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1.
METHODS: We have investigated the effects of allergen immunotherapy on the nasal responses in the guinea-pigs with allergic rhinitis. Thirty-three male Hartley guinea-pigs with allergic rhinitis were divided into three groups; those receiving intradermal injection of saline (Group 1) or 0.1% ovalbumin (Group 2) 6 days after the last intranasal sensitization, and those injected with 0.1% ovalbumin intradermally once daily for 6 consecutive days from the next day after the last intranasal sensitization (Group 3). RESULTS: The dye leakage and histamine content into the nasal lavage significantly decreased at 30 min after antigen challenge in Group 3, compared with Group 1 or 2. We also observed the change of mast cell numbers in superficial nasal mucosa, lamina propria and injected dorsal skin. The number of mast cells in superficial nasal mucosa significantly decreased in Group 3 compared with Group 1 or 2, but not those in nasal lamina propria or dorsal skin. CONCLUSIONS: These results suggest that the improvements of nasal responses such as dye leakage and histamine content may be caused by the decrease of mast cell numbers in the superficial mucosal layer after the specific immunotherapy, which may be developing tolerance and one of the mechanisms underlying the beneficial effect of immunotherapy.  相似文献   

2.
Acoustic rhinometry is a recently developed method for the objective assessment of nasal patency. In this study, acoustic rhinometry was used to measure changes in nasal cavity dimensions in the immediate response to nasal allergen challenge in eight pollen-sensitive subjects. Acoustic rhinometric changes were compared with subjective symptoms, as well as histamine in nasal secretions, cytology of nasal mucosal scrapings, and changes in olfactory function. A significantly greater decrease in nasal airway caliber occurred following allergen challenge as compared to buffer diluent challenge in the same individuals (70% +/- 7% versus 22% +/- 5%). During an allergic response, a strong correlation was found between the minimum cross-sectional area and the volume of the nasal cavity measured by acoustic rhinometry (r = .9). However, no correlation was observed between nasal airway caliber and concomitant subjective congestion reported by the subjects. A modest decrease in olfactory function was seen following allergen challenge (3.1 +/- 1.4 fewer odors identified correctly out of 20; p = .08). However, the alterations of olfactory function did not correlate with changes in nasal patency. The results presented in this study demonstrate that acoustic rhinometry has great potential as a reproducible method for the objective assessment of nasal obstruction occurring in nasal allergen challenge studies.  相似文献   

3.
BACKGROUND: The reliable interpretation of the nasal provocation test in allergy diagnosis requires objective and measurable monitoring parameters for clinical practice. The clinical usefulness of the nasal provocation test has been limited by scanty knowledge of the specificity and sensitivity of the test and a lack of reference values. OBJECTIVE: To test and compare three objective monitoring parameters of a nasal provocation test in occupational allergic rhinitis. To evaluate the magnitude of the nasonasal effects in a unilateral allergen challenge. METHODS: The monitoring parameters of the nasal reaction were derived from the minimum cross-sectional area on acoustic rhinometry, the nasal resistance on active anterior rhinomanometry and the amount of nasal secretion measured at 15 min intervals for 60 min. Twenty-three bovine-allergic dairy and beef cattle farmers and 19 exposed, non-allergic control subjects were challenged first with a control solution and then with the cow allergen. RESULTS: All the three monitoring parameters showed high specificity and sensitivity in finding allergic and non-allergic subjects. The secretion parameter was found to be slightly superior to the acoustic rhinometry and rhinomanometry parameters. The side difference in the nasal response between the allergen-challenged and the contralateral diluent-challenged cavity was significant for all the parameters among the allergic subjects. The contralateral secretion amount was 1/3 of the ipsilateral secretion, indicating the magnitude of the contralateral nasonasal reflex. A nasonasal reflex was also noted in the nasal patency monitoring. The coefficient of variation was significantly lower for the acoustic rhinometry than for the rhinomanometry (P=0.0001). The optimal threshold values for a positive test were a secretion amount of 100 mg, a 15% decrease in the minimum cross-sectional area and a 50% increase in the resistance for the observation period of 30 min and correspondingly 210 mg, 30% and 100% for 60 min. CONCLUSION: The low-pressure aspiration of the nasal secretion from the anterior part of the nasal cavity was found to be a reliable and practical monitoring parameter to be used together with acoustic rhinometry or rhinomanometry in the nasal provocation test for clinical purposes. Although significant nasonasal effects took place in the unilateral allergen challenge, the response was more prominent in the allergen-challenged than in the contralateral diluent-challenged nasal cavity in most allergic subjects.  相似文献   

