Sublingual or subcutaneous immunotherapy for allergic rhinitis?

Comparison of Long-term Efficacy of Subcutaneous Immunotherapy in Pediatric and Adult Patients With Allergic Rhinitis

Purpose

Data comparing the long-term efficacy and safety of subcutaneous immunotherapy (SCIT) using house dust mite (HDM) in children and adults with allergic rhinitis (AR) are limited. This study aimed to compare the long-term effects of HDM-SCIT in a cohort of Chinese pediatric and adult patients with AR.

Methods

A total of 124 pediatric and adult AR patients received HDM-SCIT for 3 years, with 118 patients being followed-up for 2 years. Prior to treatment (baseline), at the end of the 3-year treatment periods (third year) and 2 years after the discontinuation of treatment (fifth year), all patients were evaluated for total nasal symptom scores (TNSS), daily medication score (DMS), total combined score (TCS; symptoms [nasal + ocular] + DMS) and quality of life (QoL). Safety was assessed according to adverse events reported.

Results

After 3-year treatment, HDM-SCIT significantly improved symptoms and QoL scores at the end of the third and fifth years in both groups. Better improvements were observed in the third and fifth years based on baseline, in children compared to adults (TNSSΔ3: 6.66 vs. 5.41, P = 0.011; TCSΔ3: 4.30 vs. 3.83, P = 0.027 and TNSSΔ5: 6.16 vs. 4.86, P = 0.037; TCSΔ5: 4.11 vs. 3.62, P = 0.044).Shorter duration of AR history before SCIT (<10 vs. ≥10 years) resulted in better improvements at the end of the third and fifth years (TCSΔ3: 4.12 vs. 3.13, P = 0.036; TCSΔ5: 3.90 vs. 3.09, P = 0.033). HDM-SCIT was safe and comparable in both children and adults with AR.

Conclusions

Children with AR may achieve better long-term efficacy of HDM-SCIT than adults with AR.

Role of Der p 1-specific B cells in immune tolerance during 2 years of house dust mite-specific immunotherapy

BACKGROUND

Long-term follow-up of allergen-specific B cells in terms of immunoglobulin isotype expression, plasmablast differentiation, and regulatory B (Breg) cell development during allergen-specific immunotherapy (AIT) has not been reported.

OBJECTIVE

Allergen-specific B-cell responses during 2 years of house dust mite AIT were compared between responder and nonresponder patients.

METHODS

B cells specific for Der p 1 were detected by using the fluorochrome-labeled allergen method. The frequency of IgA-, IgG₁- and IgG₄-switched Der p 1-specific B cells, plasmablasts, and IL-10- and IL-1 receptor antagonist (IL-1RA)-producing Breg cells were investigated and correlated to clinical response to AIT.

RESULTS

Sixteen of 25 patients completed the 2-year study. Eleven responder patients showed a successful response to AIT, as measured by a decrease in symptom-medication scores from 13.23 ± 0.28 to 2.45 ± 0.24 (P = .001) and a decrease in skin prick test reactivity to house dust mite from 7.0 ± 1.3 to 2.7 ± 0.5 mm (P = .001). IgG₄⁺ and IgA⁺ Der p 1-specific B cells showed a significant increase after AIT, with a significantly greater frequency in responders compared with nonresponders in the IgG₄⁺ but not the IgA⁺ fraction. The frequency of plasmablasts and IL-10- and/or IL-1RA-producing Breg cells was greater among responders compared with nonresponders after 2 years. The increased frequency of Der p 1-specific IgG4⁺ B cells, plasmablasts, and IL-10⁺ and dual-positive IL-10⁺IL-1RA⁺ Breg cells significantly correlated with improved clinical symptoms over the course of AIT.

CONCLUSION

Allergen-specific B cells in patients responding to AIT are characterized by increased numbers of IgA- and IgG₄-expressing Der p 1-specific B cells, plasmablasts, and IL-10⁺ and/or IL-1RA⁺ Breg cells.

Recent developments and highlights in allergen immunotherapy

Allergen immunotherapy (AIT) is the only disease-modifying treatment option for patients with IgE-mediated inhalant allergies. Though used in clinical practice for more than 100 years, most innovations in AIT efficacy and safety have been developed in the last two decades. This expert review aimed to highlight the recent progress in AIT for both application routes, the sublingual (SLIT) and subcutaneous (SCIT) forms. As such, it covers recent aspects regarding efficacy and safety in clinical trials and real-life data and outlines new concepts in consensus and position papers as well as in guidelines for AIT. Potential clinical and nonclinical biomarkers are discussed. This review also focuses on potential future perspectives in AIT, such as alternative application routes, immune-modulating adjuvants, and recombinant vaccines. In conclusion, this state of the art review provides a comprehensive overview of AIT and highlights unmet needs for the future.

Tregitope-linked Refined Allergen Vaccines for Immunotherapy in Cockroach Allergy

Allergen-specific immunotherapy (AIT) facilitates long-term resolution of allergic morbidity resulting in reduced drug use and increased refractoriness to new sensitization. AIT effectiveness has been demonstrated in seasonal and perennial allergies, and insect stings. However, data and studies in AIT relative to cockroach (CR) allergy are relatively scarce. In this study, mice allergic to American CR (Periplaneta americana) were treated with a liposome (L)-entrapped vaccine made of mouse Tregitope289-Per a 9 of the CR, Tregitope167-Per a 9, or Per a 9 alone - or placebo. Allergic mice that received an individual vaccine intranasally had reduced Th2 response, reduced lung inflammation, and reduced respiratory tissue remodeling. However, only L-Tregitope289-Per a 9 and L-Tregitope167-Per a 9 induced expression of immunosuppressive cytokine genes (IL-10, TGF-β, and IL-35 for L-Tregitope289-Per a 9, and IL-10 and TGF-β for L-Tregitope167-Per a 9) and increment of idoleamine-2,3-dioxygenase 1 (IDO1), indicating that these vaccines caused allergic disease suppression and reversal of respiratory tissue remodeling via generation of regulatory lymphocytes. Liposome entrapped-recombinant Per a 9 (L-Per a 9) did not cause upregulation of immunosuppressive cytokine genes and IDO1 increment; rather, L-Per a 9 induced high expression of IFN-γ in lungs of treated mice, which resulted in mitigation of allergic manifestations. This study provides compelling evidence that both liposome-entrapped vaccines made of single refined major allergen alone and single refined major allergen linked with Tregitopes are effective for reducing allergen-mediated respiratory tissue inflammation and remodeling, but through different mechanisms.

