From MASK-air and SILAM to CATALYSE (Climate Action To Advance HeaLthY Societies in Europe).

Plant species vary under different climatic conditions and the distribution of pollen in the air. Trends in pollen distribution can be used to assess the impact of climate change on public health. In 2015, the Mobile Airways Sentinel networK for rhinitis and asthma (MASK-air®) was launched as a project of the European Innovation Partnership on Active and Healthy Ageing (EIP-on-AHA, DG Santé and DG CONNECT). This project aimed to develop a warning system to inform patients about the onset of the pollen season, namely, the System for Integrated modeLling of Atmospheric coMposition (SILAM). A global-to-meso-scale dispersion model was developed by the Finnish Meteorological Institute (FMI). It provides quantitative information on atmospheric pollution of anthropogenic and natural origins, particularly on allergenic pollens. Impact of Air Pollution on Asthma and Rhinitis (POLLAR, EIT Health) has combined MASK-air clinical data with SILAM forecasts. A new Horizon Europe grant (Climate Action to Advance HeaLthY Societies in Europe [CATALYSE]; grant agreement number 101057131), which came into force in September 2022, aims to improve our understanding of climate change and help us find ways to counteractit. One objective of this project is to develop early warning systems and predictive models to improve the effectiveness of strategies for adapting to climate change. One of the warning systems is focused on allergic rhinitis (CATALYSE Task 3.2), with a collaboration between the FMI (Finland), Porto University (Portugal), MASK-air SAS (France), ISGlobal (Spain), Hertie School (Germany), and the University of Zurich (Switzerland). It is to be implemented with the support of the European Academy of Allergy and Clinical Immunology. This paper reports the planning of CATALYSE Task 3.2.

From MASK-air and SILAM to CATALYSE(Climate Action To Advance HeaLthY Societiesin Europe)

Plant species vary under different climatic conditions and the distribution of pollen in the air. Trends in pollen distribution can be used to assess the impact of climate change on public health. In 2015, the Mobile Airways Sentinel networK for rhinitis and asthma (MASK-air®) was launched as a project of the European Innovation Partnership on Active and Healthy Ageing (EIP-on-AHA, DG Santé and DG CONNECT). This project aimed to develop a warning system to inform patients about the onset of the pollen season, namely, the System for Integrated modeLling of Atmospheric coMposition (SILAM). A global-to-meso–scale dispersion model was developed by the Finnish Meteorological Institute (FMI). It provides quantitative information on atmospheric pollution of anthropogenic and natural origins, particularly on allergenic pollens. Impact of Air Pollution on Asthma and Rhinitis (POLLAR, EIT Health) has combined MASK-air clinical data with SILAM forecasts. A new Horizon Europe grant (Climate Action to Advance HeaLthY Societies in Europe [CATALYSE]; grant agreement number 101057131), which came into force in September 2022, aims to improve our understanding of climate change and help us find ways to counteractit. One objective of this project is to develop early warning systems and predictive models to improve the effectiveness of strategies for adapting to climate change. One of the warning systems is focused on allergic rhinitis (CATALYSE Task 3.2), with a collaboration between the FMI (Finland), Porto University (Portugal), MASK-air SAS (France), ISGlobal (Spain), Hertie School (Germany), and the University of Zurich (Switzerland). It is to be implemented with the support of the European Academy of Allergy and Clinical Immunology. This paper reports the planning of CATALYSE Task 3.2 (AU)