4.
PURPOSE: To evaluate the effectiveness and safety of olopatadine hydrochloride and to determine its optimal concentration and the onset and duration of action for treating allergic conjunctivitis. Olopatadine is a new topical ophthalmic antiallergic agent that demonstrates activity as both an antihistamine and a mast cell stabilizer. Two double-masked, randomized, placebo-controlled, contralateral eye comparison studies were conducted using the conjunctival allergen challenge model. METHODS: A total of 169 subjects received 0.05% or 0.1% olopatadine. Study subjects were healthy adult men and women with a history of active allergic conjunctivitis within the previous two seasons but not receiving current treatment. With an allergen dose that produced signs and symptoms of allergic conjunctivitis at visits 1 and 2, the conjunctival allergen challenge was performed 27 minutes after study drug administration at the third visit (onset-of-action challenge) and at 8 hours after study drug administration at the fourth visit (duration-of-action challenge). Olopatadine was administered in one eye and placebo in the opposite eye. Itching and redness were scored for both eyes at 3, 10, and 20 minutes after the conjunctival allergen challenge. RESULTS: Both 0.05% and 0.1% concentrations of olopatadine were significantly (P < .05) more effective than placebo in inhibiting itching and redness at all evaluations when administered 27 minutes or 8 hours before the conjunctival allergen challenge. There were no serious or drug-related ocular or nonocular adverse events in either study. CONCLUSION: These findings demonstrate the rapid and prolonged (at least 8 hours) ocular antiallergic action of olopatadine.  相似文献   

5.
The possible mode of action of the lately demonstrated steroid effect on the immediate type allergic reaction was investigated. The influence of a topical steroid, budesonide, on the effects that released mediators have on the nasal mucosa was also studied. A nasal histamine challenge study was performed in a double-blind, cross-over fashion, a 1-week pretreatment with budesonide or placebo preceding the challenge. Symptoms were recorded by means of symptom score as well as objectively via rhinomanometry. In contrast to a previous allergen challenge study, the steroid was found to have minimal effect on the histamine-induced nasal symptoms. It is therefore concluded that other modes of steroid action must also be involved in the steroid effect on the immediate type allergic reaction.  相似文献   

6.
BACKGROUND: Salmeterol is a long-acting beta2-adrenergic agonist that is widely used in the treatment of asthma. It has been suggested that non-bronchodilator actions of salmeterol may contribute to its efficacy. OBJECTIVE: To further evaluate the potential non-bronchodilator actions of salmeterol in vivo, using a model of nasal challenge with allergen. METHODS: Twelve asymptomatic subjects with seasonal allergic rhinitis participated in a randomized, double-blind, placebo-controlled crossover trial of the effects of a single dose of 100 microg of salmeterol on the response to allergen challenge. Sneezing and symptom scores, and levels of histamine and albumin in nasal lavages, were measured throughout the protocol. Concentrations of tryptase, prostaglandin D2 and lysozyme were measured during the acute allergic response, while levels of IL-3, IL-5 and IL-8 were measured at later time points. Numbers of eosinophils and of total white blood cells were also recorded. RESULTS: Salmeterol did not affect sneezing or symptom scores at any point. During the immediate response to allergen challenge, mast cell activation, reflected by concentrations of histamine, tryptase and prostaglandin D2, and serous glandular secretion, assessed by measurements of lysozyme, were unaffected by salmeterol treatment but vascular permeability, reflected by concentrations of albumin in nasal lavages, was significantly reduced. At later time points, salmeterol had no effect on levels of histamine or albumin and did not affect cellular infiltration. Concentrations of IL-3, IL-5 and IL-8 were not increased by allergen challenge in these subjects, so the effects of salmeterol could not be evaluated. CONCLUSIONS: Treatment with a single dose of salmeterol had no effect on activation of mast cells or cellular infiltration but inhibited vascular permeability. The ability of salmeterol to inhibit antigen-induced vascular permeability may contribute to its therapeutic efficacy in asthma.  相似文献   

