New opportunities and challenges in the assessment of drugs for atopic diseases

Prioritizing research challenges and funding for allergy and asthma and the need for translational research-The European Strategic Forum on Allergic Diseases

The European Academy of Allergy and Clinical Immunology (EAACI) organized the first European Strategic Forum on Allergic Diseases and Asthma. The main aim was to bring together all relevant stakeholders and decision-makers in the field of allergy, asthma and clinical Immunology around an open debate on contemporary challenges and potential solutions for the next decade. The Strategic Forum was an upscaling of the EAACI White Paper aiming to integrate the Academy's output with the perspective offered by EAACI's partners. This collaboration is fundamental for adapting and integrating allergy and asthma care into the context of real-world problems. The Strategic Forum on Allergic Diseases brought together all partners who have the drive and the influence to make positive change: national and international societies, patients' organizations, regulatory bodies and industry representatives. An open debate with a special focus on drug development and biomedical engineering, big data and information technology and allergic diseases and asthma in the context of environmental health concluded that connecting science with the transformation of care and a joint agreement between all partners on priorities and needs are essential to ensure a better management of allergic diseases and asthma in the advent of precision medicine together with global access to innovative and affordable diagnostics and therapeutics.

Direct assessment of skin epithelial barrier by electrical impedance spectroscopy

BACKGROUND

Many skin and mucosal inflammatory disorders, such as atopic dermatitis, have been associated with an impaired epithelial barrier function, which allows allergens, pollutants, or microbes to enter the tissue and activate the immune response. The aim of this study was to establish a method to directly assess in vivo the epidermal barrier function by electrical impedance (EI) spectroscopy.

METHODS

Mice epidermal barrier was damaged by epicutaneous application of proteases and cholera toxin and by tape stripping. EI and transepidermal water loss (TEWL) were measured before and after the application. Additionally, histological analysis, immunofluorescence staining, and RT-PCR were performed on skin biopsies to evaluate the epithelial barrier.

RESULTS

A few hours after papain application, a dose-dependent reduction of EI was detected, reflecting the decreased barrier function. At the same time, an increase of TEWL was observed, with a significant negative correlation with EI, demonstrating that EI changes were directly linked to barrier defects. Twenty-four and 48 hours after the treatment, EI starts to increase to background levels, indicating tissue healing and restoration of skin barrier. Barrier disruption was confirmed by histological analysis showing an impaired stratum corneum and higher cellular infiltration after papain application. In addition, immunofluorescence staining and RT-PCR showed downregulation of molecules involved in the barrier function, such as filaggrin, occludin, and claudin-1, and mRNA levels of filaggrin, loricrin, and involucrin. Comparable results were observed after tape stripping and cholera toxin treatment.

CONCLUSION

Electrical impedance spectroscopy is a rapid and reliable diagnostic tool to detect skin barrier defects.

Efficacy of Probiotic Therapy on Atopic Dermatitis in Adults Depends on the C-159T Polymorphism of the CD14 Receptor Gene - A Pilot Study

BACKGROUND:

The C-159T polymorphism of the CD14 receptor gene can be associated with the development of atopic dermatitis. Probiotics can modulate chronic inflammation through activation of the CD14 receptor. So, the efficacy of probiotic therapy can be dependent on this genetic polymorphism.

AIM:

The purpose of the study was to investigate the efficacy of adding probiotic (Lactobacillus acidophilus, LA-5 and Bifidobacterium animalis subsp. lactis, BB-12) to standard treatment (ointment of fluticasone propionate 0.005% and emollient) of atopic dermatitis in adults during 28 days, depending on the stratification of patients on CC or TT genotypes of the CD14 receptor gene.

MATERIAL AND METHODS:

The study included 37 adult patients with AD. There were identified 19 patients with exogenous (IgE-dependent) and 18 with endogenous (IgE-dependent) AD. To evaluate the efficacy of the probiotics all patients were divided into three groups for both exogenous and endogenous AD. The first group was selected from patients with CC genotype (C-159T) who received standard therapy (ointment of fluticasone propionate 0.005% – 2 times a day, emollients – 2 times a day) and probiotic (Lactobacillus acidophilus, LA-5 and Bifidobacterium animalis subsp. lactis, BB-12 - 1 capsule 2 times per day) The second group included patients with CC genotype, who received only standard therapy. The third group was presented by patients with TT genotype (C-159T) who received standard therapy and probiotic. The SCORAD and DLQI parameters were evaluated on Day 0, 14 and 28. The level of IL-4, IL-5, IL-10, TGF-β cytokines was determined on Day 0 and Day 28.

