New visions in specific immunotherapy in children: an iPAC summary and future trends

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Efficacy of sublingual immunotherapy for allergic asthma: retrospective meta-analysis of randomized, double-blind and placebo-controlled trials

BACKGROUND

Allergen-specific immunotherapy (SIT) is the only available curative choice with a disease-modifying effect against respiratory allergies. The efficacy of SIT via the sublingual route was demonstrated by a number of clinical trials. This meta-analysis was performed to investigate the clinical efficacy and safety of sublingual-specific immunotherapy (SLIT) for allergic asthma.

METHODS

PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched for randomized, double-blind and placebo-controlled (DBPC) trials evaluating the efficacy and safety of SLIT on allergic asthma. Subgroup analyses were performed according to age, type of allergen and duration of SLIT treatment.

RESULTS

Sixteen randomized DBPC trials comprising 794 patients in total met the inclusion criteria. The results suggest that SLIT significantly reduces both symptom [standardized mean difference (SMD), -0.74; P=0.006] and medication scores (SMD, -0.78; P=0.02) compared with placebo. SLIT offers a better clinical response in mite sensitive asthmatics but without confirmed proof from subgroup analyses. Prolonged duration of treatment for more than 12 months brings no additive effects. Improvement in the skin prick test was also observed following immunotherapy. There was no consistent effect on forced expiratory volume in 1 s, serum levels of antigen-specific immunoglobulin G4 and immunoglobulin E in the treated group. The risk of adverse effects was relative risk 2.23 (P=0.01).

CONCLUSIONS

SLIT is safe and clinically effective in reducing symptoms and medication use for allergic asthma. Our subgroup analyses failed to identify a disproportionate benefit of SLIT in any specific group of asthmatics, but some possible trends did emerge.

Paediatric rhinitis: position paper of the European Academy of Allergy and Clinical Immunology

Rhinitis is a common problem in childhood and adolescence and impacts negatively on physical, social and psychological well-being. This position paper, prepared by the European Academy of Allergy and Clinical Immunology Taskforce on Rhinitis in Children, aims to provide evidence-based recommendations for the diagnosis and therapy of paediatric rhinitis. Rhinitis is characterized by at least two nasal symptoms: rhinorrhoea, blockage, sneezing or itching. It is classified as allergic rhinitis, infectious rhinitis and nonallergic, noninfectious rhinitis. Similar symptoms may occur with other conditions such as adenoidal hypertrophy, septal deviation and nasal polyps. Examination by anterior rhinoscopy and allergy tests may help to substantiate a diagnosis of allergic rhinitis. Avoidance of relevant allergens may be helpful for allergic rhinitis (AR). Oral and intranasal antihistamines and nasal corticosteroids are both appropriate for first-line AR treatment although the latter are more effective. Once-daily forms of corticosteroids are preferred given their improved safety profile. Potentially useful add-on therapies for AR include oral leukotriene receptor antagonists, short bursts of a nasal decongestant, saline douches and nasal anticholinergics. Allergen-specific immunotherapy is helpful in IgE-mediated AR and may prevent the progression of allergic disease. There are still a number of areas that need to be clarified in the management of rhinitis in children and adolescents.

The history of pediatric allergy in Europe - from a working group to ESPACI and SP-EAACI

A Working Group on Pediatric Allergology was formed in 1984, which rapidly developed to become the European Society on Pediatric Allergology and Clinical Immunology (ESPACI) in 1988 with its own journal, Pediatric Allergology and Immunology. ESPACI worked together with the European Academy of Allergology and Clinical Immunology (EAACI) to form a Section of Pediatrics within EAACI (SP-EAACI) in 1996. The ESPACI and the SP-EAACI formally merged in 2001. Within the EAACI organization, the Pediatric Section has continued to grow. The Pediatric Section is working to develop pediatric allergology across Europe, focusing on postgraduate education, facilitating the research agenda and advocating for children and adolescents with allergies.

Immunological approaches for tolerance induction in allergy

Allergy is the consequence of an inappropriate inflammatory immune response generated against harmless environmental antigens. In allergic disorders such as asthma and rhinitis, the Th2 mediated phenotype is a result of loss of peripheral tolerance mechanisms. In cases such as these, approaches such as immunotherapy attempt to treat the underlying cause of allergic disease by restoring tolerance. Immunotherapy initiates many complex mechanisms within the immune system that result in initiation of innate immunity, activation of both cellular and humoral B cell immunity, as well as triggering T regulatory subsets which are major players in the establishment of peripheral tolerance. Though studies clearly demonstrate immunotherapy to be efficacious, research to improve this treatment is ongoing. Investigation of allergenicity versus immunogenicity, native versus modified allergens, and the use of adjuvant and modality of dosing are all current strategies for immunotherapy advancement that will be reviewed in this article.

