Tablet allergen immunotherapy: the anaphylaxis issue.

For the first time 15 years ago, tablet allergen immunotherapy (T-AIT) formulations were approved by regulatory agencies for treating allergic rhinitis caused by grass pollen in adults and children aged >5 years. Extensive evidences existed about effectiveness and safety of AIT. However, the safety profile is particularly compelling in children. Generally, T-AIT causes local reactions, mostly in the oral cavity, that are usually mild-to-moderate and often self-resolving. However, systemic allergic reactions are also observed with T-AIT, anaphylaxis representing the most fearsome adverse event, considering that it occurs in subjects treated for allergic rhinitis. Therefore, we conducted a literature search of patients reporting anaphylaxis because of T-AIT. Nine cases of anaphylactic reactions were reported in literature. Notably, no death was reported using T-AIT. This outcome was very important as it underscored the substantial safety of T-AIT. However, T-AIT deserves careful attention, mainly in the pediatric population. In this regard, after the first report of anaphylactic reaction at the first administration of T-AIT, manufacturers recommended that the first dose should be administered in a medical facility in the presence of staff with experience in managing anaphylaxis and the patient should be observed for at least 30 min. Interestingly, reported anaphylactic reactions were due to grass pollen extracts, with no report concerning other allergen extracts. However, it is relevant to note that anaphylactic reactions because of T-AIT are not reported in recent years.

Structural and Immunological Features of PR-10 Allergens: Focusing on the Major Alder Pollen Allergen Aln g 1.

Today, allergies have become a serious problem. PR-10 proteins are clinically relevant allergens that have the ability to bind hydrophobic ligands, which can significantly increase their allergenicity potential. It has been recently shown that not only the birch pollen allergen Bet v 1 but also the alder pollen allergen Aln g 1, might act as a true sensitizer of the immune system. The current investigation is aimed at the further study of the allergenic and structural features of Aln g 1. By using qPCR, we showed that Aln g 1 was able to upregulate alarmins in epithelial cells, playing an important role in sensitization. With the use of CD-spectroscopy and ELISA assays with the sera of allergic patients, we demonstrated that Aln g 1 did not completely restore its structure after thermal denaturation, which led to a decrease in its IgE-binding capacity. Using site-directed mutagenesis, we revealed that the replacement of two residues (Asp27 and Leu30) in the structure of Aln g 1 led to a decrease in its ability to bind to both IgE from sera of allergic patients and lipid ligands. The obtained data open a prospect for the development of hypoallergenic variants of the major alder allergen Aln g 1 for allergen-specific immunotherapy.

[Initial study of trap and identification of environmental pollens and fungi spores in Samborondon, Ecuador]. / Estudio inicial de captación e identificación de pólenes y hongos ambientales en Samborondón, Ecuador.

OBJETIVO: To identify and registry the most important aeroallergens trapped at the aerobiology station in the city of Samborondon, Ecuador. METHODS: Pollen grains and fungal spore counts were performed according to the standardized technique with a Hirst-type collection equipment, Burkard spore trap for seven days, following the recommendations of the National Allergy Bureau (NAB) of the American Academy of Allergy Asthma and Immunology (AAAAI). The equipment was installed on the roof of the Universidad de Especialidades Espiritu Santo (UEES), 25 m above ground level, coordinates: 2°07 ́57 ́ ́S 79°52 ́06 ́ ́W, in the city of Samborondon. The sampling period was performed from November 2022 to April 2023. RESULTS: We identified the following pollen families: Poaceae (258 grains/m3), Apocynaceae (Plumeria rubra pc) (214 grains/m3), Lamiaceae (180 grains/m3), Asteraceae Ambrosía spp.- (60 grains/m3), Chenopodiacea (27 grains/m3), Myrtaceae (17 grains/m3), Pinaceae (11 grains/m3), Betulaceae (7 grains/m3). Also identified fungical spores: Fuzariella spp./Leptosphaeria spp. (1899/m3), Cladosporium spp. (1407/m3), Nigrospora spp. (1183/m3), Dreschlera/Helmintosporum spp. (329/m3), Alternaria spp. (98/m3), Pithomyces spp. (79/m3), Curvularia spp. (48/m3), Stemphylium spp. (46/m3). CONCLUSIONS: We reported the first study of aerobiology (capture and identification of environmental pollens and fungi) in the city of Samborondon. The inhabitants of this area are exposed to different aeroallergens with a predominance of Poaceaes pollen and Fuzzariella spp./Leptosphaeria spp. spores. The identified allergens should be part of the usual allergy studies. The results of this first preliminary study should be compared with information from the forthcoming years, which will help to identify variations in the concentration of seasonal aeroallergens, annual fluctuations, and extend the traps to other parts of the city.

