Development of an allergen extract for sublingual immunotherapy--evaluation of Staloral

Management of Allergic Rhinitis in the United Arab Emirates: Expert Consensus Recommendations on Allergen Immunotherapy

Allergic rhinitis (AR) is a chronic inflammatory condition of the upper airways caused by a type I hypersensitivity reaction triggered by environmental allergens. AR is associated with significant morbidity and affects patients' quality of life, emotional well-being, productivity, and cognitive functioning. As AR prevalence and morbidity have increased significantly worldwide, similar observations have been noted in the United Arab Emirates (UAE) with AR becoming a potential public health issue. Management of AR in the UAE is mainly provided by non-allergy specialists relying on first-line treatments such as intranasal steroids and antihistamines, with often suboptimal and short-term efficacy. Allergen Immunotherapy (AIT) is the only currently available disease-modifying treatment option in the form of either subcutaneous or sublingual allergen immunotherapy that has been proven to have long-term benefits. This article aims to provide recommendations regarding the use of AIT for managing AR in the UAE, considering both the current landscape in the Emirati healthcare system and local experience.

Current advances in house dust mite allergen immunotherapy (AIT): Routes of administration, biomarkers and molecular allergen profiling

Allergy to house dust mites (HDM) is a perennial respiratory disease that affect more than half a billion people worldwide. Dermatophagoides pteronyssinus and D. farinae, two HDM species, are major sources of indoor allergens triggering allergic inflammation. Although symptomatic drugs are widely used to block the allergic reaction, allergen immunotherapy is the only curative treatment of IgE-mediated type I respiratory allergies. In this article, we review recent advances in various routes of allergen immunotherapy. We particularly focus on subcutaneous (SCIT) and sublingual (SLIT) immunotherapy, used as a reference therapy since they have transformed allergic treatments by improving symptoms (asthma and rhinitis) as well as the quality of life of patients. We also highlight recent data in more exploratory routes (i.e., oral, intralymphatic, epicutaneous and intradermal) and discuss respective advantages of various route, as well as their foreseen modes of action. Finally, we provide an update on biomarkers as well as on the relevance of the molecular profiling of allergic individuals related to treatment efficacy or asthma prediction.

Update about Oralair® as a treatment for grass pollen allergic rhinitis

Sublingual immunotherapy (SLIT) is a well-tolerated, safe, and effective approach to treating allergic rhinitis (AR). Oralair® is a five-grass pollen SLIT tablet containing natural pollen allergens from five of the major grass species responsible for seasonal AR due to grass pollen allergy. Recommended use is in a pre-coseasonal regimen, starting daily treatment approximately 4 months before the start of the pollen season, with treatment then continued daily throughout the season; treatment should continue for 3–5 y. Clinical efficacy and safety of Oralair® in patients with grass pollen-induced AR has been demonstrated in a comprehensive clinical development program of randomized controlled trials. Effectiveness has been substantiated in subsequent observational studies with sustained efficacy following treatment cessation and a favorable level of adherence, quality of life, benefit, and satisfaction for the patients. Supportive evidence for a benefit in reducing the risk or delaying the development of allergic asthma is emerging.

IgE binding activities and in silico epitope prediction of Der f 32 in Dermatophagoides farinae

Dermatophagoides farinae is a common indoor allergen source that produces more than 30 allergens, which induces diverse allergic diseases such as allergic rhinitis, allergic asthma and atopic dermatitis. Der f 32 is an inorganic pyrophosphatase and an important allergen from Dermatophagoides farinae. In the present study, Der f 32 was cloned, expressed and purified in order to better understand its structure and immunogenicity. Immunoblotting analysis and ELISA showed 5 of 5 positive reactions to recombinant Der f 32 using serum from house dust mite (HDM)-allergic patients. We constructed homology modeling and predicted epitopes of Der f 32 via bioinformatic tools. The sequence and structural analysis indicated that Der f 32 belonged to the pyrophosphatase family and represented a special structure of external α-helices and internal antiparallel closed β-sheets. In addition, eight B-cell epitopes and four T-cell epitopes were predicted. B-cell epitopes were 24-31, 111-121, 135-140, 168-172, 200-207, 214-220, 237-243, and 268-274 and T-cell epitopes were 47-55, 78-90, 127-135 and 143-151. The B-cell epitopes were distributed completely on the surface of Der f 32 and were located largely in random coils of secondary structures. Hydrophobic and charged amino acids comprised more than 80% of the residues of B-cell epitopes and may participate in IgE binding. The T-cell epitopes were located primarily in the interior of Der f 32 and, to a certain extent avoided degradation by proteases. The structures of T-cell epitopes were surrounded by B-cell epitopes, and this arrangement may have important biological significance for maintaining the immunogenicity of allergens.