Allergen immunotherapy in people, dogs, cats and horses - differences, similarities and research needs

In human patients with seasonal allergic rhinoconjunctivitis sensitized to grass pollen, the first successful allergen immunotherapy (AIT) was reported in 1911. Today, immunotherapy is an accepted treatment for allergic asthma, allergic rhinitis and hypersensitivities to insect venom. AIT is also used for atopic dermatitis and recently for food allergy. Subcutaneous, epicutaneous, intralymphatic, oral and sublingual protocols of AIT exist. In animals, most data are available in dogs where subcutaneous AIT is an accepted treatment for atopic dermatitis. Initiating a regulatory response and a production of "blocking" IgG antibodies with AIT are similar mechanisms in human beings and dogs with allergic diseases. Although subcutaneous immunotherapy is used for atopic dermatitis in cats, data for its efficacy are sparse. There is some evidence for successful treatment of feline asthma with AIT. In horses, most studies evaluate the effect of AIT on insect hypersensitivity with conflicting results although promising pilot studies have demonstrated the prophylaxis of insect hypersensitivity with recombinant antigens of biting midges (Culicoides spp.). Optimizing AIT using allergoids, peptide immunotherapy, recombinant allergens and new adjuvants with the different administration types of allergen extracts will further improve compliance and efficacy of this proven treatment modality.

Precision/Personalized Medicine in Allergic Diseases and Asthma

Like many other chronic diseases, every allergic patient has different characteristics based on clinical course, treatment responsiveness and disease outcomes, which are associated with the genetic and epigenetic control of molecular mechanisms and environment. This variability necessitates the establishment of patient-tailored and precision approaches in handling allergic disorders. Better understanding of the underlying pathophysiological mechanisms for the development of allergic disorders will provide more rationale strategies based on individual cases in controlling and treating these disorders. Endotyping, phenotyping, genotyping and theratyping, and biomarkers are keywords in this area and have been gaining lots of attention in the field of precision medicine, which aims to revolutionize patient care and develop better prevention and treatment strategies. In addition, precision health is a new concept that brings precise approaches to the scene for being healthy and prevention of allergic disease and asthma. The specialty of allergy has a leading role in the field, because allergen-specific immunotherapy started 105 years ago, and is historically a leading personalized/precision medicine approach in all medicine disciplines providing the possibility of cure in an individualized manner instead of conventional symptomatic treatments.

Duration of Allergen Immunotherapy for Long-Term Efficacy in Allergic Rhinoconjunctivitis

RATIONALE

Subcutaneous and sublingual immunotherapy are effective for allergic rhinitis. An important question is whether allergen immunotherapy provides a sustained clinical effect after treatment cessation. In view of potential side effects, cost and the necessary patient commitment, long-term benefit is an important consideration for the recommendation of immunotherapy over standard pharmacotherapy.

PURPOSE OF REVIEW

In this review, we analyse the existing evidence for long-term effects of both routes of administration in the context of double-blind, placebo-controlled, randomised clinical trials that included a follow-up phase of at least 1 year after treatment cessation.

RECENT FINDINGS

Overall, evidence suggests that 3 years of either subcutaneous or sublingual immunotherapy result in clinical benefit and immunological changes consistent with allergen-specific tolerance sustained for at least 2-3 years after treatment cessation.

SUMMARY

The data presented here support recommendations in international guidelines that both routes of administration should be continued for a minimum of 3 years. Gaps in the evidence remain regarding the long-term efficacy of immunotherapy for perennial rhinitis and studies performed in children.

New approaches to allergen immunotherapy

OBJECTIVE

New insights into mechanisms should enable strategic improvement of allergen immunotherapy, aiming to make it safer, faster, more effective, and able to induce long-term tolerance. We review novel approaches with potential to translate into clinical use.

DATA SOURCES

Database searches were conducted in PubMed, Scopus, and Google Scholar.

STUDY SELECTIONS

Search terms were based on current and novel approaches in immunotherapy. Literature was selected primarily from recent randomized double-blinded placebo-controlled trials and meta-analyses.

RESULTS

Alum, microcrystalline tyrosine, and calcium phosphate are adjuvants in current use. Toll-like receptor-4 agonists combined with allergen have potential to shorten duration of treatment. Other novel adjuvants, nanoparticles, and virus-like particles in combination with allergen have shown early promise. Omalizumab lessens systemic side effects but does not improve efficacy. Intralymphatic immunotherapy for aeroallergens, epicutaneous immunotherapy for food allergens, and use of modified allergens (allergoids), recombinant allergens (and hypoallergenic variants), and T- and B-cell peptide approaches have shown evidence of efficacy and permitted shortened courses but have only rarely been compared with conventional extracts.

CONCLUSION

Novel routes of immunotherapy, use of modified allergens, and combination of allergens with immunostimulatory adjuvants or immune modifiers have been developed to augment downregulation of T-helper cell type 2 immunity and/or induce "protective" blocking antibodies. Although these strategies have permitted shortened courses, confirmatory phase 3 trials are required to confirm efficacy and safety and head-to-head trials are required for comparative efficacy. Currently, subcutaneous and sublingual immunotherapies using in-house standardized crude extracts remain the only approaches proved to induce long-term tolerance.

The global development and clinical efficacy of sublingual tablet immunotherapy for allergic diseases

Allergy immunotherapy (AIT) is a treatment option for respiratory allergy that is complementary to pharmacotherapy, with a distinct mechanism of action. Alternative methods to subcutaneous administration of AIT that enable patients to safely self-administer AIT is considered an unmet clinical need. The sublingual immunotherapy tablet (SLIT-tablet) is an orally disintegrating pharmaceutical formulation (oral lyophilisate) containing standardized allergens. SLIT-tablets have been developed for sublingual immunotherapy (SLIT) of cedar-pollen, grass-pollen, ragweed-pollen, tree-pollen, and house dust mite allergies. It is a once-daily tablet treatment to be self-administered after the first dose has been provided under the supervision of a physician with experience in the diagnosis and treatment of allergic diseases. Once the first dose is adequately tolerated, subsequent doses may be self-administered. SLIT-tablets have proven efficacy for allergic rhinitis (AR) with and without conjunctivitis (C) and allergic asthma (AA) in adults, children, and poly-sensitized allergic patients. Meta-analyses indicate that SLIT-tablets have superior or similar efficacy compared with anti-allergic pharmacotherapies for seasonal AR and superior efficacy for perennial AR. SLIT-tablets have also demonstrated clinically relevant improvements of asthma, with significant reductions in the following: daily inhaled corticosteroid use, risk of asthma exacerbations, and asthma symptoms. SLIT-tablets are generally well tolerated, with a low risk of systemic allergic reactions. The most common treatment-related adverse events are mild-moderate oral reactions. Current evidence supports SLIT-tablets to be considered as an alternative or add-on treatment to pharmacotherapy for AR/C and asthma. Future SLIT developments may include early intervention to prevent the development or progression of allergic disease in children.