OBJETIVO: Identificar y registrar los aeroalérgenos más importantes captados en la estación de aerobiología en la ciudad de Samborondón, Ecuador. MÉTODOS: Los conteos de granos de polen y esporas de hongos se realizaron según la técnica estandarizada, con un equipo colector tipo Hirst, Burkard spore trap for seven days, siguiendo las recomendaciones de la National Allergy Bureau (NAB) de la American Academy Allergy Asthma and Immunology (AAAAI). El equipo se instaló en la azotea de la Universidad Espíritu Santo (UEES), en la ciudad de Samborondón, a 25 m de altura desde el nivel del suelo, 2°07´57´´S 79°52´06´´O. El periodo de captación se llevó a cabo entre noviembre de 2022 y abril de 2023. RESULTADOS: Identificamos las siguientes familias polínicas: Poaceae (258 granos/m3), Apocynaceae (Plumeria rubra pc) (214 granos/m3), Lamiaceae (180 granos/m3), Asteraceae Ambrosía spp.- (60 granos/m3), Chenopodiacea (27 granos/m3), Myrtaceae (17 granos/m3), Pinaceae (11 granos/m3), Betulaceae (7 granos/m3). Además esporas fúngicas: Fuzariella spp./Leptosphaeria spp. (1899/m3), Cladosporium spp. (1407/m3), Nigrospora spp. (1183/m3), Dreschlera/Helmintosporum spp. (329/m3), Alternaria spp. (98/m3), Pithomyces spp. (79/m3), Curvularia spp. (48/m3), Stemphylium spp. (46/m3). CONCLUSIONES: Se reporta el primer estudio de aerobiología (captación e identificación de pólenes y hongos ambientales), en la ciudad de Samborondón. Los habitantes de esta zona están expuestos a diferentes aeroalérgenos con predominancia al polen de Poaceaes y esporas de Fuzzariella spp./Leptosphaeria spp. Los alérgenos identificados deberían formar parte de los estudios alergológicos habituales. Los resultados de este primer estudio preliminar deberían ser comparados con información de los siguientes años para ayudar a identificar las variaciones de concentración de aeroalérgenos estacionales, las fluctuaciones anuales, y extender los captadores a otros puntos de la ciudad.

[Aerobiological study in Lima, Perú. ¿Tipuana-Tipu, perhaps a new allergen?] / Estudio aerobiológico en Lima, Perú. ¿Tipuana-Tipu, tal vez un nuevo alérgeno?

OBJECTIVE: To report the Tipuana tipu pollen as a new allergen capable of triggering allergic symptoms. METHODS: The pollen counts were made according to standardized technique with a Burkard seven days following the European Aerobiology Society´s Network Group recommendations.1 The trap was installed on the roof of Clinica SANNA, El Golf, San Isidro, which is 20 m high, 12°5'54"S 77°3'6"W in the west-south of the Lima urban area. The sampling period was performed from September 2020 to October 2021. Collection of Tipuana tipu pollens and Preparation of Tipuana tipu pollen extracts 1:20 w/v was done using a previously described method.2 We carried out systematic skin prick testing with Tipuana tipu pollen extract and other aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis), molds (Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Penicillium notatum), cat and dog danders, Periplaneta americana, grass six mix, weed mix (Inmunotek, Spain) on 80 patients (18 to 50 years old) seen in our allergy center, they suffering from november to january rhinitis and/or conjunctivitis symptoms. The majority living near avenues and large green areas, where Tipuana trees grew. RESULTS: We found a total of 952 grains/m3 of Tipuana tipu pollen between November 2020 to january 2021, with the maximum concentration of 37 grains/m3 on December 10th. We also found other airborne pollen Types: Poaceae, Myrtaceae, Compositae and Betulaceae. 14/80 patients (17,5%) showed positive skin prick test only to Tipuana tipu extract. Most of the patients with positive tests to Tipuana extract presented symptoms of rhinoconjunctivitis during the Tipuana pollination period. Four patients showed positive skin prick test to Tipuana tipu and grass 6 mix extracts, most of the rest of our patients were sensitized to dust mites' extracts (Dermatophagoides pteronyssinus). CONCLUSIONS: The west-south population of Lima urban city is exposed to Tipuana tipu pollen. We do not foud previous publications about Tipuana tipu allergy. Almost 18% of the patients tested in our sample were mono-sensitized to this pollen. The results of this study should be compared with data from the forthcoming years, to identify seasonal and annual fluctuations, extend the traps to other locations in Lima, and of course try to standardize and improve the Tipuana tipu pollen extract.