Las especies de plantas varían según las diferentes condiciones climáticas y la distribución del polen en el aire. Las tendencias en la distribución del polen se pueden utilizar para evaluar el impacto del cambio climático en la salud pública. En 2015, se lanzó la red Mobile Airways Sentinel para la rinitis y el asma (MASK-air ® ) como proyecto de la Asociación Europea de Innovación sobre Envejecimiento Activo y Saludable (EIP-on-AHA, DG Santé y DG CONNECT). Este proyecto tenía como objetivo desarrollar un sistema de alerta para informar a los pacientes sobre el inicio de la temporada de polen, concretamente, el Sistema de modelización integrada de la composición atmosférica (SILAM). El Instituto Meteorológico Finlandés (FMI) desarrolló un modelo de dispersión de escala global a meso. Proporciona información cuantitativa sobre la contaminación atmosférica de origen antropogénico y natural, en particular sobre pólenes alergénicos. Impacto de la contaminación del aire en el asma y la rinitis (POLLAR, EIT Health) ha combinado los datos clínicos de MASK-air con las previsiones de SILAM. Una nueva subvención de Horizonte Europa (Acción climática para promover sociedades saludables en Europa [CATALYSE]; acuerdo de subvención número 101057131), que entró en vigor en septiembre de 2022, tiene como objetivo mejorar nuestra comprensión del cambio climático y ayudarnos a encontrar formas de contrarrestarlo. Uno de los objetivos de este proyecto es desarrollar sistemas de alerta temprana y modelos predictivos para mejorar la eficacia de las estrategias de adaptación al cambio climático(AU)

Adherence to inhaled corticosteroids and long-acting ß2-agonists in asthma: A MASK-air study.

INTRODUCTION: Adherence to controller medication is a major problem in asthma management, being difficult to assess and tackle. mHealth apps can be used to assess adherence. We aimed to assess the adherence to inhaled corticosteroids+long-acting ß2-agonists (ICS+LABA) in users of the MASK-air® app, comparing the adherence to ICS+formoterol (ICS+F) with that to ICS+other LABA. MATERIALS AND METHODS: We analysed complete weeks of MASK-air® data (2015-2022; 27 countries) from patients with self-reported asthma and ICS+LABA use. We compared patients reporting ICS+F versus ICS+other LABA on adherence levels, symptoms and symptom-medication scores. We built regression models to assess whether adherence to ICS+LABA was associated with asthma control or short-acting beta-agonist (SABA) use. Sensitivity analyses were performed considering the weeks with no more than one missing day. RESULTS: In 2598 ICS+LABA users, 621 (23.9%) reported 4824 complete weeks and 866 (33.3%) reported weeks with at most one missing day. Higher adherence (use of medication ≥80% of weekly days) was observed for ICS+other LABA (75.1%) when compared to ICS+F (59.3%), despite both groups displaying similar asthma control and work productivity. The ICS+other LABA group was associated with more days of SABA use than the ICS+F group (median=71.4% versus 57.1% days). Each additional weekly day of ICS+F use was associated with a 4.1% less risk in weekly SABA use (95%CI=-6.5;-1.6%;p=0.001). For ICS+other LABA, the percentage was 8.2 (95%CI=-11.6;-5.0%;p<0.001). CONCLUSIONS: In asthma patients adherent to the MASK-air app, adherence to ICS+LABA was high. ICS+F users reported lower adherence but also a lower SABA use and a similar level of control.

Rhinitis associated with asthma is distinct from rhinitis alone: The ARIA-MeDALL hypothesis.

Asthma, rhinitis, and atopic dermatitis (AD) are interrelated clinical phenotypes that partly overlap in the human interactome. The concept of "one-airway-one-disease," coined over 20 years ago, is a simplistic approach of the links between upper- and lower-airway allergic diseases. With new data, it is time to reassess the concept. This article reviews (i) the clinical observations that led to Allergic Rhinitis and its Impact on Asthma (ARIA), (ii) new insights into polysensitization and multimorbidity, (iii) advances in mHealth for novel phenotype definitions, (iv) confirmation in canonical epidemiologic studies, (v) genomic findings, (vi) treatment approaches, and (vii) novel concepts on the onset of rhinitis and multimorbidity. One recent concept, bringing together upper- and lower-airway allergic diseases with skin, gut, and neuropsychiatric multimorbidities, is the "Epithelial Barrier Hypothesis." This review determined that the "one-airway-one-disease" concept does not always hold true and that several phenotypes of disease can be defined. These phenotypes include an extreme "allergic" (asthma) phenotype combining asthma, rhinitis, and conjunctivitis. Rhinitis alone and rhinitis and asthma multimorbidity represent two distinct diseases with the following differences: (i) genomic and transcriptomic background (Toll-Like Receptors and IL-17 for rhinitis alone as a local disease; IL-33 and IL-5 for allergic and non-allergic multimorbidity as a systemic disease), (ii) allergen sensitization patterns (mono- or pauci-sensitization versus polysensitization), (iii) severity of symptoms, and (iv) treatment response. In conclusion, rhinitis alone (local disease) and rhinitis with asthma multimorbidity (systemic disease) should be considered as two distinct diseases, possibly modulated by the microbiome, and may be a model for understanding the epidemics of chronic and autoimmune diseases.

