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Piotin A, Godet J, Domis N, de Blay F. Rhinoconjunctivitis severity induced by cat exposure influences early and late asthmatic responses: Evidence from an environmental exposure chamber. Clin Exp Allergy 2024; 54:596-606. [PMID: 38660824 DOI: 10.1111/cea.14485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/10/2024] [Accepted: 04/09/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND The impact of allergic rhinoconjunctivitis on the early (EAR) and late asthmatic response (LAR) has yet to be assessed during optimal allergen exposure conditions. OBJECTIVE We aimed to assess predictive factors of the EAR and LAR and to evaluate the relation between rhinitis, conjunctivitis and asthma induced by cat allergen exposure in an environmental exposure chamber (EEC). METHODS Data from two cohort studies involving asthmatic patients with cat allergy who performed a cat allergen exposure challenge in ALYATEC EEC were analysed. Spirometry, visual analogue scale (VAS) for asthma, VAS for rhinitis, Total Nasal Symptoms Score, Total Ocular Symptoms Score (TOSS), Rhinoconjunctivitis Total Symptoms Score and Abelson score were used to assess asthma, rhinitis and conjunctivitis during and after exposure. RESULTS An EAR occurred in 65.1% of patients, 32.1% of whom had a LAR. The diameter of the prick test to cat allergens and non-specific bronchial hypersensitivity level were independent risk factors for EAR (p < .05). No independent risk factors for LAR were identified. Rhinoconjunctivitis severity during exposure correlated with the asthma VAS during EAR and LAR (p < .05). Allergen exposure time needed to trigger an EAR correlated with the Abelson score during exposure (p < .05). The asthma VAS and TOSS during exposure correlated with faster LAR occurrence (p < .05). CONCLUSION Prick test size and non-specific bronchial hypersensitivity level were confirmed as independent predictive factors of EAR during allergen exposure in an EEC. This study demonstrated the relation between the severity of rhinitis, conjunctivitis and asthma induced by allergen exposure for both EAR and LAR.
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Affiliation(s)
- Anays Piotin
- Division of Asthma and Allergy, Chest Diseases Department, Strasbourg University Hospital, Strasbourg, France
- Physiology and Functional Exploration Service, University Hospital of Strasbourg, Strasbourg, France
| | - Julien Godet
- Public Health Department, Strasbourg University Hospital, Strasbourg, France
| | - Nathalie Domis
- ALYATEC Environmental Exposure Chamber, Strasbourg, France
| | - Frédéric de Blay
- Division of Asthma and Allergy, Chest Diseases Department, Strasbourg University Hospital, Strasbourg, France
- ALYATEC Environmental Exposure Chamber, Strasbourg, France
- EA 3070 Federation of Translational Medicine, FHU Homicare, University of Strasbourg, Strasbourg, France
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Kalayci O, Miligkos M, Pozo Beltrán CF, El-Sayed ZA, Gómez RM, Hossny E, Le Souef P, Nieto A, Phipatanakul W, Pitrez PM, Xepapadaki P, Jiu-Yao W, Papadopoulos NG. The role of environmental allergen control in the management of asthma. World Allergy Organ J 2022; 15:100634. [PMID: 35341023 PMCID: PMC8917313 DOI: 10.1016/j.waojou.2022.100634] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/08/2022] [Accepted: 02/01/2022] [Indexed: 11/26/2022] Open
Abstract
Allergen exposure may exacerbate asthma symptoms in sensitized patients. Allergen reduction or avoidance measures have been widely utilized; however, there is ongoing controversy on the effectiveness of specific allergen control measures in the management of children with asthma. Often, allergen avoidance strategies are not recommended by guidelines because they can be complex or burdensome, although individual patients may benefit. Here we explore the potential for intervention against exposure to the major allergens implicated in asthma (ie, house dust mites, indoor molds, rodents, cockroaches, furry pets, and outdoor molds and pollens), and subsequent effects on asthma symptoms. We critically assess the available evidence regarding the clinical benefits of specific environmental control measures for each allergen. Finally, we underscore the need for standardized and multifaceted approaches in research and real-life settings, which would result in the identification of more personalized and beneficial prevention strategies.
