Novel strategies for the treatment of grass pollen-induced allergic rhinitis

An epicutaneous therapeutic pollen-allergen extract delivery system in an allergic rhinitis mouse model: based on allergen loading on DC-specific aptamers conjugated nanogolds

BACKGROUND

Gold nanoparticles (GNPs) have previously been suggested as appropriate carriers for allergen-specific immunotherapy (AIT). In this study, we assessed efficacy of GNPs and dendritic cells (DC)-specific aptamer-modified GNPs (Apts-GNP) for epicutaneous immunotherapy (EPIT) in the case of pollen allergen extracts containing a variety of allergenic and non-allergenic components.

METHODS

BALB/c mice were sensitized to the total protein extract of Platanus orientalis pollen and epicutaneously treated in different groups either with free P. orientalis total pollen extract, naked GNPs, total extract loaded GNPs, and total extract loaded Apts-GNPs with and without skin-penetrating peptides (SPPs). Then, the specific IgE level (sIgE), total IgE concentration (tIgE) in the serum sample, IL-4, IL-17a, IFN-γ, and IL-10 cytokine concentrations in re-stimulated splenocytes with the total extract and mixture of recombinant allergens, nasopharyngeal lavage fluid (NALF) analysis, and histopathological analysis of lung tissue were evaluated.

RESULTS

This study indicated the total extract-loaded GNPs, especially Pla. ext (50 μg)-GNPs, significantly decreased sIgE, tIgE, IL-17a, and IL-4 concentrations, immune cells and eosinophils infiltration in NALF, and increased IL-10 and IFN-γ concentrations compared with the PBS-treated group. In addition, the histopathological analysis of lung tissue showed a significant decrease in allergic inflammation and histopathological damage. The DC-targeted group revealed the most significant improvement in allergic-related immune factors with no histopathological damage compared with the same dose without aptamer.

CONCLUSION

Loading total protein extract on the GNPs and the Apt-modified GNPs could be an effective approach to improve EPIT efficacy in a pollen-induced allergic mouse model.

Pollen grading prediction scale for patients with Artemisia pollen allergy in China: A 3-day moving predictive model

BACKGROUND

Artemisia pollen is the most prevalent outdoor aeroallergen causing respiratory allergies in Beijing, China. Pollen allergen concentrations have a direct impact on the quality of life of those suffering from allergies. Artemisia pollen deposition grading predictions can provide early warning for the protection and treatment of patients as well as provide a scientific basis for allergen specific clinical immunotherapy.

OBJECTIVE

To develop a model of Artemisia pollen grading to predict development in patients with pollen allergy.

METHODS

Artemisia pollen data from four pollen monitoring stations in Beijing as well as the number of Artemisia pollen allergen serum specific immunoglobulin E positive cases in Beijing Tongren Hospital from 2014 to 2016 were used to develop a statistical model of pollen deposition and provide optimised threshold values.

RESULTS

A logarithmic correlation existed between the number of patients with Artemisia pollen allergy and Artemisia pollen deposition, and the average pollen deposition for three consecutive days was most correlated with the number of allergic patients. Based on the threshold of the number of patients and the characteristics of Artemisia pollen, a five-stage pollen deposition grading model was developed to predict the degree of pollen allergy.

CONCLUSIONS

Graded prediction of pollen deposition may help pollen allergic populations benefit from preventive interventions before onset.

Evaluation of Intralymphatic Immunotherapy in Allergic Rhinitis Patients: A Systematic Review and Meta-analysis

Background

Intralymphatic immunotherapy (ILIT) is short-course administration of allergen-specific immunotherapy (AIT). This study is aimed at assessing the clinical efficacy and safety of ILIT in patients with allergic rhinitis (AR).

Methods

MEDLINE, PUBMED, and Cochrane Library were used to conduct electronic searches for clinical trials comparing ILIT and placebo in patients with AR. The final search took place on August 24, 2022. Cochrane Handbook for Systematic Reviews of Interventions was used to assess the risk of bias in the included studies. The outcomes included combined symptom and medication scores (CSMS), visual analog scale (VAS), allergic rhinoconjunctivitis quality of life (RQLQ), Skin-prick test (SPT), and adverse events (AEs). Data were synthesized as mean difference (MD)/standard mean difference (SMD) or risk difference (RD) and 95% confidence interval (CI).