Identification by cluster analysis of patients with asthma and nasal symptoms using the MASK-air® mHealth app.

BACKGROUND: The self-reporting of asthma frequently leads to patient misidentification in epidemiological studies. Strategies combining the triangulation of data sources may help to improve the identification of people with asthma. We aimed to combine information from the self-reporting of asthma, medication use and symptoms to identify asthma patterns in the users of an mHealth app. METHODS: We studied MASK-air® users who reported their daily asthma symptoms (assessed by a 0-100 visual analogue scale - "VAS Asthma") at least three times (either in three different months or in any period). K-means cluster analysis methods were applied to identify asthma patterns based on: (i) whether the user self-reported asthma; (ii) whether the user reported asthma medication use and (iii) VAS asthma. Clusters were compared by the number of medications used, VAS asthma levels and Control of Asthma and Allergic Rhinitis Test (CARAT) levels. FINDINGS: We assessed a total of 8,075 MASK-air® users. The main clustering approach resulted in the identification of seven groups. These groups were interpreted as probable: (i) severe/uncontrolled asthma despite treatment (11.9-16.1% of MASK-air® users); (ii) treated and partly-controlled asthma (6.3-9.7%); (iii) treated and controlled asthma (4.6-5.5%); (iv) untreated uncontrolled asthma (18.2-20.5%); (v) untreated partly-controlled asthma (10.1-10.7%); (vi) untreated controlled asthma (6.7-8.5%) and (vii) no evidence of asthma (33.0-40.2%). This classification was validated in a study of 192 patients enrolled by physicians. INTERPRETATION: We identified seven profiles based on the probability of having asthma and on its level of control. mHealth tools are hypothesis-generating and complement classical epidemiological approaches in identifying patients with asthma.

Treatment of allergic rhinitis during and outside the pollen season using mobile technology. A MASK study.

BACKGROUND: The analysis of mobile health (mHealth) data has generated innovative insights into improving allergic rhinitis control, but additive information is needed. A cross-sectional real-world observational study was undertaken in 17 European countries during and outside the estimated pollen season. The aim was to collect novel information including the phenotypic characteristics of the users. METHODS: The Allergy Diary-MASK-air-mobile phone app, freely available via Google Play and App, was used to collect the data of daily visual analogue scales (VASs) for overall allergic symptoms and medication use. Fluticasone Furoate (FF), Mometasone Furoate (MF), Azelastine Fluticasone Proprionate combination (MPAzeFlu) and eight oral H1-antihistamines were studied. Phenotypic characteristics were recorded at entry. The ARIA severity score was derived from entry data. This was an a priori planned analysis. RESULTS: 9037 users filled in 70,286 days of VAS in 2016, 2017 and 2018. The ARIA severity score was lower outside than during the pollen season. Severity was similar for all treatment groups during the pollen season, and lower in the MPAzeFlu group outside the pollen season. Days with MPAzeFlu had lower VAS levels and a higher frequency of monotherapy than the other treatments during the season. Outside the season, days with MPAzeFlu also had a higher frequency of monotherapy. The number of reported days was significantly higher with MPAzeFlu during and outside the season than with MF, FF or oral H1-antihistamines. CONCLUSIONS: This study shows that the overall efficacy of treatments is similar during and outside the pollen season and indicates that medications are similarly effective during the year.