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Yang WH, Kelly S, Haya L, Mehri R, Ramesh D, DeVeaux M, Wang CQ, Meier P, Narula S, Shawki F, Pennington R, Perlee L, O'Brien MP. Cat allergen exposure in a naturalistic exposure chamber: a prospective observational study in cat-allergic subjects. Clin Exp Allergy 2021; 52:265-275. [PMID: 34962661 PMCID: PMC9303194 DOI: 10.1111/cea.14087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/06/2021] [Accepted: 12/25/2021] [Indexed: 12/01/2022]
Abstract
Background To determine the proportion and reproducibility of cat‐allergic mild asthmatics with early asthmatic response (EAR) during cat allergen exposure in a naturalistic exposure chamber (NEC). Methods This was a prospective, observational study in 30 cat‐allergic mild asthmatics who received two 180‐min cat‐allergen (Felis domesticus allergen 1 [Fel d 1]) challenges 27 days apart in an NEC. Results An EAR (≥20% reduction from baseline in forced expiratory volume in 1 s [FEV1]) was observed in 67% and 52% of subjects at first and second NEC exposure, respectively, with similar median time to EAR; 44% of subjects had an EAR on days 1 and 28. Late asthmatic response (≥15% reduction in FEV1 within 24 h of NEC exit) was observed in 33% of subjects following either exposure. Average FEV1 and total nasal symptom score during NEC exposure were highly correlated within subjects between NEC exposures (r = 0.91, p < 0.0001; r = 0.73, p < 0.001), but total ocular symptom score was not. Time to EAR, but not average FEV1, was significantly associated with NEC Fel d 1 concentration, which was variable. There were no serious adverse events; 12/30 subjects experienced 20 adverse events (including asthma, 10%; headache, 10%). Conclusions The NEC model demonstrates that average FEV1 change is highly reproducible and has a low correlation with cat allergen levels. However, time to EAR and incidence of EAR are less reproducible and are highly correlated with NEC allergen levels. Average FEV1, rather than incidence of EAR or time to EAR, could be considered as an endpoint for interventional trials testing cat‐specific anti‐allergy therapies using an NEC.
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Affiliation(s)
| | | | - Laura Haya
- Red Maple Trials, Inc., Ottawa, ON, Canada
| | - Rym Mehri
- Red Maple Trials, Inc., Ottawa, ON, Canada
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A case of lactoferrin-induced occupational asthma. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2020; 8:3600-3602. [PMID: 32835873 DOI: 10.1016/j.jaip.2020.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 11/22/2022]
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5
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Gao M, Shen X, Mao S. Factors influencing drug deposition in the
nasal cavity upon delivery via nasal sprays. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2020. [DOI: 10.1007/s40005-020-00482-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Arora P, Ansari SH, Anjum V, Mathur R, Ahmad S. Investigation of anti-asthmatic potential of Kanakasava in ovalbumin-induced bronchial asthma and airway inflammation in rats. JOURNAL OF ETHNOPHARMACOLOGY 2017; 197:242-249. [PMID: 27502540 DOI: 10.1016/j.jep.2016.07.082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 07/17/2016] [Accepted: 07/30/2016] [Indexed: 06/06/2023]
Abstract
ETHNO-PHARMACOLOGICAL RELEVANCE Kanakasava is an Indian traditional Ayurvedic formulation containing Datura (Datura metel), Vasaca (Adhatoda vasica), Dhataki (Woodfordia fruticosa) and Grape (Vitis vinifera) extracts as major constituents and used to treat pulmonary diseases including coughing, breathing difficulty and asthma. The present study was designed to assess the safety and therapeutic efficacy of Kanakasava against ovalbumin-induced bronchial asthma and related airway inflammation in rats due to lack of evidence based therapeutic efficacy data. MATERIAL AND METHODS Male wistar rats were sensitized with allergen (ovalbumin, 40mg/rat+aluminum hydroxide, 2.0mg/rat) and treated orally with standard dexamethasone (2.5mg/kg, b.w.) or Kanakasava (1.23 and 2.46ml/kg, b.w.) from