7.
BACKGROUND: Cetirizine is an antihistamine, largely used in the treatment of allergic rhinoconjunctivitis, which also exerts anti-allergic activity. OBJECTIVE: To evaluate cetirizine as treatment for children with rhinitis due to pollen allergy, and to evaluate its anti-allergic activity in such a clinical condition. METHODS: The study was designed as parallel groups, double-blind, placebo-controlled, randomized. Twenty allergic children were enroled and subdivided in two groups, receiving a 4 week treatment during the pollen season. The following parameters were monitored: clinical symptoms evaluated by the allergist before and after treatment and by the patients through a daily diary card, inflammatory cells count, expression of ICAM-1 on nasal epithelial cells, inflammatory mediator levels in nasal lavage and peripheral blood before and after treatment, and pollen counts. RESULTS: This study shows that cetirizine treatment is able to reduce: clinical symptoms (P < 0.01), inflammatory cell infiltrate (P < 0.03), ICAM-1 expression on epithelial cells (P < 0.05), and soluble ICAM-1 (P < 0.05) and ECP (P < 0.05) in nasal lavage. CONCLUSION: Cetirizine is able to clinically improve nasal symptoms due to pollen allergy and to reduce allergic inflammation, which is related to allergen exposure.  相似文献   

8.
In order to detect and characterize allergen-specific T cells in the airways of atopic asthmatics, we measured proliferation and cytokine production by bronchoalveolar lavage (BAL) T cells isolated from Dermatophagoides pteronyssinus (Der p)-sensitive asthmatics and nonatopic control subjects, and compared the results with those generated using peripheral blood (PB) T cells. BAL and PB mononuclear cells were collected 24 h after segmental allergen challenge by fibreoptic bronchoscopy and venepuncture, respectively. T cells purified from BAL and PB were stimulated with autologous, irradiated antigen-presenting cells and D. pteronyssinus extract or a control, nonallergen antigen (M. tuberculosis purified protein derivative [PPD]). IL-5 and IFN-gamma concentrations were measured in culture supernatants by ELISA, and T-cell proliferation by 3H-thymidine uptake. D. pteronyssinus-induced proliferation of T cells derived from both BAL and PB was elevated in asthmatics when compared with control subjects (p < 0.05), whereas PPD-induced proliferation was equivalent in both compartments. In the asthmatics, D. pteronyssinus-induced proliferative responses of equivalent numbers of BAL and PB T cells obtained after allergen challenge were statistically equivalent. Nevertheless, BAL T cells stimulated with D. pteronyssinus produced significantly greater amounts of IL-5 than did PB T cells (p < 0.05). Allergen-induced proliferation and IL-5 production by BAL T cells in the asthmatics after segmental allergen challenge correlated with the percentages of eosinophils in the BAL fluid (p < 0.01). Further, BAL T cells from asthmatic patients produced significantly higher amounts of IL-5 than did the same number of cells from nonatopic control subjects (p < 0.05). We conclude that, in D. pteronyssinus-sensitive asthmatics, allergen-specific T cells can be detected in the bronchial lumen after allergen challenge and that allergen-induced proliferation and IL-5 production by these cells correlates with local eosinophil influx. Although bronchial luminal T cells show an equivalent proliferative response to allergen stimulation as compared with PB T cells, they do produce more IL-5, consistent with the hypothesis that local differentiation or priming of these cells within the bronchial mucosal environment results in upregulation of allergen-induced IL-5 secretion.  相似文献   