Guidance to 2018 good practice: ARIA digitally-enabled, integrated, person-centred care for rhinitis and asthma.

AIMS: Mobile Airways Sentinel NetworK (MASK) belongs to the Fondation Partenariale MACVIA-LR of Montpellier, France and aims to provide an active and healthy life to rhinitis sufferers and to those with asthma multimorbidity across the life cycle, whatever their gender or socio-economic status, in order to reduce health and social inequities incurred by the disease and to improve the digital transformation of health and care. The ultimate goal is to change the management strategy in chronic diseases. METHODS: MASK implements ICT technologies for individualized and predictive medicine to develop novel care pathways by a multi-disciplinary group centred around the patients. STAKEHOLDERS: Include patients, health care professionals (pharmacists and physicians), authorities, patient's associations, private and public sectors. RESULTS: MASK is deployed in 23 countries and 17 languages. 26,000 users have registered. EU GRANTS 2018: MASK is participating in EU projects (POLLAR: impact of air POLLution in Asthma and Rhinitis, EIT Health, DigitalHealthEurope, Euriphi and Vigour). LESSONS LEARNT: (i) Adherence to treatment is the major problem of allergic disease, (ii) Self-management strategies should be considerably expanded (behavioural), (iii) Change management is essential in allergic diseases, (iv) Education strategies should be reconsidered using a patient-centred approach and (v) Lessons learnt for allergic diseases can be expanded to chronic diseases.

2020 ARIA CARE PATHWAYS FOR ALLERGIC RHINITIS - GEORGIA.

Allergic rhinitis is the most common chronic disease worldwide. Treatment guidelines have improved the knowledge on rhinitis and have had a significant impact on AR management. In 20 years, ARIA has considerably evolved from the first multi-morbidity guideline in respiratory diseases to the digital transformation of health and care. Allergic rhinitis in Georgia, Next-generation ARIA-GRADE guidelines and ARIA, 2020 care pathways for Allergen Immunotherapy have been discussed in this review.

Prophylactic management of children at risk for recurrent upper respiratory infections: the Preventia I Study.

BACKGROUND: Given the morbidity and mortality of asthma and the recent dramatic increase in its prevalence, pharmacologic prophylaxis of this disease in children at risk would represent a major medical advance. OBJECTIVES: The Preventia I Study was designed to evaluate the efficacy and long-term safety of loratadine in reducing the number of respiratory infections in children at 24 months. A secondary objective was to investigate the benefit of loratadine treatment in preventing the onset of respiratory exacerbations. METHODS: Preventia I was a randomized placebo-controlled study involving 22 countries worldwide. The children were 12-30 months of age at enrollment and had experienced at least five episodes of ENT infections, and no more than two episodes of wheezing during the previous 12 months. Phase I was a 12-month double-blind period during which the children were treated with loratadine 5 mg/day (2.5 mg/day for children

Effect of loratadine on nitrogen dioxide-induced changes in electrical resistance and release of inflammatory mediators from cultured human bronchial epithelial cells.

