu et al. 2O04; Pohunek, Warner et al. 2005). The findings
associated with airway remodeling (smooth muscle hypertrophy and reticular basement
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