OBJETIVO: Reportar al polen de Tipuana tipu como un nuevo alérgeno capaz de desencadenar síntomas alérgicos. MÉTODOS: Los conteos de polen se realizaron según la técnica estandarizada con un equipo colector tipo Hirst, Burkard spore trap for seven days, siguiendo las recomendaciones del grupo de la Red Europea de Sociedades de Aerobiología1. El equipo se instaló en la azotea de la Clínica SANNA El Golf, San Isidro, a 20 m de altura desde el nivel del suelo, 12°5'54"S 77°3'6"O en la zona suroeste del área urbana de Lima. El periodo de captación se llevó a cabo entre septiembre de 2020 y octubre de 2021. La recolección de granos de polen de Tipuana tipu, y la preparación del extracto alergénico (peso/volumen) 1:20 p/v, se realizó usando metodología previamente descrita2. Se realizaron estudios de pruebas cutáneas (skin prick test), en 80 pacientes (entre 18 y 50 años), con sintomatología de rinoconjuntivitis; referían, además, mayor intensidad de sus síntomas entre noviembre y enero. La mayoría de pacientes dijeron vivir cerca a avenidas y parques donde había árboles de Tipuana tipu. Fueron evaluados en el servicio de Alergología de la Clínica SANNA, El Golf, San Isidro. Se aplicaron extractos de polen de Tipuana tipu, y otros aeroalérgenos como ácaros del polvo (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis), hongos ambientales (Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Penicillium notatum), epitelios de gato y perro, Periplaneta americana, mezclas de seis gramíneas, mezclas de malezas (Inmunotek, España). RESULTADOS: Encontramos un total de 952 granos/m3 de polen de Tipuana tipu entre noviembre de 2020 y enero de 2021; con la máxima concentración de 37 granos/m3 el 10 de diciembre. También identificamos otras familias polínicas: Poaceae, Myrtaceae, Compositae y Betulaceae. 14/80 pacientes (el 17,5%), resultaron positivos solo al extracto de Tipuana tipu, en el skin prick test. La mayoría de los pacientes con resultado positivo al extracto de Tipuana tipu referían síntomas de rinoconjuntivitis durante el periodo de polinización de los árboles de Tipuana. Cuatro pacientes tuvieron positividad al extracto de Tipuana tipu, y al extracto en mezcla de seis gramíneas; la mayoría del resto de pacientes mostraron sensibilidad a ácaros del polvo doméstico (Dermatophagoides pteronyssinus). CONCLUSIONES: Los habitantes de la zona suroeste de la ciudad urbana de Lima están expuestos al polen de Tipuana tipu. No hemos encontrado publicaciones previas sobre alergia a este tipo de polen. Casi un 18% de pacientes estudiados en nuestra muestra, estuvieron monosensibilizados al extracto del polen de Tipuana tipu. Los resultados de este estudio deberían ampliarse y ser comparados con data en los años siguientes, identificar fluctuaciones estacionales y anuales, extender los captadores a otras locaciones en Lima, y por supuesto, intentar estandarizar y mejorar el extracto del polen de Tipuana Tipu.

[Identification and sensitization to environmental fungal spores in Lima City, Peru]. / Identificación y sensibilización a hongos ambientales en Lima, Perú.

