J Korean Med Sci.  2008 Jun;23(3):390-396. 10.3346/jkms.2008.23.3.390.

Atopy May Be an Important Determinant of Subepithelial Fibrosis in Subjects with Asymptomatic Airway Hyperresponsiveness

• Sohn SW
• Chang YS
• Lee HS
• Chung DH
• Lee CT
• Kim YH
• Kim YK
• Min KU
• Kim YY
• Cho SH

• KMID: 1786874
• DOI: http://doi.org/10.3346/jkms.2008.23.3.390

Abstract

The bronchial pathology of asymptomatic airway hyperreponsiveness (AHR) subjects is not well understood, and the role of atopy in the development of airway remodeling is unclear. The aim of this study was to evaluate whether atopy is associated with airway remodeling in asymptomatic AHR subjects. Five groups, i.e., atopic or non-atopic subjects with asymptomatic AHR, atopic or non-atopic healthy controls, and subjects with mild atopic asthma, were evaluated by bronchoscopic biopsy. By electron microscopy, mean reticular basement membrane (RBM) thicknesses were 4.3+/-1.7 micrometer, 3.4+/-1.8 micrometer, 2.5+/-1.5 micrometer, 2.6+/-1.1 micrometer, and 2.3+/-1.2 micrometer in the mild atopic asthma, atopic and non-atopic asymptomatic AHR, atopic and nonatopic control groups, respectively (p=0.002). RBM thicknesses were significantly higher in the mild atopic asthma group and in the atopic asymptomatic AHR group than in the other three groups (p=0.048). No significant difference in RBM thickness was observed between the atopic asymptomatic AHR group and the mild atopic asthma group (p>0.05), nor between non-atopic asymptomatic AHR group and the two control groups (p>0.05). By light microscopy, subepithelial layer thicknesses between the groups showed the same results. These findings suggest that RBM thickening occurs in subjects with atopic asymptomatic AHR, and that atopy plays an important role in airway remodeling.

Keyword

Asymptomatic Airway Hyperresponsiveness; Atopy; Airway Remodeling; Reticular Basement Membrane; Subepithelial Layer Thickness

MeSH Terms

Adult
Asthma/epidemiology/*pathology
Basement Membrane/*pathology/ultrastructure
Biopsy
Bronchi/pathology
Bronchial Hyperreactivity/epidemiology/*pathology
Bronchoscopy
Female
Fibrosis
Follow-Up Studies
Humans
Hypersensitivity, Immediate/*epidemiology
Male
Microscopy, Electron
Respiratory Mucosa/*pathology/ultrastructure
Risk Factors

Figure

• 

  Fig. 1 Reticular basement membrane (RBM) thicknesses. A, atopic asymptomatic AHR (n=5); B, non-atopic asymptomatic AHR (n=7); C, mild atopic asthma (n=2); D, atopic control (n=7); and E, non-atopic control (n=7). Horizontal bars within the graph indicate the mean values. The mean values of RBM thicknesses in A and C were significantly higher than in B, D, and E (p=0.048). No significant differences were observed between A and C or between B, D, and E in terms of mean RBM thickness.

• 

  Fig. 2 Bronchial histopathology (electron microscopy, ×3,750) in (A) atopic asymptomatic AHR, (B) non-atopic asymptomatic AHR, (C) mild atopic asthma, and (D) atopic control. RBM thicknesses showed greater in (A) and (C) than in (B) and (D).

• 

  Fig. 3 Subepithelial layer thicknesses. A, atopic asymptomatic AHR (n=5); B, non-atopic asymptomatic AHR (n=7); C, mild atopic asthma (n=2); D, atopic control (n=7); and E, non-atopic control (n=7). Horizontal bars within the graph indicate the mean values. The mean values of subepithelial layer thicknesses in A and C were significantly higher than in B, D, and E (p=0.04). No significant differences were observed between A and C or between B, D, and E in terms of mean subepithelial layer thickness.

• 

  Fig. 4 Bronchial histopathology (light microscopy, H&E staining, ×400) in (A) atopic asymptomatic AHR, (B) non-atopic asymptomatic AHR, (C) mild atopic asthma, and (D) atopic control. Subepithelial layer thicknesses showed greater in (A) and (C) than in (B) and (D).

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