Skin, gut, and lung barrier: Physiological interface and target of intervention for preventing and treating allergic diseases.

The epithelial barriers of the skin, gut, and respiratory tract are critical interfaces between the environment and the host, and they orchestrate both homeostatic and pathogenic immune responses. The mechanisms underlying epithelial barrier dysfunction in allergic and inflammatory conditions, such as atopic dermatitis, food allergy, eosinophilic oesophagitis, allergic rhinitis, chronic rhinosinusitis, and asthma, are complex and influenced by the exposome, microbiome, individual genetics, and epigenetics. Here, we review the role of the epithelial barriers of the skin, digestive tract, and airways in maintaining homeostasis, how they influence the occurrence and progression of allergic and inflammatory conditions, how current treatments target the epithelium to improve symptoms of these disorders, and what the unmet needs are in the identification and treatment of epithelial disorders.

Nasal allergen-neutralizing antibodies correlate closely with tolerated intranasal allergen challenge dose following grass pollen subcutaneous immunotherapy in patients with local allergic rhinitis.

BACKGROUND: Local allergic rhinitis (LAR) is defined by chronic nasal symptoms, absence of atopy, positive nasal allergen challenge (NAC) and a good response to subcutaneous allergen immunotherapy (SCIT). We sought to investigate SCIT capacity to induce local and systemic blocking antibodies in LAR patients. METHODS: A RDBPC study of grass SCIT was performed, with participants receiving either SCIT (Group A; n = 10) or placebo (Group B; n = 14) in the first 6 months. Both groups subsequently received SCIT for 12 months at Year 2. Nasal and serum antibodies (IgG4, IgA1 and IgA2) and their inhibitory capacity were measured at multiple timepoints. RESULTS: The allergen concentration tolerated increased significantly at 6 months (Group A; p = .047) and 24 months (Group B; p = .049) compared with baseline and persisted until the end of the study. Induction of serum sIgA1 to Phl p was seen in Groups A and B, albeit the former being induced earlier (1.71-fold, p = .027). A significant induction in sIgG4 to Phl p 1 and 5 was observed in serum of Group A (p = .047 and p = .0039) and sIgA2 to Phl p in Group B (p = .032 and p = .0098) at 18 and 24 months, respectively. Both local and systemic blocking antibodies can inhibit allergen-IgE complexes binding to CD23 on B cells, and this correlated with level of allergen tolerated intra-nasally in Group A (serum; 𝜌 = -.47, p = .0006, nasal; 𝜌 = -.38, p = .0294). CONCLUSIONS: Grass pollen SCIT induced functional systemic blocking antibodies that correlate with the concentration of allergen tolerated following NAC, highlighting their potential as a biomarker of SCIT in LAR.

Digitally-enabled, person-centred care (PCC) in allergen immunotherapy: An ARIA-EAACI Position Paper.

In rhinitis and asthma, several mHealth apps have been developed but only a few have been validated. However, these apps have a high potential for improving person-centred care (PCC), especially in allergen immunotherapy (AIT). They can provide support in AIT initiation by selecting the appropriate patient and allergen shared decision-making. They can also help in (i) the evaluation of (early) efficacy, (ii) early and late stopping rules and (iii) the evaluation of (carried-over) efficacy after cessation of the treatment course. Future perspectives have been formulated in the first report of a joint task force (TF)-Allergic Rhinitis and Its Impact on Asthma (ARIA) and the European Academy of Allergy and Clinical Immunology (EAACI)-on digital biomarkers. The TF on AIT now aims to (i) outline the potential of the clinical applications of mHealth solutions, (ii) express their current limitations, (iii) make proposals regarding further developments for both clinical practice and scientific purpose and (iv) suggest which of the tools might best comply with the purpose of digitally-enabled PCC in AIT.

Working with companies that manufacture breastmilk substitutes: An EAACI position paper.

Breastmilk is the optimal source of nutrition for infants and should ideally be provided exclusively for the first 6 months of life, and alongside complementary food until 2 years of life. However, there are circumstances where a breastmilk substitute (BMS) may be required. This includes maternal and/or child conditions or personal preference. Whilst these circumstances should never be used as an opportunity to promote BMS, healthcare professionals (HCPs) need to have the knowledge of suitable alternatives and should always be guided by scientific and health motives when recommending a BMS. The Task Force 'Milk Formula Industry Sponsorship' from the European Academy of Allergy and Clinical Immunology (EAACI), provides with this publication recommendations for EAACI interactions with the BMS manufacturers and how this will be supervised.