Close collaboration between academia, industry and drug regulators is required in the development of allergen products for specific immunotherapy in children

Modification of the response to allergens at an early stage and thereby of the natural history of a respiratory allergic disease by preventing disease progression would constitute the key benefit of specific immunotherapy (SIT) in children. However, although allergen products for SIT have been on the market on a named-patient basis for many years, long-term efficacy, the optimal duration of the treatment and the optimal dosage have not been sufficiently elaborated until now. The enactment of the Therapy Allergen Ordinance in Germany mandates that allergen products for SIT of the most prevalent allergies must submit an application for marketing authorization to the German authorities. In line with the European Paediatric Regulation, decisions by the European Medicines Agency on agreed paediatric investigation plans must be included in these applications. These regulatory requirements provide a unique opportunity to fill the gap in knowledge concerning the benefits of SIT for children and to obtain the data needed to support evidence-based authorization of allergen products for immunotherapy. This goal can only be achieved through close cooperation between academia, drug regulators and industry as well as parent/patient organizations.

A novel approach in allergen-specific immunotherapy: combination of sublingual and subcutaneous routes

BACKGROUND

Subcutaneous allergen-specific immunotherapy (SIT) has an early onset of action, whereas repeated injections and safety concerns have limited its use in the pediatric age group. Meanwhile, the improved safety profile of the sublingual route has been accepted as an alternative despite its relatively late onset of action.

OBJECTIVE

We sought to improve the efficacy and safety of SIT with a combination of the subcutaneous route in the build-up phase and sublingual maintenance in comparison with the sublingual or subcutaneous routes alone.

METHODS

Fifty-one house dust mite-sensitized children with mild-to-moderate asthma were randomized into one of 4 groups to receive either (1) subcutaneous immunotherapy (SCIT), (2) sublingual immunotherapy (SLIT), (3) SCIT plus SLIT, or (4) pharmacotherapy. Clinical parameters were evaluated at baseline and months 1, 4, 12, and 18. Allergen-specific immunoglobulin levels and allergen-induced IL-5, IL-10, IL-13, IL-17, TGF-β, and IFN-γ levels were evaluated as well.

RESULTS

In the SCIT and SCIT plus SLIT groups, the number of asthma attacks and inhaled corticosteroid dosage decreased compared with baseline values at the months 4, 12, and 18 but only at month 12 in the SLIT group. The improvement in visual analog scores for rhinitis was significant only in the SCIT plus SLIT group. Increases in the levels of regulatory and T(H)1 cytokines were observed both in the SCIT and SLIT groups, with some differences in dynamics. Antigen-specific IgG(4) levels increased in the SCIT and SCIT plus SLIT groups but not in the SLIT group. Clinical symptom scores were correlated positively with IL-5 levels and negatively with antigen-specific IgG(4), IFN-γ, and TGF-β levels.

CONCLUSION

Our novel regimen of immunotherapy, SCIT plus SLIT, appeared promising in that it successfully combined the advantages of the 2 alternatives: rapid onset and potency in SCIT and safety and avoidance of injections in SLIT.

Immunotherapy in asthma

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. Chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing, as well as variable airflow obstruction within the lung. With time, such airflow obstruction may become permanent due to remodeling. It has been treated for more than 100 years by subcutaneous immunotherapy with allergen extracts but in recent years, other forms and types of immunotherapy have been introduced. Perhaps the most successful of these to date, is sublingual immunotherapy, which has attained significant usage in European countries but has yet to make inroads into clinical practice in North America. Other mechanisms to modify the inflammatory responses of asthma have included immunotherapy with recombinant allergens, the use of allergen peptides targeting antigen-specific T cells and the administration of Toll-like receptor agonists coupled to allergen proteins. As the inflammatory responses in asthma frequently involve IgE, a modified monoclonal antibody to IgE and interfering with its binding to the IgE receptor have gained acceptance for treating severe allergic asthma. Other monoclonal antibodies or recombinant receptor antagonists are being assessed for their ability to block other contributors to the inflammatory response. Finally, attempts have been made to generate autoantibody responses to cytokines implicated in asthma. Most of these therapies aim to modify or inhibit the so-called Th 2 immune response, which is implicated in many forms of asthma, or to inhibit cytokines involved in these responses. However, an added benefit of classical immunotherapy seems to be the ability to prevent the allergic progression to new sensitivities and new forms of allergic disease.