day 1 to day 28. Inflammatory markers, including cell counts and cytokines such as interleukins (IL-4, IL-5, IL-1β), tumor necrosis factor (TNF-α), leukotriene (LTD-4), immunoglobulin (IgE), nitric oxide and nitrite levels in both blood and broncheo alveolar lavaged fluid (BALF) were analyzed. Abdominal mesentery was studied histologically for mast cell degranulation, whereas lung functions were investigated by spirometer. Method was also developed to quantify gallic acid and ethyl gallate content in Kanakasava by HPTLC for its quality control. RESULTS None of the rats exhibited mortality and Kanakasava was found to be safe at the tested doses. Treatment with Kanakasava significantly (P<0.01) reversed elevated levels of IgE, cytokines, nitrites and influx of eosinophils and neutrophils in blood and BALF. These findings were further supported by the significant improvement in lung functions (P<0.01) and suppression (P<0.01) of degranulation of mast cells. The content of gallic acid and ethyl gallate in Kanakasava was found to be 1.94% and 0.98%, respectively. CONCLUSION These findings demonstrated the preventive effect of Kanakasava in allergen induced model of asthma providing scientific basis for its traditional use in Ayurveda, since long time.
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Affiliation(s)
- Poonam Arora
- Department of Pharmacognosy & Phytochemistry, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi 110062, India
| | - S H Ansari
- Department of Pharmacognosy & Phytochemistry, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi 110062, India.
| | - Varisha Anjum
- Department of Pharmacognosy & Phytochemistry, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi 110062, India
| | - Rajani Mathur
- Department of Pharmacology, Delhi Institute of Pharmaceutical Sciences and Research (DIPSAR), New Delhi, India
| | - Sayeed Ahmad
- Department of Pharmacognosy & Phytochemistry, Faculty of Pharmacy, Jamia Hamdard (Hamdard University), New Delhi 110062, India.
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Scadding GW, Eifan A, Penagos M, Dumitru A, Switzer A, McMahon O, Phippard D, Togias A, Durham SR, Shamji MH. Local and systemic effects of cat allergen nasal provocation. Clin Exp Allergy 2015; 45:613-23. [PMID: 25303516 PMCID: PMC4778413 DOI: 10.1111/cea.12434] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/29/2014] [Accepted: 09/01/2014] [Indexed: 01/05/2023]
Abstract
Background Cat allergen is widely distributed in homes and schools; allergic sensitization is common. Objective To develop a model of cat allergen nasal challenge to establish dose–response and time–course characteristics and investigate local and systemic biomarkers of allergic inflammation. Methods Nineteen cat‐allergic individuals underwent titrated nasal challenge, range 0.243 to 14.6 μg/mL Fel d1, and matched diluent‐only provocation. Clinical response to 8 h was assessed by symptom scores and peak nasal inspiratory flow (PNIF). Nasal fluid was collected using polyurethane sponges and analysed by ImmunoCAP and multiplex assays. Whole blood flow cytometry for basophil surface CD63, CD107a, and CD203c was carried out at baseline and 6 h post‐challenge. Results A dose–response to allergen was seen in symptom scores and PNIF, maximal at 10 000 BU/mL (4.87 μg/mL Fel d1), P < 0.0001 vs. diluent. Nasal fluid tryptase was elevated at 5 min after challenge (P < 0.05 vs. diluent); eotaxin, IL‐4, ‐5, ‐9, and ‐13 were increased at 8 h (P < 0.05 to P < 0.0001 vs. diluent); TSLP was undetectable; IL‐10, IL‐17A, and IL‐33 were unchanged compared to diluent challenge. Nasal fluid IL‐5 and IL‐13 correlated inversely with PNIF after challenge (IL‐5, r = −0.79, P < 0.0001; IL‐13, r = −0.60, P = 0.006). Surface expression of CD63 and CD107a was greater at 6 h than at baseline, both in the presence (both P < 0.05) and absence (CD63, P < 0.01; CD107a, P < 0.05) of in vitro allergen stimulation; no changes were seen on diluent challenge day. Conclusions Cat allergen nasal challenge produces local and systemic Th2‐driven inflammatory responses and has potential as a surrogate outcome measure in clinical trials.