Patient-reported outcome measures in severe asthma: an expert consensus.

OBJECTIVE: The study aimed to reach a consensus on the most relevant patient-reported outcomes (PROs), the corresponding measures (PROMs), and measurement frequency during severe asthma patient follow-up. METHODS: Two Delphi rounds were conducted. The questionnaire was developed based on a systematic literature review, a focus group with patients, and a nominal group with experts. It assessed PROs' relevance and the appropriateness (A) and feasibility (F) of PROMs using a Likert scale (1=totally agree; 9=totally disagree). The consensus was established when ≥75% of participants agreed (1-3) or disagreed (7-9). RESULTS: Sixty-three professionals (25 hospital pharmacists, 14 allergists, 13 pulmonologists, and 11 nurses) and 5 patients answered the Delphi questionnaire. A consensus was reached on all PROs regarding their relevance. Experts agreed on the use of ACT (A:95.24%; F:95.24%), mini AQLQ (A:93.65; F:79.37%), mMRC dyspnea scale (A:85.71%; F:85.71%), TAI (A:92.06%; F:85.71%), MMAS (A:75.40%; F:82%), and the dispensing register (A:96.83%; F:92.06%). Also considered suitable were: SNOT-22 (A:90.48%; F:73.80%), PSQI (A:82.54; F:63.90%), HADS (A:82.54; F:64%), WPAI (A:77.78%; F:49.20%), TSQM-9 (A:79.37; F:70.50%) and knowledge of asthma questionnaire (A:77%; F:68.80%); however, their use in clinical practice was considered unfeasible. Panelists also agreed on the appropriateness of EQ-5D, which was finally included despite being considered unfeasible (A: 84.13%; F:67.20%) in clinical practice. Agreement was reached on using ACT, TAI, mMRC, and a dispensing register every three months; mini-AQLQ and MMAS every six months; and EQ-5D every twelve months. CONCLUSION: This consensus paves the way toward patient-centered care, promoting the development of strategies supporting routine assessment of PROs in severe asthma management.

Group 2 innate lymphoid cells are key in lipid transfer protein allergy pathogenesis.

Background: Immunopathology in food allergy is characterized by an uncontrolled type 2 immune response and specific-IgE production. Recent studies have determined that group 2 innate lymphoid cells (ILC2) participate in the food allergy pathogenic mechanism and their severity. Our objective was to investigate the role of ILC2 in peach-allergic patients due to non-specific lipid transfer protein (Pru p 3) sensitization. Methods: The immune response in peripheral blood mononuclear cells was characterized in lipid transfer protein-allergic patients and healthy controls. We have analyzed the Pru p 3 uptake on ILC2, the expression of costimulatory molecules, and their involvement on the T-cell proliferative response and cytokine production under different experimental conditions: cytokines involved in group 2 innate lymphoid cell activation (IL-33 and IL-25), Pru p 3 as main food allergen, and the combination of both components (IL-33/IL-25+Pru p 3) using cell sorting, EliSpot, flow cytometry, and confocal microscopy. Results: Our results show that Pru p 3 allergen is taken up by group 2 innate lymphoid cells, regulating their costimulatory molecule expression (CD83 and HLA-DR) depending on the presence of Pru p 3 and its combination with IL-33/IL-25. The Pru p 3-stimulated ILC2 induced specific GATA3+Th2 proliferation and cytokine (IL-4, IL-5, and IL-13) production in lipid transfer protein-allergic patients in a cell contact-dependent manner with no changes in Tbet+Th1- and FOXP3+Treg cell differentiation. Conclusions: The results indicate that in lipid transfer protein-allergic patients, the responsible allergen, Pru p 3, interacts with group 2 innate lymphoid cells, promoting a Th2 cell response. Our results might be of interest in vivo, as they show a role of group 2 innate lymphoid cells as antigen-presenting cells, contributing to the development of food allergy. Consequently, group 2 innate lymphoid cells may be considered as potential therapeutic targets.