Background: Tree nut allergy is usually life-long and potentially life-threatening. Standard of care consists of strict avoidance of the culprit nut and symptomatic treatment of accidental reactions. Objective: To evaluate the potential therapeutic options for desensitization of patients with IgE-mediated tree nut allergy, focusing on, but not limited to, immunotherapy. Methods: We systematically searched three bibliographic databases for studies published until July 2022 for active treatments of IgE-mediated allergy to tree nuts (walnut, hazelnut, pistachio, cashew, and almond) with allergen-specific immunotherapy (AIT) using oral (OIT), sublingual (SLIT), epicutaneous (EPIT) or subcutaneous (SCIT) delivery, or with other disease-modifying treatments. Results: We included 17 studies (three randomized, double-blinded, placebo-controlled, five quasi-experimental prospective cohorts, five prospective cohorts, two retrospective cohorts, and two case reports. Three studies investigated sublingual immunotherapy, five investigated oral immunotherapy to a single tree nut, and six used multi-food oral immunotherapy with (four) or without (two) omalizumab. The remaining studies investigated the effectiveness of monoclonal antibodies in multi-food allergic patients, including patients with a tree nut allergy. The heterogeneity of the studies prevented pooling and meta-analysis. Conclusion: Even though strict avoidance remains the standard of care for patients with tree nut allergy, alternative approaches have been tested in clinical trials and real-life studies. These new concepts require further investigation with more well-designed studies including well-characterized nut allergic patients before implementing them in daily clinical practice.

Background Patients with severe asthma may present with characteristics representing overlapping phenotypes, making them eligible for more than one class of biologic. Our aim was to describe the profile of severe adult asthma patients eligible for both anti-IgE and anti-IL5/5R and to compare the effectiveness of both classes of treatment in real life. Methods This was a prospective cohort study that included adult severe asthma patients from 22 countries enrolled into the International Severe Asthma registry (ISAR) who were eligible for both anti-IgE and anti-IL5/5R. The effectiveness of anti-IgE and anti-IL5/5R was compared in a 1:1 matched cohort. Exacerbation rate was the primary effectiveness endpoint. Secondary endpoints included long-term-oral corticosteroid (LTOCS) use, asthma-related emergency room (ER) attendance and hospital admissions. Results In the matched analysis (n=350/group), the mean annualized exacerbation rate decreased by 47.1% in the anti-IL5/5R group and 38.7% in the anti-IgE group. Patients treated with anti-IL5/5R were less likely to experience a future exacerbation (adjusted IRR 0.76; 95% CI 0.64, 0.89; p<0.001) and experienced a greater reduction in mean LTOCS dose than those treated with anti-IgE (37.44% vs 20.55% reduction; p=0.023).) There was some evidence to suggest that patients treated with anti-IL5/5R experienced fewer asthma-related hospitalizations (IRR 0.64; 95% CI 0.38, 1.08), but not ER visits (IRR 0.94, 95% CI 0.61, 1.43). Conclusions In real life, both anti-IgE and anti-IL5/5R improve asthma outcomes in patients eligible for both biologic classes, however anti-IL5/5R was superior in terms of reducing asthma exacerbations and LTOCS use.

Background: From early life, respiratory viruses are implicated in the development, exacerbation and persistence of respiratory conditions such as asthma. Complex dynamics between microbial communities and host immune responses, shape immune maturation and homeostasis, influencing health outcomes. We evaluated the hypothesis that the respiratory virome is linked to systemic immune responses, using peripheral blood and nasopharyngeal swab samples from preschool-age children in the PreDicta cohort. Methods: Peripheral blood mononuclear cells from 51 children (32 asthmatics, 19 healthy controls), participating in the 2-year multinational PreDicta cohort were cultured with bacterial (Bacterial-DNA, LPS) or viral (R848, Poly:IC, RV) stimuli. Supernatants were analyzed by Luminex for the presence of 22 relevant cytokines. Virome composition was obtained using untargeted high troughput sequencing of nasopharyngeal samples. The metagenomic data were used for the characterization of virome profiles and the presence of key viral families (Picornaviridae, Anelloviridae, Siphoviridae). These were correlated to cytokine secretion patterns, identified through hierarchical clustering and principal component analysis. Results: High spontaneous cytokine release was associated with increased presence of Prokaryotic virome profiles and reduced presence of Eukaryotic and Anellovirus profiles. Antibacterial responses did not correlate with specific viral families or virome profile, however, low antiviral responders had more Prokaryotic and less Eukaryotic virome profiles. Anelloviruses and Anellovirus-dominated profiles were equally distributed amongst immune response clusters. The presence of Picornaviridae and Siphoviridae was associated with low interferon-λ responses. Asthma or allergy did not modify these correlations. Conclusions: Antiviral cytokines responses at a systemic level reflect the upper airway virome composition. Individuals with low innate interferon responses have higher abundance of Picornaviruses (mostly Rhinoviruses) and bacteriophages. Bacteriophages, particularly Siphoviridae appear to be sensitive sensors of host antimicrobial capacity, while Anelloviruses are not affected by TLR-induced immune responses.