RESULTS:

The results of our study found that the addition of probiotics (Lactobacillus acidophilus, LA-5 and Bifidobacterium animalis subsp. lactis, BB-12) to standard treatment (ointment of fluticasone propionate 0.005%, emollient) significantly increased the effectiveness of treatment of atopic dermatitis in adults with exogenous form and CC genotype (C-159T), confirmed by clinical (a significant decrease of SCORAD and DLQI indices) and immunological criteria (a significant decrease of IL-4 and an increase of TGF-β).

CONCLUSION:

Simultaneous determination of the exogenous or endogenous form, identification of the C-159T genotypes, evaluation of the serum level of IL-4 and TGF-β can serve as an algorithm for the personalised treatment of patients with atopic dermatitis.

Validation of Patient-Reported Outcomes for Clinical Trials in Allergic Rhinitis: A Systematic Review

Although regulatory authorities have recently recommended the use of a combined symptom-medication score as a primary efficacy end point, none has been psychometrically validated. Here, we sought to determine to what extent allergic rhinitis (AR)-related patient-reported outcomes (symptom scores, medication scores, disease control scores, and satisfaction or quality-of-life scales) have been assessed for construct, content, and/or criterion validity, reliability, responsiveness, and the minimal clinically important difference. We searched the PubMed database from January 1997 to June 2018 with logical combinations of key words related to validation, AR, and patient-rated outcomes and scales. From a total of 1705 potentially relevant publications, 55 were reviewed. Despite the current emphasis on a combined symptom-medication score for evaluating the efficacy of allergen immunotherapy in AR, symptom scores have not been extensively validated, and we did not find any publications describing the validation of a medication score. Disease control scales (mainly the Rhinitis Control Assessment Test, the Control of Allergic Rhinitis and Asthma Test, and the Allergic Rhinitis Control Test) and health-related quality-of-life scales (mainly the Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ] and the mini-RQLQ) have been extensively validated in AR but have some practical disadvantages as primary efficacy criteria in clinical trials.

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.

Changing perspectives in atopic dermatitis

Atopic dermatitis (AD) is a multifaceted disease that involves a complex interplay between the skin and the immune system. The course of the disease depends strongly on the genetic background of the patient and on yet poorly-defined environmental factors. Changes in lifestyle could be behind the dramatic rise in the prevalence of AD across continents; including hygienic conditions, food, social habits, skin microbiome or exposure to a number of allergens. Although AD typically develops in childhood and disappears after a few years, in a relatively large number of patients it continues into adulthood. Adult AD can also appear de novo but it is often underdiagnosed and its treatment can be challenging. New, highly effective drugs are being developed to manage moderate and severe forms of the disease in adults. In this review, we highlight the most recent developments in diagnostic tools, current insights into the mechanistic basis of this disease, and therapeutic innovations.

Clinical phenotypes and endophenotypes of atopic dermatitis: Where are we, and where should we go?

Atopic dermatitis (AD) is a paradigmatic chronic inflammatory skin disease characterized by a complex pathophysiology and a wide spectrum of the clinical phenotype. Despite this high degree of heterogeneity, AD is still considered a single disease and usually treated according to the "one-size-fits-all" approach. Thus more tailored prevention and therapeutic strategies are still lacking. As for other disciplines, such as oncology or rheumatology, we have to approach AD in a more differentiated way (ie, to dissect and stratify the complex clinical phenotype into more homogeneous subgroups based on the endophenotype [panel of biomarkers]) with the aim to refine the management of this condition. Because we are now entering the era of personalized medicine, a systems biology approach merging the numerous clinical phenotypes with robust (ie, relevant and validated) biomarkers will be needed to best exploit their potential significance for the future molecular taxonomy of AD. This approach will not only allow an optimized prevention and treatment with the available drugs but also hopefully help assign newly developed medicinal products to those patients who will have the best benefit/risk ratio.

How to Define Atopic Dermatitis?

Although atopic dermatitis (AD) is the most common skin disorder, there remains an ongoing debate on this denomination, its definition and the binary view based on immunoglobulin E measurement. The wide spectrum of the clinical phenotype of AD reflects the complex genetic and pathophysiologic mechanisms underlying the disease. The diagnostic criteria have to be reconsidered and adapted to different ethnic populations. There is an urgent need for biomarker discovery further supporting the clinical diagnostic criteria as well as the precision medicine approach on a global level.