IL-31 transgenic mice show reduced allergen-induced lung inflammation.

Interleukin-31 (IL-31) is a Th2 cell-derived cytokine that has been closely linked to pruritic skin inflammation. More recently, enhanced IL-31 serum levels have also been observed in patients with allergic rhinitis and allergic asthma. Therefore, the main aim of this study was to unravel the contribution of IL-31 to allergen-induced lung inflammation. We analyzed lung inflammation in response to the timothy grass (Phleum pratense) pollen allergen Phl p 5 in C57BL/6 wild-type (wt) mice, IL-31 transgenic (IL-31tg) mice, and IL-31 receptor alpha-deficient animals (IL-31RA-/- ). IL-31 and IL-31RA levels were monitored by qRT-PCR. Cellular infiltrate in bronchoalveolar lavage fluid (BALF) and lung tissue inflammation, mucus production as well as epithelial thickness were measured by flow cytometry and histomorphology. While allergen challenge induced IL-31RA expression in lung tissue of wt and IL-31tg mice, high IL-31 expression was exclusively observed in lung tissue of IL-31tg mice. Upon Phl p 5 challenge, IL-31tg mice showed reduced numbers of leukocytes and eosinophils in BALF and lung tissue as well as diminished mucin expression and less pronounced epithelial thickening compared to IL-31RA-/- or wt animals. These findings suggest that the IL-31/IL-31RA axis may regulate local, allergen-induced inflammation in the lungs.

Immunochemical and physical quantitation of grass and olive pollen allergens: correlation with asthma admissions in Cáceres, Spain

BACKGROUND: The association between pollen counts and allergen levels in the air is controversial. OBJECTIVES: The aims of the study were to quantify total and major allergen levels of Phleum pratense and Olea europaea and to analyze their correlation with grass and olive pollen counts and the number of asthma attacks attended at Complejo Hospitalario Universitario, Cáceres, Spain. MATERIAL AND METHODS: A volumetric air sampler and a Burkard spore trap were used for pollen and aeroallergen collection during April- June 2011. Filters were extracted, and major allergens were quantified using enzyme-linked immunosorbent assay. RESULTS: May was the main grass pollination period, with a maximum peak of 1362 grains/m3 (May 13). The main pollination period for olive was April 30-May 20, with a maximum peak of 851 grains/m3 (May 11). A moderate correlation was observed between asthma exacerbations and grass pollen counts or Phleum total allergen levels; this became stronger when a 3-day offset was introduced. A significant association was observed between asthma exacerbations and total olive allergen or olive pollen grain levels when a 1-day offset was introduced. The maximum correlation (moderate-high) was observed 4 days and 6 days away from the maximum olive pollen peak and the maximum Ole e 1 peak level, respectively. CONCLUSIONS: This study reveals a significant correlation between grass and olive pollination and an increase in the number of visits to the emergency room for asthma attacks. The aerobiological pattern of allergen levels in the air is similar to that of pollen counts during the grass and olive pollination periods

ANTECEDENTES: La relación entre los niveles de pólenes en el aire y los niveles de alérgenos es controvertida. OBJETIVOS: El objetivo de este estudio fue cuantificar los niveles de alérgenos principales y totales de Phleum pratense y Olea europaea, y analizar su relación con los niveles de pólenes y el número de crisis asmáticas atendidas en el Complejo Hospitalario de Cáceres, España. MATERIAL Y MÉTODOS: Se captaron pólenes y aeroalérgenos durante Abril-Junio de 2011, utilizando un colector de aire volumétrico y una trampa Burkard. Se extrajeron los alérgenos de los filtros y se cuantificaron mediante ELISA. RESULTADOS: Mayo fue el periodo de mayor polinización, (13 de Mayo, pico máximo de 1.362 granos de polen de gramíneas/m3). El mayor periodo de polinización del olivo fue del 30 de Abril al 20 de Mayo, (11 de Mayo, pico máximo: 851 granos de polen de olivo/m3). Se observó una correlación moderada entre los niveles de polen o alérgenos totales y exacerbaciones de asma, que aumentó al introducir un desfase de 3 días (Phleum), y de 1 día (olivo). La máxima correlación se observó a los 4 y 6 días del pico máximo de polen y de Ole e 1, respectivamente. CONCLUSIONES: Este estudio muestra una correlación significativa entre la polinización de gramíneas y olivo y el aumento del número de visitas a urgencias debidas a crisis asmáticas. Los patrones aerobiológicos de los niveles de alérgenos en el aire son comparables a los recuentos de pólenes durante los periodos de polinización de gramíneas y olivo

Dose-response relationship of a new Timothy grass pollen allergoid in comparison with a 6-grass pollen allergoid.