9.
BACKGROUND: Bradykinin, a potent inflammatory mediator, is released during allergic and non-allergic rhinitis and asthma in man. Nasal bradykinin challenge induces a dose-dependent plasma leakage into the nasal cavity and relevant symptoms of rhinitis. OBJECTIVE: We now report on substance P generation during nasal bradykinin challenge in vivo. METHODS: The effect of locally applied bradykinin on substance P generation was studied in nine individuals, allergic to grass pollen and six non-allergic controls. In the allergics TAME-esterase activity, histamine and substance P concentrations were measured in nasal lavages and correlated to the clinical symptoms. RESULTS: Substance P concentrations in nasal lavages increased in a dose-dependent fashion during nasal bradykinin challenge in both groups. In the allergic group Substance P-increases correlated with the production of TAME-esterase activity (r = 0.9, P < 0.05) whereas these allergic individuals did not produce any histamine increases. The generation of substance P and the increase of TAME-esterase activity was associated with the onset of clinical symptoms. Correlation of oedema and hypersecretion to substance P were significant by linear regression analysis (r = 0.88, P < 0.005 and r = 0.89, P < 0.02, respectively). Bradykinin induced irritations like burning and itching were short-term and rare. Serial dilutions of nasal washes produced Substance P-RIA displacement curves that paralleled the standard curve and recovery of standard substance P that was added to nasal washes was 76 +/- 4% (mean +/- SEM), n = 8. CONCLUSION: Bradykinin induces in vivo a dose-dependent plasma leakage into the nasal cavity without affecting mast cells, but stimulates nerve endings resulting in the release of the neuropeptide substance P.  相似文献   

10.
PURPOSE: To compare the activity of topical 0.05% and 0.01% mequitazine versus vehicle in the prevention of allergic conjunctivitis induced by a conjunctival provocation test with allergens. METHODS: Forty subjects with a history of grass pollen allergic conjunctivitis were enrolled in this comparative, randomized, double-masked study. Fifteen minutes before the conjunctival provocation test, subjects received one instillation alone of 0.05% mequitazine eyedrops in one eye and in the fellow eye either one drop of 0.01% dose or vehicle, at the same dosage. Then a specific conjunctival provocation test (CPT) was performed with the allergen threshold concentration previously defined. The therapeutic efficacy was assessed by the decrease in a symptomatic composite score representing the allergic reaction. RESULTS: Topical mequitazine at the dose of 0.05% significantly decreases the intensity of the allergic reaction compared to vehicle. Moreover, the group treated with this dose needed a higher allergen concentration to trigger ocular signs. The 0.01% dose appears efficient only on itching, compared to vehicle. CONCLUSION: The results of this study support the efficacy and the onset of action of 0.05% mequitazine eyedrops versus 0.01% or vehicle in the prevention of allergic conjunctivitis induced by a conjunctival provocation test.  相似文献   

11.
PURPOSE: The purpose of the study is to evaluate in a double-blind, randomized study the efficacy of lodoxamide tromethamine 0.1% versus placebo. METHODS: Signs and symptoms, tear tryptase, and tear fluid cytology were evaluated in 20 asymptomatic subjects with allergic conjunctivitis. The study included three allergen challenges in skin test-positive patients. At the first visit, a threshold dose of allergen was established. At the second visit, a bilateral ocular challenge was performed without pretreatment. At the third visit, either lodoxamide or placebo eye drops were used for 1 week before ocular challenge. RESULTS: Lodoxamide significantly reduced tryptase levels (P < 0.01), neutrophils (P < 0.04), and eosinophils (P < 0.01) in the tear fluid and significantly inhibited ocular itching (P < 0.02) when compared with that of placebo. CONCLUSIONS: Lodoxamide is effective in reducing tryptase levels and the recruitment of inflammatory cells in the tear fluid after allergen challenge.  相似文献   