OBJECTIVE: To identify and registry the most important fungal spores trapped in our aerobiology station, as well as to report the prevalence of skin sensitization to these allergens. METHODS: The pollen counts were made according to standardized technique with a Burkard seven days spore trap, following the American Academy of Allergy, Asthma and Immunology (AAAAI) through National Allergy Bureau (NAB) recommendations. The trap was installed on the roof of Clinica SANNA, El GOLF, San Isidro, which is 20 m high, 12°5'54"S 77°3'6"W in the west-south of the Lima urban area. The sampling period was performed from September 2020 to October 2021. Skin prick tests were carried out according to the recommendations of the Spanish Society of Allergology and Clinical Immunology (SEAIC) in 200 patients (18 to 60 years old) with symptoms of rhinoconjunctivitis and/or asthma, who were evaluated in the Allergology Service of Clinica SANNA el Golf. Allergenic extracts were applied, dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis), cat and dog danders, cockroach (Periplaneta americana), grass 6 mix, weed mix, molds (Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Penicillium notatum, Nigrospora spp.), INMUNOTEK-Spain provided the extracts. We also tested other fungal allergens such as Fusarium spp, Stemphylium spp, Curvularia spp, a mixture of Helmintosporum/Dreschlera spp. from the DIATER-Argentina laboratory. RESULTS: We identified spores of Alternaria alternata, Cladosporium spp., Nigrospora spp., Stemphylium spp., Fusarium spp., Curvularia spp., Dreschlera/Helmintosporum spp. The patients showed sensitization to Cladosporium herbarum (14%), Fusarium spp. (13,5%), Nigrospora spp. (8%), Alternaria Alternata (7%), Stemphylium (6%), Dreschlera/Helmintosporium spp. (5,5%), Curvularia spp. (3%), Aspergillus fumigatus (2,5%). CONCLUSIONS: The inhabitants of the south-western area of the urban city of Lima are exposed to different fungal spores with allergenic potential, with a higher concentration being identified during the summer/autumn months. Cutaneous sensitization is demonstrated in variable percentages to the fungal spores identified in this aerobiological sampling. The results of this study should be expanded and compared with data in the forthcoming years, identify seasonal and annual fluctuations and extend the traps to other locations in Lima.

OBJETIVO: Identificar y registrar las esporas de hongos más importantes captadas en nuestra estación de aerobiología, además reportar la prevalencia de sensibilización cutánea a estos alérgenos. MÉTODOS: La identificación y los conteos de esporas de hongos se realizaron según la técnica estandarizada con un equipo colector Burkard Spore Trap For Seven Days, siguiendo las recomendaciones de la National Allergy Bureau (NAB), de la American Academy Allergy Asthma and Immunology (AAAAI). El equipo se instaló a 20 m de altura desde el nivel del suelo, en la azotea de la Clínica SANNA El Golf, distrito de San Isidro, (12°5'54"S 77°3'6"O), en la zona sur-oeste del área urbana de Lima. El periodo de captación se llevó a cabo entre septiembre de 2020 y octubre de 2021. Se realizaron estudios de pruebas cutáneas (skin prick-test), según recomendaciones de la Sociedad Española de Alergología e Inmunología Clínica (SEAIC), en 200 pacientes (entre 18 y 60 años), con sintomatología de rinoconjuntivitis y/o asma. Fueron evaluados en el servicio de Alergología de la Clínica SANNA El Golf. Se aplicaron extractos alergénicos de ácaros del polvo (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis), epitelios de gato y perro, Periplaneta americana, mezclas de seis gramíneas, mezclas de malezas, hongos ambientales (Cladosporium herbarum, Alternaria alternata, Aspergillus fumigatus, Penicillium notatum, Nigrospora spp.), extractos del laboratorio INMUNOTEK-España. Además, testeamos otros alérgenos fúngicos de Fusarium spp, Stemphylium spp, Curvularia spp, una mezcla de Helmintosporum/Dreschlera spp. del laboratorio DIATER-Argentina. RESULTADOS: Identificamos esporas de Alternaria alternata, Cladosporium spp., Nigrospora spp., Stemphylium spp., Fusarium spp., Curvularia spp., Dreschlera/Helmintosporum spp. Los pacientes mostraron sensibilización a Cladosporium herbarum (14%), Fusarium spp. (13,5%), Nigrospora spp. (8%), Alternaria Alternata (7%), Stemphylium (6%), Dreschlera/Helmintosporium spp. (5,5%), Curvularia spp. (3%) y Aspergillus fumigatus (2,5%). CONCLUSIONES: Los habitantes de la zona sur-oeste de la ciudad urbana de Lima están expuestos a distintas esporas de hongos con potencial alergénico, identificándose mayor concentración durante los meses de verano y otoño. Se demuestra sensibilización cutánea en porcentajes variables a las esporas fúngicas identificadas en este muestreo aerobiológico. Los resultados de este estudio deberían ampliarse y ser comparados con data en los años siguientes, identificar fluctuaciones estacionales y anuales y extender los captadores a otras locaciones en Lima.

Acute exposure to pollen and airway inflammation in adolescents.

