The response to inhaled allergen in asthma is diminished by anti-IgE, which in bronchial mucosa is paralleled by a reduction in eosinophils and a decline in IgE-bearing cells postallergen without changing PC(20) methacholine. This suggests that the benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE-bearing cells.

Automated image analysis of bronchial tissue offers the opportunity to quantify stained area and staining intensity in a standardized way to obtain robust estimates of inflammatory cell counts and cytokine expression from multiple large areas of histopathologic sections. We compared fully automated digital image analysis with interactive digital cell counting and semiquantitative scoring of cytokine expression in terms of repeatability and agreement in bronchial biopsies in 52 patients with mild to moderate atopic asthma. Immunohistochemistry with antibodies against CD3, interleukin (IL)-4, IL-5, and interferon-gamma protein was performed on frozen tissue sections, using 3-amino-9-ethylcarbazole as chromogen and hematoxylin as counterstaining. IL-4 and IL-5 messenger RNAs were localized by in situ hybridization without hematoxylin staining. Separation of 3-amino-9-ethylcarbazole and hematoxylin-stained pixels was achieved by linear combination of red- and blue-filtered gray-scale images. Using baseline biopsy specimens, fully automated CD3+ cell counts showed perfect repeatability (r = 1.0) and a strong linear relationship with the interactive procedure (r = 0.98). Automated densitometry showed perfect repeatability (1.0) and a moderate to strong relationship with semiquantitative scoring of protein and messenger RNA expression (r = 0.43-0.89). Relationships between automated and semiquantitative assessments of changes in cytokine expression during 2 years of follow-up were moderate to strong (r = 0.40-0.84). We conclude that fully automated cell counts and automated densitometric analyses in bronchial tissue of patients with asthma are unbiased and help to reduce variability in inflammatory outcomes.

The common cold is a highly prevalent, uncomplicated upper airway disease. However, rhinovirus (RV) infection can lead to exacerbation of asthma, with worsening in airway hyperresponsiveness and bronchial inflammation. The current authors questioned whether such involvement of the intrapulmonary airways is disease specific.Twelve nonatopic, healthy subjects (forced expiratory volume in one second (FEV1) w80% predicted, provocation concentration causing a 20% fall in FEV1 (PC20) w8 mg?mL -1 ) were experimentally infected with RV16. Next to PC20 and the maximal response to methacholine (MFEV1 and MV940p), the numbers of mucosal inflammatory cells and epithelial intercellular adhesion molecule (ICAM)-1 expression in bronchial biopsies were assessed before and 6 days after RV16 inoculation.RV16 infection induced a small but consistent increase in maximal airway narrowing, without a change in PC20. There was a significant increase in bronchial epithelial ICAM-1 expression after RV16, whereas inflammatory cell counts did not change. Nevertheless, the change in the number of submucosal CD3z cells was correlated with the change in MV940p.In conclusion, rhinovirus infection in normal subjects induces a limited, but significant increase in maximal airway narrowing, which is associated with changes in bronchial T-cell numbers. Together with the upregulation of bronchial epithelial intercellular adhesion molecule-1, these findings indicate that, even in healthy subjects, rhinovirus infection affects the intrapulmonary airways.