Allergen-specific immunotherapy in atopic eczema

House Dust Mite Precision Allergy Molecular Diagnosis (PAMD@) in the Th2-prone Atopic Dermatitis Endotype

Atopic dermatitis (AD) endotyping might be important for developing personalized diagnostic and therapeutic strategies to the different phenotypes. The current study investigated the IgE molecular profile to Dermatophagoides pteronyssinus (D. pteronyssinus) in a subset of patients afflicted with varying severity stages of atopic dermatitis in a subtropical region subjected to a high perennial house dust mite (HDM) exposure. We selected patients showing a clinically relevant sensitization to HDM with mild-to-moderate and severe AD according to their basal Severity Scoring Atopic Dermatitis (SCORAD) index. Skin prick test (SPT) with standardized mite extracts, as well as a Precision Allergy Molecular Diagnosis (PAMD@) panel including nine different D. pteronyssinus allergens and the related protein allergenic characterization, were assessed in all serum samples. A total of 80 European American AD patients with the marked T2 endotype confirmed their eligibility for the study. Major allergens (Der p 23, Der p 2, and Der p 1) were present in more than 86% of all subjects, with mid-tier allergens (Der p 5, Der p 7, and Der p 21) reaching up to 65%. A serodominant role for Der p 11 could not be quantitatively confirmed in the present cohort. The proposed component resolved diagnosis (CRD) panel appeared to be sufficient to obtain a precise D. pteronyssinus molecular diagnosis in AD patients subjected to a climate-dependent high-mite allergen exposure. The raised seroprevalence of IgE response to Der p 23 confirmed this constituent as a major D. pteronyssinus allergen in severe stages of atopic dermatitis. A clinically driven molecular approach appears to be essential to frame a more precise diagnosis and therapy of this heterogeneous allergic condition.

Allergic Rhinitis: What Do We Know About Allergen-Specific Immunotherapy?

Allergic rhinitis (AR) is an IgE-mediated disease that is characterized by Th2 joint inflammation. Allergen-specific immunotherapy (AIT) is indicated for AR when symptoms remain uncontrolled despite medication and allergen avoidance. AIT is considered to have been effective if it alleviated allergic symptoms, decreased medication use, improved the quality of life even after treatment cessation, and prevented the progression of AR to asthma and the onset of new sensitization. AIT can be administered subcutaneously or sublingually, and novel routes are still being developed, such as intra-lymphatically and epicutaneously. AIT aims at inducing allergen tolerance through modification of innate and adaptive immunologic responses. The main mechanism of AIT is control of type 2 inflammatory cells through induction of various functional regulatory cells such as regulatory T cells (Tregs), follicular T cells (Tfr), B cells (Bregs), dendritic cells (DCregs), innate lymphoid cells (IL-10⁺ ILCs), and natural killer cells (NKregs). However, AIT has a number of disadvantages: the long treatment period required to achieve greater efficacy, high cost, systemic allergic reactions, and the absence of a biomarker for predicting treatment responders. Currently, adjunctive therapies, vaccine adjuvants, and novel vaccine technologies are being studied to overcome the problems associated with AIT. This review presents an updated overview of AIT, with a special focus on AR.

Mite allergy and atopic dermatitis: Is there a clear link? (Review)

Atopic dermatitis (AD) represents a widespread chronic skin disease associated with different atopic disorders and allergies. These associations, similar to overall AD pathophysiology, are entangled, multifactorial and they are yet to be clarified. IgE and non IgE mediated pathomechanisms appear to be implicated in AD. Allergens constitute key aspects in AD pathogenesis, as they may serve as trigger factors. This review emphasizes mainly house dust mites (HDM), as they are likely the most relevant airborne allergen for AD. Here we review in a concise form the mite allergens, the role of molecular diagnosis and the treatment strategies for HDM. Strategies of avoiding allergens, with a few exceptions, are not enough to control children's AD; recent studies show HDM avoidance procedures in diagnosed AD are insufficient. Regardless, some guidelines acknowledge the benefit of mattress and pillow covers in patients with dust mite sensitization that are unresponsive to optimal AD management. Most clinical trials investigating allergen-specific immunotherapy (AIT) as a potential treatment for AD were done with adult patients; a scarce number of studies looked into the efficacy of AIT as a treatment option in children suffering from AD, with conflicting data among them. One of the most feasible of these studies showed significant improvement of AD outcomes only in the mild/moderate group, but not in the severe group. Uncontrolled studies are hard to interpret, considering the natural history of remitting and relapsing of AD, in many of the patients, without clinical interventions. More AIT studies, especially pediatric studies, are required in order to either prove the reproducibility of positive results or to deny its effectiveness.