BACKGROUND: Subcutaneous allergen immunotherapy with grass pollen allergoids has been proven to be effective and safe in the treatment of patients with allergic rhinoconjunctivitis. Based on the extensive cross-reactivity among Pooideae species, it has been suggested that grass pollen extracts could be prepared from a single species, rather than from a multiple species mixture. OBJECTIVE: To find the optimal dose of a Phleum pratense (P. pratense) allergoid preparation and compare its efficacy and safety to a 6-grass pollen allergoid preparation. METHODS: In this double-blind, placebo-controlled study (EudraCT: 2011-000674-58), three doses of P. pratense allergoid (1800 therapeutic units (TU), standard-dose 6000 TU and 18 000 TU) were compared with placebo and the marketed 6-grass pollen allergoid (6000 TU). In a pre-seasonal dosing regimen, 102 patients were randomized to five treatment groups and received nine subcutaneous injections. The primary efficacy endpoint was the change in weal size (late-phase reaction [LPR]) in response to the intracutaneous testing (ICT) before and after treatment, comparing the active allergoids to placebo. Secondary outcomes were the change in Total Nasal Symptom Score (TNSS) assessed in the allergen exposure chamber (AEC), the changes in P. pratense-serum-specific IgG4 and the incidence of adverse events (AEs). RESULTS: All three doses of the P. pratense and the 6-grass pollen allergoid preparations were significantly superior to placebo for the primary outcome, whereas there were no significant differences in the change in TNSS. Compared to the standard-dose, the high-dose of P. pratense did not produce any additional significant benefit, but showed a slight increase in AEs. Yet this increase in AEs was lower than for the 6-grass pollen preparation. CONCLUSIONS & CLINICAL RELEVANCE: The standard-dose of the new P. pratense allergoid was comparable to the marketed 6-grass pollen preparation at equal dose for the parameters measured.

Effect of 2 Years of Treatment With Sublingual Grass Pollen Immunotherapy on Nasal Response to Allergen Challenge at 3 Years Among Patients With Moderate to Severe Seasonal Allergic Rhinitis: The GRASS Randomized Clinical Trial.

Importance: Sublingual immunotherapy and subcutaneous immunotherapy are effective in seasonal allergic rhinitis. Three years of continuous treatment with subcutaneous immunotherapy and sublingual immunotherapy has been shown to improve symptoms for at least 2 years following discontinuation of treatment. Objective: To assess whether 2 years of treatment with grass pollen sublingual immunotherapy, compared with placebo, provides improved nasal response to allergen challenge at 3-year follow-up. Design, Setting, and Participants: A randomized double-blind, placebo-controlled, 3-parallel-group study performed in a single academic center, Imperial College London, of adult patients with moderate to severe seasonal allergic rhinitis (interfering with usual daily activities or sleep). First enrollment was March 2011, last follow-up was February 2015. Interventions: Thirty-six participants received 2 years of sublingual immunotherapy (daily tablets containing 15 µg of major allergen Phleum p 5 and monthly placebo injections), 36 received subcutaneous immunotherapy (monthly injections containing 20 µg of Phleum p 5 and daily placebo tablets) and 34 received matched double-placebo. Nasal allergen challenge was performed before treatment, at 1 and 2 years of treatment, and at 3 years (1 year after treatment discontinuation). Main Outcomes and Measures: Total nasal symptom scores (TNSS; range; 0 [best] to 12 [worst]) were recorded between 0 and 10 hours after challenge. The minimum clinically important difference for change in TNSS within an individual is 1.08. The primary outcome was TNSS comparing sublingual immunotherapy vs placebo at year 3. Subcutaneous immunotherapy was included as a positive control. The study was not powered to compare sublingual immunotherapy with subcutaneous immunotherapy. Results: Among 106 randomized participants (mean age, 33.5 years; 34 women [32.1%]), 92 completed the study at 3 years. In the intent-to-treat population, mean TNSS score for the sublingual immunotherapy group was 6.36 (95% CI, 5.76 to 6.96) at pretreatment and 4.73 (95% CI, 3.97 to 5.48) at 3 years, and for the placebo group, the score was 6.06 (95% CI, 5.23 to 6.88) at pretreatment and 4.81 (95% CI, 3.97 to 5.65) at 3 years. The between-group difference (adjusted for baseline) was -0.18 (95% CI, -1.25 to 0.90; [P = .75]). Conclusions and Relevance: Among patients with moderate to severe seasonal allergic rhinitis, 2 years of sublingual grass pollen immunotherapy was not significantly different from placebo in improving the nasal response to allergen challenge at 3-year follow-up. Trial Registration: clinicaltrials.gov Identifier: NCT01335139; EudraCT Number: 2010-023536-16.