INTRODUCTION: Pollen exposure is known to exacerbate allergic asthma and allergic rhinitis symptoms, yet few studies have investigated if exposure to pollen affects lung function or airway inflammation in healthy children. METHODS: We evaluated the extent to which higher pollen exposure was associated with differences in airway inflammation and lung function among 490 early adolescent participants (mean age of 12.9 years) in Project Viva, a prebirth cohort based in Massachusetts. We obtained regional daily total pollen counts, including tree, grass, and weed pollen, from a Rotorod pollen counter. We evaluated associations of 3- and 7-day moving averages of pollen with fractional exhaled nitric oxide (FeNO) and lung function using linear regression models and evaluated the linearity of associations with penalized splines. We tested if associations of pollen with FeNO and lung function were modified by current asthma diagnosis, history of allergic rhinitis, aeroallergen sensitivity, temperature, precipitation, and air pollution. RESULTS: Three- and 7-day median pollen concentrations were 19.0 grains/m3 (IQR: 73.4) and 20.9 grains/m3 (IQR: 89.7). In main models, higher concentrations of total pollen over the preceding 3 and 7 days were associated with a 4.6% (95% CI: 0.1,9.2) and 7.4% (95% CI: 0.9,14.3) higher FeNO per IQR of pollen, respectively. We did not find associations of pollen with lung function in main models. Asthma, allergic rhinitis, precipitation, and air pollution (nitrogen dioxide and ozone) modified associations of pollen with lung function (Pinteraction < 0.1), while temperature, sex, and aeroallergen sensitization did not. CONCLUSION: Short-term exposure to pollen was associated with higher FeNO in early adolescents, even in the absence of allergic sensitization and asthma.

M2 Macrophages Upregulated by Allergen Exposure in Seasonal Allergic Rhinitis.

INTRODUCTION: Macrophages play a central role in balancing the immune response by switching phenotypes between the M1 and M2 profiles according to a delicate equilibrium. Based on a previous clinical trial (NCT03649139), this study aimed to evaluate the change in M2 macrophages during pollen exposure in seasonal allergic rhinitis (SAR). METHODS: Nasal symptom scores were recorded. Peripheral M2 macrophages were investigated according to cell surface markers, and M2-associated cytokine/chemokine release in serum and nasal secretion were assessed. In vitro pollen stimulation tests were performed, and polarized macrophage subsets were analyzed by flow cytometry. RESULTS: Compared to baseline, the percentage of peripheral CD163+ M2 macrophages in CD14+ monocytes increased during the pollen season (p < 0.001) and at the end of treatment (p = 0.004) in the SLIT group. The percentage of CD206+CD86- M2 cells in M2 macrophages during the pollen season was higher than that at baseline and at the end of SLIT. On the other hand, the percentage of CD206-CD86+ M2 cells in M2 macrophages significantly increased at the end of treatment in the SLIT group compared to baseline (p = 0.049), the peak pollen period (p = 0.017), and the placebo group (p = 0.0023). M2-associated chemokines CCL26 and YKL-40 were significantly increased during the pollen season in the SLIT group and remained higher at the end of SLIT than at baseline. Correspondingly, in vitro study demonstrated that Artemisia annua promoted M2 macrophage polarization in pollen-induced AR patients. CONCLUSION: Significant M2 macrophage polarization was promoted when patients with SAR were exposed to the allergen, either naturally exposed in pollen seasons or subjectively continuously exposed during the course of SLIT.

Ex Vivo Immunomodulatory Effects of Lactobacillus-, Lacticaseibacillus-, and Bifidobacterium-Containing Synbiotics on Human Peripheral Blood Mononuclear Cells and Monocyte-Derived Dendritic Cells in the Context of Grass Pollen Allergy.

Sensing of the intestinal microbiota by the host immune system is important to induce protective immune responses. Hence, modification of the gut microbiota might be able to prevent or treat allergies, mediated by proinflammatory Th2 immune responses. The aim was to investigate the ex vivo immunomodulatory effects of the synbiotics Pollagen® and Kallergen®, containing the probiotic bacterial strains Lactobacillus, Lacticaseibacillus and Bifidobacterium, in the context of grass pollen allergy. Peripheral blood mononuclear cells (PBMCs) from grass pollen-allergic patients and healthy controls were stimulated with grass pollen extract (GPE) and synbiotics and Gata3 expression and cytokine secretion analyzed. Monocyte-derived dendritic cells (MoDCs) cells were matured in the presence of GPE and synbiotics, co-cultured with autologous naïve T cells and maturation markers and cytokine secretion analyzed. GPE stimulation of PBMCs from grass pollen-allergic patients resulted in a significant higher production of the Th2 cytokines IL-4, IL-5, IL-9 and IL-13 compared to healthy controls. Gata3+CD4+ T cell induction was independent of the allergic status. The synbiotics promoted IL-10 and IFN-γ secretion and downregulated the GPE-induced Th2-like phenotype. Co-culturing naïve T cells with MoDCs, matured in the presence of GPE and synbiotics, shifted the GPE-induced Th2 cytokine release towards Th1-Th17-promoting conditions in allergic subjects. The investigated synbiotics are effective in downregulating the GPE-induced Th2 immune response in PBMCs from grass pollen-allergic patients as well as in autologous MoDC-T cell stimulation assays. In addition to increased IL-10 release, the data indicates a shift from a Th2- to a more Th1- and Th17-like phenotype.

