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Background Childhood hospitalization related to asthma remains at historically high levels, and its incidence is on the rise world-wide. Previously, we have demonstrated that aldose reductase (AR), a regulatory enzyme of polyol pathway, is a major mediator of allergen-induced asthma pathogenesis in mouse models. Here, using AR null (AR -/- ) mice we have investigated the effect of AR deficiency on the pathogenesis of ragweed pollen extract (RWE)-induced allergic asthma in mice and also examined the efficacy of enteral administration of highly specific AR inhibitor, fidarestat. Methods The wild type (WT) and AR -/- mice were sensitized and challenged with RWE to induce allergic asthma. AR inhibitor, fidarestat was administered orally. Airway hyper-responsiveness was measured in unrestrained animals using whole body plethysmography. Mucin levels and Th2 cytokine in broncho-alveolar lavage (BAL) were determined using mouse anti-Muc5A/C ELISA kit and multiplex cytokine array, respectively. Eosinophils infiltration and goblet cells were assessed by H&E and periodic acid Schiff (PAS)-staining of formalin-fixed, paraffin-embedded lung sections. T regulatory cells were assessed in spleen derived CD4 + CD25 + T cells population. Results Deficiency of AR in mice led to significantly decreased PENH, a marker of airway hyper-responsiveness, metaplasia of airway epithelial cells and mucus hyper-secretion following RWE-challenge. This was accompanied by a dramatic decrease in infiltration of eosinophils into sub-epithelium of lung as well as in BAL and release of Th2 cytokines in response to RWE-challenge of AR -/- mice. Further, enteral administration of fidarestat significantly prevented eosinophils infiltration, airway hyper-responsiveness and also markedly increased population of T regulatory (CD4 + CD25 + FoxP3 + ) cells as compared to RWE-sensitized and challenged mice not treated with fidarestat. Conclusion Our results using AR -/- mice strongly suggest the role of AR in allergic asthma pathogenesis and effectiveness of oral administration of AR inhibitor in RWE-induced asthma in mice supports the use of AR inhibitors in the treatment of allergic asthma.

The topic of ragweed pollen (RW) versus house dust mites (HDMs) has often been deliberated, but the increasing incidence of co-sensitization between them has been scarcely addressed. Utilizing Sprague Dawley rats, we explored the effects of co-sensitization with the combination of HDMs and RW pollen extracts in correlation with high-fructose diet (HFrD) by in vitro tracheal reactivity analysis in isolated organ bath and biological explorations. Our findings unveiled interrelated connections between allergic asthma, dyslipidemia, and HFrD-induced obesity, shedding light on their compounding role through inflammation. The increased CRP values and airway hyperresponsiveness to the methacholine challenge suggest a synergistic effect of obesity on amplifying the existing inflammation induced by asthma. One of the major outcomes is that the co-sensitization to HDMs and RW pollen led to the development of a severe allergic asthma phenotype in rats, especially in those with HFrD. Therefore, the co-sensitization to these allergens as well as the HFrD may play a crucial role in the modulation of systemic inflammation, obesity, and airway reactivity.

Background: Allergic rhinitis and allergic asthma are respiratory tract diseases predominantly triggered by allergens such as pollens, house dust mite, mold etc. The prevalence of respiratory allergens varies according to geographic location. Ragweed (Ambrosia artemisiifolia), a prevalent weed particularly in South America and Europe, is being investigated for its sensitization frequency in the Black Sea region of our country. This study aims to evaluate ragweed and other allergens associated with respiratory allergic diseases in this region and determine their disease frequency. Materials and methods: A retrospective analysis was performed on patients diagnosed with allergic rhinitis, conjunctivitis, and asthma who attended the Immunology and Allergy outpatient clinic at Samsun Training and Research Hospital between 2017 and 2024. Data from 3,000 diagnosed patients were examined. Results: Of the 3,000 patients, 2,124 (70%) were female and 876 (30%) were male. All patients were diagnosed with allergic rhinitis, while conjunctivitis was observed in 2,300 patients (76%), and asthma was diagnosed in 1,382 patients (46.6%). The most frequently detected allergen was house dust mite (75%). Ragweed pollen was identified as the most common cause of seasonal allergic rhinitis (15%). Moreover, ragweed pollen was found to be the allergen associated with the highest risk of asthma development (p-value: 6.69 × 10−52). Conclusion: Ragweed pollen allergy is common in our region, and the allergenicity load is high. The sensitization rate may increase over time. If the prevalence is determined accurately, appropriate preventive measures and treatments can be developed.

