Reticular basement membrane (RBM) thickness and airway responses to inhaled methacholine (MCh) were studied in perennial allergic asthma ( n = 11), perennial allergic rhinitis ( n = 8), seasonal allergic rhinitis ( n = 5), and chronic obstructive pulmonary disease (COPD, n = 9). RBM was significantly thicker in asthma (10.1 ± 3.7 μm) and perennial rhinitis (11.2 ± 4.2 μm) than in seasonal rhinitis (4.7 ± 0.7 μm) and COPD (5.2 ± 0.7 μm). The dose (geometric mean) of MCh causing a 20% decrease of 1-s forced expiratory volume (FEV₁) was significantly higher in perennial rhinitis (1,073 μg) than in asthma (106 μg). In COPD, the slope of the linear regression of all values of forced vital capacity plotted against FEV₁ during the challenge was higher, and the intercept less, than in other groups, suggesting enhanced airway closure. In asthma, RBM thickness was positively correlated ( r = 0.77) with the dose (geometric mean) of MCh causing a 20% decrease of FEV₁ and negatively correlated ( r = −0.73) with the forced vital capacity vs. FEV₁ slope. We conclude that 1) RBM thickening is not unique to bronchial asthma, and 2) when present, it may protect against airway narrowing and air trapping. These findings support the opinion that RBM thickening represents an additional load on airway smooth muscle.

Deep breaths taken before inhalation of methacholine attenuate the decrease in forced expiratory volume in 1 s and forced vital capacity in healthy but not in asthmatic subjects. We investigated whether this difference also exists by using measurements not preceded by full inflation, i.e., airway conductance, functional residual capacity, as well as flow and residual volume from partial forced expiration. We found that five deep breaths preceding a single dose of methacholine 1) transiently attenuated the decrements in forced expiratory volume in 1 s and forced vital capacity in healthy ( n = 8) but not in mild asthmatic ( n = 10) subjects and 2) increased the areas under the curve of changes in parameters not preceded by a full inflation over 40 min, during which further deep breaths were prohibited, without significant difference between healthy ( n = 6) and mild asthmatic ( n = 16) subjects. In conclusion, a series of deep breaths preceding methacholine inhalation significantly enhances bronchoconstrictor response similarly in mild asthmatic and healthy subjects but facilitates bronchodilatation on further full inflation in the latter.

Background: Nasal obstruction is a typical symptom of allergic rhinitis. Allergic rhinitis is characterized by a Th2-dependent inflammation. The aim of this study was to evaluate the possible relationships between allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in patients with nasal obstruction due to seasonal allergic rhinitis. Methods: Fifty patients (31 males and 19 females, mean age 31.9 ± 4.8 years) with seasonal allergic rhinitis were evaluated during the pollen season. All of them had moderate to severe nasal obstruction. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were assessed in all subjects. Inflammatory cells were counted by conventional staining; IL-4, IL-5, IL-8, and IFNγ were measured by immunoassay on fluids recovered from nasal lavage. Results: Significant positive relationships were demonstrated between eosinophil infiltration and IL-4 levels (p < 0.0001), eosinophils and IL-5 levels (p < 0.0001), and eosinophils and IL-8 levels (p < 0.0001). Significant negative relationships were demonstrated between eosinophil infiltration and IFNγ levels (p < 0.0001) and eosinophil infiltration and nasal airflow (p < 0.001). Conclusions: This study demonstrates the close connection between Th2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship between eosinophil infiltration and nasal airflow. These findings constitute first evidence of the relationship between nasal airflow impairment and Th2-related inflammation in seasonal allergic rhinitis.

We studied nine asthmatic patients with a history of exercise-induced asthma (EIA) in order to investigate whether inflammatory changes in the airways occur after exercise and are eventually associated with the development of a late-phase asthmatic response. On two separate study days, bronchoalveolar lavage (BAL), bronchial lavage (BL), and bronchial biopsy (BB) were performed 3 h after an exercise or a methacholine (MCh) challenge. On two other separate occasions, FEV1 was monitored for 12 h after identical exercise and MCh challenges not followed by BAL, BL, and BB. We found a greater percentage of eosinophils in BAL after exercise versus MCh challenge (p < 0.05). In five patients, BAL eosinophils after exercise were ⩾ 2% of total inflammatory and immunoeffector cells. In three of these patients an FEV1 fall > 20% of control was recorded 5 to 12 h after exercise. However, two of these patients had 2% or more eosinophils in BAL and similar late falls of FEV1 after MCh challenge. The percentage of degranulating mast cells in BB was higher (p < 0.05) after EIA than after MCh, but no significant differences were found in BL histamine and leukotrienes. We conclude that (1) exercise may enhance mast cell degranulation and eosinophilic inflammation of the airways, and (2) a delayed bronchoconstriction after exercise is not specific to EIA but is more likely the result of fluctuations in lung function associated with airway inflammation.