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Background: Effector cells assays provide an overall measure of responsiveness to allergen, but the lack of reliable and high‐throughput assays limits the clinical utility. We aimed to develop a high‐throughput basophil activation test based on human progenitor cell‐derived basophils (PCB) and investigate the role of PCB activation test (PCBAT) in allergic diseases. Methods: Progenitor cell‐derived basophils were differentiated from CD34+ progenitor cells and sensitized with sera from subjects sensitized to cat, peanut or atopic controls. Sensitized PCBs were stimulated with increasing concentrations of the corresponding allergens in vitro. Degranulation was assessed by measuring CD63 expression using flow cytometry. The correlations between PCBAT and clinical allergy were assessed. Results: Following passive sensitization of the mature PCBs with serum and allergen stimulation, an allergen specific dose‐dependent increase in CD63 expression was observed. Sera from subjects sensitized to cat (n = 35, of which 17 subjects had clinical reactivity quantified using inhaled allergen challenge), peanut allergic (n = 30, of which 15 subjects had clinical reactivity validated using double blind, placebo controlled food challenges [DBPCFC]), peanut‐sensitized but tolerant subjects (n = 5) were used to sensitize PCBs. PCBAT area under the curve (AUC) correlated with sIgE (r2 =.49, p =.001) in subjects sensitized to cat (sIgE ≥ 0.35KU/L). The provocation concentration of inhaled cat allergen (PC20) correlated with PCBAT AUC (r2 =.33, p =.016). In subjects sensitized to peanut, PCBAT AUC was highly correlated with sIgE to Ara h 2 (r2 =.59, p <.0001). Peanut threshold cumulative dose during DBPCFC was negatively correlated with PCBAT AUC (r2 =.57, p =.001) and IgE to Ara h1 (r2 =.55, p =.007), but not with sIgE to whole peanut or Ara h2. All peanut‐sensitized but tolerant subjects showed no reaction to peanut on PCBAT. Conclusion: Progenitor cell‐derived basophils activation test is a high‐throughput assay, which correlates with clinical allergy and may confer a powerful alternative tool in allergy testing. [ABSTRACT FROM AUTHOR]

The Allergy to Peanuts imPacting Emotions And Life study (APPEAL) explored the psychosocial burden of living with self-reported peanut allergy experienced by children, teenagers, adults and caregivers in the UK and Ireland. A two-stage (quantitative survey and qualitative interview [APPEAL-1]), cross-sectional study of the psychosocial burden of peanut allergy (APPEAL-2) was conducted. Quantitative data were evaluated using descriptive statistics and qualitative data were analysed using MAXQDA software. A conceptual model specific to UK and Ireland was developed using the concepts identified during the analysis. A total of 284 adults in the UK and Ireland completed the APPEAL-1 survey and 42 individuals participated in APPEAL-2. Respondents reported that peanut allergy restricts their choices in various situations, especially with regard to choosing food when eating out (87% moderately or severely restricted), choosing where to eat (82%), special occasions (76%) and when buying food from a shop (71%). Fifty-two percent of survey participants and 40% of interview participants reported being bullied because of PA. Psychological impact of peanut allergy included feeling at least moderate levels of frustration (70%), uncertainty (79%), and stress (71%). The qualitative analysis identified three different types of coping strategies (daily monitoring or vigilance, communication and planning) and four main areas of individuals' lives that are impacted by peanut allergy (social activities, relationships, emotions and work [adults and caregivers only]). The extent of the impact reported varied substantially between participants, with some reporting many negative consequences of living with peanut allergy and others feeling it has minimal impact on their health-related quality of life. This large survey and interview study highlight the psychosocial burden of peanut allergy for adults, teenagers, children and caregivers in the UK and Ireland. The analysis demonstrates the wide variation in level of impact of peanut allergy and the unmet need for those individuals who experience a substantial burden from living with peanut allergy. [ABSTRACT FROM AUTHOR]

The first five points in Savic et al Table 1 describe unambiguous non-allergic manifestations, patients with no personal history of penicillin allergy or patients who have tolerated penicillin after the presumed allergic reaction.[1] These patients do not warrant further allergy work-up,[[2], [4]] and the penicillin allergy label can and should be removed without further investigations. Towards a safe and efficient de-labelling penicillin allergy service by non-allergists Keywords: allergens; clinical immunology; drug allergy; epitopes; IgEimmunologic tests EN allergens clinical immunology drug allergy epitopes IgEimmunologic tests 378 379 2 03/15/23 20230301 NES 230301 To the Editor, We read with great interest the 'BSACI guideline for the set-up of penicillin allergy de-labelling services by non-allergists working in a hospital setting' by Savic et al.[1] which provides guidance on evaluation and testing of patients with a possibly erroneous penicillin allergy label. [Extracted from the article]