Specific immunotherapy improves asthma related quality of life in childhood

BACKGROUND

Asthma is the most common chronic illness in childhood and really affects the everyday life of patients who suffer from it. Since asthma is a common disease, there is a great endeavour to achieve the most appropriate treatment option. Despite inhaled corticosteroids and leukotrien receptor antagonists both being routinely used in asthma treatment, specific immunotherapy is still questioned. There are numerous aspects affecting asthma-related quality of life, such as age; seasons; disease control and severity etc, which are well studied -apart from the type of treatment. With this study we aimed to stress the influence of asthma treatment on quality of life.

METHODS

A total of 102 children, aged 6-18 years, were assigned to classic asthma therapy (n=50) and specific immunotherapy (n=52). The quality of life is assessed using the Standardized Pediatric Asthma Quality of Life Questionnaire (PAQLQ) interviewer-administered Turkish version. Pulmonary function testing was performed on the same day, after the questionnaire was completed.

RESULTS

The PAQLQ total scores were significantly higher in the specific immunotherapy group (p<0.001). Apart from emotional function domain scores; symptoms domain and activity limitation domain scores were higher in the specific immunotherapy group. Emotional function domain scores were similar in the two groups (p>0.05). There were no statistically significant differences in pulmonary function testing results between the two groups (p>0.05). There was a linear correlation between FEV1%, FVC level and total and domain scores of PAQLQ with Spearman Correlation tests.

[Secondary and tertiary prevention of allergic asthma in children]

Asthma is a disease of the lung epithelial barrier, most often associated with allergy in children. Asthma and allergy are two distinct diseases, but the phenotypic expression of asthma depends on atopic status. A better definition of phenotypes of asthma would result in better targeting of prevention and treatment modalities. Secondary prevention aims to prevent the onset of asthma and the acquisition of new sensitizations in sensitized children. Studies concerning allergen avoidance are insufficient to reach a definitive conclusion and antihistamines have not been shown to be effective. The results for specific immunotherapy suggest a benefit to prevent transition from allergic rhinitis to asthma and the onset of new sensitizations. Tertiary prevention aims to reduce symptoms in children with an existing allergic asthma diagnosis. The avoidance of known respiratory allergens will only be effective in combination with management of the whole environment. Specific immunotherapy has a real place, in combination with background therapy. It should be used according to guidelines in appropriately treated patients.

Evaluation of treatment satisfaction in children with allergic disease treated with an antihistamine: an international, non-interventional, retrospective study

BACKGROUND AND OBJECTIVES

Histamine H(1)-receptor antagonists (antihistamines) have been shown to be efficacious and safe in children and are recommended as first-line treatment for the symptoms of allergic rhinitis and urticaria. No published study to date has directly compared satisfaction with the different antihistamines in children in a real-life clinical setting. This study aimed to investigate parent and physician satisfaction with the efficacy and tolerability of oral antihistamine treatment in children and to compare satisfaction between levocetirizine and the other antihistamines used by children in this cohort.

METHODS

This was an international Observational Survey in Children with Allergic Rhinitis (OSCAR). Children aged 2-12 years, with a history of an allergic condition leading to a consultation, were enrolled from 424 primary-care/specialist allergy clinics across Bulgaria, India, Portugal, Romania, Russia, South Korea and Spain. At the consultation, parents and physicians of eligible children completed questionnaires evaluating their satisfaction with specific antihistamines currently employed for management of the child's allergic condition, as well as their intention for future use of that treatment. Parents' satisfaction scores for efficacy, tolerability and global satisfaction with the antihistamine used were primary study outcomes, while physicians' satisfaction scores for the same measures were secondary outcomes. Other secondary outcomes were parents' rating of the impact of the antihistamine treatment on their child's sleep and school performance, and parents' and physicians' willingness to use/recommend the same antihistamine in the future.