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Affiliation(s)
- G W Scadding
- Allergy and Clinical Immunology, Imperial College London, London, UK
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Chemokine profiles in blood associated with delayed asthmatic response to allergen challenge. Respir Med 2012; 107:47-59. [PMID: 23117099 DOI: 10.1016/j.rmed.2012.09.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 09/04/2012] [Accepted: 09/18/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND Patients with bronchial asthma having been challenged with allergen develop various types of asthmatic response, such as immediate (IAR), late (LAR) or delayed (DYAR) response, due to different immunologic mechanisms. The DYAR, beginning 26-32 h, reaching maximum between 32 and 48 h and resolving within 56 h after the challenge, differs from IAR and LAR in clinical and immunologic features. OBJECTIVES To investigate the changes in the serum concentrations of chemokines associated with the isolated form of DYAR. METHODS In 22 patients the repeated DYAR (p < 0.001) was supplemented with recording of blood cell counts and serum concentrations of chemokines before, and up to 72 h after the bronchial challenge by means of enzyme-linked immunoassay, (ELISA). RESULTS The DYAR was associated with (a) significantly increased serum concentrations (p < 0.05) of CCL 2, CCL 3, CCL 4, CCL 7, CCL 20, CXCL 1, CXCL 8, CXCL 9, CXCL 10 and CXCL 11, and (b) significantly decreased serum concentrations, (p < 0.05) of CCL 5, CCL 11, CCL 17, CCL 22, CCL 24 and CCL 26, as compared with their pre-challenge as well as the PBS control values. No significant chemokine changes were recorded during the PBS controls (p > 0.1). CONCLUSIONS These results, together with changes in the blood cell counts, provide evidence for an involvement of activated Th(1), cells and NK cells (CCL-2, -3, -4, -20, CXCL-9,-10,-11), neutrophils (CCL-20, CXCL-1,-8) and monocytes (CCL-2,-3,-4, -7, CXCL-10), upon co-operation of other cell types, such as epithelial, endothelial and dendritic cells, in the immunologic mechanism(s) underlying the DYAR.
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9
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Robinson DS. Utility of inhaled allergen challenge in clinical diagnosis and management of asthma: what never? Well, hardly ever! Clin Exp Allergy 2012; 41:606-8. [PMID: 21488992 DOI: 10.1111/j.1365-2222.2011.03736.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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10
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Hedlin G, van Hage M. The role of immunotherapy in the management of childhood asthma. Ther Adv Respir Dis 2012; 6:137-46. [PMID: 22438265 DOI: 10.1177/1753465812439793] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Subcutaneous immunotherapy (SCIT) is still questioned as a safe and efficacious way of treating allergic asthma in children. In a Cochrane review published in 2010 it was, however, concluded that SCIT has significant and beneficial effects on symptoms and medication use in both children and adults with mostly mild asthma. Only a few studies have been performed to specifically study if SCIT in children with moderate asthma reduces the need for inhaled corticosteroids. There are conflicting results that illustrate the problem of the heterogeneity of the asthma disease and the fact that allergies may play different roles on the severity and symptoms of the disease. Furthermore, children with severe allergic asthma are often sensitized to multiple allergens, which makes SCIT both complicated and less safe to administer. On the other hand, if the child suffers from asthmatic symptoms despite adherence to pharmacotherapy, omalizumab or a combination of omalizumab and allergen immunotherapy might be useful. There is a need for more studies on this combination before it can be considered as an additional therapy in children with asthma and severe allergies. Sublingual immunotherapy (SLIT) has also been shown to improve asthma symptoms and medication use. SLIT is safe although its efficacy compared with SCIT has been studied very little. Another approach is to try to prevent asthma by treating children with SCIT for allergic rhinoconjunctivitis before asthma has developed. The most attractive prospect, however, is to find ways of preventing asthma by vaccination against the most common viruses, particularly rhinovirus. There is evidence that there are children at high risk of developing asthma in whom a viral infection can also enhance the risk of allergen sensitization. So far this vaccination has not been achievable although research is in progress.