Two grass pollen tablets commercially available for allergy immunotherapy display different IgE epitope repertoires

Background

The distribution of Pooideae species varies across Europe. Especially, Timothy is less represented in Southern than in Northern Europe. Since allergenic cross-reactivity between pollens from different grasses is only partial, grass pollen-allergic patients are expected to display different sensitization profiles, with specific IgE directed against different combinations of allergenic epitopes, depending on their living places in Europe and the grasses they are exposed to. In this context, this study aimed at comparing two tablets commercially available for allergy immunotherapy, namely a 5-grass (Cocksfoot, Meadow-grass, Rye-grass, Sweet vernal-grass and Timothy) and a 1-grass (Timothy) pollen tablets, for their ability to represent the sensitization profiles of patients, depending on whether they live in Southern or Northern Europe.

Methods

Sera were collected from adult patients living in Spain (n = 19) and Sweden (n = 22). Tablets were compared for their ability to inhibit the binding of patient serum IgE to pollen allergens from twelve grasses commonly distributed throughout Europe, as determined by the areas under the curves obtained by ELISA-inhibition. Tablets were adjusted to an equivalent allergenic activity, based on the CBER/FDA bioequivalent allergy unit.

Results

Inhibition of the IgE binding to pollen allergens from twelve grasses was significantly stronger with the 5-grass than with the 1-grass pollen tablet (p < 0.0001), regardless of whether patients were considered as a whole or by geographical area. This difference between tablets was significantly greater for Southern than Northern European patients (p < 0.05).

Conclusions

Compared to the 1-grass tablet, the 5-grass tablet generally covers better the sensitization profiles of European patients, especially patients from Southern Europe, in principle less exposed to pollen from Timothy than from other grasses. The 5-grass tablet is therefore expected to elicit larger spectra of blocking antibodies, which might have implications in light of the generally accepted mechanisms of allergy immunotherapy.

Electronic supplementary material

The online version of this article (10.1186/s13601-019-0253-z) contains supplementary material, which is available to authorized users.

Effect of tablets containing probiotic candidate strains on gingival inflammation and composition of the salivary microbiome: a randomised controlled trial

The aim of the study was to investigate clinical and microbial effects of probiotic candidate strains in patients with moderate gingivitis. The null hypothesis was that the clinical measurements with treatment would not differ from placebo. 47 adult patients were enrolled in a randomised placebo-controlled trial with a 4-week intervention of tablets containing a mix of Lactobacillus rhamnosus PB01, DSM 14869 and Lactobacillus curvatus EB10, DSM 32307 or placebo. Clinical examinations and samplings were done at baseline and after 2, 4 and 6 weeks. The clinical endpoints were general bleeding on probing (BOP), general plaque index (PI) and flow of gingival crevicular fluid (GCF). In addition, the concentration of selected cytokines (interleukin (IL)-1β, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-α)) in GCF was determined with multiplex immunoassays. The profiles of the salivary microbiome were analysed with Next Generation Sequencing (NGS) and qPCR. In contrast to the placebo group, there was a significant reduction in BOP and amount of GCF (P<0.05) after 4 weeks in the probiotic test group when compared with baseline. The general PI was less affected although there was a tendency of decreased plaque levels in the probiotic group (P=0.05-0.09). The cytokines were unaffected by the intervention as well as the salivary microbiome. The Shannon index showed no significant differences between the groups or alterations over time. The occurrence of both probiotic strains increased in saliva of the test subjects during the intervention but returned to baseline levels within 2 weeks. Although a marked improvement in gingival health was recorded in the probiotic group, the null hypothesis could not be rejected.

Expression, purification and epitope analysis of Pla a 3 allergen from Platanus acerifolia pollen