Consensus-based European guidelines for treatment of atopic eczema (atopic dermatitis) in adults and children: part II

This guideline was developed as a joint interdisciplinary European project, including physicians from all relevant disciplines as well as patients. It is a consensus-based guideline, taking available evidence from other guidelines, systematic reviews and published studies into account. This second part of the guideline covers antimicrobial therapy, systemic treatment, allergen-specific immunotherapy, complementary medicine, psychosomatic counselling and educational interventions, whereas the first part covers methods, patient perspective, general measures and avoidance strategies, basic emollient treatment and bathing, dietary intervention, topical anti-inflammatory therapy, phototherapy and antipruritic therapy. Management of AE must consider the individual clinical variability of the disease. Systemic immunosuppressive treatment with cyclosporine, methotrexate, azathioprine and mycophenolic acid is established option for severe refractory cases, and widely available. Biologicals targeting the T helper 2 pathway such as dupilumab may be a safe and effective, disease-modifying alternative when available. Oral drugs such as JAK inhibitors and histamine 4 receptor antagonists are in development. Microbial colonization and superinfection may cause disease exacerbation and can require additional antimicrobial treatment. Allergen-specific immunotherapy with aeroallergens may be considered in selected cases. Psychosomatic counselling is recommended especially in stress-induced exacerbations. Therapeutic patient education ('Eczema school') is recommended for children and adult patients. General measures, basic emollient treatment, bathing, dietary intervention, topical anti-inflammatory therapy, phototherapy and antipruritic therapy have been addressed in the first part of the guideline.

Allergen immunotherapy in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic relapsing skin disease, characterized by flare-up due to the exposure to allergens in patients sensitized to them. Currently, therapy of AD is mainly based on symptomatic treatment and avoidance of irritating/allergenic factors, house dust mites being particularly important. Allergen immunotherapy (AIT) is suggested to be the only etiologic treatment, to modify the natural history of the disease. Areas covered: The aim of this review is investigating the putative role of AIT in AD through the evaluation of the most recent scientific literature. Several studies have been conducted since 1970, with promising results in improving the clinical outcome of AD, but they often lack the necessary scientific rigorousness. Moreover, heterogeneity of the studies makes it very difficult to compare and to analyze data in a systematic review or meta-analysis. Expert commentary: As a result of the above-mentioned limitations, the treatment of AD with causative aeroallergen can nowadays be suggested only as an add-on therapy in selected patients who are non-responsive to the traditional therapy.

Debates in allergy medicine: specific immunotherapy efficiency in children with atopic dermatitis

Allergen specific immunotherapy (AIT) has been the only pathogenetically relevant treatment of IgE-mediated allergic diseases (ADs) for many years. The use of AIT for atopic dermatitis (AD) treatment is dubious and has both followers and opponents. The improvement of subcutaneous AIT (SCIT) and introduction of Sublingual immunotherapy (SLIT) gives prospects of their application both for adults and children suffering from AD. This review presents results of scientific research, system and meta-analyses that confirm the clinical efficacy of AIT for children with AD who has the sensitization to allergens of house dust mite, grass and plant pollen suffering from co-occurring respiratory ADs and with moderate and severe course of allergic AD. There have been analyzed the most advanced achievements in AIT studies as well as there have been specified the unmet needs in AD. The preliminary diagnostics of IgE-mediated AD and pathophysiological disorders, including immune ones, will allow a doctor to develop appropriate comprehensive treatment algorithm for children's AD aimed at its correction. The including of AIT to the children's comprehensive therapy program is reasonable only if AD has the allergic form. It is necessary better to design the randomized research studies and to acquire extended clinical practice in children with AD. Use of the successes of molecular-based allergy diagnostics will help to optimize and personalize the process of selecting the necessary allergens to determine the most appropriate vaccines for children considering the results of the allergen component diagnostics. The strategy of treatment of children with AD in future will be based on individual target therapy.