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Affiliation(s)
- Gunilla Hedlin
- Centre for Allergy Research, Karolinska Institutet, PO Box 287, SE-17177 Stockholm, Sweden.
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11
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van de Pol MA, Lutter R, van Ree R, van der Zee JS. Increase in allergen-specific IgE and ex vivo Th2 responses after a single bronchial challenge with house dust mite in allergic asthmatics. Allergy 2012; 67:67-73. [PMID: 21958117 DOI: 10.1111/j.1398-9995.2011.02722.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Airway responsiveness to allergen in patients with allergic asthma is studied by bronchial allergen challenge. Although the typical features of the early and late responses on lung function and bronchial inflammation after allergen challenge are well known, little has been reported as yet on any changes in systemic allergic and immunologic parameters after 4-6 weeks. METHODS In a clinical study, 27 subjects with allergic asthma and house dust mite (HDM) allergy underwent a bronchial allergen challenge with HDM. Blood samples were collected before and 5 weeks after allergen challenge. Serum levels of total IgE and allergen-specific IgE were measured, and peripheral blood mononuclear cells were isolated and stimulated ex vivo with HDM to determine the allergen-specific T-cell cytokine response. RESULTS Five weeks after bronchial allergen challenge with HDM, the amount of circulating IgE against HDM and the major allergenic components Der p1 and Der p2 was significantly increased (10.8% and 8.8%, respectively). IgE antibodies against other environmental allergens decreased (grass pollen) or remained unchanged (cat dander). Allergen-induced Th2-cytokine production was also significantly increased (P< 0.001, P=0.014, and P=0.006 for IL-4, IL-5, and IL-13, respectively). The increase in Der p1- and Der p2-specific IgE in serum correlated with increased numbers of Th2-cytokine-producing cells (Rs=0.56, P=0.002 and Rs=0.54, P=0.004 for IL-4 and IL-13, respectively). CONCLUSIONS A single bronchial allergen challenge with HDM is accompanied by increased levels of allergen-specific IgE for HDM in serum and an enhanced Th2 response to HDM still detectable 5 weeks after challenge.
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Affiliation(s)
- M A van de Pol
- Departments of Pulmonology Experimental Immunology Otorhinolaryngology, Academic Medical Center, University of Amsterdam, the Netherlands
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12
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Walker SM, Durham SR, Till SJ, Roberts G, Corrigan CJ, Leech SC, Krishna MT, Rajakulasingham RK, Williams A, Chantrell J, Dixon L, Frew AJ, Nasser SM. Immunotherapy for allergic rhinitis. Clin Exp Allergy 2011; 41:1177-200. [DOI: 10.1111/j.1365-2222.2011.03794.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Kämpe M, Janson C, Stålenheim G, Stolt I, Carlson M. Experimental and seasonal exposure to birch pollen in allergic rhinitis and allergic asthma with regard to the inflammatory response. CLINICAL RESPIRATORY JOURNAL 2010; 4:37-44. [PMID: 20298416 DOI: 10.1111/j.1752-699x.2009.00140.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIMS Seasonal allergy is an interesting model to study the pathophysiological mechanisms involved in allergic inflammation. However, experimental allergen exposure is easier to perform and standardise. The primary aim of this study was to compare the inflammatory responses to high-dose bronchial challenge and natural exposure during birch pollen season. The second aim was to compare the responses of patients with allergic rhinitis and allergic asthma, respectively to both types of allergen exposure. METHODS Fifteen birch pollen-allergic patients (seven with asthma and eight with rhinitis) and five healthy individuals were studied during pollen season and after challenge with birch allergen. Symptoms, medication and peak expiratory flow rate (PEFR) were recorded, and blood samples, spirometry and induced sputum were analysed during season and after challenge. RESULTS Patients with allergic asthma demonstrated a greater bronchial responsiveness to bronchial provocation with birch allergen than patients with rhinitis (P = 0.04) whereas no difference was found regarding nasal challenge. No significant association was found between the level of responsiveness and the inflammatory response after seasonal exposure. Seasonal exposure was related to a more marked systemic inflammatory blood-eosinophil increase than bronchial challenge [(median) (0.25 vs 0.11 x 109/L, P = 0.03)] and after nasal challenge, respectively [(median) (0.25 vs 0.04 x 109/L, P = 0.003)]. A significant correlation in eosinophil cationic protein in induced sputum was found between the experimental and seasonal exposure (rho = 0.62, P = 0.02). CONCLUSIONS Bronchial allergen challenge with inhalation of birch pollen gives a similar inflammatory response in the airway but less systemic inflammation than seasonal exposure in birch pollen allergic patients with asthma and rhinitis.