Pretreatment IgE sensitization patterns determine the molecular profile of the IgG4 response during updosing of subcutaneous immunotherapy with timothy grass pollen extract.

BACKGROUND: Allergen immunotherapy is an effective treatment of allergic rhinoconjunctivitis. Clinical efficacy is associated with improvement of basophil sensitivity and an increase in allergen-specific immunoglobulin concentration. OBJECTIVE: We sought to determine whether changes in allergen component-specific serum IgE and IgG4 levels during the updosing phase of subcutaneous immunotherapy (SCIT) are biomarkers of the immunologic changes that can lead to treatment efficacy. METHODS: Twenty-four subjects with grass pollen-induced allergic rhinoconjunctivitis were randomized 3:1 to receive SCIT (Alutard SQ) or to an open control group. IgE and IgG4 concentrations were determined for the major allergens Phl p 1 or Phl p 5 by using ImmunoCAP and for 8 grass pollen molecules by using Immuno Solid-phase Allergy Chip (ISAC) before treatment and after updosing. RESULTS: Levels of specific IgE against the dominant major allergens Phl p 1 and Phl p 5 increased from a mean of 23.0 to 48.8 kU/L (P = .01, n = 18) during the updosing phase in ImmunoCAP measurements but decreased from a median of 4.6 ISAC specific units (ISU) to 2.14 ISU (P < .0001, n = 102) when measured by using ISAC against 8 grass allergen components. The updosing phase induced a specific IgG4 level increase from a median of 0 ISU before treatment to 0.83 ISU after 12 weeks (P < .0001, n = 102) but only for allergen molecules to which pretreatment-specific IgE antibodies were detected (Spearman σ = 0.72, P < .0001, n = 102). CONCLUSION: Pretreatment allergen component-specific IgE appears to determine the induction of IgG4 in the updosing phase. Induced IgG4 seems to suppress IgE levels on ISAC, resulting in a marked decrease in ISAC-measured specific IgE levels after updosing of SCIT. Thus this decrease in ISAC IgE levels can be used to monitor the blocking effect of allergen-specific immunotherapy-induced non-IgE antibodies.

Safety of sublingual immunotherapy Timothy grass tablet in subjects with allergic rhinitis with or without conjunctivitis and history of asthma.

BACKGROUND: Patients with asthma may be more susceptible to adverse events (AEs) with sublingual immunotherapy tablet (SLIT-tablet) treatment, such as severe systemic reactions and asthma-related events. Using data from eight trials of grass SLIT-tablet in subjects with allergic rhinitis with/without conjunctivitis (AR/C), AE frequencies were determined in adults and children with and without reported asthma. METHODS: Data from randomized, double-blind, placebo-controlled trials of Timothy grass SLIT-tablet MK-7243 (2800 BAU/75 000 SQ-T, Merck/ALK-Abelló) were pooled for post hoc analyses. Subjects with uncontrolled and severe asthma were excluded from the trials. Frequencies for treatment-emergent AEs (TEAEs), local allergic swelling (mouth or throat), systemic allergic reactions, and asthma-related treatment-related AEs (TRAEs) were calculated. RESULTS: Among adults (n = 3314) and children (n = 881), 24% and 31%, respectively, had reported asthma. No serious local allergic swellings or serious systemic allergic reactions occurred in subjects with asthma treated with SLIT-tablet. There was no evidence of increased TEAEs, systemic allergic reactions, or severe local allergic swellings in adults or children with asthma treated with grass SLIT-tablet versus subjects without asthma in or outside of pollen season. There were 6/120 asthma-related TRAEs assessed as severe with grass SLIT-tablet and 2/60 with placebo, without a consistent trend among subjects with and without asthma (5 and 3 events, respectively). CONCLUSIONS: In the AR/C subjects with reported well-controlled mild asthma included in these studies, grass SLIT-tablet did not increase TEAE frequency, severe local allergic swelling, or systemic allergic reactions versus subjects without asthma. There was no indication that treatment led to acute asthma worsening.