This systematic review evaluates the potential therapeutic options for desensitization of patients with IgE-mediated tree nut allergy, focusing, but not limited to, on immunotherapy. We searched three bibliographic databases for studies published until July 2022 for active treatments of IgE-mediated allergy to tree nuts (walnut, hazelnut, pistachio, cashew, and almond) with allergen-specific immunotherapy (AIT) using oral (OIT), sublingual (SLIT), epicutaneous (EPIT) or subcutaneous (SCIT) delivery, or with other disease-modifying treatments. We included 26 studies, but the heterogeneity of the studies prevented pooling and meta-analysis. Immunotherapy with hazel pollen extracts might benefit patients with a secondary nut allergy due to cross-reactivity with PR-10 or profilin panallergens but is unlikely to be beneficial in patients with a severe nut allergy caused by seed storage proteins. Sublingual immunotherapy has a moderate efficacy but a favorable safety profile. Oral immunotherapy (OIT), single, or multi-nut, with or without omalizumab, is the most studied approach. In general, tree nut OIT is effective in conferring protection from accidental exposures, with safety similar to that demonstrated by peanut OIT. The observed cross-desensitization between tree nuts straightly affects the management options for multi-nut allergic patients.

Background: The impact of physical activity (PA) on immune response is a hot topic in exercise immunology, but studies involving asthmatic children are scarce. We examine the level of PA and TV attendance (TVA) in asthmatic children to assess the role on asthma control and immune response to various stimulants. Methods: Weekly PA and daily TVA were obtained from questionnaires at inclusion of the PreDicta study. PBMC cultures were stimulated with phytohemagglutinin (PHA), R848, poly I:C and zymosan. Cytokines were measured and quantified in cell culture supernatants using luminometric multiplex immunofluorescence beads-based assay. Results: Asthmatic preschoolers showed significantly more TVA than their healthy peers (58.6% vs. 41.5% 1-3h daily and only 25.7% vs. 47.2% ≤ 1h daily). Poor asthma control was associated with less frequent PA (75% no or occasional activity in uncontrolled vs. 20% in controlled asthma; 25% ≥ 3x weekly vs. 62%). Asthmatics with increased PA exhibited elevated cytokine levels in response to stimulants, suggesting a readiness of circulating immune cells for type-1, -2 and -17 cytokine release compared to low-PA and high-TVA subjects. Low PA and high TVA were associated with increased proinflammatory cytokines. Proinflammatory cytokines were correlating with each other in in-vitro immune responses of asthmatic children, but not healthy controls. Conclusion: Asthmatic children show more sedentary behavior than healthy subjects, while poor asthma control leads to a decrease in PA. Asthmatic children profit from exercise, as elevated cytokine levels in stimulated conditions indicate an immune system prepared for a strong response in case of infection.

Background: The aim of the current investigation was to explore predisposing factors for food protein induced allergic proctocolitis (FPIAP) in Greek infants relevant in the maternal diet, during pregnancy and breastfeeding, as relevant knowledge is limited. Methods: A multicenter retrospective case-control study was conducted in 6 regions in Greece, with 96 mothers of infants with and 141 mothers of infants without a history of FPIAP. Maternal dietary habits during pregnancy and breastfeeding were evaluated with validated questionnaires: a) The Mediterranean Diet (MedDiet) Score, and b) The Mediterranean Oriented Culture Specific Semi-Quantitative Food Frequency Questionnaire. Statistical tests, modeling and exploration of the FPIAP risk in relation to the maternal diet using elastic net regression models were performed with R software and Studio. Results: FPIAP was associated with cow’s milk (83.6%), egg (7.3 %), and wheat, beef (6.4%) in the maternal diet. Adherence to MedDiet was similar among the mothers, but mothers of FPIAP infants consumed more vegetables (p=0.018) and olive oil (p=0.003). Elastic net prediction models showed that, in this Mediterranean population, increased consumption during pregnancy and lactation of common allergens, whole grain products, homemade food, fish and shellfish, fruit offered protection; conversely, high intake of vegetables, sugar and total fat, and non-stick/grilled cooking, increased the risk of FPIAP, as did high intake of salt and white flour during lactation. Conclusions: Components of a maternal Mediterranean diet can protect against FPIAP when traditional cooking methods are adopted and fish, fruit and whole wheat products are consumed frequently.