Platanus acerifolia (P. acerifolia) is an important cause of pollinosis in cities. The use of allergen extracts on patients with allergic diseases is the most commonly applied method to attempt to treat pollinosis. Pla a 3, a non‑specific lipid transfer protein, is a major allergen present in P. acerifolia pollen extracts. In the present study, the Pla a 3 gene was sub‑cloned into a pSUMO‑Mut vector using Stu I and Xho I sites and transformed into the Arctic Express™ (DE3) RP E. coli host strain. The purified Pla a 3 allergen was analyzed by western blotting and the results revealed that the Pla a 3 allergen has the ability to bind IgE in the P. acerifolia pollen of allergic patients' sera. Moreover, the authors predicted the potential B cell epitopes of the Pla a 3 allergen using the DNAStar Protean system, the Bioinformatics Predicted Antigenic Peptides system and the BepiPred 1.0 server. In addition, the T cell epitopes were predicted by the SYFPEITHI database and the NetMHCII‑2.2 server. As a result, two B cell epitopes (35‑45 and 81‑86) and four potential T cell epitopes including 2‑15, 45‑50, 55‑61 and 67‑73 were predicted in the present study. The current results can be used to contribute to allergen immunotherapies and useful in peptide‑based vaccine designs of pollen allergy.

Evaluation of a sublingual immunotherapy solution in olive-induced respiratory allergy in Jordan: a retrospective observational study

Background

Olive pollen is an important cause of respiratory allergy in the Middle East. In this study, the clinical characteristics of adults and children with confirmed allergic rhinitis (AR; with or without asthma) in Jordan were described, and the use of sublingual immunotherapy (SLIT) in a real-life clinical setting was assessed.

Methods

This retrospective observational study evaluated the clinical features of olive-induced allergy and the use of an SLIT solution of standardized extracts toward Ole e 1 given in a pre- and coseasonal scheme with a daily dose of 300 index of reactivity for two consecutive seasons. Inclusion criteria were as follows: ≥5 years of age, AR, proven olive sensitization, and at least 2 years follow-up after SLIT initiation. The following data were recorded at SLIT initiation: clinical characteristics, rhinitis and asthma symptom scores, and concomitant symptomatic medications. During follow-up and at the end of each season, the following data were recorded: symptom progression/scores, any changes to symptomatic medications, and treatment compliance. The secondary objective was to determine any effect on quality of life, use of concomitant AR medications, and treatment compliance.

Results

Eighty-six patients with seasonal AR were included in this analysis (52.3% with coexisting asthma). Between the initiation of treatment and the end of second pollen season, symptoms of AR and asthma were decreased by 79.5% and 41.7%, respectively, with an improvement in quality of life score in 71.5% of the patients (P<0.0001 for all). Physicians reported that after 2 years of SLIT, there was an improvement in the symptoms of both AR (95.2%) and asthma (93.3%), with 98.8% of the patients showing good treatment compliance. A reduction in symptomatic medications was also found. SLIT was well tolerated with no systemic reactions being reported.

Conclusion

In children and adults with olive-associated respiratory allergy in Jordan, the use of a pre- and coseasonal SLIT with a 300 index of reactivity daily dose is effective in reducing the clinical burden of AR and asthma with no tolerability issues.

Comparison of allergenic extracts from different origins: the value of the FDA's bioequivalent allergy unit (BAU)

INTRODUCTION

Allergy immunotherapy (AIT) is the only disease-modifying intervention for the treatment of allergic diseases. The clinical effectiveness of AIT is clearly dose-dependent, so it is important that clinicians can assess and compare the potency of the various products available. However, this is not possible in practice, because manufacturers use different methods to determine potency. Therefore, a clear need exists for adoption of a 'gold-standard' measure of allergenicity. The bioequivalent allergy unit (BAU) is thus far the only allergen unit approved by a regulatory agency (the US Food and Drug Administration), with European regulatory authorities yet to adopt a common unit.

AREAS COVERED

Using PubMed, we performed a review of the literature on measures of allergen extract potency, use of the BAU, and BAU assessment for grass pollen tablets. Expert commentary: There is an obvious benefit to allergists and patients for having a single, comparable unit across products, and we strongly support the adoption of a single, 'gold-standard' unit of measurement for all products. Use of the BAU allows a clear comparison of the potency of allergen products from different manufacturers, and enables better understanding of the potential reasons for any differences in administration and dosing protocols between these products.

Choosing the optimal dose in sublingual immunotherapy: Rationale for the 300 index of reactivity dose