Days with severe symptoms: an additional efficacy endpoint in immunotherapy trials.

BACKGROUND: In immunotherapy trials, primary and secondary endpoints often focus on average symptom and medication scores during the pollen season or on days with low symptoms and low medication use. Thus, there is a need for endpoints describing the treatment effect on the most troublesome days in the pollen season. AIMS OF THE STUDY: A possible additional efficacy endpoint, days with severe symptoms during the pollen season, was investigated using data from a multicentre, double-blind, randomized, placebo-controlled trial of the SQ-standardized grass allergy immunotherapy tablet (AIT) (Grazax, Phleum pratense, 75,000 SQ-T/2,800 BAU, ALK, Hørsholm, Denmark). METHODS: The trial included 634 subjects (N(Grass AIT) = 316; N(Placebo) = 318) with grass pollen-induced rhinoconjunctivitis. Six different definitions of a day with severe symptoms were suggested. The number of days with severe symptoms was analysed and odds ratios were calculated. RESULTS: The number and percentage of days with severe symptoms differed between definitions, but overall the analysis of days with severe symptoms showed consistent results (odds ratios: 2.0-3.4) for the different definitions. All definitions showed a reduced risk of having days with severe symptoms in the grass AIT group when compared to the placebo group. CONCLUSIONS: Days with severe symptoms during the pollen season is a relevant additional efficacy endpoint, which can be used in immunotherapy trials to support the clinical interpretation of commonly used efficacy endpoints.

Long-term clinical efficacy in grass pollen-induced rhinoconjunctivitis after treatment with SQ-standardized grass allergy immunotherapy tablet.

BACKGROUND: Sustained and disease-modifying effects of sublingual immunotherapy have never before been confirmed in a large-scale randomized, double-blind, placebo-controlled trial. OBJECTIVE: We sought to investigate sustained efficacy 1 year after a 3-year period of daily treatment with the SQ-standardized grass allergy immunotherapy tablet Grazax (Phleum pratense 75,000 SQ-T/2,800 BAU; ALK-Abelló, Hørsholm, Denmark). METHODS: A randomized, double-blind, placebo-controlled, phase III trial including adults with a history of moderate-to-severe grass pollen induced rhinoconjunctivitis inadequately controlled by symptomatic medications. The analysis set comprised 257 subjects at the follow-up. Efficacy end points were rhinoconjunctivitis symptom and medication scores, quality of life, and percentages of symptom and medication free days. Immunologic end points included grass pollen-specific serum IgG4 and IgE-blocking factor. Safety was assessed based on adverse events. RESULTS: Significant improvements in efficacy were consistently shown during 3 years' treatment. One year after treatment, the active group showed sustained reductions in mean rhinoconjunctivitis symptom scores (26%, P < .001) and medication scores (29%, P = .022) when compared with placebo. This level was similar to the efficacy observed during the 3-year treatment period. The differences in percentages of symptom- and medication-free days were significant during and 1 year after treatment. The active group also reported sustained and significant improvements in quality of life. Sustained clinical benefit was accompanied by immunologic changes. No safety issues were identified. CONCLUSION: Three years of treatment with the SQ-standardized grass allergy immunotherapy tablet resulted in consistent clinical improvement and accompanying immunologic changes that were sustained 1 year after treatment, which is indicative of disease modification and associated long-term benefits.

Grass pollen immunotherapy as an effective therapy for childhood seasonal allergic asthma.