Common ragweed pollen allergy has become a health burden worldwide. One of the major allergens in ragweed allergy is Amb a 1, which is responsible for over 90% of the IgE response in ragweed-allergic patients. The major allergen isoform Amb a 1.01 is the most allergenic isoform in ragweed pollen. So far, no recombinant Amb a 1.01 with similar allergenic properties to its natural counterpart (nAmb a 1.01) has been produced. Hence, this study aimed to produce a recombinant Amb a 1.01 with similar properties to the natural isoform for improved ragweed allergy management. Amb a 1.01 was expressed in insect cells using a codon-optimized DNA construct with a removable N-terminal His-Tag (rAmb a 1.01). The recombinant protein was purified by affinity chromatography and physicochemically characterized. The rAmb a 1.01 was compared to nAmb a 1.01 in terms of the IgE binding (enzyme-linked immunosorbent assay (ELISA), immunoblot) and allergenic activity (mediator release assay) in well-characterized ragweed-allergic patients. The rAmb a 1.01 exhibited similar IgE reactivity to nAmb a 1.01 in different IgE-binding assays (i.e., IgE immunoblot, ELISA, quantitative ImmunoCAP inhibition measurements). Furthermore, the rAmb a 1.01 showed comparable dose-dependent allergenic activity to nAmb a 1.01 regarding basophil activation. Overall, the results showed the successful expression of an rAmb a 1.01 with comparable characteristics to the corresponding natural isoform. Our findings provide the basis for an improvement in ragweed allergy research, diagnosis, and immunotherapy.

Background: Ragweed (Ambrosia elatior) has become invasive in Europe, causing significant respiratory issues. Subcutaneous allergen immunotherapy (SCIT) has long been used to manage pollen allergies, but sublingual immunotherapy (SLIT) has gained interest. Objective: This study aimed to evaluate the clinical benefits of ragweed SLIT under real-world in a cohort of Hungarian patients allergic to ragweed pollen. Methods: We retrospectively reviewed the clinical records of 57 patients during the 2015 and 2016 ragweed pollen seasons. Patients were divided into two groups: Group 1 (n = 29), who had not received immunotherapy, and Group 2 (n = 28), who had previously undergone immunotherapy with another sublingual preparation. All patients were treated with Oraltek® ragweed for 4–6 months, initiating 2–4 months before the pollen season and rest of the period was 2 months of the 2016 pollen season. Symptom score (SS), medication score (MS), and combined symptom and medication score (CSMS) were evaluated intra- and intergroup. Results: Pollen counts were consistent between 2015 and 2016. All patients showed significant improvement in SS, MS, and CSMS, with a large effect size (>0.8). Group 2 had significantly lower SS and CSMS in 2015 because of prior immunotherapy. By 2016, both groups exhibited marked improvements, with Group 1 showing a 75% improvement in CSMS. No local or systemic reactions were recorded, indicating a high safety profile. Conclusions: Ragweed SLIT significantly improved symptoms and reduced use of medication in patients allergic to ragweed pollen. The treatment was effective even in patients with previous immunotherapy, with a high benefit–risk ratio demonstrated by the absence of adverse reactions. These findings support the use of Oraltek SLIT for managing ragweed pollen allergy.

One of the key input parameters for numerical pollen forecasts is the distribution of pollen sources. Generally, three different methodologies exist to assemble such distribution maps: (1) plant inventories, (2) land use data in combination with annual pollen counts, and (3) ecological modeling. We have used six exemplary maps for all of these methodologies to study their applicability and usefulness in numerical pollen forecasts. The ragweed pollen season of 2012 in France has been simulated with the numerical weather prediction model COSMO-ART using each of the distribution maps in turn. The simulated pollen concentrations were statistically compared to measured values to derive a ranking of the maps with respect to their performance. Overall, approach (2) resulted in the best correspondence between observed and simulated pollen concentrations for the year 2012. It is shown that maps resulting from ecological modeling that does not include a sophisticated estimation of the plant density have a very low predictive skill. For inventory maps and the maps based on land use data and pollen counts, the results depend very much on the observational site. The use of pollen counts to calibrate the map enhances the performance of the model considerably.

Ragweed allergy is a major public health concern. Within Europe, ragweed is an introduced species and research has indicated that the amounts of ragweed pollen are likely to increase over Europe due to climate change, with corresponding increases in ragweed allergy. To address this threat, improving our understanding of predisposing factors for allergic sensitisation to ragweed and disease is necessary, specifically focusing upon factors that are potentially modifiable (i.e., environmental). In this study, a total of 4013 children aged 2–13 years were recruited across Croatia to undergo skin prick tests to determine sensitisation to ragweed and other aeroallergens. A parental questionnaire collected home environment, lifestyle, family and personal medical history, and socioeconomic information. Environmental variables were obtained using Geographical Information Systems and data from nearby pollen, weather, and air pollution stations. Logistic regression was performed (clustered on school) focusing on risk factors for allergic sensitisation and disease. Ragweed sensitisation was strongly associated with ragweed pollen at levels over 5000 grains m–3 year−1 and, above these levels, the risk of sensitisation was 12–16 times greater than in low pollen areas with about 400 grains m–3 year−1. Genetic factors were strongly associated with sensitisation but nearly all potentially modifiable factors were insignificant. This included measures of local land use and proximity to potential sources of ragweed pollen. Rural residence was protective (odds ratio (OR) 0.73, 95% confidence interval (CI) 0.55–0.98), but the factors underlying this association were unclear. Being sensitised to ragweed doubled (OR 2.17, 95% CI 1.59–2.96) the risk of rhinoconjunctivitis. No other potentially modifiable risk factors were associated with rhinoconjunctivitis. Ragweed sensitisation was strongly associated with ragweed pollen, and sensitisation was significantly associated with rhinoconjunctivitis. Apart from ragweed pollen levels, few other potentially modifiable factors were significantly associated with ragweed sensitisation. Hence, strategies to lower the risk of sensitisation should focus upon ragweed control.