Mechanisms of allergen-specific immunotherapy: Diverse mechanisms of immune tolerance to allergens

OBJECTIVE

The aim of this review is to provide an overview of the current knowledge on the mechanisms of allergen immunotherapy based on the recent publications and clinical trials.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

In this review, we focus on diverse mechanisms of AIT and provide an insight into alternative routes of administration. Additionally, we review and discuss the most recent studies investigating potential biomarkers and highlight their role in clinical settings.

RESULTS

Successful allergen-specific immunotherapy (AIT) induces the reinstatement of tolerance toward allergens and represents a disease-modifying treatment. In the last decades, substantial progress in understanding the mechanisms of AIT has been achieved. Establishment of long-term clinical tolerance to allergens engages a complex network of interactions, modulating the functions of basophils, mast cells, allergen-specific regulatory T and B cells, and production of specific antibodies. The reduction of symptoms and clinical improvement is achieved by skewing the immune response away from allergic inflammation.

CONCLUSION

Although the complex nature of AIT mechanisms is becoming more clear, the need to discover reliable biomarkers to define patients likely to respond to the treatment is emerging.

MiR-302e attenuates allergic inflammation in vitro model by targeting RelA

Allergic inflammation is the foundation of allergic rhinitis and asthma. Although microRNAs are implicated in the pathogenesis of various diseases, information regarding the functional role of microRNAs in allergic diseases is limited. Herein, we reported that microRNA-302e (miR-302e) serves as an important regulator of allergic inflammation in human mast cell line, HMC-1 cells. Our results showed that miR-302e is the dominant member of miR-302 family expressed in HMC-1 cells. Moreover, the expression of miR-302e was significantly decreased in response to phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187 or ovalbumin (OVA) stimulation. Overexpression of miR-302e blocked PMA/A23187 or OVA induced the increase in inflammatory cytokines levels, such as IL-1β, IL-6, tumor necrosis factor (TNF)-α and thymic stromal lymphopoietin, while miR-302 inhibition further promoted the release of these cytokines. Mechanistically, we found that miR-302e is a novel miRNA that targets RelA, a gene known to be involved in regulating inflammation, through binding to the 3'-UTR of RelA mRNA. Ectopic miR-302e remarkably suppressed the luciferase activity and expression of RelA, whereas down-regulation of miR-302e increased RelA luciferase activity and expression. Pharmacological inhibition of NF-κB reversed the augmented effect of miR-302e down-regulation on inflammatory cytokines level. Taken together, the present study demonstrates miR-302e limits allergic inflammation through inhibition of NF-κB activation, suggesting miR-302e may play an anti-inflammatory role in allergic diseases and function as a novel therapeutic target for the treatment of these diseases.

The relevance of house dust mites allergy in clinical practice: the epidemiological impact on allergen immunotherapy

House dust mite (HDM) is the most common cause of respiratory allergy worldwide. The impact of HDM allergy is influenced by a number of factors, including local climate. We investigated such issue in Italy, using a real-life setting, including outpatients visited at allergy clinics. In 9143 patients (7873 adults and 1270 children) who were evaluated in 15 allergy clinics, investigating as well the rate of prescription of allergen immunotherapy. The present study confirms that Mediterranean climate is associated with a higher prevalence of mite allergy than continental climate. This significant difference may have an impact on allergen immunotherapy prescription, which should be more common in areas with higher prevalence of HDM allergy.

Next generation immunotherapy for tree pollen allergies

Tree pollen induced allergies are one of the major medical and public health burdens in the industrialized world. Allergen-Specific Immunotherapy (AIT) through subcutaneous injection or sublingual delivery is the only approved therapy with curative potential to pollen induced allergies. AIT often is associated with severe side effects and requires long-term treatment. Safer, more effective and convenient allergen specific immunotherapies remain an unmet need. In this review article, we discuss the current progress in applying protein and peptide-based approaches and DNA vaccines to the clinical challenges posed by tree pollen allergies through the lens of preclinical animal models and clinical trials, with an emphasis on the birch and Japanese red cedar pollen induced allergies.

Adjuvants for allergy immunotherapeutics

Allergic diseases are reaching epidemic proportions in developed countries. In particular, food allergy is increasing in prevalence and severity, thus becoming an important socioeconomic burden. Numerous cell types and cell populations, which form an intricate and balanced network, are involved in an immune response. This balance is occasionally disturbed, leading to the onset of different diseases, such as allergic diseases. Antihistamines and corticosteroids provide some degree of relief from the symptoms of allergic conditions. However, the only treatment that can revert the disease is immunotherapy. Nevertheless, specific immunotherapy has at least 2 major drawbacks: it is time-consuming, and it can produce local and even systemic allergic side effects. Immunotherapy's potential goes beyond our current knowledge of the immune response; nevertheless, we can still design strategies to reach a safer immune modulation for treating allergies. This review deals with the use of adjuvants to reduce the undesirable side effects associated with specific allergen immunotherapy. For example, nanoparticles used as immunoadjuvants are offering promising results in preclinical assays.

Subcutaneous immunotherapy suppresses Th2 inflammation and induces neutralizing antibodies, but sublingual immunotherapy suppresses airway hyperresponsiveness in grass pollen mouse models for allergic asthma

BACKGROUND

Both subcutaneous and sublingual allergen immunotherapy (SCIT and SLIT) have been shown to effectively suppress allergic manifestations upon allergen exposure, providing long-term relief from symptoms in allergic disorders including allergic asthma. Clinical studies directly comparing SCIT and SLIT report a different kinetics and magnitude of immunological changes induced during treatment. Comparative studies into the mechanisms underlying immune suppression in SCIT and SLIT are lacking.