Efficacy and safety of sublingual versus subcutaneous immunotherapy in children with allergic rhinitis: a systematic review and meta-analysis.

Aim: To systematically compare the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in children with allergic rhinitis (AR). Methods: PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to March 2, 2023. Outcomes included symptom scores (SSs), medication scores (MSs), symptom and medication scores (SMSs), new sensitizations, development of asthma, improvement, and treatment-related adverse events (TRAEs). The quality of the included studies was assessed by the modified Jadad scale and Newcastle-Ottawa scale (NOS). Meta-regression was carried out to explore the source of heterogeneity. Subgroup analysis was further conducted in terms of study design [randomized controlled trials (RCTs), cohort studies], allergen [house dust mites (HDMs), grass pollen], treatment duration (≥ 24, 12-23 or < 12 months), allergen immunotherapy (AIT) modality (drops or tablets), and AIT protocol [continuous, pre-seasonal, co-seasonal, or after the grass pollen season (GPS)]. Sensitivity analysis was conducted for all outcomes. A Bayesian framework and a Monte Carlo Markov Chain (MCMC) model were developed for indirect comparison. Results: Totally 50 studies with 10813 AR children were included, with 4122 treated with SLIT, 1852 treated with SCIT, and 4839 treated with non-SLIT or non-SCIT therapy. For direct comparison, the SLIT group had a similar SS to the SCIT group [pooled standardized mean difference (SMD): 0.41, 95% confidence interval (CI): -0.46, 1.28, P = 0.353]. Comparable MSs were observed in the SLIT and SCIT groups (pooled SMD: 0.82, 95%CI: -0.88, 2.53, P = 0.344). For indirect comparison, no significant differences were found in SSs (pooled SMD: 1.20, 95% credibility interval (CrI): -1.70, 4.10), MSs (pooled SMD: 0.57, 95%CrI: -1.20, 2.30), SMSs (pooled SMD: 1.80, 95%CrI: -0.005, 3.60), new sensitizations [pooled relative risk (RR): 0.34, 95%CrI: 0.03, 3.58], and development of asthma (pooled RR: 0.68, 95%CrI: 0.01, 26.33) between the SLIT and SCIT groups; the SLIT group illustrated a significantly lower incidence of TRAEs than the SCIT group (pooled RR: 0.17, 95%CrI: 0.11, 0.26). Conclusion: Considering both efficacy and safety, SLIT might be a more favorable AIT than SCIT in the treatment of pediatric AR, which may serve as a decision-making reference for clinicians. Systematic review registration: PROSPERO (CRD42023460693).

Allergen Profile of London Plane Tree Pollen: Clinical and Molecular Pattern in Central Spain

Background: Platanus acerifolia (London plane tree) is a deciduous tree of the Platanaceae family. Sensitization to this plant varies withgeography. Madrid, located in central Spain, has one of the highest London plane tree pollen concentration levels on the Iberian Peninsula.Objectives: We evaluated both the clinical characteristics and the molecular sensitization pattern of patients with allergy to London planetree pollen in the region of Madrid.Patients and Methods: Thirty-eight patients allergic to London plane tree pollen were selected according to their clinical symptoms andpositive results in skin prick testing and/or specific IgE determination. Serum was collected, and allergen components were evaluatedusing immunodetection techniques as well as ImmunoCAP. The IgE-binding proteins detected were identified and characterized usingmass spectrometry.Results: Analysis of serum samples from allergic patients revealed 9 IgE-binding bands in London plane tree pollen extract. Among these,the 45-kDa protein, which corresponded to Pla a 2, was detected in 76.3% of patients. However, the 18-kDa (Pla a 1) and 9-kDa (Pla a 3)bands were detected in 44.7% and 23.7% of sera, respectively. These results were confirmed using purified proteins. Characterization ofthe allergen revealed the 27-kDa protein to be glutathione-S-transferase.Conclusions: The molecular profile of patients sensitized to London plane tree pollen differs from that reported in studies from otherlocations. In the population we studied, the prevalence of Pla a 2 was higher than that of Pla a 1 and Pla a 3. In addition, the minorallergen previously referred to as Pla a 4 was characterized as glutathione-S-transferase. (AU)