Results

Thirteen studies (454 participants) were included in this study. The ILIT group had better clinical improvement on the CSMS (random effects model, SMD-0.85, 95% CI [-1.58, -0.11], P = 0.02) and RQLQ (fixed-effects model, MD-0.42, 95% CI [0.69, 0.15], P = 0.003) than the placebo group. The booster injection was beneficial for CSMS (P < 0.0001), and the 4-week injection interval was superior to the 2-week injection period for improving VAS (P < 0.0001). Local swelling or erythema was the main AE following injection (random effects model, RD 0.16, 95% CI [0.05, 0.27], P = 0.005). Discussion. For individuals with AR, ILIT is safe and effective. ILIT alleviates clinical symptoms and reduces pharmaceutical consumption without causing severe AEs. However, the validity of this study is compromised by the substantial heterogeneity and risk of bias in the included researches. RegistrationCRD42022355329.

Molecular Aspects of Allergen-Specific Immunotherapy in Patients with Seasonal Allergic Rhinitis

A systematic review and narrative synthesis of publications was undertaken to analyze the role of component-resolved diagnosis technology in identifying polysensitization for the provision of allergen-specific immunotherapy to patients with seasonal allergic rhinitis. A search of publications was carried out in electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search helped to identify 568 publications, 12 of which were included in this review. Overall, 3302 patients were enrolled. The major finding was that component-resolved diagnostics change the choice of relevant allergens for allergen-specific immunotherapy in at least 50% of cases. Sensitization to allergen components differs with age, type of disease, and overall disease duration. Patients who had both bronchial asthma and allergic rhinitis were sensitized to a larger number of allergens than patients who had bronchial asthma alone.

Data mining assessment of Poaceae pollen influencing factors and its environmental implications

Poaceae pollen is highly allergenic, with a marked contribution to the pollen worldwide allergy prevalence. Pollen counts are defined by the species present in the considered area, although year-to-year oscillations may be triggered by different parameters, among which are weather conditions. Due to the predominant role of Poaceae pollen in the allergenicity in urban green areas, the aim of this study was the analysis of pollen trends and the influence of meteorology to forecast relevant variations in airborne pollen levels. The study was carried out during the 1993-2020 period in Ourense, in NW Iberian Peninsula. We used a volumetric Lanzoni VPPS 2000 trap for recording Poaceae airborne pollen grains, and meteorological daily data were obtained from the Galician Institute for Meteorology and Oceanography. The main indexes of the pollen season and their trends were calculated. A correlation analysis and 'C5.0 Decision Trees and Rule-Based Models' data mining algorithm were applied to determine the influence of meteorological conditions on pollen levels. We detected atmospheric Poaceae pollen during 139 days on average, mainly from April to August. The mean pollen grains amount recorded during the pollen season was 4608 pollen grains, with the pollen maximum peak of 276 pollen/m³ on 27 June. We found no statistically significant trends and slight slopes for the seasonal indexes, similarly to previous Poaceae studies in the same region. The calculated C5.0 model offered defined results, indicating that the combination of mean temperature above 17.46 °C and sunlight exposure higher than 12.7 h is conductive to significantly high pollen levels. The obtained results make possible the identification of risk moments during the pollen season for the activation of protective measures for sensitized population to grass pollen.

Sensitization Profiles of Timothy Grass Pollen in Northern China

Purpose

Grass pollen is an important cause of IgE-mediated allergy in countries worldwide, especially within Europe. However, there has been no research on grass pollen allergy in northern China. We aimed to determine the status of grass pollen allergy and the sensitization patterns to Phleum pratense (P. pratense) in northern China.

Patients and Methods

Pollen data were collected for three geographic areas (Beijing, Shenmu, Shizuishan) in northern China. The study enrolled 101 patients (62 men; age range, 1–64 years; median age, 10 years) who had allergic rhinoconjunctivitis and/or asthma during the grass pollen season and positive skin prick test results positive to P. pratense. Serum-specific IgE (sIgE) against Phl p 1, Phl p 2, Phl p 5, Phl p 6, Phl p 7, Phl p 12 was measured by ImmunoCAP.