OBJECTIVE

We aimed to establish an experimental model for grass pollen (GP) SCIT and SLIT that would allow a head-to-head comparison of the two treatments.

METHODS

BALB/c mice were sensitized with GP extract, followed by SCIT and SLIT treatments with various GP dosages. Subsequently, we challenged mice with GP and measured airway responsiveness (AHR), GP-specific immunoglobulins, ear swelling tests (EST), eosinophilic inflammation in bronchoalveolar lavage fluid (BALF), and T cell cytokine release after restimulation of lung cells (IL-5, IL-10, and IL-13).

RESULTS

We find that SLIT treatment was able to suppress allergen-induced AHR, while allergic inflammation was not effectively suppressed even at the highest GP dose in this model. In contrast, SCIT treatment induced higher levels of GP-specific IgG1, while SLIT was superior in inducing a GP-specific IgG2a response, which was associated with increased Th1 activity in lung tissue after SLIT, but not SCIT treatment. Interestingly, SCIT was able to suppress Th2-type cytokine production in lung cell suspensions, while SLIT failed to do so.

CONCLUSIONS AND CLINICAL RELEVANCE

In conclusion, GP-SCIT suppresses Th2 inflammation and induced neutralizing antibodies, while GP-SLIT suppresses the clinically relevant lung function parameters in an asthma mouse model, indicating that the two application routes depend on partially divergent mechanisms of tolerance induction. Interestingly, these data mirror observations in clinical studies, underscoring the translational value of these mouse models.

A Three-Year Course of House Dust Mite Sublingual Immunotherapy Appears Effective in Controlling the Symptoms of Allergic Rhinitis

Background Allergic rhinitis is the most common allergic disorder. Although the management of the disease is successful in many patients, based on guidelines, some of them remain with symptoms uncontrolled with pharmacotherapy. Presently, there is no substantiated information on the control of allergic rhinitis in patients who underwent sublingual immunotherapy. Objective The purpose of this prospective follow-up study was to assess the control of allergic rhinitis in adults after a three-year course of house dust mite sublingual immunotherapy. Methods This prospective real-life study was designed to include adults with moderate to severe allergic rhinitis sensitized to house dust mite who underwent a three-year course of sublingual immunotherapy. Control of symptoms was assessed by Rhinitis Control Assessment Test (RCAT) after three years of house dust mite sublingual immunotherapy. Additionally, patients assessed their symptoms by utilizing a visual analog scale. Results A total number of 86 consecutively enrolled patients (46 (53.49%) men; mean age 26.10 years (SD = 5.85)) with moderate to severe allergic rhinitis and clinically relevant sensitization to house dust mite were evaluated. When assessed by RCAT on the third year, 74 (86.05%) had well-controlled symptoms and 20 (27.03%) of them were completely controlled. A significant reduction in visual analog scale scores-from 7.52 cm at baseline to 2.31 cm-was established ( P < 0.0001). There was a strong negative correlation between RCAT scores and visual analog scale (r = -0.65; P < 0.01). Conclusion This study provided evidence that a three-year course of house dust mite sublingual immunotherapy appears effective in controlling the symptoms of allergic rhinitis.

Immunotherapy for pet allergies

Allergic diseases compose a serious challenge for modern societies. Their individual, medical and economical burden is large. As humans spend most of their time indoors, exposure to indoor allergens is a significant contributor to the development of allergic sensitization and respiratory allergies, such as allergic rhinoconjunctivitis and asthma. One important source of indoor allergens are pets, in particular cats and dogs. Allergens from these and other mammals spread effectively and they are encountered widely in public places. If patient education, allergen avoidance and pharmacotherapy do not suffice for controlling the symptoms of pet allergy, allergen immunotherapy can be a treatment option. Current information on allergen immunotherapy in pet allergy suggests that it can be effective in reducing allergic symptoms. However, the low number of high-quality randomized controlled trials of allergen immunotherapy in pet allergy warrants for further investigations.

Allergen immunotherapy for the treatment of respiratory allergies in the elderly

PURPOSE OF REVIEW

Respiratory allergies, including asthma and allergic rhinitis can also occur in the elderly. Allergen immunotherapy for allergic diseases is the only disease-modifying treatment for patients with allergies available thus far. Here, we review current evidence supporting the use of allergen immunotherapy in the elderly and discuss its efficacy and utility for the treatment of respiratory allergic diseases in this setting.

RECENT FINDINGS

Subcutaneous and/or sublingual immunotherapy are effective therapeutic options in not only young but also older patients. Allergen immunotherapy reduces medication and symptom scores in the elderly and can thus be safely prescribed in this population.

SUMMARY

Elderly individuals with proven, clinically relevant immunoglobulin E sensitization to inhalant allergens may benefit from allergen immunotherapy for respiratory allergic diseases. Older patients without contraindications should therefore be considered for treatment, with the additional benefit of reduced medication and symptom scores.

A roadmap towards personalized immunology

Big data generation and computational processing will enable medicine to evolve from a "one-size-fits-all" approach to precise patient stratification and treatment. Significant achievements using "Omics" data have been made especially in personalized oncology. However, immune cells relative to tumor cells show a much higher degree of complexity in heterogeneity, dynamics, memory-capability, plasticity and "social" interactions. There is still a long way ahead on translating our capability to identify potentially targetable personalized biomarkers into effective personalized therapy in immune-centralized diseases. Here, we discuss the recent advances and successful applications in "Omics" data utilization and network analysis on patients' samples of clinical trials and studies, as well as the major challenges and strategies towards personalized stratification and treatment for infectious or non-communicable inflammatory diseases such as autoimmune diseases or allergies. We provide a roadmap and highlight experimental, clinical, computational analysis, data management, ethical and regulatory issues to accelerate the implementation of personalized immunology.

A Retrospective Study of Clinical Response Predictors in Subcutaneous Allergen Immunotherapy With House Dust Mites for Allergic Rhinitis

Purpose

House dust mites (HDM) are major allergens that cause allergic rhinitis (AR). Allergen-specific subcutaneous immunotherapy (SCIT) has been shown to be clinically beneficial in many clinical trials. Such trials, however, are not reflective of all patient populations. The aim of this study was to describe the efficacy and safety of SCIT in routine clinical practice in Korean adults with AR sensitized to HDM.