Sublingual immunotherapy (SLIT) is an effective and well-tolerated method of treating allergic respiratory diseases associated with seasonal and perennial allergens. In contrast to the subcutaneous route, SLIT requires a much greater amount of antigen to achieve a clinical effect. Many studies have shown that SLIT involves a dose–response relationship, and therefore it is important to use a proven clinically effective dose from the onset of treatment, because low doses are ineffective and very high doses may increase the risk of side effects. A well-defined standardization of allergen content is also crucial to ensure consistent quality, potency and appropriate immunomodulatory action of the SLIT product. Several methods of measuring antigenicity are used by manufacturers of SLIT products, including the index of reactivity (IR), standardized quality tablet unit, and bioequivalent allergy unit. A large body of evidence has established the 300 IR dose of SLIT as offering optimal efficacy and tolerability for allergic rhinitis due to grass and birch pollen and HDM, and HDM-induced moderate, persistent allergic asthma. The 300 IR dose also offers consistency of dosing across a variety of different allergens, and is associated with higher rates of adherence and patient satisfaction. Studies in patients with grass pollen allergies showed that the 300 IR dose has a rapid onset of action, is effective in both adults and children in the short term and, when administered pre-coseasonally in the long term, and maintains the clinical benefit, even after cessation of treatment. In patients with HDM-associated AR and/or asthma, the 300 IR dose also demonstrated significant improvements in symptoms and quality of life, and significantly decreased use of symptomatic medication. The 300 IR dose is well tolerated, with adverse events generally being of mild or moderate severity, declining in frequency and severity over time and in the subsequent courses. We discuss herein the most important factors that affect the selection of the optimal dose of SLIT with natural allergens, and review the rationale and evidence supporting the use of the 300 IR dose.

New product development with the innovative biomolecular sublingual immunotherapy formulations for the management of allergic rhinitis

The molecular allergy technique, currently defined as component-resolved diagnosis, significantly improved the diagnosis of allergy, allowing for differentiation between molecules actually responsible for clinical symptoms (genuine sensitizers) and those simply cross-reacting or shared by several sources (panallergens), thus influencing the appropriate management of a patient's allergy. This also concerns allergen immunotherapy (AIT), which may be prescribed more precisely based on the component-resolved diagnosis results. However, the advance in diagnosis needs to be mirrored in AIT. According to consensus documents and to expectations of specialists, therapy should be based on standardized extracts containing measured amounts of the clinically relevant molecules, ie, the major allergens. The new generation of extracts for sublingual immunotherapy fulfills these requirements and are thus defined as biomolecular (BM). BM refers to natural extracts with a defined content of major allergens in micrograms. All Staloral BM products are indicated for the treatment of allergic rhinitis with or without asthma. The effectiveness of AIT is related to its ability to modify the immunological response of allergic subjects. The 5-grass and house dust mite extracts were evaluated addressing the T helper 1, T helper 2, and T helper 3 cells by polymerase chain reaction array on mRNA extracted from Waldeyer's ring tissue (adenoids). Sublingual immunotherapy with a defined content of major allergens in micrograms induced a strong downregulation of genes involved in T helper 2 and T helper 1 activation and function, allowing the definition of the immunologic effect as "bio-homeostatic". This clinical and immunological model must be implemented with respect to other allergens, thus expanding the application of a treatment with a unique disease-modifying capacity.

In Silico Prediction of T and B Cell Epitopes of Der f 25 in Dermatophagoides farinae

The house dust mites are major sources of indoor allergens for humans, which induce asthma, rhinitis, dermatitis, and other allergic diseases. Der f 25 is a triosephosphate isomerase, representing the major allergen identified in Dermatophagoides farinae. The objective of this study was to predict the B and T cell epitopes of Der f 25. In the present study, we analyzed the physiochemical properties, function motifs and domains, and structural-based detailed features of Der f 25 and predicted the B cell linear epitopes of Der f 25 by DNAStar protean system, BPAP, and BepiPred 1.0 server and the T cell epitopes by NetMHCIIpan-3.0 and NetMHCII-2.2. As a result, the sequence and structure analysis identified that Der f 25 belongs to the triosephosphate isomerase family and exhibited a triosephosphate isomerase pattern (PS001371). Eight B cell epitopes (11-18, 30-35, 71-77, 99-107, 132-138, 173-187, 193-197, and 211-224) and five T cell epitopes including 26-34, 38-54, 66-74, 142-151, and 239-247 were predicted in this study. These results can be used to benefit allergen immunotherapies and reduce the frequency of mite allergic reactions.

Will sublingual immunotherapy offer benefit for asthma?

Evidence shows that sublingual immunotherapy (SLIT) is indicated in patients with allergic rhinitis (AR). In this article we discuss whether SLIT could offer benefit for children and adults with asthma.We reviewed individual trials on SLIT in asthmatic patients, but also asthma data reported in some SLIT trials conducted in AR patients. Findings were complemented with data from systematic reviews and metaanalysis on the subject since 2000 and some guidelines that mention immunotherapy for asthma treatment. In AR patients with concomitant persistent asthma, SLIT reduces medication needs while maintaining symptom control. This holds especially true for house dust mite SLIT. Data on pollen SLIT and lung symptom improvement with SLIT, however, are less convincing. Therefore, we suggest SLIT should be added as an optional add-on therapy for patients with asthma whenever a causative allergen has been demonstrated and AR is associated with asthma. For the future, SLIT should be studied in specifically designed asthma studies in allergic asthmatics without AR.