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Affiliation(s)
- Mary Kämpe
- Department of Medical Sciences, Respiratory Medicine and Allergology, University Hospital, Uppsala, Sweden
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Grainge C, Howarth PH. Repeated high-dose inhalation allergen challenge in asthma. CLINICAL RESPIRATORY JOURNAL 2010; 5:150-5. [PMID: 21679350 DOI: 10.1111/j.1752-699x.2010.00212.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Inhalation allergen challenge in humans is used to investigate lung pathophysiology and responses to novel therapies. However, the single high-dose allergen challenges that are commonly performed do not mimic repeated symptomatic environmental allergen exposure. OBJECTIVES To develop and evaluate the safety of a repeated high-dose symptomatic inhalation allergen challenge model. METHODS Sixteen subjects with atopic asthma were recruited. Each underwent three inhalation allergen challenges using house dust mite (Dermatophagoides pteronyssinus) antigen at 48-h intervals with a target of symptom induction and an early asthmatic reaction fall in forced expiratory volume in 1 s (FEV(1) ) of 15% from baseline. RESULTS All of the subjects completed the three-challenge protocol and the target immediate airway bronchoconstrictor response was achieved in all the subjects at all challenges. There were no adverse events recorded. The early asthmatic reaction was similar for the three challenges whether measured as mean maximal fall in FEV(1) or mean area under the curve. The late asthmatic reaction was also similar over the three challenges with no evidence of priming or desensitisation. Symptom scores and reliever medication use significantly increased over the time of the challenges. Baseline lung function and reversibility was unchanged 4 days after the last challenge. CONCLUSION We demonstrate that repeated high-dose inhaled house dust mite allergen challenge in human volunteers with mild asthma is safe, repeatable and acceptable. This allows the use of this model in further studies focused on understanding the pathophysiology of allergen induced asthma and the impact of therapeutic interventions.
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Affiliation(s)
- Christopher Grainge
- University of Southampton School of Medicine, Infection, Inflammation and Immunology Division, Southampton General Hospital, Southampton, UK.