12.
BACKGROUND: Prostaglandin D2 (PGD2) is a very important mast cell product during the early-phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established. OBJECTIVE: Quantitative determination of PGD2 in nasal secretions of atopic patients (n = 17) after nasal allergen challenge (NAC) and in non-allergic healthy volunteers (n = 10). METHODS: The nasal microsuction sampling technique was used to obtain the nasal secretions with an exactly known and minimally diluted volume. A sensitive and specific enzyme immunoassay was chosen to measure the more stable 11-methoxime derivative of PGD2, which was obtained after extraction in acetone/ethanol and conversion using methoxamine-HCl. The concentrations of PGD2 in nasal secretions obtained from 10 non-allergic healthy volunteers were used as reference values. RESULTS: There was no significant difference in the concentrations of PGD2 between men (median: 569 pg/mL) and women (median: 407 pg/mL), nor between the baseline concentrations from atopic patients (median: 410 pg/mL) and non-allergic controls (median: 477 pg/mL). In the atopic patient group, PGD2 did not significantly increase during the entire sampling period after NAC. The absence of PGD2 response contrasted with the nasal symptoms manifested by sneezing, increased nasal airway resistance, and the significant increases of the concentrations of histamine, tryptase, and leukotriene C4 (LTC4) 5 min after NAC. CONCLUSION: This observation suggests that the measurement of PGD2 alone in the nasal secretions does not give reliable information on mast cell activation during a nasal allergic reaction.  相似文献   

13.
BACKGROUND: The level of histamine in nasal lavage fluid has been used as an index of mast cell/basophil activation in a number of studies. Obviously, such an index can only be valid if changes in the secretory activity of nasal glands do not affect the level of histamine in lavage fluid (i.e. hypersecretion, without a simultaneous activation of mast cells/basophils in the nasal mucosa, must not increase the level of histamine). OBJECTIVES: To asses the effect of nasal hypersecretion on histamine levels in lavage fluid. METHODS: Nasal challenges were performed with methacholine and allergen in grass pollen-allergic patients and non-allergic controls. Nasal lavage fluid was collected before and repeatedly for nine hours after nasal challenge, and the level of histamine was compared with that of a specific mast cell-derived enzyme, tryptase. In addition, the effect of methacholine on basophils was examined in vitro. RESULTS: Allergen challenge of allergic patients produced sneezing and a significant increase in histamine and tryptase levels, whereas challenge of non-allergic subjects produced no such response. Interestingly, challenge with methacholine also induced a significant increase in histamine levels. This increase was seen in both allergic and non-allergic subjects and it was not associated with any sneezing or increase in tryptase levels, indicating that mast cells were not activated. Furthermore, stimulation of basophils with methacholine did not induce any histamine release in vitro. CONCLUSIONS: Apparently, there exists a pool of histamine in the human nose that can be transferred to lavage fluid during glandular hypersecretion. The source of this histamine is yet to be identified. As the level of histamine seems to be affected by the secretory activity of nasal glands, we question the use of this single mediator as an index of mast cell/basophil activation in nasal lavage studies.  相似文献   