RESULTS

A total of 4581 patients were enrolled; 3048 (66.5%) had allergic rhinitis (55.9% persistent allergic rhinitis and 44.1% intermittent allergic rhinitis), and 663 (14.5%) had urticaria as primary conditions. Additionally, 2465 patients (53.8%) suffered from other allergic diseases, including allergic asthma (33.3%), atopic dermatitis (17.6%), food allergy (5.3%), other allergies (5.0%) and drug hypersensitivity (2.0%). Parents' and physicians' satisfaction scores were closely concordant and demonstrated significantly greater global satisfaction for the second-generation antihistamines than for the first-generation antihistamines. Levocetirizine (n = 2339) and fexofenadine (n = 42) generally scored highest for efficacy, tolerability and global satisfaction, as well as for impact on the child's ability to function at school, quality of school activities and quality of sleep. Furthermore, >97% of parents and physicians indicated their desire to continue or recommend the use of levocetirizine in the future. Somnolence, the most commonly reported adverse event in this survey, was observed predominantly in patients treated with first-generation antihistamines. Among second-generation antihistamines, reports of somnolence were most frequent in the cetirizine group.

CONCLUSION

Second-generation antihistamines have a better risk:benefit ratio than first-generation antihistamines, indicating that the latter should be avoided or their use limited in children whenever possible. Levocetirizine and fexofenadine were perceived by parents and physicians to produce significantly higher treatment satisfaction than the majority of the other antihistamines with respect to overall efficacy and tolerability, and impact on the child's sleep and school activities. The newer antihistamine levocetirizine seems to be a preferred and appropriate future treatment choice for children with allergic diseases.

Ultra-short course immunotherapy in children and adolescents during a 3-yrs post-marketing surveillance study

Ultra-short course immunotherapy (uSCIT) has shown good efficacy and tolerability in children and adolescents with seasonal allergic rhinitis (SAR), conjunctivitis and/or asthma in clinical studies. Here, we investigate the efficacy of uSCIT in the juvenile subpopulation of a 3-year post-marketing surveillance (PMS) study. To assess the differences in the efficacy of uSCIT between adults and children respectively adolescents enrolled in a PMS study. In a prospective open study 422 patients aged 6-18 years with SAR, conjunctivitis and/or asthma received four pre-seasonal injections with pollen allergoids formulated with monophosphoryl lipid A (MPL, Pollinex Quattro) over a minimum of 3 weeks. Efficacy was evaluated by response to therapy and consumption of anti-allergic medication during the pollen season. Tolerability was evaluated by patients' acceptance of therapy. These results were compared with the adult subpopulation of this study. Response to treatment was assessed as good or very good in 94% of patients, mirroring findings for the entire cohort. Further improvements were noted in patients receiving subsequent courses of therapy. Anti-allergic medication use decreased from 83% to 24% of patients after the first treatment course (p < 0.0001). Therapy was well accepted by children/adolescents and considered 'very good' or 'good' by 93% of juveniles. No serious adverse events or cases of anaphylaxis were reported. This subanalysis indicated that uSCIT with Pollinex Quattro had similar efficacy and tolerability in children/adolescents and adults. The convenient dosing regimen and favourable safety profile of uSCIT may support a wider uptake of uSCIT in this patient population.

Allergic rhinitis

Childhood rhinitis may be classified into non-allergic and allergic. Allergic rhinitis is further divided into seasonal and perennial. Seasonal rhinitis is a disease particularly of teenagers and young adults and appears to be less common in primary and pre school age children. In seasonal rhinitis, with relevant grass pollen sensitization, the link between the allergen exposure and rhinitis is clear cut. However, in other situations such as perennial rhinitis and house dust mite allergen sensitization, the link between symptoms and allergen exposure is less certain. Avoidance of allergens often proves to be difficult in practice. Intranasal steroids are the treatment of choice for persistent moderate-severe allergic rhinitis and are more effective than antihistamines for relief of nasal obstruction. Antihistamines are effective for control of histamine related symptoms such as itching, rhinorrhoea and sneezing. The use and benefits of sublingual or injectable immunotherapy in children are controversial.

Scientific rationale for the Finnish Allergy Programme 2008-2018: emphasis on prevention and endorsing tolerance

In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both the costs and morbidity of asthma. The time, in the wake of the Asthma Programme, is now opportune for a national allergy programme, particularly as in the past few years, fundamentally more essential data on tolerance and its mechanisms have been published. In this review, the scientific rationale for the Finnish Allergy Programme 2008-2018 is outlined. The focus is on tolerance and how to endorse tolerance at the population level.