Lipid-Droplet Formation Drives Pathogenic Group 2 Innate Lymphoid Cells in Airway Inflammation.

Innate lymphoid cells (ILCs) play an important role in the control and maintenance of barrier immunity. However, chronic activation of ILCs results in immune-mediated pathology. Here, we show that tissue-resident type 2 ILCs (ILC2s) display a distinct metabolic signature upon chronic activation. In the context of allergen-driven airway inflammation, ILC2s increase their uptake of both external lipids and glucose. Externally acquired fatty acids are transiently stored in lipid droplets and converted into phospholipids to promote the proliferation of ILC2s. This metabolic program is imprinted by interleukin-33 (IL-33) and regulated by the genes Pparg and Dgat1, which are both controlled by glucose availability and mTOR signaling. Restricting dietary glucose by feeding mice a ketogenic diet largely ablated ILC2-mediated airway inflammation by impairing fatty acid metabolism and the formation of lipid droplets. Together, these results reveal that pathogenic ILC2 responses require lipid metabolism and identify ketogenic diet as a potent intervention strategy to treat airway inflammation.

A pediatric randomized, controlled trial of German cockroach subcutaneous immunotherapy.

BACKGROUND: Cockroach allergy contributes to morbidity among urban children with asthma. Few trials address the effect of subcutaneous immunotherapy (SCIT) with cockroach allergen among these at-risk children. OBJECTIVES: We sought to determine whether nasal allergen challenge (NAC) responses to cockroach allergen would improve following 1 year of SCIT. METHODS: Urban children with asthma, who were cockroach-sensitized and reactive on NAC, participated in a year-long randomized double-blind placebo-controlled SCIT trial using German cockroach extract. The primary endpoint was the change in mean Total Nasal Symptom Score (TNSS) during NAC after 12 months of SCIT. Changes in nasal transcriptomic responses during NAC, skin prick test wheal size, serum allergen-specific antibody production, and T-cell responses to cockroach allergen were assessed. RESULTS: Changes in mean NAC TNSS did not differ between SCIT-assigned (n = 28) versus placebo-assigned (n = 29) participants (P = .63). Nasal transcriptomic responses correlated with TNSS, but a treatment effect was not observed. Cockroach serum-specific IgE decreased to a similar extent in both groups, while decreased cockroach skin prick test wheal size was greater among SCIT participants (P = .04). A 200-fold increase in cockroach serum-specific IgG4 was observed among subjects receiving SCIT (P < .001) but was unchanged in the placebo group. T-cell IL-4 responses following cockroach allergen stimulation decreased to a greater extent among SCIT versus placebo (P = .002), while no effect was observed for IL-10 or IFN-γ. CONCLUSIONS: A year of SCIT failed to alter NAC TNSS and nasal transcriptome responses to cockroach allergen challenge despite systemic effects on allergen-specific skin tests, induction of serum-specific IgG4 serum production and down-modulation of allergen-stimulated T-cell responses.

Neutralizing IgG4 antibodies are a biomarker of sustained efficacy after peanut oral immunotherapy.

BACKGROUND: Clinical efficacy of oral immunotherapy (OIT) has been associated with the induction of blocking antibodies, particularly those capable of disrupting IgE-allergen interactions. Previously, we identified mAbs to Ara h 2 and structurally characterized their epitopes. OBJECTIVE: We investigated longitudinal changes during OIT in antibody binding to conformational epitopes and correlated the results with isotype and clinical efficacy. METHODS: We developed an indirect inhibitory ELISA using mAbs to block conformational epitopes on immobilized Ara h 2 from binding to serum immunoglobulins from peanut-allergic patients undergoing OIT. We tested the functional blocking ability of mAbs using passive cutaneous anaphylaxis in mice with humanized FcεRI receptors. RESULTS: Diverse serum IgE recognition of Ara h 2 conformational epitopes are similar before and after OIT. Optimal inhibition of serum IgE occurs with the combination of 2 neutralizing mAbs (nAbs) recognizing epitopes 1.2 and 3, compared to 2 nonneutralizing mAbs (non-nAbs). After OIT, IgG4 nAbs, but not IgG1 or IgG2 nAbs, increased in sustained compared to transient outcomes. Induction of IgG4 nAbs occurs after OIT only in those with sustained efficacy. Murine passive cutaneous anaphylaxis after sensitization with pooled human sera is significantly inhibited by nAbs compared to non-nAbs. CONCLUSIONS: Serum IgE conformational epitope diversity remains unchanged during OIT. However, IgG4 nAbs capable of uniquely disrupting IgE-allergen interactions to prevent effector cell activation are selectively induced in OIT-treated individuals with sustained clinical efficacy. Therefore, the induction of neutralizing IgG4 antibodies to Ara h 2 are clinically relevant biomarkers of durable efficacy in OIT.