14.
AIMS: Allergic rhinitis is the most frequent disease mediated by immunoglobulin E (IgE). Nasal challenge is the gold standard for the diagnosis of allergic rhinitis. Skin tests (ST) are the most used diagnostic method to detect the presence of specific IgE bind to skin mast cells. The exposition of the nasal mucous membrane to the allergen is followed by an increase of the local eosinophils; the count of eosinophils in nasal mucous (ENM) is a diagnostic test for allergic rhinitis. Enzymatic RAST or enzymatic allergo-sorbent test (ESA) measures the level of serum allergen-specific IgE. OBJECTIVE: To measure the sensitivity, specificity, and diagnostic precision of ST, EAST and ENM in allergic rhinitis. METHOD: We studied 241 individuals, 162 of them had allergic rhinitis, and 79 were healthy controls. They underwent nasal challenge and intradermic ST for Dermatophagoies spp (acarus). Fraxinus americana (Ash-tree), Amaranthus palmieri (quelite), Cynodon Dactylon (capriola) and Felis catus (cat), EAST for Dermatophagoides pteronyssinus (acarus), and ENIVI. Results of ST, EAST and ENIVI were compared with their corresponding nasal challenge, and the prevalence of allergic rhinitis for each allergen was calculated. The best cut point was assessed by means of receiver-operator curves (ROC), and sensitivity, specificity, positive predictive value, negative predictive value, inter-observer concordance coefficient, area under ROC (0), standard error of 0 (SEO), and 95% confidence interval of 0 of each test were calculated using the best cut point. RESULTS: ST and EAST had the best sensitivity and specificity. ENM had the lowest sensitivity and specificity. CONCLUSION: For the diagnosis of Dermatophagoides spp allergic rhinitis ST for Dermatophagoides spp and EAST for Dermatophagoides pteronyssinus have the same diagnostic precision. According to the indexes for diagnostic precision, and inter-observer concordance coefficient, ST and EAST are useful to diagnose allergic rhinitis induced by the evaluated allergens. ENIVI is a test that is not very useful for the diagnosis of allergic rhinitis.  相似文献   

15.
BACKGROUND: Multiple mediators including prostaglandin D2 and leukotriene B4 have been shown to increase in nasal secretions during the early response to nasal challenge with antigen. OBJECTIVE: Our objective was to investigate the time course of prostanoid and leukotriene B4 release into nasal secretions on both the ipsilateral and contralateral side after a unilateral nasal allergen challenge. METHODS: We performed a controlled, randomized trial. Six volunteers were challenged unilaterally with antigen or diluent in a randomized order and discs were used to collect nasal secretions from both nostrils at 2 min intervals for 20 min after the challenge. Prostanoids and leukotriene B4 (LTB4) in recovered nasal secretions were measured by combined capillary gas chromatography-negative ion chemical ionization mass spectrometry (GC/MS). RESULTS: Nasal allergen challenge resulted in a significant and immediate increase in symptoms and sneezing. PGD2 was significantly elevated above diluent values (0.6 +/- 0.6 pg) 30 s after removal of the allergen disc (P < 0.05), reached its peak (423.2 +/- 182.4 pg) at 2 min and then slowly decreased. PGD2 also increased on the contralateral side after unilateral allergen challenge, reaching peak values about six times lower than on the ipsilateral side (70.8 +/- 21.7 pg at 6 min). Levels of 9a, 11b-PGF2 after antigen provocation became significantly higher than after diluent (0 +/- 0 pg) on the ipsilateral side at 2 min (17.2 +/- 5.9 pg), and reached peak levels at 4 min (25.1 +/- 8.0 pg). LTB4 also increased significantly on the side of challenge. For the other prostanoids measured (PGF2, PGF2 alpha, TxB2, 6kPGF1 alpha), no significant changes in either ipsilateral or contralateral secretions were observed after allergen challenge. CONCLUSIONS: Our study described the kinetics of PGD2 and LTB4 release as well as the contralateral release of PGD2.  相似文献   

16.
Allergen-induced late nasal responses (LNRs) are associated with a cellular infiltrate in which CD4+ cells are prominent. These cells have been shown to be the major cellular source of Th2-type cytokines. Mechanisms responsible for the local accumulation of CD4+ cells in the nasal mucosa after allergen exposure are unclear. IL-16 is a potent chemoattractant for CD4+ cells in vitro and may play a significant role in recruiting CD4+ cells in LNRs. We investigated the expression of IL-16 messenger RNA and immunoreactivity in nasal biopsy specimens from 17 subjects with allergic rhinitis. A biopsy specimen of the nasal inferior turbinate was obtained before and 24 hours after local nasal provocation with grass pollen extract after 6 weeks of treatment with either topical fluticasone propionate (n = 9) or placebo (n = 8) nasal spray twice daily. IL-16 mRNA-positive cells and IL-16-immunoreactive cells were identified in both the epithelium and the subepithelial tissue at baseline. Within the placebo-treated group, the numbers of epithelial and subepithelial IL-16 mRNA-positive cells and IL-16-immunoreactive cells were significantly increased 24 hours after challenge compared with baseline (p < 0.001). Topical glucocorticoid therapy resulted in a decrease in allergen-induced epithelial immunoreactive cells and subepithelial IL-16 mRNA-positive cells. The numbers of CD4+ cells increased after antigen challenge compared with baseline (p < 0.05), and this increase was inhibited by glucocorticoid treatment. There were significant correlations between epithelial and subepithelial IL-16 immunoreactivity and CD4+ cell infiltration after antigen challenge. The upregulation of IL-16 expression in allergic nasal mucosa after antigen challenge may have critical implications in the accumulation of CD4+ cells in response to antigen exposure. Steroid-mediated inhibition of IL-16 may be partly responsible for the decrease in local CD4+ cells after topical glucocorticoid therapy.  相似文献   