BACKGROUND: Recent studies have demonstrated that some antihistamines can attenuate histamine-induced release of inflammatory mediators from bronchial epithelial cells. OBJECTIVE: The purpose of study was to test the hypothesis that loratadine may influence pollution-induced inflammation of the airways by modulating epithelial membrane integrity and the synthesis and/or release of inflammatory mediators from airway epithelial cells. METHODS: We have cultured human bronchial epithelial cell (HBEC) cultures from surgical explants and investigated the effect of loratadine on NO2-induced changes in both electrical resistance of HBEC cultures and release of IL-8, RANTES, and soluble intercellular adhesion molecule-1 (sICAM-1) from these cells after exposure for 6 hours to either air or 400 ppb NO2. RESULTS: Exposure for 6 hours to NO2 significantly decreased the electrical resistance of HBEC cultures by 18.1% from baseline (P <.05). Incubation with 0.25 to 25 micromol/L loratadine did not alter the NO2-induced decrease in the electrical resistance of HBEC cultures. NO2 also significantly increased the release of IL-8 from a control value of 52.5 pg/microgram cellular protein to 81.9 pg/microgram cellular protein (P <.05), RANTES from a control value of 0.023 pg/microgram cellular protein to 0.062 pg/microgram cellular protein (P <.05), and sICAM-1 from a control value of 7.7 pg/microgram cellular protein to 16.3 pg/microgram cellular protein (P <.05). The NO2-induced release of all 3 mediators was significantly attenuated by incubation of HBECs with 25 micromol/L loratadine. Incubation with 2.5 micromol/L loratadine also significantly attenuated the NO2-induced release of RANTES and sICAM-1, but not IL-8. CONCLUSIONS: These results suggest that loratadine has the potential to reduce airway inflammation by modulating the release of inflammatory cytokines from airway epithelial cells.

Changes in skin-test reactivity do not correlate with clinical efficacy of H1-blockers in seasonal allergic rhinitis.

New-generation H1-blockers may possess antiallergic properties, and their effect may differ, depending on the target organ. A double-blind, placebo-controlled, parallel-group study was carried out during the pollen season to compare the clinical effect on nasal and conjunctival symptoms of astemizole (10 mg o.d.) and loratadine (10 mg o.d.) with their effect on skin-test reactivity to allergen and histamine. Thirty-eight patients (12-56 years of age) were studied. Nasal and ocular symptoms were recorded daily from days 4 to 7. Skin prick tests with serial concentrations of allergens and one concentration of histamine were carried out before and at the end of the 7-day treatment period. Parallel-line bioassay, analysis of variance, and covariance were used to analyze skin test data. Loratadine and astemizole significantly decreased symptoms from baseline (P < 0.004 and P < 0.006). Skin-test reactivity to allergen and histamine was more profoundly decreased by astemizole than loratadine. The histamine covariant was more important in the allergen effect of astemizole than in that of loratadine. Two H1-blockers having the same clinical effect on nasal and ocular symptoms during the pollen season have totally different effects on skin-test reactivity. Skin-test reactivity to allergen or histamine is not predictive of the clinical efficacy of H1-blockers during seasonal allergic rhinitis.

Inhibitory effect of loratadine on leukotriene B4 production by neutrophils either alone or during interaction with human airway epithelial cells.

Leukotriene B4 (LTB4), an inflammatory mediator, is a potent chemoattractant for neutrophils (PMN) that plays an important role in the late reaction in asthma. Human airway epithelial cells (HAEC) can interact with PMN to increase LTB4 production. The aim of this study was to determine the influence of loratadine, an antihistaminic drug, on the production of LTB4 by PMN either alone or during interaction with transformed HAEC. The effect of tumour necrosis factor-alpha (TNF-alpha) was also examined. LTB4 production was measured by RP-HPLC after cell stimulation with calcium ionophore. Loratadine (0.25-25 microM) induced a significant and dose-dependent decrease of LTB4 production by PMN alone whereas it was up-regulated by TNF-alpha. As reported by others, we confirmed the increase of LTB4 release when PMN were cocultured with HAEC as compared to PMN alone. Addition of loratadine to HAEC before co-culture with PMN induced a significant decrease of LTB4 formation by cell interaction. This effect was noted when HAEC were washed following incubation with loratadine, demonstrating a direct action of the drug on this cell type. Moreover, the TNF-alpha-induced stimulation of LTB4 release that we demonstrated in PMN-HAEC interaction was also inhibited by loratadine. These results indicate that loratadine might reduce inflammatory reaction by a direct effect on PMN LTB4 production but also through an influence on HAEC during interaction with PMN.

Inhibitory activity of loratadine and descarboxyethoxyloratadine on histamine-induced activation of endothelial cells.

