Influence of natural antigenic exposure on bronchoalveolar lavage in subjects with pollen-induced rhinitis

Bronchial hyperresponsiveness in seasonal allergic rhinitis patients is associated with increased IL-18 during natural pollen exposure

BACKGROUND

The mechanism of bronchial hyperresponsiveness (BHR) is not certain in seasonal allergic rhinitis (SAR) patients.

OBJECTIVE

We aimed to investigate the effects of natural pollen exposure on IL-18 and its relationship with BHR.

METHODS

Thirty-two SAR patients with grass pollen sensitivity, 14 nonallergic rhinitis (NAR) patients and 17 normal-controls were included. Sixteen SAR patients had BHR during pollen season and off-season. Serum IL-18 levels were measured in SAR patients during pollen season between May-August and off-season between November-February. IL-18 levels were measured in NAR patients and normal controls once.

RESULTS

During pollen season, SAR patients with BHR had significantly increased levels of IL-18 than those without BHR (279.2 ± 161.1 versus 145.3 ± 101.0 pg/ml, p=0.012). Serum IL-18 levels were not different between SAR patients with and without BHR during off-season (233.8 ± 139.7 versus 183.2 ± 162.9 pg/ml, p=0.16). Serum IL-18 levels in SAR patients during pollen season (212.3 ± 148.8 pg/ml) and off-season (208.5 ± 151.5 pg/ml) were not different than those NAR patients (224.8 ± 180.1 pg/ml, p=0.98 and p=1.0, respectively) and normal controls (174.8 ± 76.0 pg/ml, p=0.60 and p=0.76, respectively).

CONCLUSION

The results suggested us that BHR in SAR patients is associated with increased IL-18 during natural pollen exposure.

Effect of intranasal triamcinolone acetonide on bronchial hyper-responsiveness in children with seasonal allergic rhinitis and comparison of perceptional nasal obstruction with acoustic rhinometric assessment

OBJECTIVE

Many patients with allergic rhinitis (AR) have bronchial hyper-responsiveness (BHR), and seasonal variation of BHR has been demonstrated in these patients. We aimed to investigate how BHR in children with seasonal AR is modified by triamcinolone acetonide aqueous nasal spray (TANS) therapy during the pollen season. A secondary aim was to assess the efficacy of TANS on nasal congestion by acoustic rhinometry and symptom scores.

METHODS

A total of 34 children aged 7-18 years with grass pollen-induced AR and 18 age and sex-matched healthy controls were included in study. The patients were divided into the following two subgroups: 22 patients who had AR only; and 12 patients who had AR and asthma. All of them had a baseline BHR (PC20FEV1 methacholine < 8mg/ml). All patients received 220 microg TANS once daily for 4 weeks following a 1-week run-in period. Nasal patency was measured by acoustic rhinometry and patients recorded their nasal obstruction scores in a diary.

RESULTS

There was no significant difference at baseline pulmonary function test parameters between the patients and the healthy control children. None of the control subjects had BHR. Asthmatic children with AR had significantly reduced baseline PC20FEV1 when compared with the AR only group [mean +/- S.E.M., (1.60 +/- 0.57 mg/ml versus 2.93 +/- 0.42 mg/ml, P = 0.021)]. The mean PC20FEV1 values increased slightly at the end of treatment in both group (from 1.60 +/- 0.57 mg/ml to 3.25 +/- 1.11 and from 2.93 +/- 0.42 mg/ml to 3.93 +/- 1.41 mg/ml), but the change was not statistically significant. TANS produced substantial symptomatic recovery in nasal obstruction according to patients' daily diary assessments, and significantly improved all objective acoustic rhinometry parameters.

CONCLUSIONS

Once-daily intranasal TANS 220 microg effectively controlled nasal obstruction in children with seasonal AR according to subjective and objective assessments, and blocked the increase in BHR to methacholine after high-load natural pollen exposure. There was no correlation between patients' own subjective assessment of nasal obstruction and objective acoustic rhinometric assessment.