Methods

We reviewed medical records of 304 patients with AR treated at an allergy clinic of a tertiary hospital using SCIT with aluminum hydroxide-adsorbed allergen extract targeting HDM alone or with pollens for at least 1 year from 2000 to 2012. Patients with asthma were excluded. Rates of remission, defined as no further requirement of maintenance medication, over time were determined by means of life tables and extension of survival analysis. Specific immunoglobulin E (IgE) levels to HDM were categorized into 6 classes.

Results

The mean time until achieving remission was 4.9±0.1 years, and the cumulative incidence of remission from AR was 76.6%. Severe AR (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.23-0.69; P=0.001), specific IgE levels to HDM ≥17.5 kU/L (OR, 1.85; 95% CI, 1.01-3.37; P=0.045), and duration of immunotherapy ≥3 years (OR, 7.37; 95% CI, 3.50-15.51; P<0.001) were identified as significant predictors of clinical remission during SCIT for patients with AR sensitized to HDM. Overall, 73 patients (24.0%) experienced adverse reactions to SCIT, and only 1 case of anaphylaxis (0.3%) developed.

Conclusions

SCIT with HDM was found to be effective and safe for patients with AR. Specific IgE levels to HDM and a duration of SCIT ≥3 years may be predictors of clinical responses to SCIT in AR patients.

Ultra-short-course booster is effective in recurrent grass pollen-induced allergic rhinoconjunctivitis

BACKGROUND

A relevant proportion of allergic rhinoconjunctivitis (ARC) patients experience recurrent symptoms after successfully completing allergen immunotherapy (AIT). This prospective, controlled, noninterventional study used internationally standardized instruments to determine the clinical effects of a preseasonal, ultra-short-course booster AIT on clinical outcome parameters.

METHODS

This two-arm study included patients aged ≥12 years with recurrent grass pollen-induced seasonal AR who had completed a successful course of any grass pollen AIT at least 5 years before enrolment. Overall, 56 patients received one preseasonal short-course booster AIT using tyrosine-absorbed grass pollen allergoids containing the adjuvant monophosphoryl lipid A (MPL® ); 51 control patients received symptomatic medication. The combined symptom and medication score (CSMS) was recorded in the (peak) grass pollen season. Furthermore, concomitant (antiallergic) medication use, the patients' state of health, Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) results and safety/tolerability of the treatment were assessed.

RESULTS

The CSMS in the peak grass pollen season was significantly lower in the booster AIT group (Δ=38.4%, P<.01). Moreover, significantly more patients in this group used no concomitant antiallergic medication throughout the peak grass pollen season. Twice as many patients in the booster AIT group as in the control group reported having a better state of health than in the preceding season. MiniRQLQ results showed significant differences favouring the booster AIT. The booster AIT was generally well tolerated, with only two patients reporting mild, grade 1 systemic adverse events.

CONCLUSION

Booster AIT using tyrosine-absorbed allergoids containing the adjuvant MPL® effectively prevents re-occurrence of symptoms in patients with grass pollen-induced ARC.

Quality of life improvement after a three-year course of sublingual immunotherapy in patients with house dust mite and grass pollen induced allergic rhinitis: results from real-life

BACKGROUND

Along with its high prevalence, the burden of allergic rhinitis rests upon the serious impact on quality of life of patients. Allergic rhinitis is associated with impairments in daily activities, work and school performance, and practical problems. Patients suffer from sleep disorders and emotional problems. Тhe advantages of sublingual immunotherapy on quality of life have only recently begun to emerge. The objective of this prospective real-life study was to evaluate the effect of a three-year course of sublingual immunotherapy with house dust mite (HDM) and grass pollen extracts on quality of life in adults with allergic rhinitis.

METHODS

A total number of 191 adult patients [105 (54,979%) men; mean age 27.3 years (SD-6.14)] with moderate to severe allergic rhinitis and clinically relevant sensitization to house dust mites or grass pollen were prospectively evaluated in the course of management of their disease. Health-related quality of life was assessed by Rhinoconjunctivitis Quality of Life Questionnaire at baseline and after three-year course of sublingual immunotherapy.

RESULTS

The mean overall Qol score assessed at baseline and at the end of the third year of treatment decreased significantly in patients treated with HDM extract (from 2.95 to 0.76) as well as with Grass pollen extract (from 2.83 to 1.22) (р < 0.001). The improvements in treated with HDM extract were as followed: activities - 3.52 to 0.68; sleep- 2.48 to 0.31; general problems - 1.79 to 0.49; practical problems - 3.57 to 0.68; nasal symptoms - 3.91 to 0.74; eye symptoms - 2.92 to 0.39; emotions - 3.03 to 0.39. The improvements in grass pollen group were: activities - 3.68 to 1.69; sleep- 1.85 to 0.84; general problems - 1.74 to 0.97; practical problems - 3.52 to 1.37; nasal symptoms - 3.72 to 1.57; eye symptoms - 3.58 to 1.3; emotions - 2.48 to 1.19.

CONCLUSION

Our study conducted in real life provided evidence that a three-year course of SLIT with HDM extract as well as with grass pollen extract significantly increased QoL in patients with allergic rhinitis.

Advances and highlights in allergen immunotherapy: On the way to sustained clinical and immunologic tolerance

Allergen immunotherapy (AIT) is an effective treatment strategy for allergic diseases and has been used for more than 100 years. In recent years, however, the expectations on concepts, conduct, statistical evaluation, and reporting have developed significantly. Products have undergone dose-response and confirmative studies in adults and children to provide evidence for the optimal dosage, safety, and efficacy of AIT vaccines using subcutaneous and sublingual delivery pathways in large patient cohorts, ensuring solid conclusions to be drawn from them for the advantage of patients and societies alike. Those standards should be followed today, and products answering to them should be preferred over others lacking optimization and proof of efficacy and safety. Molecular and cellular mechanisms of AIT include early mast cell and basophil desensitization effects, regulation of T- and B-cell responses, regulation of IgE and IgG₄ production, and inhibition of responses from eosinophils, mast cells, and basophils in the affected tissues. There were many developments to improve vaccination strategies, demonstration of new molecules involved in molecular mechanisms, and demonstration of new biomarkers for AIT during the last few years. The combination of probiotics, vitamins, and biological agents with AIT is highlighting current advances. Development of allergoids and recombinant and hypoallergenic vaccines to skew the immune response from IgE to IgG₄ and regulation of dendritic cell, mast cell, basophil, innate lymphoid cell, T-cell, and B-cell responses to allergens are also discussed in detail.