Oralair(®): a causal treatment for grass pollen-induced allergic rhinoconjunctivitis

Grass pollen-induced allergic rhinoconjunctivitis is a common disease, comprising more than just the classic symptoms of nasal obstruction, sneezing, rhinorrhea and itchy, watery eyes. Sufferers deal with severe impairments in daily life. Allergic rhinoconjunctivitis is also considered an important risk factor in the development of asthma. Allergen avoidance, medication for symptomatic treatment and allergen-specific immunotherapy are cornerstones in therapeutic management, but immunotherapy is the only available treatment that is able to affect the natural course of allergy. In recent decades, clinical trials have investigated the efficacy and safety of subcutaneous immunotherapy. To date, efforts have been made to develop more convenient routes of administration. Substantial improvement may be achieved through the application of sublingual tablets. This article discusses the development process of immunotherapy and the clinical background of the Oralair(®) (Stallergènes, Hauts-de-Seine, France) five-grass pollen tablet. Furthermore, it outlines this tablet's efficacy and safety properties.

Specific immunotherapy for allergic rhinitis to grass and tree pollens in daily medical practice-symptom load with sublingual immunotherapy compared to subcutaneous immunotherapy

Abstract Background. Despite strong evidence for subcutaneous and sublingual immunotherapy for the treatment of allergic rhinoconjunctivitis, comparative data are scarce. Objectives. We performed an individual patient data meta-analysis of four observational studies to compare the effectiveness of both application routes. Methods. After individual analysis, a subsequent analysis of the total data pool was performed. Descriptive and explorative data analysis methods were used. Results. Altogether 847 patients (382 male, 453 female) aged 3-78 years (mean age 28.3 years) were treated with specific immunotherapy: 665 (78.5%) patients sublingual and 182 (21.5%) subcutaneous. The majority of patients (61.6%) in both treatment groups started specific immunotherapy due to severe rhinitis symptoms which occurred frequently or very frequently. Most patients in both treatment groups had moderate to severe conjunctivitis symptom load which occurred frequently or very frequently. Median rhinitis and conjunctivitis symptom loads decreased during both treatments to the same extent. Similar improvements in the symptom loads were observed in patients stratified for age, disease duration, and presence or absence of mild to moderate asthma. Conclusion. The effectiveness of sublingual and subcutaneous immunotherapy with pollen extracts appeared virtually equal in daily medical routine. Due to the advantageous safety profile, the sublingual application may be favorable.

Sublingual immunotherapy in daily medical practice: effectiveness of different treatment schedules - IPD meta-analysis

OBJECTIVE

To compare the effectiveness of perennial and co-seasonal high-dose sublingual immunotherapy (SLIT) treatments as well as ultra-rush and classical titrations in a real-world setting for pollen allergens.

METHODS

An individual patient data (IPD) meta-analysis was performed of three open, prospective observational studies on high-dose SLIT using IR-standardised allergen extracts in patients with allergic rhinitis with and without asthma.

RESULTS

In total, 1052 patients aged 24.9 years (mean) were treated with SLIT and included in this IPD meta-analysis. Individual studies and total data pool analyses revealed consistent improvements in rhinoconjunctivitis symptom scores. Stratified analyses revealed consistent improvements in symptomatic score and medication score regardless of the type of sensitisation and type of treatment. Ultra-rush titration resulted in considerably more pronounced improvement in symptom scores than classical titration, possibly due to better compliance of patients receiving that supervised titration. Adverse events occurred in 24% of patients during titration and in 18% of patients during maintenance treatment. The vast majority of events (89% and 87%) were mild-to-moderate, predominantly local symptoms in the oral cavity. There were no differences detected between the study titration or treatment schedules. No serious adverse reactions were reported. Nearly all patients (88%) decided to continue SLIT after completion of the studies.

CONCLUSION

High-dose SLIT with seasonal allergens given as co-seasonal or perennial treatment appears to be effective and well-tolerated in daily medical practice. Improved compliance under ultra-rush titration and seasonal SLIT treatment may further enhance effectiveness. Randomised controlled trials are requested for the further evaluation of these findings.