Clinical relevance of spore and pollen counts

Many people with allergies monitor daily pollen and spore counts with the belief that they can act on that information to improve their health. Because many factors can affect personal exposure, the value of community-wide counts for an individual is questionable. These factors include the presence of local pollen and spore sources, diurnal variations, weather effects, air pollution, and a particle-free bioaerosol. To take advantage of bioparticulate counts, the public needs to be informed about their meaning and factors that can influence personal exposure.

Comparison of allergen-induced changes in bronchial hyperresponsiveness and airway inflammation between mildly allergic asthma patients and allergic rhinitis patients

Bronchial eosinophilic inflammation and bronchial hyperresponsiveness (BHR) are the main features of allergic asthma (AA), but they have also been demonstrated in allergic rhinitis (AR), suggesting a continuity between both diseases. In spite of not fully reproducing natural allergenic exposure, the allergen bronchial provocation test (A-BPT) has provided important knowledge of the pathophysiology of AA. Our aim was to verify the existence of a behavior of AA and AR airways different from the allergen bronchial challenge-induced airway eosinophilic inflammation and BHR changes. We studied a group of 31 mild and short-evolution AA and 15 AR patients, sensitized to Dermatophagoides pteronyssinus. The A-BPT was performed with a partially biologically standardized D. pteronyssinus extract, and known quantities of Der p 1 were inhaled. Peripheral blood (eosinophils and ECP) and induced sputum (percentage cell counts, ECP, albumin, tryptase, and interleukin [IL]-5) were analyzed, before and 24 h after A-BPT. Methacholine BHR, assessed before and 32 h after the A-BPT, was defined by M-PD20 values and, when possible, by maximal response plateau (MRP). The A-BPT was well tolerated by all the patients. AA presented a lower Der p 1 PD20 and a higher occurrence of late-phase responses (LPR). M-PD20 values decreased in AA, but not in AR, patients. MRP values increased in both groups. Eosinophils numbers and ECP levels increased in blood and sputum from both AA and AR, but only the absolute increment of sputum ECP levels was higher in AA than AR patients (P = 0.025). The A-BPT induced no change in sputum albumin, tryptase, or IL-5 values. We conclude as follows: 1) In spite of presenting a lower degree of bronchial sensitivity to allergen, AR patients responded to allergen inhalation with an eosinophilic inflammation enhancement very similar to that observed among AA. 2) MRP levels increased in both AA and AR patients after allergen challenge; however, M-PD20 values significantly changed only in the AA group, suggesting that the components of the airway response to methacholine were controlled by different mechanisms. 3) It is possible that the differences between AR and AA lie only in the quantitative bronchial response to allergen inhalation.

Kinetics and quantitation of eosinophil and neutrophil recruitment to allergic lung inflammation in a brown Norway rat model

We quantitated neutrophil and eosinophil migration into lung parenchyma using specific peroxidase enzyme assays, and into the bronchoalveolar compartment by bronchoalveolar lavage (BALF), in sensitized brown Norway (BN), Fischer, and Lewis rats and also assessed the lungs by histopathology. Fourteen days after sensitization with ovalbumin (OA in alum [given subcutaneously] and OA with Bordetella pertussis [given intraperitoneally]), rats were challenged with an OA aerosol for 1 h. In BN rats, there was marked perivascular and peribronchial edema, focal hemorrhages, and increase in lung wet weight and BALF protein content, accompanied by neutrophilic infiltration at 3-14 h postchallenge. Few eosinophils were seen at 14 h in lung tissue or in BALF. Neutrophils peaked at 24 h in parenchyma ([94 +/- 7] x 10[6]) and in BALF ([2.7 +/- 0.4] x 10[6]) and declined rapidly thereafter. Marked eosinophil infiltration into parenchyma was apparent by 24 h. Eosinophil accumulation peaked at 48 h in parenchyma ([127 +/- 18] x 10[6]) and at 72 h in BALF ([10 +/- 2.4] x 10[6]), comprising up to 85% of lavage cells at this time. Lung eosinophilia persisted for at least 6 d with only a slow decline or clearance, not approximating baseline until day 13 after challenge. Histopathology showed peribronchial and interstitial eosinophilic pneumonia, most severe on day 3. In contrast to the BN rats, essentially no pulmonary inflammation was observed in Lewis and Fischer rats. This model in the BN rat, and the specific peroxidase assays for quantitating tissue eosinophils and neutrophils, should be useful for investigating the regulation of allergen-induced eosinophil and neutrophil migration into and clearance from the lung.