Background Food allergy is an increasing public health issue and the most common cause of life-threatening anaphylactic reactions. Conventional allergy tests assess for the presence of allergen-specific IgE, significantly overestimating the rate of true clinical allergy and resulting in overdiagnosis and adverse effect on health-related quality of life. Objective To undertake initial validation and assessment of a novel diagnostic tool, we used the mast cell activation test (MAT). Methods Primary human blood-derived mast cells (MCs) were generated from peripheral blood precursors, sensitized with patients' sera, and then incubated with allergen. MC degranulation was assessed by means of flow cytometry and mediator release. We compared the diagnostic performance of MATs with that of existing diagnostic tools to assess in a cohort of peanut-sensitized subjects undergoing double-blind, placebo-controlled challenge. Results Human blood-derived MCs sensitized with sera from patients with peanut, grass pollen, and Hymenoptera (wasp venom) allergy demonstrated allergen-specific and dose-dependent degranulation, as determined based on both expression of surface activation markers (CD63 and CD107a) and functional assays (prostaglandin D 2 and β-hexosaminidase release). In this cohort of peanut-sensitized subjects, the MAT was found to have superior discrimination performance compared with other testing modalities, including component-resolved diagnostics and basophil activation tests. Using functional principle component analysis, we identified 5 clusters or patterns of reactivity in the resulting dose-response curves, which at preliminary analysis corresponded to the reaction phenotypes seen at challenge. Conclusion The MAT is a robust tool that can confer superior diagnostic performance compared with existing allergy diagnostics and might be useful to explore differences in effector cell function between basophils and MCs during allergic reactions. [ABSTRACT FROM AUTHOR]

Background: Peanut allergy, for which there are no approved treatment options, affects patients who are at risk for unpredictable and occasionally life-threatening allergic reactions., Methods: In a phase 3 trial, we screened participants 4 to 55 years of age with peanut allergy for allergic dose-limiting symptoms at a challenge dose of 100 mg or less of peanut protein (approximately one third of a peanut kernel) in a double-blind, placebo-controlled food challenge. Participants with an allergic response were randomly assigned, in a 3:1 ratio, to receive AR101 (a peanut-derived investigational biologic oral immunotherapy drug) or placebo in an escalating-dose program. Participants who completed the regimen (i.e., received 300 mg per day of the maintenance regimen for approximately 24 weeks) underwent a double-blind, placebo-controlled food challenge at trial exit. The primary efficacy end point was the proportion of participants 4 to 17 years of age who could ingest a challenge dose of 600 mg or more, without dose-limiting symptoms., Results: Of the 551 participants who received AR101 or placebo, 496 were 4 to 17 years of age; of these, 250 of 372 participants (67.2%) who received active treatment, as compared with 5 of 124 participants (4.0%) who received placebo, were able to ingest a dose of 600 mg or more of peanut protein, without dose-limiting symptoms, at the exit food challenge (difference, 63.2 percentage points; 95% confidence interval, 53.0 to 73.3; P<0.001). During the exit food challenge, the maximum severity of symptoms was moderate in 25% of the participants in the active-drug group and 59% of those in the placebo group and severe in 5% and 11%, respectively. Adverse events during the intervention period affected more than 95% of the participants 4 to 17 years of age. A total of 34.7% of the participants in the active-drug group had mild events, as compared with 50.0% of those in the placebo group; 59.7% and 44.4% of the participants, respectively, had events that were graded as moderate, and 4.3% and 0.8%, respectively, had events that were graded as severe. Efficacy was not shown in the participants 18 years of age or older., Conclusions: In this phase 3 trial of oral immunotherapy in children and adolescents who were highly allergic to peanut, treatment with AR101 resulted in higher doses of peanut protein that could be ingested without dose-limiting symptoms and in lower symptom severity during peanut exposure at the exit food challenge than placebo. (Funded by Aimmune Therapeutics; PALISADE ClinicalTrials.gov number, NCT02635776 .).

Asthma and allergy share a similar and very close course, especially through childhood. Considerable research effort has been put in untangling these associations; however, it is now becoming obvious that this is an exceedingly difficult task. In fact, each research breakthrough further perplexes this picture, as we are steadily moving toward the era of personalized medicine and we begin to appreciate that what we thought to be a single disease, asthma, is in fact an accumulation of distinct entities. In the context of this "syndrome," which is characterized by several, as of yet poorly defined endotypes and phenotypes, the question of the link of "asthma" with allergy probably becomes non-relevant. In this review, we will revisit this question while putting the emphasis on the multifaceted nature of asthma.