BACKGROUND: The allergic inflammatory reaction is characterized by leucocyte adherence and infiltration processes which are controlled by the expression of adhesion molecules on the surface of vascular endothelium. One of the main mediators implicated in allergic reactions is represented by histamine. Histamine is a potent activator of endothelial cells (EC): it induces the expression of P-selectin on the surface of endothelium and the secretion of IL-6 and IL-8. OBJECTIVES: Loratadine (L), a histamine H1-antagonist, and one of its active metabolites, descarboxyethoxyloratadine (DCL), were studied at different concentrations for their ability to reduce the histamine-induced activation of human umbilical vein EC (HUVEC). METHODS: HUVEC were stimulated in the presence of histamine at 10(-6) M, 10(-5) M and 10(-4) M. We assessed by ELISA the expression of P-selectin on EC surface, as well as cytokine production in EC supernatants of 24 h culture. RESULTS: Our results showed that for a 10(-4) M-histamine stimulation, L and DCL have a similar inhibitory effect on P-selectin expression (IC50 = 13 x 10[-9] M and 23 x 10[-9] M, respectively). L and DCL inhibited significantly IL-6 and IL-8 secretion induced by histamine with a more powerful efficiency of the active metabolite. For the dose of 10(-4) M histamine, a 50% inhibition of IL-6 secretion was obtained for a dose of DCL equal to 2.6 x 10(-12) M whereas the same magnitude of effects were only reached for a higher concentration of L (0.3 x 10[-6] M). Similar results were obtained for IL-8 (IC50 = 0.2 x 10[-6] M for L and 10[-9] M for DCL). Analysis of IL-8 mRNA expression by RT-PCR was in accordance with these data. CONCLUSION: These results demonstrate that both L and DCL are active to reduce the histamine-induced activation of EC. Interestingly, DCL seems to be effective at lesser concentrations especially to inhibit cytokine secretion.

Reduction of soluble ICAM-1 levels in nasal secretion by H1-blockers in seasonal allergic rhinitis.

ICAM-1, a transmembrane glycoprotein promoting adhesion in immunologic and inflammatory reactions, was found to be increased on nasal epithelial cells of patients with allergic rhinitis. Loratadine, an H1-blocker, was found to reduce in vitro the expression of ICAM-1 on nasal epithelial cells. A double-blind, parallel-group study was carried out during the pollen season to compare the effect of two H1-blockers, cetirizine (10 mg OD) and loratadine (10 mg OD), on the release of soluble ICAM-1 in nasal secretions. A group of untreated patients was used as a control group. sICAM-1 was measured by enzyme immunoassay before and after 2 weeks of treatment. Symptoms were significantly decreased in the actively treated groups. sICAM-1 levels were unchanged in the control group but were significantly reduced in the two treated groups (P < 0.015, Wilcoxon's W test). This study shows that two H1-blockers, loratadine and cetirizine, have a similar effect on sICAM-1 released in nasal secretions during the pollen season.

Adjunct effect of loratadine in the treatment of acute sinusitis in patients with allergic rhinitis.

H1-blockers are often added to the standard treatment of acute sinusitis, but this is not supported by a controlled study. A multicentric, randomized, double-blind, placebo-controlled, parallel-group study was done in 139 allergic patients (15-65 years) to assess the adjunct efficacy of loratadine in acute exacerbation of rhinosinusitis. Sinusitis was diagnosed by symptoms and confirmed by rhinoscopy and sinus radiograph. Allergy was characterized by skin tests, RAST, and history. Patients were treated with antibiotics (14 days), oral corticosteroids (10 days), and loratadine (10 mg OD) or placebo (28 days). Treatment efficacy was assessed over 28 days by symptom scores quoted daily by patients. Physicians also rated total symptom scores at entry and at day 28. At entry, both groups had similar symptoms. Placebo-treated patients improved significantly, but patients who received loratadine had a significantly greater improvement in sneezing (P = 0.003) after 14 days, and in nasal obstruction (P = 0.002) after 28 days. Physicians found that patients receiving loratadine were significantly improved compared to placebo patients (P = 0.0125). Loratadine in addition to standard therapy was found to improve the control of some symptoms of sinusitis.