17.
Many types of allergens may be present in the indoor environment and may lead to sensitization and respiratory allergy. Common indoor allergens include dust mites, animal dander, cockroach exposure and molds. Exposure to indoor pollutants, such as tobacco smoke, wood-burning stoves or fireplaces and chemical sprays, can precipitate and exacerbate symptoms. An allergic reaction in the airways caused by natural exposure to allergens has been shown to lead to an increase in inflammatory reaction, increased airway hyperresponsiveness and increased eosinophils in bronchoalveolar lavage. Other research has demonstrated that asthma symptoms correlate with levels of domestic dust mite and cockroach exposure. In the case of dust mites, ending exposure results in symptomatic relief.  相似文献   

18.
To investigate the role of H1 receptor-mediated effects in allergic rhinitis, we challenged 12 allergic volunteers with allergen 2 hours after administration of either placebo or 60 mg of terfenadine. Filter paper discs were used for the unilateral administration of allergen and the collection of nasal secretions. Secretion weights, levels of histamine in recovered nasal secretions, and nasal airway resistance (NAR) were measured for each nostril separately, and the number of sneezes was counted. After placebo treatment, allergen challenge led to significant increases in ipsilateral and contralateral secretion weights, ipsilateral histamine levels, ipsilateral NAR, and sneezing. Contralateral histamine levels were not elevated. H1 antagonism with terfenadine markedly reduced the number of sneezes and partially decreased ipsilateral and contralateral secretion weights, without affecting the increase in NAR. Terfenadine premedication also lowered the amount of histamine in ipsilateral secretions after allergen challenge. Performing identical nasal challenges with a 10-fold lower dose of antigen produced similar results. Previous studies showed that terfenadine had no effect on methacholine provocation and completely abolished ipsilateral and contralateral secretion weights after histamine challenge. We conclude that sneezing after allergen challenge is caused almost exclusively by a reflex initiated through H1 receptors and that H1 antagonism has no influence on allergen-induced increases in NAR. Unilateral allergen challenge leads to bilateral increases in secretion weights, which are only partially inhibited by terfenadine, suggesting the involvement of mediators other than histamine in the nasonasal reflex. As reported earlier, terfenadine also decreases allergen-induced histamine release after challenge with the highest dose of antigen.  相似文献   

19.
355 out-patients with signs of bronchial asthma were studied with special reference to animal dander sensitization. Case histories allowed the clinical diagnosis of an allergy to animal dander in 75 patients (21.1%). Skin testing is a useful means, as large reactions appear in most cases of animal dander allergy (60.7% are greater than or equal to + + + -reactions). Skin reactions, however, often are "false positive" or "false negative". Therefore, bronchial provocation tests are necessary if the case history is doubtful and/or the skin reaction is less than a + + + -reaction. There is a positive correlation between skin reaction and bronchial provocation test. No negative inhalation tests were seen when the skin reaction was greater than + + +. However, a positive inhalation test can be correlated with a negative or weakly positive skin test. The probability of common structural properties of different mammalian dander allergens is discussed. Avoidance of exposure to the animal is recommended as the therapy of choice.  相似文献   

20.
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