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Leemans J, Kirschvink N, Clercx C, Cambier C, Gustin P. Functional response to inhaled salbutamol and/or ipratropium bromide in Ascaris suum-sensitised cats with allergen-induced bronchospasms. Vet J 2009; 186:76-83. [PMID: 19699123 DOI: 10.1016/j.tvjl.2009.07.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 07/07/2009] [Accepted: 07/25/2009] [Indexed: 11/19/2022]
Abstract
Knowledge about the use of inhaled bronchodilators in cats with so-called 'feline asthma' is limited and relies on the experience of clinicians treating these patients. A randomised controlled four-way crossover study was therefore designed to compare the effects of salbutamol (SAL, 100 μg), ipratropium bromide (IB, 20 μg) and a combination of both (SAL/IB, 100 μg/20 μg), delivered through a pressurised metered-dose inhaler (pMDI) connected to a spacing chamber, on allergen-induced bronchospasms in five Ascaris suum (AS)-sensitised cats. Four AS bronchial provocation challenges were carried out at 1 week intervals, followed by one of four treatment protocols: SAL, IB, SAL/IB or control (untreated). Enhanced pause (Penh), an estimator of airflow limitation measured by barometric whole-body plethysmography, was repeatedly assessed within 120 min following the administration of each treatment protocol. Responses to inhaled medications were evaluated by calculating the area under the time-response curves (AUC) from 0 to 60 or 120 min after drug administration (AUC(0-60), AUC(0-120)), as well as the times required for half-recovery (T(50%)) or for returning to nearly basal conditions (T(20%)). No significant differences were found among the four study groups, with reference to the mean AUC(0-60), T(20%) and T(50%) values of Penh (P>0.05). Mean AUC(0-120) values of Penh were similar between the bronchodilators tested, but were significantly lower than those in the untreated group. It was concluded that inhalation of SAL, IB and SAL/IB via pMDI failed to improve most Penh-derived parameters, which suggested that these bronchodilators were of limited efficacy in reversing allergen-induced bronchospasm in cats. However, further studies using a larger number of animals are warranted to investigate if different drugs or delivery devices or higher dosages may be more effective.
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Affiliation(s)
- Jérôme Leemans
- Section of Pharmacology, Pharmacotherapy and Toxicology, Department for Functional Sciences B41, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
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Abstract
Asthma is suspected from a history of key symptoms, including cough, wheezing, dyspnea, chest tightness, and increased mucus production. A positive family or personal history of atopic diseases and diseases that are comorbid with asthma, such as allergic rhinitis and rhinosinusitis, is also important. The differential diagnosis of asthma is broad and includes potentially life-threatening diseases. Pediatric asthma and psychiatric mimics require special attention to prevent misdiagnosis. Differentiating asthma from these other disease states by history alone is not always possible. Because accurate diagnosis is critical to successful treatment, objective testing by spirometry and methacholine challenge should be employed.
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Fernandez-Rodriguez S, Ford WR, Broadley KJ, Kidd EJ. Establishing the phenotype in novel acute and chronic murine models of allergic asthma. Int Immunopharmacol 2008; 8:756-63. [PMID: 18387519 DOI: 10.1016/j.intimp.2008.01.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 01/09/2008] [Accepted: 01/25/2008] [Indexed: 11/16/2022]
Abstract
Allergic asthma is a chronic disease of the airways, with superimposed acute inflammatory episodes which correspond to exacerbations of asthma. Two novel models of allergic asthma have been developed in mice receiving the same allergen sensitisation, but with acute or chronic allergen exposures, the latter to mimic the human situation more closely. Ovalbumin-sensitised mice were challenged by ovalbumin inhalation twice on the same day for the acute model, and 18 times over a period of 6 weeks for the chronic model. Lung function was monitored in conscious, unrestrained mice immediately after the last challenge for up to 12 h. Airway responsiveness to inhaled methacholine and serum antibody levels were determined 24 h after challenge. Bronchoalveolar inflammatory cell recruitment was determined at 2 or 24 h. Acute and chronically treated mice had similar early and late asthmatic responses peaking at 2 h and 7-8 h, respectively. IgE and IgG antibody levels, compared with naïve mice, and eosinophil infiltration, compared with naïve and saline challenge, were elevated. Airway hyperresponsiveness to methacholine was observed 24 h after challenge in both models. The acute model had higher levels of eosinophilia, whereas the chronic model showed hyperresponsiveness to lower doses of methacholine and had higher levels of total IgE and ovalbumin-specific IgG antibodies. Both novel murine models of allergic asthma bear a close resemblance to human asthma, each offering particular advantages for studying the mechanisms underlying asthma and for evaluating existing and novel therapeutic agents.
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Affiliation(s)
- Sofia Fernandez-Rodriguez
- Division of Pharmacology, Welsh School of Pharmacy, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, UK
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