Consensus Conference on Clinical Management of pediatric Atopic Dermatitis

The Italian Consensus Conference on clinical management of atopic dermatitis in children reflects the best and most recent scientific evidence, with the aim to provide specialists with a useful tool for managing this common, but complex clinical condition. Thanks to the contribution of experts in the field and members of the Italian Society of Pediatric Allergology and Immunology (SIAIP) and the Italian Society of Pediatric Dermatology (SIDerP), this Consensus statement integrates the basic principles of the most recent guidelines for the management of atopic dermatitis to facilitate a practical approach to the disease. The therapeutical approach should be adapted to the clinical severity and requires a tailored strategy to ensure good compliance by children and their parents. In this Consensus, levels and models of intervention are also enriched by the Italian experience to facilitate a practical approach to the disease.

Retrospective Analysis on the Effects of House Dust Mite Specific Immunotherapy for More Than 3 Years in Atopic Dermatitis

PURPOSE

In extrinsic atopic dermatitis (AD), house dust mites (HDM) play a role in eliciting or aggravating allergic lesions. The nature of skin inflammation in AD has raised a growing interest in allergen-specific immunotherapy (SIT). Thus, we assessed clinical improvement and laboratory parameters for evaluation of the benefit of long-term SIT.

MATERIALS AND METHODS

A total of 217 AD patients who were treated with SIT for at least 3 years were retrospectively assessed, by using their investigator global assessment, pruritus scores, loss of sleep (LOS), total serum IgE, and eosinophil counts collected. Patients were additionally classified into subgroups according to age, initial AD severity and mono- or multi-sensitization to include different individual factors in the evaluation of SIT efficacy. Lastly, we compared laboratory data of good responders to SIT with that of poor responders to SIT.

RESULTS

Improvement after SIT therapy was observed in 192 out of 217 patients (88.4%). Among these patients, 138 (63.5%) achieved excellent, near-complete or complete clinical remission. Significant reduction of pruritus, LOS, and the mean value of total serum IgE were observed (p<0.01). Better outcome was found in patients younger than 12 years of age (p=0.024). Patients with moderate to severe AD showed better treatment outcomes (p=0.036). Patients sensitized only to HDM had the better response to treatment, but SIT was also effective in multi-sensitized groups (p=1.051). No significant differences in baseline laboratory results were observed between good and poor responders (p>0.05).

CONCLUSION

We emphasize the usefulness of long-term HDM SIT as a disease-modifying therapy for AD.

Allergen-Specific Immunotherapy with Monomeric Allergoid in a Mouse Model of Atopic Dermatitis

Atopic dermatitis (AD) is a widespread and difficult to treat allergic skin disease and is a tough challenge for healthcare. In this study, we investigated whether allergen-specific immunotherapy (ASIT) with a monomeric allergoid obtained by succinylation of ovalbumin (sOVA) is effective in a mouse model of atopic dermatitis. An experimental model of AD was reproduced by epicutaneous sensitization with ovalbumin (OVA). ASIT was performed with subcutaneous (SC) administration of increasing doses of OVA or sOVA. The levels of anti-OVA antibodies, as well as cytokines, were detected by ELISA. Skin samples from patch areas were taken for histologic examination. ASIT with either OVA or sOVA resulted in a reduction of both the anti-OVA IgE level and the IgG1/IgG2a ratio. Moreover, ASIT with sOVA increased the IFN-γ level in supernatants after splenocyte stimulation with OVA. Histologic analysis of skin samples from the sites of allergen application showed that ASIT improved the histologic picture by decreasing allergic inflammation in comparison with untreated mice. These data suggest that ASIT with a succinylated allergen represents promising approach for the treatment of AD.