Benefit of SLIT and SCIT for Allergic Rhinitis and Asthma

Allergen immunotherapy (AIT) has been in use since more than one century, when Leonard Noon experimentally proved its efficacy in hayfever (Noon, in Lancet 1:1572-3, 1911). Since then, AIT was administered only as subcutaneous injections (SCIT) until the sublingual route (SLIT) was proposed in 1986. The use of SLIT was proposed following several surveys from the USA and UK that repeatedly reported fatalities due to SCIT (Lockey et al. in J Allergy Clin Immunol 75(1): 166, 1985; Lockey et al. in J Allergy Clin Immunol 660-77, 1985; Committee on the safety of medicines. CSM update. Desensitizing vaccines. Br Med J, 293: 948, 1986). These reports raised serious concerns about the safety and the risk/benefit ratio of AIT. Many cases of life-threatening events with SCIT were due to avoidable human errors in administration, but a relevant fraction of them remained unexplained and unpredictable (Aaronson and Gandhi in J Allergy Clin Immunol 113: 1117-21, 2014). Subsequently, in a few years, SLIT gained credibility and was included in the official documents and guidelines (Table 1) (Bousquet et al. in J Allergy Clin Immunol 108(5 Supp):S146-S150, 2001; Canonica et al. in Allergy 64 (Supp 91):1-59, 2009) as a viable alternative to traditional SCIT. Of note, the local bronchial (aerosol) and the intranasal route of administration were attempted after the 1970s as alternatives to SCIT: the bronchial route was soon abandoned due to the poor efficacy and/or side effects, and the local nasal route, although effective and safe, was judged substantially impractical (Canonica and Passalacqua in J Allergy Clin Immunol 111: 437-48, 2003). In contrast to SCIT, SLIT was tested in very large clinical trials (need references), including hundreds of patients and with dose-ranging experimental designs, so that some products (tablets) for grass, mite, and ragweed were officially approved as commercial drugs by regulatory agencies such as the Food and Drug Administration and the European Medicines Agency and the optimal content for the maintenance dose was identified for selected allergens. In parallel, the knowledge on the mechanisms of action of AIT was rapidly refined, leading to further improvements, such as the chemically modified extracts and the use of adjuvants to enhance efficacy and safety. In addition, in the last 10 years, there has been an increasing scientific and clinical interest in AIT applied to food allergies, in particular in children, with the use of orally administered extracts (Albin and Nowak-Węgrzyn in Immunol Allergy Clin North Am 35: 77-100, 2015). The results are so far encouraging, at least for cow's milk, egg, and peanut, although the use of treatment is still restricted to clinical trials or within specialized centers. Finally, the introduction of molecular- or component-resolved diagnosis has allowed detailing the prescription of AIT, by better delineating true sensitization versus cross-reactivity (Canonica et al. in World Allergy Organ J 6(1):17, 2013). This latter point is also in strict relation to the use of recombinant, engineered or highly purified molecules, instead of raw extracts, for the desensitization process.

Therapeutic intranasal instillation of allergen-loaded microbubbles suppresses experimental allergic asthma in mice

Despite proven efficiency, subcutaneous immunotherapy for aeroallergens is impaired by the duration of the protocol, the repeated injections and potential side-effects associated with the doses of allergen administered. Intranasal delivery of immunotherapeutic agents may overcome several of these drawbacks, provided that an efficient allergen delivery vehicle can be identified. This study evaluates whether intranasally delivered gas-filled microbubble (MB)-associated ovalbumin (OVA), used as a model allergen, can serve as a therapeutic treatment in a mouse model of established allergic asthma. Lung and systemic production of pro-tolerogenic markers, including Foxp3⁺ CD4 T cells, IL-10, and TGF-β, as well as the Th1-type cytokine IFN-γ, was observed after intranasal immunization with OVA-MB. Post-treatment, aerosol-sensitized mice exhibited the same pattern of markers. Moreover, decrease of eosinophils and neutrophils in BALs, lower frequencies of Th2 cytokine- and IL-17-producing CD4 T cells in lungs and reduced specific IgE in BALs and sera after allergen challenge were observed. Concomitantly, lung resistance and mucus production diminished in OVA-MB-treated animals. Thus, therapeutic intranasal administration of OVA-MBs in established experimental allergic asthma allows modulating pathology-associated immune and physiological parameters usually triggered after exposure to the allergen.

Beneficial effects of Galectin-9 on allergen-specific sublingual immunotherapy in a Dermatophagoides farinae-induced mouse model of chronic asthma

BACKGROUND

Allergen-specific sublingual immunotherapy is a potential disease-modifying treatment for allergic asthma. Galectin-9 (Gal-9), a β-galactoside-binding protein with various biologic effects, acts as an immunomodulator in excessive immunologic reactions by expanding regulatory T cells (Treg) and enhancing transforming growth factor (TGF)-β signaling. We investigated the efficacy of sublingually administered Gal-9 as an adjuvant to a specific allergen in a Dermatophagoides farinae (Df)-induced mouse model of chronic asthma.

METHODS

BALB/c mice were intranasally sensitized with Df extract 5 days/week for 5 weeks, and then sublingual Df-allergen extract for 2 weeks (5 days/week). Three days after the final sublingual treatment, mice were intranasally challenged with Df extract. The early asthmatic response (EAR) was evaluated 5 min after the last Df challenge. Airway hyperresponsiveness (AHR) was assayed and bronchoalveolar lavage (BAL) was performed 24 h after the last allergen challenge. Serum IgE and cytokine levels, and number of inflammatory cells in the BAL fluid (BALF) were analyzed.

RESULTS

Sublingual Df treatment in the presence of Gal-9, but not alone, significantly reduced AHR; EAR; number of eosinophils and interleukin-13 in the BALF; and serum IgE levels. BALF TGF-β1 levels were significantly increased in the presence of Gal-9 compared with Df alone. Treg depletion blocked the inhibitory effects of Gal-9 on the EAR, AHR, eosinophilic airway inflammation, and Df-specific serum IgE levels, and suppressed BALF TGF-β1 levels.

CONCLUSIONS

Gal-9 exhibited beneficial effects of sublingual Df allergen-specific immunotherapy in a Df-induced mouse model of chronic asthma, possibly by Gal-9-induced TGF-β1 production in the lung.