Evaluation of clinical outcomes of efficacy in food allergen immunotherapy trials, COFAITH EAACI task force.

Food allergy is a global public health problem that until recent years lacked any aetiological treatment supported by academy, industry and regulators. Food immunotherapy (AIT) is an evolving treatment option, supported by clinical practice and industry trial data. Recent AIT meta-analyses have highlighted the difficulty in pooling safety and efficacy data from AIT trials, due to secondary heterogeneity in the study. An EAACI task force (CO-FAITH) initiated by the Paediatric Section was created to focus on AIT efficacy outcomes for milk, egg and peanut allergy rather than in trial results. A systematic search and a narrative review of AIT controlled clinical trials and large case series was conducted. A total of 63 manuscripts met inclusion criteria, corresponding to 23, 21 and 22 studies of milk, egg and peanut AIT, respectively. The most common AIT efficacy outcome was desensitization, mostly defined as tolerating a maintenance phase dose, or reaching a particular dose upon successful exit oral food challenge (OFC). However, a large degree of heterogeneity was identified regarding the dose quantity defining this outcome. Sustained unresponsiveness and patient-reported outcomes (e.g. quality of life) were explored less frequently, and to date have been most rigorously described for peanut AIT versus other allergens. Change in allergen threshold assessed by OFC remains the most common efficacy measure, but OFC methods suffer from heterogeneity and methodological disparity. This review has identified multiple heterogeneous outcomes related to measuring the efficacy of AIT. Efforts to better standardize and harmonize which outcomes, and how to measure them must be carried out to help in the clinical development of safe and efficacious food allergy treatments.

Preventive allergen immunotherapy with inhalant allergens in children.

The efficacy and safety of preventive allergen immunotherapy (pAIT) in children are currently under investigation. Here, we provide an overview of pAIT with respiratory allergens concerning the prevention of new sensitizations, allergic disease onset and progression as well as further immunomodulatory effects. Three databases were searched for clinical pAIT studies in children. Selected publications were reviewed for preventive outcomes according to prevention level (primary, secondary, and tertiary), allergen type, administration route, dose, and treatment duration. The primary prevention approach appears safe but showed no allergen-specific effect on new sensitizations. Secondary prevention seems feasible and may induce regulatory T cell-mediated immunotolerance. The number of studies at these prevention levels is limited. Tertiary prevention with grass and/or tree pollen-based pAIT has shown efficacy in preventing disease progression from allergic rhinitis/conjunctivitis to asthma. Data on tertiary pAIT with house dust mites and other allergen types are inconclusive. Subcutaneous and sublingual routes appear similarly effective, but head-to-head comparative paediatric studies are scarce. Additionally, there are fewer placebo-controlled studies. Nevertheless, immunomodulatory outcomes of pAIT are encouraging. Currently, limited but favourably suggestive evidence is available for preventing respiratory allergic diseases in children by pAIT. Primary and secondary prevention have potential and warrant further investigation through well-designed studies.

Two-year post-treatment outcomes following peanut oral immunotherapy in the Probiotic and Peanut Oral Immunotherapy-003 Long-Term (PPOIT-003LT) study.

BACKGROUND: Few studies have examined long-term outcomes following oral immunotherapy (OIT); none have examined long-term risks and benefits associated with distinct clinical outcomes (desensitization, remission). METHODS: Participants completing the probiotic and peanut oral immunotherapy (PPOIT) -003 randomized trial were enrolled in a follow-on study, PPOIT-003LT. Peanut ingestion, reactions, and health-related quality of life (HRQOL) were monitored prospectively. Outcomes at 1-year and 2-years post-treatment were examined by treatment group and by post-OIT clinical outcome (remission, desensitization without remission [DWR], allergic). RESULTS: 86% (151/176) of eligible children enrolled. Post-treatment peanut ingestion at 2-years post-treatment were similar for PPOIT (86.7%) and OIT (78.7%) groups, both higher than placebo (10.3%). Reactions reduced over time for all treatment and clinical outcome groups (PPOIT 31.7% to 23.3%, OIT 37.7% to 19.7%, placebo 13.8% to 6.9%; remission 27.5% to 15.9%; DWR 57.9% to 36.8%; allergic 11.6% to 7%). At 2-years post-treatment, similar proportions of remission and allergic participants reported reactions (RD 0.09 (95%CI -0.03, 0.20), p = .127), whereas more DWR participants reported reactions than remission (remission vs DWR: RD -0.21 (95%CI -0.39; -0.03), p = .02) and allergic (DWR vs allergic: RD 0.30 (95%CI 0.13, 0.47), p = .001) participants. At 2-years post-treatment, 0% remission versus 5.3% DWR versus 2.3% allergic participants reported adrenaline injector usage. Remission participants had significantly greater HRQOL improvement (adjusted for baseline) compared with both DWR (MD -0.54 (95%CI -0.99, -0.10), p = .017) and allergic (MD -0.82 (95%CI -1.25, -0.38), p < .001). CONCLUSION: By 2-years post-treatment, remission participants reported fewer reactions, less severe reactions and greater HRQOL improvement compared with DWR and allergic participants, indicating that remission is the patient-preferred treatment outcome over desensitization or remaining allergic.