Results

The pollen season of P. pratense was from June to September in Beijing, May to September in Shenmu and July to August in Shizuishan. P. pratense pollen accounted for 2–3% of the annual pollen index of total pollen counts. Among 101 patients with positive skin prick test results to P. pratense, 72% had detectable sIgE to P. pratense. Phl p 12 was the most frequently recognized component (45%), followed by Phl p 1 (22%), Phl p 5 (14%), Phl p 6 (8%) and Phl p 7 (3%). No patients had sIgE to Phl p 2. Ten sensitization patterns to the six components were observed. High rate of sIgE to Phl p 12 was positively correlated with co-sensitization to weed or tree pollen.

Conclusion

Considering the pollen concentration, P. pratense was a minor pollen allergen in northern China and its pollen season overlapped with that of weed pollen. IgE sensitization to P. pratense was likely to be induced by cross-reactivity between grass pollen allergy and weed/tree pollen allergy.

Early nonreactivity in the conjunctival provocation test predicts beneficial outcome of sublingual immunotherapy

BACKGROUND

Clinical practice needs a common parameter that can provide an early, reliable estimation of the outcome of sublingual immunotherapy (SLIT) in an upcoming pollen season. We investigated whether the conjunctival provocation test (CPT) can predict the beneficial outcome of SLIT in patients with allergic rhinoconjunctivitis after 4 weeks of treatment.

METHODS

We conducted two separate prospective, randomized, double-blind, placebo-controlled, multicenter trials. Adults 18-75 years of age received placebo or SLIT tablets containing tree or grass pollen allergoids and underwent CPTs. Participants receiving SLIT were divided into two groups (reactive, nonreactive) according to their CPT reactions after 4 weeks of treatment. These two groups were compared with regard to clinical outcome parameters (total combined score, rhinoconjunctivitis total symptom score, total rescue medication score, well days) assessed during the pollen season for the 14-day (tree) or 30-day (tree/grass) peaks and for the entire 60-day seasons. Participants' global evaluations of therapy after completing treatment were also compared.

RESULTS

The tree pollen trial randomized 188 participants; 182 participants were evaluable, 76 of whom received SLIT and were suitable for this post hoc analysis. The grass pollen trial included 90 participants; 82 participants were evaluable, 44 of whom underwent SLIT. Comparing SLIT participants who reacted to the CPT after 4 weeks (tree: 77.6%; grass: 79.5%) with those who ceased to show a reaction (tree: 22.4%; grass: 20.5%) (tree: P = 0.0001; grass: P = 0.003), the total combined score for the 14-day (P = 0.017) and 30-day peaks (P = 0.042) as well as the rhinoconjunctivitis total symptom score assessed for the 14-day peak (P = 0.024) were significantly lower in the nonreactive group of the tree pollen trial. In the grass pollen trial, the nonreactive group rated their SLIT treatment significantly better (P = 0.019).

CONCLUSIONS

Using clinically meaningful outcome parameters during the pollen season, both trials independently led to similar results when comparing participants' reactions to the CPT 4 weeks after beginning SLIT. These results suggest that CPT allows an early estimation of allergic rhinoconjunctivitis symptoms before an upcoming season. Thus, the CPT can be used as a valuable parameter to predict the beneficial outcome of ongoing SLIT.

TRIAL REGISTRATION

Both trials registered with the Medical Ethics Committee of the North Rhine Medical Council (EudraCT numbers 2012-004916-79 (grass pollen trial) and 2013-002129-43 (tree pollen trial)) and the German Federal Ministry of Health (Paul-Ehrlich-Institut).

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Poaceae pollen as the leading aeroallergen worldwide: A review

The Poaceae family comprises over 12 000 wind-pollinated species, which release large amounts of pollen into the atmosphere. Poaceae pollen is currently regarded as the leading airborne biological pollutant and the chief cause of pollen allergy worldwide. Sensitization rates vary by country, and those variations are reviewed here. Grass pollen allergens are grouped according to their protein structure and function. In Poaceae, although species belonging to different subfamilies are characterized by distinct allergen subsets, there is a considerable degree of cross-reactivity between many species. Cross-reactivity between grass pollen protein and fresh fruit pan-allergens is associated with the appearance of food allergies. The additional influence of urban pollution may prompt a more severe immunological response. The timing and the intensity of the pollen season are governed by species genetics, but plant phenology is also influenced by climate; as a result, climate changes may affect airborne pollen concentrations. This article reviews the findings of worldwide research which has highlighted the major impact of climate change on plant phenology and also on the prevalence and severity of allergic disease.