A practical guide to the sublingual immunotherapy tablet adverse event profile: implications for clinical practice

OBJECTIVES

Treatment with allergy immunotherapy improves allergic rhinoconjunctivitis, but can also improve comorbidities associated with allergic rhinitis such as asthma. Sublingual immunotherapy (SLIT)-tablets are a convenient and efficacious method of allergy immunotherapy. They are self-administered after the first tablet has been provided under medical supervision. Therapy may elicit local reactions or, rarely, systemic allergic reactions. The objective of this report is to inform healthcare practitioners about the safety and tolerability profile of SLIT-tablets and use this information to provide practical guidance that may inform patients regarding potential adverse reactions and how to manage them.

METHODS

Pooled analyses of safety data from completed randomized, multicenter, double-blind, placebo-controlled phase 2 and phase 3 US and EU trials of timothy grass, short ragweed, and SQ house dust mite SLIT-tablets were conducted to characterize safety and tolerability.

RESULTS

SLIT-tablets are generally well tolerated. No life-threatening events, serious systemic allergic reactions, or events that compromised the airway have been reported. The most common treatment-related adverse events (AEs) are oral site reactions, most of which begin on day 1 of treatment, recur for less than 2 weeks, and resolve after approximately 30-60 minutes. Systemic allergic reactions have been managed with conventional pharmacotherapy. Reactions treated with epinephrine are uncommon, but have been reported. Treatment of AEs, treatment discontinuation considerations, and patient FAQs regarding SLIT-tablet safety/tolerability are discussed.

CONCLUSIONS

This report gives healthcare providers valuable information to educate patients regarding what to expect in terms of SLIT-tablet safety and tolerability. Practical guidance is also provided to ensure proper treatment of any adverse reactions.

Allergic rhinitis: the eligible candidate to mite immunotherapy in the real world

As standard drug treatment of allergic rhinitis (AR) is not completely satisfactory, allergen immunotherapy (AIT) represents the only current treatment with the potential to modify the natural history. House dust mite (HDM) allergy is very common. The aim of the current experience was to describe the clinical profile of HDM-allergic patients with AR who received AIT in a real world model, such as allergy clinics. Globally, 239 patients (126 adults and 113 children; 107 females and 132 males; mean age 21 years, age range 6-56 years) were evaluated. AIT was prescribed in 59 patients (24.7%), 44 adults (35%) and 15 children (13.3%). The current findings deriving from this real world multicentre study are consistent with previous investigations on HDM-AIT and define some clinical characteristics of the eligible candidate to this treatment. In fact, severity of ocular-nasal symptoms and over-use of symptomatic medications may typify the ideal candidate to HDM-AIT and SLIT was the preferred choice.

Effect of adjuvanted and standard sublingual immunotherapy on respiratory function in pure rhinitis due to house dust mite over a 5-year period

BACKGROUND

Allergen-specific immunotherapy (AIT) still remains the only causal treatment for IgE mediated respiratory diseases (rhinitis/asthma) In addition to the observed clinical decrease in symptoms, AIT can provide a long-lasting and preventive effect. In particular it can modify the progression from rhinitis to asthma.

METHODS

The study was observational, open, non randomized, controlled, prospective and performed in a real-life setting. Patients with pure mite-induced allergic rhinitis were followed-up, receiving adjuvanted SLIT (aSLIT), standard SLIT (sSLIT) or drug treatment alone, according to their preference starting between 2008 and 2009. The possible onset of asthma, changes in pulmonary function and bronchial hyperreactivity (BHR) were assessed over a 5-year horizon. Also the onset of new sensitizations and symptoms-medication score (SMS) were evaluated.

RESULTS

One hundred forty two patients fulfilling the inclusion criteria were assessed at baseline, and 124 had the 5-year evaluation (age range 8-57, 69 male). After 5 years of treatment, new sensitizations appeared differentially among treatments with 58.1% of new sensitizations in the drug treatment group, 13.2% in the sSLIT patients, and 8.1% in the aSLIT patients. At the end of 5 years, SMS significantly changed (P < 0.001) in all groups, with a negative trend for controls, as compared to the SLIT treatments. The SMS decreased in both SLIT groups at 5 years, with no change in patients on drug treatment alone. The use of salbutamol (absent at baseline), showed an overall increase only in the group receiving drugs alone with a significant difference at 5 years (P < 0.001). Considering the MCh challenge, there was a difference among treatments (P < 0.001) in PD20 after 5 years: the control group had a lower PD20 at 5 years. No significant difference in PD20 was detected between sSLIT and aSLIT. The FEV1 significantly decreased in controls, with no change in the sSLIT group and a significant increase in aSLIT as compared to sSLIT.

DISCUSSION

Despite the limitations inherent to a real-life setting study (absence of randomization and control, small sample size, lack of intermediate timepoint assessment) the results of this study evidenced that the investigated SLIT product, either adjuvanted or not, had a positive effect on the evolution of respiratory allergy due to house dust mite.

CONCLUSION

In the real life setting, considering a 5-year period, aSLIT and sSLIT reduced the onset of new sensistizations and maintained intact the pulmonary function, as compared to patients receiving drug treatment alone.

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

IMPORTANCE

Sublingual immunotherapy and subcutaneous immunotherapy are effective in seasonal allergic rhinitis. Three years of continuous treatment with subcutaneous immunotherapy and sublingual immunotherapy has been shown to improve symptoms for at least 2 years following discontinuation of treatment.

OBJECTIVE

To assess whether 2 years of treatment with grass pollen sublingual immunotherapy, compared with placebo, provides improved nasal response to allergen challenge at 3-year follow-up.

DESIGN, SETTING, AND PARTICIPANTS

A randomized double-blind, placebo-controlled, 3-parallel-group study performed in a single academic center, Imperial College London, of adult patients with moderate to severe seasonal allergic rhinitis (interfering with usual daily activities or sleep). First enrollment was March 2011, last follow-up was February 2015.

INTERVENTIONS

Thirty-six participants received 2 years of sublingual immunotherapy (daily tablets containing 15 µg of major allergen Phleum p 5 and monthly placebo injections), 36 received subcutaneous immunotherapy (monthly injections containing 20 µg of Phleum p 5 and daily placebo tablets) and 34 received matched double-placebo. Nasal allergen challenge was performed before treatment, at 1 and 2 years of treatment, and at 3 years (1 year after treatment discontinuation).

MAIN OUTCOMES AND MEASURES

Total nasal symptom scores (TNSS; range; 0 [best] to 12 [worst]) were recorded between 0 and 10 hours after challenge. The minimum clinically important difference for change in TNSS within an individual is 1.08. The primary outcome was TNSS comparing sublingual immunotherapy vs placebo at year 3. Subcutaneous immunotherapy was included as a positive control. The study was not powered to compare sublingual immunotherapy with subcutaneous immunotherapy.