Antecedentes: Platanus acerifolia es un árbol de hoja caduca de la familia Platanaceae. La sensibilización frente a esta planta varía enfunción de la zona geográfica. Madrid, ubicada en el centro de España, tiene uno de los mayores niveles de concentración de polen deeste árbol en la Península Ibérica.Objetivo: Evaluar las características clínicas y los patrones moleculares de sensibilización en pacientes con alergia al plátano de sombraen la región de Madrid.Pacientes y Métodos: Treinta y ocho pacientes alérgicos al polen del plátano de sombra fueron seleccionados de acuerdo con los síntomasclínicos, pruebas cutáneas positivas y/o IgE específica. El suero se recogió y se evaluaron los componentes alérgicos mediante técnicas deinmunodetección, así como ImmunoCAP. Las proteínas que unían IgE fueron identificadas y caracterizadas por espectrometría de masas.Resultados: El análisis de los sueros de los pacientes alérgicos reveló 9 bandas que captaban IgE en los extractos de polen de plátano desombra. Entre estas, la proteína de 45 kDa, correspondiente a Pla a 2, se detectó en el 76,3% de los pacientes. Sin embargo, las bandasde 18 kDa (Pla a 1) y 9 kDa (Pla a 3) fueron reconocidas en el 44,7% y 27,3%, respectivamente. Estos resultados se confirmaron usandoproteínas purificadas. La caracterización de los alérgenos identificó la proteína de 27 kDa como una glutatión S-transferasa.Conclusiones: El perfil molecular de los pacientes sensibilizados al polen del plátano de sombra varía respecto al descrito en estudios deotras localizaciones. Nuestra población muestra una mayor prevalencia de Pla a 2 comparado con Pla a 1 y Pla a 3. Además, el alérgenominoritario previamente denominado Pla a 4 fue caracterizado como una glutatión-S-transferasa. (AU)

Eosinophilic Esophagitis due to Aeroallergens: A Systematic Review and Update

Eosinophilic esophagitis is a chronic antigen-mediated esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by TH2 inflammation (at least 15 eosinophils/high power field) when other secondary systemic and local causes of esophageal eosinophilia are excluded. Although this disease was initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that aeroallergens may also play a role in pathogenesis and disease course. Some studies support seasonal variations in the diagnosis of eosinophilic esophagitis and disease exacerbations owing to the increase in aeroallergens to which patients are sensitized. It is also known that this disease can be caused by extensive, identifiable exposure to aeroallergens and after treatment with specific immunotherapy based on food or aeroallergens. It was recently postulated that treatment of allergic rhinoconjunctivitis can improve the symptoms of eosinophilic esophagitis, although data are limited to case reports and small series. Currently, biomarkers and biologic therapies are not helpful for diagnosis or inducing clinical and histological remission of the disease. Nevertheless, there are high hopes for dupilumab. This review aims to give visibility to the involvement of aeroallergens in the triggering and exacerbation of eosinophilic esophagitis, since many of them, in addition to being airborne and inhalant, can also be ingested as food. Clearly, we must try to identify the cause of the disease to ensure remission. (AU)

Allergenicity to worldwide invasive grass Cortaderia selloana as environmental risk to public health.

Allergies to grass pollen affects about 20% of the population worldwide. In the last few decades, the South American grass Cortaderia selloana (CS, Pampas grass) has expanded worldwide in a variety of countries including the USA, Australia and Western Europe. In many of these locations, CS has strikingly spread and has now been classified an invasive species. Many pernicious consequences of CS have been reported for local biodiversity, landscape and structures. However, the effect on human health has not been studied. To investigate this issue, we have chosen a European region on the northern cost of Spain where CS spread is overwhelming, Cantabria. We obtained CS pollen extract and analysed the allergenic reaction of 98 patients that were allergic to pollen of local grasses. We determined the skin reaction and the presence of specific IgE antibodies (sIgE) to CS or to a typical autochthonous grass, Phleum pratense. We also compared the seasonal symptoms with reported grass pollen counts in the area. The results strongly suggest that CS can cause respiratory allergies at a similar extent to the local grasses. Given that CS pollinises later than the local grasses, this would extend the period of grass allergies in the region for about three months every year, as stated by most of the patients. This is the first study reported on the effects of the striking expansion of CS on human health. Considering the strong impact that respiratory allergies have on the population, our results suggest that CS can currently constitute a relevant environmental health issue.