A review of loratadine in the treatment of patients with allergic bronchial asthma.

Patients with seasonal or allergic bronchial asthma experience an immediate allergic response caused by allergen-specific immunoglobulin E-mediated histamine release. The release of histamine and other chemical mediators may trigger airway hyperresponsiveness and exaggerated bronchoconstriction, characteristic features of allergic bronchial asthma. Traditional antihistamines have demonstrated only moderate activity of short duration against this disease. In contrast, loratadine, a potent, nonsedating, histamine-1-receptor antagonist with activity in seasonal and perennial allergic rhinitis, has demonstrated effective control of asthma symptoms, improved pulmonary function, and long duration of action in patients with allergic bronchial asthma. This review summarizes preclinical evidence for the antiallergic activity of loratadine and the results of clinical studies with oral loratadine in patients with allergic bronchial asthma.

Antihistamines and production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro: evaluation of the effects of loratadine and cetirizine.

1. In this study, we compared the effects of two antihistamine drugs on the production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by the use of an enzyme-linked immunosorbent assay. 3. Epithelial cells spontaneously released both cytokines and tumor necrosis factor alone induced a significant increase in this production but loratadine and cetirizine had no effect at the various concentrations studied. 4. The antihistamines have no effect and this suggests that histamine plays no role in cytokine production under these conditions.

Evaluation of a composite scoring system in conjunctival challenge with allergen: reproducibility and evolution during loratadine treatment.

The reproducibility of any challenge and its sensitivity to change during therapeutic interventions should always be examined before any drug trial is conducted. Conjunctival challenge has been widely used to assess objectively the efficacy of antiallergic treatments. A double-blind, placebo-controlled, crossover study was carried out in 26 patients allergic to grass pollen to test the reproducibility of a composite symptom score during placebo and control days, and to check the ability of loratadine to increase the provocative dose inducing a positive challenge. Conjunctival challenge was carried out with increasing concentrations of a standardized orchard grass pollen extract until a composite symptom score of 5 was reached. The provocative dose inducing a positive challenge was similar for the baseline (6.94 +/- 8.7 index of reactivity (IR)) and placebo days (20.0 +/- 32.5 IR) and was significantly increased (P < 0.01 and P < 0.001) when patients received loratadine (117.3 +/- 136.8 IR). This study shows that the composite score used was reproducible and sensitive to change, making it possible to use in drug trials.

Inhibitory activity of loratadine and descarboethoxyloratadine on expression of ICAM-1 and HLA-DR by nasal epithelial cells.

Nasal epithelial cells represent the first barrier against noxious agents and allergens. In allergic rhinitis, these cells are activated and histamine may be involved in this activation. Loratadine and one of its active metabolites, descarboethoxyloratadine, were studied for their ability to reduce the activation of nasal epithelial cells by histamine. Nasal turbinates or polyps were removed during surgery from 19 subjects, and nasal epithelial cells were recovered after enzymatic digestion. The in vitro activation of epithelial cells with histamine using an optimal dose (1 microM) and an optimal time (24 h) of incubation was studied, and the effect of loratadine or descarboethoxyloratadine (10 microM) was investigated. The expression of membrane markers (intercellular adhesion molecule-1 (ICAM-1) and a human leukocyte class II antigen (HLA-DR) was assessed by immunocytochemical analysis using an alkaline-antialkaline phosphatase (APAAP) system. The spontaneous expression of both markers was not significantly different in cells recovered from nasal turbinates or polyps, and there was a highly significant increase in the numbers of cells expressing ICAM-1 and HLA-DR following incubation with histamine. Loratadine or descarboethoxyloratadine significantly blocked these effects. This study shows a new possible antiallergic effect of H1-blockers and suggests that their effects on epithelial cells may be relevant in vivo.