Background and objectives: Ragweed pollen is a major source of allergen, which has rarely been observed in Romania until now. In this study, we evaluated the symptoms and associated factors in patients with allergic rhinitis to ragweed pollen in two distinct regions of Romania. Materials and Methods: We evaluated the records of patients newly diagnosed with allergic rhinitis induced by ragweed pollen in two allergological centers from North-West (NW) and Central parts of Romania between 2013 and 2015. The patients were clinically evaluated regarding disease length, presence, and severity of the allergic rhinitis symptoms and the association with other allergic manifestations (asthma and conjunctivitis). Results: The sensitization to ragweed was significantly higher in the NW part compared to the Central part (18.27% vs 4.1%, p < 0.001). More patients with monosensitization to ragweed pollen were observed in the NE center (27%) compared to the Central one (20.7%). Patients with monosensitization to ragweed pollen presented more severe forms of rhinitis (70% vs 31.5%, p = 0.02) in the NW part compared to polysensitized patients. The total symptoms score was significantly higher in patients from the Central part compared to the NW part (9.21 ± 2.01 vs 5.76 ±1.96, p < 0.001). Bronchial asthma was associated at a similar frequency to allergic rhinitis in both centers, but it was more frequently observed in monosensitized patients in the NW center. Allergic conjunctivitis was more frequently reported by patients from the Central part (75.86 vs 41.9, p = 0.02), while in the NW region it was noticed more commonly in monosensitized patients (65% vs 33.33, p = 0.02). Conclusions: Allergic rhinitis to ragweed pollen has been more frequently reported in the NW part of Romania. Patients with severe forms of rhinitis were observed in the central part, while in the NW the severe forms of disease were reported by patients with monosensitization. Ragweed pollen is intensely allergogenic and determines association of ocular and asthma symptoms. Co-sensitization increases the risk of asthma association.

There is a growing consensus on the benefits of sublingual-swallow immunotherapy in the treatment of allergic diseases. This randomized, double-blind placebo-controlled study was undertaken to assess the efficacy and safety of sublingual immunotherapy with standardized ragweed pollen extract tablets, in patients with an allergic rhinitis. A total of 110 outpatients were randomized (immunotherapy [I]: 55; placebo [P]: 55), of whom 99 were analyzable for efficacy (I: 48; P: 51) and 106 analyzable for safety (I: 53; P: 53). After a 28-day progression phase, the patients received a maintenance treatment during 6.5 months. Efficacy variables included a global assessment of efficacy (patient/ investigator), symptoms and medication scores as well as the frequency of asthma attacks. In the active treatment group, 43 patients completed the study, versus 49 on placebo. During the whole period of pollination, the difference favoring immunotherapy was highly significant for the global assessment by the patient (p = 0.004) and by the investigator (p = 0.005). Adverse reactions were reported more often in the active treatment but mild or moderate, and they abated after dose adjustment. A subgroup analysis of those patients receiving the highest dose of immunotherapy (3 tablets 3 times a week) showed a highly significant response for rhinitis and conjunctivitis total scores by comparison to lower dosages. This study confirms the efficacy and safety of sublingual immunotherapy and strongly suggests a dose-response relationship.

Ambrosia artemisiifolia L. is a noxious invasive alien species in Europe. It is an important aeroallergen and millions of people are exposed to its pollen. The main aim of this study is to show that atmospheric concentrations of Ambrosia pollen recorded in Denmark can be derived from local or more distant sources. This was achieved by using a combination of pollen measurements, air mass trajectory calculations using the HYPLIT model and mapping all known Ambrosia locations in Denmark and relating them to land cover types. The annual pollen index recorded in Copenhagen during a 15-year period varied from a few pollen grains to more than 100. Since 2005, small quantities of Ambrosia pollen has been observed in the air every year. We have demonstrated, through a combination of Lagrangian back-trajectory calculations and atmospheric pollen measurements, that pollen arrived in Denmark via long-distance transport from centres of Ambrosia infection, such as the Pannonian Plain and Ukraine. Combining observations with results from a local scale dispersion model show that it is possible that Ambrosia pollen could be derived from local sources identified within Denmark. The high allergenic capacity of Ambrosia pollen means that only small amounts of pollen are relevant for allergy sufferers, and just a few plants will be sufficient to produce enough pollen to affect pollen allergy sufferers within a short distance from the source. It is necessary to adopt control measures to restrict Ambrosia numbers. Recommendations for the removal of all Ambrosia plants can effectively reduce the amount of local pollen, as long as the population of Ambrosia plants is small.