RESULTS

Among 106 randomized participants (mean age, 33.5 years; 34 women [32.1%]), 92 completed the study at 3 years. In the intent-to-treat population, mean TNSS score for the sublingual immunotherapy group was 6.36 (95% CI, 5.76 to 6.96) at pretreatment and 4.73 (95% CI, 3.97 to 5.48) at 3 years, and for the placebo group, the score was 6.06 (95% CI, 5.23 to 6.88) at pretreatment and 4.81 (95% CI, 3.97 to 5.65) at 3 years. The between-group difference (adjusted for baseline) was -0.18 (95% CI, -1.25 to 0.90; [P = .75]).

CONCLUSIONS AND RELEVANCE

Among patients with moderate to severe seasonal allergic rhinitis, 2 years of sublingual grass pollen immunotherapy was not significantly different from placebo in improving the nasal response to allergen challenge at 3-year follow-up.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01335139; EudraCT Number: 2010-023536-16.

Allergic diseases in the elderly: biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging.

Allergen-specific immunotherapy: is it vaccination against toxins after all?

IgE-mediated allergies, in particular allergic rhinoconjunctivitis and asthma, have reached epidemic proportions, affecting about one-third of the population in developed countries. The most effective treatment for allergies is specific immunotherapy (SIT), which involves the injection of increasing doses of an allergen extract to allergic individuals. The current form of SIT was first introduced in 1911 and recently celebrated its 100th birthday for the treatment of hay fever. The concept of this therapy at the time was straightforward, as it was believed that pollen contained toxins against which the patient could be vaccinated. However, the understanding became blurred with the discovery that IgE antibodies were the effector molecules of the allergic response. Subsequent research focused on the idea that SIT should induce tolerance keeping the IgE antibodies at bay. In this review, we will discuss the various hypotheses for the mechanism of SIT and we will put forward the concept that allergens may be viewed as 'protoxins' which need to be activated by IgE antibodies. Within this framework, protoxin-neutralizing antibodies are the key effector molecules while a shift to Th1 or Treg cells mainly contributes to the efficacy of SIT by helping B cells to produce neutralizing IgG antibodies.

Asthma phenotypes in children and stratified pharmacological treatment regimens

INTRODUCTION

Asthma is the most common inflammatory disease in childhood. The interaction of genetic, environmental and host factors may contribute to the development of childhood asthma and defines its progress, including persistence and severity. Until now, various classifications of childhood asthma phenotypes have been suggested based on patient's age during onset of symptoms, type of inflammatory cells, response to treatment and disease severity. Many efforts have been carried out to identify childhood asthma phenotypes and to clarify which are the risk factors that define asthma prediction and the response to therapy. The identification of asthma phenotypes has not only prognostic but also therapeutic role. However, the classification of asthma phenotypes is complex due to the heterogeneity of the disease. Areas covered: The current childhood asthma phenotypes and the new therapeutic strategies for each phenotype are reviewed. Expert commentary: There are multiple phenotypes in childhood asthma and it is crucial to define them before the initiation of personalized treatment. Both the therapeutic strategy and monitoring should follow the recent guidelines.

Allergen-Specific Immunotherapy

Allergen-specific immunotherapy remains the only causal treatment of allergic disease to date. Its efficacy in symptom reduction was demonstrated in double blind, placebo-controlled studies of allergic rhinoconjunctivitis, allergic asthma, and Hymenoptera venom hypersensitivity, including long-term effects after discontinuation of treatment. In addition, immunotherapy decreases the risk of developing new sensitisations to aeroallergens in monosensitised patients and allergic asthma in patients with mere allergic rhinitis. The mechanism of immunotherapy entails redirection of the T lymphocyte response from a T helper cell Type 2 phenotype in favour of induction of regulatory T cells and/or immune deviation toward a T helper cell Type 1 phenotype, with resulting inhibition of downstream effector pathways and induction of immunoglobulin G-associated blocking antibodies. Two main application forms are used in clinical practice: subcutaneous immunotherapy and sublingual immunotherapy. The advantage of subcutaneous immunotherapy is its proven efficacy over a broad range of indications. Disadvantages are systemic allergic reactions and inconvenience for the patient due to frequent doctor visits. Sublingual immunotherapy has been shown to result in less systemic allergic reactions and may be more convenient due to home application; however, efficacy has only been proven for allergic rhinitis. For clinicians, the adherence to practice guidelines and thorough knowledge of allergen products, application routes, indications, immunomodulatory mechanisms, efficacy, safety, and cost-effectiveness is important for successful treatment and will be addressed in this review article.

Atractylone, an active constituent of KMP6, attenuates allergic inflammation on allergic rhinitis in vitro and in vivo models

KMP6 (Pyeongwee-San) is a Korean Medicine used to treat gastrointestinal disorders. Recently, we reported KMP6 had beneficial effects on allergic inflammatory diseases. The aim of this study was to evaluate the effects of atractylone (Atr), a constituent of KMP6, on allergic rhinitis (AR) and to identify the mechanism responsible for these effects. The anti-allergic inflammatory effects of Atr were evaluated on phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-stimulated human mast cell line, HMC-1 cells and in an ovalbumin (OVA)-induced AR animal model using Western blotting, quantitative real-time PCR, ELISA, and immunohistochemistry methods. In HMC-1 cells, Atr and KMP6 attenuated PMACI-caused proinflammatory cytokine production and mRNA expression. We found that PMACI induced caspase-1/nuclear factor (NF)-κB/mitogen activated protein kinases (MAPKs) activation. PMACI-caused caspase-1/NF-κB/MAPKs activations were attenuated by Atr and KMP6. In AR animal model, Atr and KMP6 reduced AR clinical symptoms and biomarkers including rub scores, total IgE, histamine, prostaglandin D₂, thymic stromal lymphopoietin, interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-13, tumor necrosis factor-α, cyclooxygenase-2, intercellular adhesion molecule-1, and macrophage inflammatory protein-2. In addition, Atr and KMP6 attenuated eosinophils and mast cells invasions into nasal mucosa tissues and diminished mast cell-derived caspase-1 activation. These results indicate that Atr is an active constituent of KMP6 and a potential therapeutic agent for AR.