BACKGROUND: Few studies have investigated the use of specific immunotherapy (SIT) for childhood seasonal allergic asthma. OBJECTIVE: We sought to examine the efficacy and safety of SIT with Alutard SQ grass pollen (Phleum pratense Alutard SQ; ALK-Abelló, Hørsholm, Denmark) in children with seasonal allergic asthma. METHODS: A randomized, double-blind, placebo-controlled study assessing the efficacy of grass pollen SIT over 2 pollen seasons was performed. Children (3-16 years) with a history of seasonal allergic asthma sensitized to grass pollen (P pratense) and requiring at least 200 microg of inhaled beclomethasone equivalent per day were enrolled. Subjects with symptomatic asthma or rhinoconjunctivitis outside the grass pollen season were excluded. The primary outcome measure was a combined asthma symptom-medication score during the second pollen season. Secondary outcome measures included end-point titration skin prick testing and conjunctival and bronchial provocation testing to allergen, sputum eosinophilia, exhaled nitric oxide, and adverse events. RESULTS: Thirty-nine subjects were enrolled. Thirty-five subjects provided data for analysis. The use of SIT was associated with a substantial reduction in asthma symptom-medication score compared with that after placebo (P = .04). There were also significant reductions in cutaneous (P = .002), conjunctival (P = .02), and bronchial (P = .01) reactivity to allergen after SIT compared with that after placebo. The 2 groups had similar levels of airway inflammation, despite a trend toward less inhaled steroid use in the active group. No serious adverse events were reported, and no subjects withdrew because of adverse events. CONCLUSION: The study has shown that SIT is effective and well tolerated in children with seasonal allergic asthma to grass pollen.

Single dose topical corticosteroid inhibits IL-5 and IL-13 in nasal lavage following grass pollen challenge.

BACKGROUND: Nasal lavage is a noninvasive method of obtaining inflammatory exudates following nasal allergen challenge (NAC), and permits cells and released mediators to be evaluated. OBJECTIVE: To determine the effects of a single dose of topical steroid on eosinophils and levels of chemokines and cytokines in nasal lavage fluid following NAC in patients with allergic rhinitis. METHODS: Patients with grass pollen seasonal allergic rhinitis (n = 32) out of the allergy season received either nasal budesonide (100 microg per nostril) or matched placebo before allergen challenge in a double blind two-way crossover design. A semi-automated mixed bead array system was employed to measure multiple chemokines and cytokines in small volumes (50 microl) of nasal lavage supernatants. RESULTS: Following NAC there was a rapid onset of nasal symptoms together with nasal eosinophilia, and the appearance of IL-5 and IL-13 in lavages between 4 and 8 h. Elevated levels of eotaxin, RANTES, IL-8 and MCP-1 were also detected following allergen challenge. A single dose of nasal budesonide caused a decrease in symptoms (P < 0.05) and nasal eosinophils (P < 0.05) with selective abrogation of IL-5 and IL-13 responses (P < 0.05), but a lack of effect on levels of eotaxin, RANTES, IL-8 and MCP-1. CONCLUSION: This study suggests that a single dose of nasal steroid has the capacity to selectively abolish IL-5 and IL-13 responses following NAC. This model should be convenient for testing novel anti-inflammatory and immunoregulatory agents intended for the treatment of allergic rhinitis.

Intratracheal instillation of cytoplasmic granules from Phleum pratense pollen induces IgE- and cell-mediated responses in the Brown Norway rat.

BACKGROUND: Release of cytoplasmic granules from grass pollen upon contact with water is thought to be an important source of airborne allergens. OBJECTIVES: To investigate the humoral and cellular responses to intratracheal instillation of Phleum pratense (timothy grass) pollen cytoplasmic granules (PCG) in the Brown Norway rat. METHODS: PCG were purified from timothy grass pollen by filtration through 5-microm-mesh filters. Rats were sensitized (day 0) and challenged (day 21) intratracheally with purified PCG suspended in saline (6 x 10(6) PCG/rat). Rats were then challenged 4 weeks later (1.5 x 10(6) PCG/rat). Blood samples, bronchial lymph nodes and lungs were collected from the rats 4 days after the second challenge. PCG-specific IgE and IgG1 levels and specificity were determined by ELISA and Western blotting. Pollen, pollen extract and PCG-induced proliferation of lymph node cells were monitored by [(3)H]-thymidine incorporation in a lymph node assay. Histopathological examination was carried out on the lungs. RESULTS: Specific IgE and IgG1 were present in the sera. Cultured lymph node cells proliferated in the presence of pollen, pollen extract and PCG. Western blots showed that all major pollen allergens are recognized by IgE and IgG1 from PCG-treated rats. Histopathological examination revealed features of a mild allergic reaction. CONCLUSIONS: In our rat model of allergy, purified timothy grass PCG instillation induced specific antibodies and lymph node cell responses, comparable to those obtained with intact pollen.