Background The maturation of innate immune responses in health and atopy is still incompletely understood. Methods We aimed to evaluate age-related trajectories of the TLR3 and TLR7/8 pathways across the lifespan and whether these differ between healthy and atopic individuals. Peripheral blood mononuclear cells (PBMCs) were isolated from 39 otherwise healthy atopic and 39 non-atopic subjects, aged 0-45 years. Selected cytokines involved in antiviral responses were measured by Luminex in culture supernatants of poly(I:C)- and R848-stimulated PBMCs. The non-parametric correlation between age and cytokine expression and differences in developmental trajectories between healthy and atopic were estimated. Patterns of cytokine development were identified with principal component analysis. Results Normal innate immune maturation entails significant and progressive age-related changes in the production of IL-1β, TNF-α, MIP-1β, MCP-3, IP-10, IL-10, IL-12p70 and IFN-γ upon TLR3 and/or TLR7/8 stimulation. Individual cytokines made small contributions to the observed variability; chemokines MCP-3 and IP-10 were key contributors. The development of these pathways deviated in atopic subjects with significant differences observed in the trajectories of IL-1β, MIP-1β and IL-10 synthesis. Conclusion TLR3 and TLR7/8 pathways mature during childhood, while atopy is associated with an abnormal maturation pattern. Suboptimal responses in Th1, inflammatory cytokine and chemokine production may be implicated in poor antiviral immunity in atopics, while deficient maturation of IL-10 producing capacity in the breaking of tolerance.

Background: The interplay between COVID-19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID-19 on childhood asthma outcomes. Methods: The PeARL multinational cohort included 1,054 children with asthma and 505 non-asthmatic children aged between 4-18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID-19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control. Results: During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks and hospitalizations due to asthma, in comparison to the preceding year. Sixty-six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre-bronchodilatation FEV1 and peak expiratory flow rate were improved during the pandemic. When compared to non-asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits or hospitalizations during the pandemic. However, an increased risk of URTIs emerged. Conclusion: Childhood asthma outcomes, including control, were improved during the first wave of the COVID-19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID-19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent.

Rhinitis and especially allergic rhinitis (AR) remain the most frequent hypersensitivity condition, affecting up to a quarter of the population and impacting upon the quality of life of individual patients and the health economy. Data, especially in respect to underlying pathophysiological mechanisms mainly derive from adult studies and are subsequently extrapolated in the pediatric population. Therapeutic algorithms for children with rhinitis in children are long based on the same principles as in adults. We explore and describe novel aspects of rhinitis, ranging from mechanisms to disease classification, phenotypes, diagnostic and monitoring tools, and the use of treatments, with focus on the traits of pediatric age groups.

Background: Asthma is a complex chronic inflammatory disorder, with many factors influencing its prevalence. Diet’s impact on the symptoms of the disease is still controversial, although various dietary patterns or specific nutrients have been studied. Objective: The objective of this crossover, randomised, two-period study was to examine the potential of controlling dietary histamine intake and, through this, alter asthma symptoms in children with mild intermittent asthma. Methods: Children with mild intermittent asthma were randomly assigned to either a high- (HH) or low- histamine (LH) diet, based on the Mediterranean pattern, for 4 weeks (t0). This was followed by a 2-week washout period (t1) before patients crossed to the alternative diet (t2) for an additional 4 weeks. Children were assessed at baseline and after the completion of each diet phase. They also recorded symptoms and peak flow throughout the intervention. Adherence to the dietary intervention was assessed via four random 24-hour recalls for each intervention period and comparison of selected qualitative and quantitative indices, i.e. histidine, food choices, energy, macro- and micronutrients intake. Results: Eighteen children (10 boys), with mean age 11,5±3,1years were recruited and completed the study. A trend for prolonged and more severe symptoms was observed during HH. There was good adherence to the diet during remission periods, but lower compliance during symptomatic periods, particularly for the HH group. The mean actual intake differed significantly between the two diets, not only in the histamine content but also in energy, sugar and various micronutrients, including sodium. Conclusions & Clinical Relevance: Diet may have an active and direct impact on asthma symptoms. A diet deviating from the Mediterranean standard in terms of high energy, histamine, and salt has been associated with asthma worsening. Dietary interventions in asthmatic patients should be prospectively evaluated for a longer period and with proper nutritional education.

A document by Marielena Jakobi. Click on the document to view its contents.

The International Classification of Diseases (ICD) provides a common language for use worldwide as a diagnostic and classification tool for epidemiology, clinical purposes and health management. Since its first edition, the ICD has maintained a framework distributing conditions according to topography, with the result that some complex conditions, such as allergies and hypersensitivity disorders (A/H) including anaphylaxis, have been poorly represented. The change in hierarchy in ICD-11 permitted the construction of the pioneer section addressed to A/H, which may result in more accurate mortality and morbidity statistics, including more accurate accounting for mortality due to anaphylaxis, strengthen classification, terminology and definitions. The ICD-11 was presented and adopted by the 72nd World Health Assembly in May 2019 and the implementation is ongoing worldwide. We here present the outcomes from an online survey undertaken to reach out the allergy community worldwide in order to peer review the terminology, classification and definitions of A/H introduced into ICD-11 and to support their global implementation. Data are presented here for 406 respondents from 74 countries. All of the sub-sections of the new A/H section of the ICD-11 had been considered with good accuracy by the majority of respondents. We believe that, in addition to help during the implementation phase, all the comments provided will help to improve the A/H classification and to increase awareness by different disciplines of what actions are needed to ensure more accurate epidemiological data and better clinical management of A/H patients.