Specific immunotherapy in atopic dermatitis

Allergen specific immunotherapy (SIT) using house dust mite (HDM) extracts has been performed mainly with patients of asthma and allergic rhinitis. In the meanwhile, there has been a long debate on the efficacy of SIT in atopic dermatitis (AD) with only a few double-blind placebo-controlled trials. However, several randomized controlled trials of SIT in AD revealed significant improvement of clinical symptoms and also, positive result was shown by a following meta-analysis study of these trials. In order to predict and evaluate the treatment outcome, finding a biomarker that can predict treatment responses and treatment end-points is critical but it is very challenging at the same time due to the complexity of causes and mechanisms of AD. Other considerations including standardization of the easiest and safest treatment protocol and optimizing the treatment preparations should be studied as well. This review summarizes the basics of SIT in AD including the brief mechanisms, treatment methods and schedules, and also highlights the clinical efficacy of SIT in AD along with mild, controllable adverse reactions. Immunologic effects and studies of various biomarkers are also introduced and finally, future considerations with upcoming studies on SIT were discussed.

Immunological changes after ASIT in AD allergen-specific immunotherapy and their potential correlation with clinical response in patients with atopic dermatitis patients sensitized to house dust mite

BACKGROUND

Allergen-specific immunotherapy (ASIT) is the main treatment for inducing long-term immunological and clinical tolerance in patients with IgE-mediated allergic diseases. Recent open-label and controlled studies on the efficacy of ASIT in patients with atopic dermatitis (AD) have provided promising results. However, data about possible relationship between the improvement of clinical symptoms and changes of serum cytokines are limited.

METHODS

Seventy-nine patients with moderate to severe AD sensitized to house dust mite (HDM) were enrolled. Fifty-eight patients were treated with ASIT and 11 controls received only symptomatic treatment. The disease activity in AD patients was evaluated by using the patient-oriented eczema measure (POEM) system. Serum interleukin (IL)-4, IL-10, interferon (IFN)-γ, transforming growth factor (TGF) β1, total IgE, HDM-specific IgE (s-IgE) and HDM-specific IgG4 (s-IgG4) were measured before and after 2 years of therapy.

RESULTS

The mean patient-oriented eczema measure system (POEM) score of AD patients with ASIT significantly decreased after 2 years of treatment, compared to that in patients without ASIT. After ASIT, the serum levels of IL-10, TGF-β1, IFN-γ and s-IgG4 increased, while the level of IL-4 decreased. The change in the POEM score was negatively correlated with changes of serum concentration of TGF-β1, s-IgG4 and IFN-γ. Furthermore, s-IgG4 levels were positively correlated with changes in the IL-10 levels. No correlation between POEM score and serum IL-10 or IL-4 was observed.

CONCLUSION

Clinical symptoms and the quality of life of AD with HDM sensitization could be improved after 2 years of ASIT. Changes in serum IL-10, TGF-β1, s-IgG4 and IFN-γ might be considered as biomarkers to assist clinical evaluation of the therapeutic effects of ASIT in patients with AD.

Management of difficult-to-treat atopic dermatitis

Atopic dermatitis is a complex disorder caused by the interplay between multiple genetic and environmental factors. Particularly in patients with severe disease, the effect is not just an itchy rash but also the secondary effects on the psychological well-being of the patient and their carers, particularly disturbed sleep. The aim of this review is to provide health care professionals with a holistic approach to the management of difficult-to-treat atopic dermatitis, defined as atopic dermatitis seemingly unresponsive to simple moisturizers and mild potency (classes VI and VII) topical corticosteroids. The critical importance of education and advice is emphasized, as is the seminal role of secondary bacterial infection and polyclonal T-cell activation in causing acute flares in patients with severe, generalized disease. In atypical cases or those that do not respond to treatment, alternative diagnoses should be considered.

Guidelines for treatment of atopic eczema (atopic dermatitis) Part II

The existing evidence for treatment of atopic eczema (atopic dermatitis, AE) is evaluated using the national standard Appraisal of Guidelines Research and Evaluation. The consensus process consisted of a nominal group process and a DELPHI procedure. Management of AE must consider the individual symptomatic variability of the disease. Basic therapy is focused on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin inhibitors (TCI) is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the TCI tacrolimus and pimecrolimus are preferred in certain locations. Systemic immune-suppressive treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Adjuvant therapy includes UV irradiation preferably with UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. 'Eczema school' educational programs have been proven to be helpful. Pruritus is targeted with the majority of the recommended therapies, but some patients need additional antipruritic therapies.