Airways of allergic rhinitics are 'primed' to repeated allergen inhalation challenge

The hypothesis that repeated exposure to a specific allergen will further increase bronchial responsiveness to that allergen is supported by indirect evidence. However, it has not been tested as intensely in the laboratory setting, and in some cases, conflicting results are presented. In order to test the hypothesis in the atopic subjects, allergen inhalation challenge tests were performed in 29 house dust mite (Dermatophagoides pteronyssinus) sensitive subjects with allergic rhinitis. Nine subjects displayed early asthmatic responses (EARs) to the first challenge (Group I). Twenty subjects with no significant airway response were submitted to the second challenge 24 h later. Thirteen subjects showed EARs (Group II) and two of these showed late asthmatic responses (LARs) as well. In Group II, there were significant changes between the first and second challenge in post-allergen early phase FEV1 (88.1 +/- 4.2 vs 71.7 +/- 4.2% baseline, P < 0.05) and in post-allergen late phase FEV1 (93.1 +/- 3.4 vs 86.6 +/- 7.8, P < 0.05). After the second challenge, PD20 (provocative dose of methacholine required to produce a 20% fall in FEV1) decreased significantly from the baseline values. When challenged separately with twofold dose of allergen, only three and one of the Group II showed EAR and LAR respectively. PD20 did not change significantly after this challenge. These results indicated that two repeated exposure to allergen dose, which is not enough to cause significant airway responses at a time, may provoke asthmatic airway responses in the subjects with allergic rhinitis and that this effect of priming is not attributed to the cumulative dose but to the consequent effect of repeated allergen exposure.

Different effects of nasal and bronchial glucocorticosteroid administration on bronchial hyperresponsiveness in patients with allergic rhinitis

Disorders of the upper respiratory tract, particularly allergic rhinitis, are commonly associated with bronchial hyperresponsiveness. The latter may be due to postnasal drip or to mediator or chemotactic factors into the lower airways that either directly alter airway reactivity or cause airway inflammation. The aim of this study was to compare the effect of an identical dose of nasal or bronchial corticosteroid administration on bronchial hyperresponsiveness in patients with allergic rhinitis. Eleven patients were studied. All of them were judged atopic on the basis of positive skin tests to common allergens. During control, spirometry, flow-volume curves, and specific airway conductance (SGaw) were measured. Bronchial challenges were then performed with increasing concentrations of carbachol, and dose-response curves were constructed. The concentration of carbachol that decreased SGaw by 35% from baseline (PD35) was determined by interpolating from the dose-response curve. Control measurements were repeated at 1-wk intervals to ensure that PD35 was stable in all the patients. Then the patients received for 2 wk, in a double-blind randomized crossover fashion, a topical administration of either an aerosol of 400 micrograms of beclamethasone dipropionate (B) into the nose (100 micrograms four times per day) or into the bronchi. During each trial period, identical sprays of placebo were used, the latter being administered into the nose when B was administered into the bronchi and vice versa. Measurements were then performed after 2 wk of intranasal administration and after 2 wk of intrabronchial administration.(ABSTRACT TRUNCATED AT 250 WORDS)