The Relationship between Aeroallergen Sensitization and Chronic Cough in School-Aged Children from General Population.

OBJECTIVE: Determining sensitivity to allergens is an essential step in diagnosing children with allergic diseases. Chronic cough has remained poorly understood with causative triggers. The purpose of our study was to shed light on the relationship between sensitization to aeroallergens and chronic cough. METHODS: This population-based study examined children (aged 7 years to 13 years) between June and July 2016. The 1,259 children, 72 of whom (5.7%) had a chronic cough, and 1,187 of whom (94.3%) did not (controls), completed the questionnaire, but 1,051 children completed skin prick tests (SPTs) with eight aeroallergens. RESULTS: There were positive SPT results to at least 1 allergen in 549 children (52.2%). Sensitization to house dust mite (HDM) was most common (chronic cough = 46.9%; controls = 47.2%), followed by pollen (chronic cough = 21.9%; controls = 16.5%) in both groups, but there was no difference in allergic profile and sensitization to aeroallergen (P > 0.05 for all comparisons). Multivariable analysis with adjustment for confounding indicated that children who were in sensitization to pollen had an increased risk of chronic cough (aOR = 2.387; 95% CI: 1.115 to 5.111; P = 0.025). Multivariable analysis with adjustment for confounding indicated that children who were exposed to current smoking (aOR = 4.442; 95% CI: 1.831 to 10.776; P = 0.001) and mold (aOR = 1.988; 95% CI: 1.168 to 3.383; P = 0.011) were associated with chronic cough. CONCLUSION: Sensitization to pollen should be considered as a potential contributing factor to the development of chronic cough in school-aged children.

Does the reaction size of skin prick test associated with the allergic rhinitis symptom severity?

BACKGROUND: Skin prick test (SPT) has the best positive predictive value to diagnose respiratory atopic diseases, including allergic rhinitis (AR), but the association of severity of allergic symptom and SPT reaction size has not been clearly determined yet. METHODS: In this a cross- sectional investigation, the severity of disease is classified using a visual analog scale for main symptoms, and SPT was conducted according to the principles of the European Academy of Allergy and Clinical Immunology. RESULTS: Thirty seven percent of the participants had at least one severe symptom. Patients with sensitivity to Alternaria (common allergens in humans) or tree pollens had more severe symptoms. We found that in patients who had sensitivity to Russian thistle pollen, wheal size >6 mm, was associated with more severe symptoms. CONCLUSION: Despite previous conflicts to rely on SPT test for starting immunotherapy, we recommend this test especially for patients sensitive to Alternaria, weed pollens, and tree pollens, considering the size of wheal in association with AR symptom severity.

Dosing intact birch pollen grains at the air-liquid interface (ALI) to the immortalized human bronchial epithelial cell line BEAS-2B.

In real life, humans are exposed to whole pollen grains at the air epithelial barrier. We developed a system for in vitro dosing of whole pollen grains at the Air-Liquid Interface (ALI) and studied their effect on the immortalized human bronchial epithelial cell line BEAS-2B. Pollen are sticky and large particles. Dosing pollen needs resuspension of single particles rather than clusters, and subsequent transportation to the cells with little loss to the walls of the instrumentation i.e. in a straight line. To avoid high speed impacting insults to cells we chose sedimentation by gravity as a delivery step. Pollen was resuspended into single particles by pressured air. A pollen dispersion unit including PTFE coating of the walls and reduced air pressure limited impaction loss to the walls. The loss of pollen to the system was still about 40%. A linear dose effect curve resulted in 327-2834 pollen/cm2 (± 6.1%), the latter concentration being calculated as the amount deposited on epithelial cells on high pollen days. After whole pollen exposure, the largest differential gene expression at the transcriptomic level was late, about 7 hours after exposure. Inflammatory and response to stimulus related genes were up-regulated. We developed a whole pollen exposure air-liquid interface system (Pollen-ALI), in which cells can be gently and reliably dosed.