How to hit the allergy target: A critical appraisal of intralymphatic immunotherapy with practical recommendations on ultrasound-guided injections.

BACKGROUND: Intralymphatic immunotherapy (ILIT) represents a promising novel approach treating allergic diseases. However, no standardized procedures or recommendations have been established or reported, despite the recognized fact that treatment efficacy relies on the ability to inject the allergen intranodally. OBJECTIVE: We aim to provide a critical appraisal of ILIT as a method of allergen immunotherapy and to deliver practical recommendations for accurate ILIT. METHODS: One hundred and seventy-three ILIT injections were performed in 28 (47%) women and 32 (53%) men with median age of 29 years (21-59). The injections were ultrasound-guided and recorded for retrospective analysis with respect to injection location, needle visibility, medication release, and patient characteristics. RESULTS: The results show that the correct positioning of the needle within the lymph node (LN) was most critical. If the whole length of the needle bevel was not inserted into the LN, substance backflush into the interstitium was observed. Selecting a more superficial LN and inserting the needle at a smaller angle towards the LN significantly improved needle visibility in the ultrasound. Longitudinal results showed that continuous practice significantly correlated with improved needle visibility and more accurate ILIT injections. CONCLUSION: Based on our results and practical experience, we propose several recommendations for LN selection and the correct handling of ultrasound probe and needle. We are confident that ILIT standardization and training will be important as to meet the goals of good safety and efficacy of ILIT.

Immunotherapy and biologics in the management of IgE-mediated food allergy: Systematic review and meta-analyses of efficacy and safety.

Food allergy (FA) is a potentially life-threatening chronic condition that is becoming an increasing public health problem worldwide. This systematic review (SR) was carried out to inform the development of clinical recommendations on the treatment of IgE-mediated FA with biologics and/or IT for the update of the EAACI guidelines. A SR of randomized-controlled trials or quasi-controlled trials was carried out. Studies were identified via comprehensive search strategies in Medline, Embase, and Cochrane Library, up to April 2022. POPULATION: Human adults, children, and adolescents with IgE-mediated FA. INTERVENTION: IT and/or biologics. COMPARATOR: Placebo or standard-of-care (allergen avoidance). OUTCOME: Efficacy (desensitization, sustained unresponsiveness (SU), remission), quality of life, and safety (systemic and local adverse reactions (AR)). The Cochrane RoB tool was used to assess the risk of bias. It was reported according to PRISMA and registered in PROSPERO CRD4202229828. After screening, 121 studies were included (111 for IT and 10 for biologics). Most studies had a high risk of bias and showed high heterogeneity in design and results. Metanalysis showed a positive effect of biologics and IT in terms of relative risk (RR) for achieving tolerance to the culprit food compared to avoidance or placebo. Omalizumab for any FA showed a RR of 2.17 [95% confidence interval: 1.22, 3.85]. For peanut allergy, oral IT (OIT) had a RR of 11.94 [1.76, 80.84] versus avoidance or placebo, sublingual IT (SLIT) had a RR of 3.00 [1.04, 8.66], and epicutaneous IT (EPIT) of 2.16 [1.56, 3.00]. OIT had a RR of 5.88 [2.27, 15.18] for cow's milk allergy, and of 3.43 [2.24, 5.27] for egg allergy. There was insufficient data on SLIT or EPIT for the treatment of egg and milk allergies. Most ARs reported were mild. For OIT the most common AR involved the gastrointestinal system and for EPIT, AR's most commonly affected the skin. There was limited data on severe or life-threatening ARs. There was limited evidence for long term efficacy and quality of life. In conclusion, biologics and IT, alone or in combination, are effective in achieving desensitization while on active treatment but more evidence is needed on long-term tolerance as current evidence is not of high quality. Adverse events while on therapy are generally mild to moderate but a long-term comprehensive safety profile is missing. There is a critical need to optimize and standardize desensitization protocols and outcome measures to facilitate our understanding of the efficacy and safety as well as to allow for comparison between interventions.

AM-301, a barrier-forming nasal spray, versus saline spray in seasonal allergic rhinitis: A randomized clinical trial.

RATIONALE: Saline nasal sprays are frequently used in the management of seasonal allergic rhinitis (SAR) for the cleansing and clearing of aeroallergens from the nasal cavity. Also using a drug-free approach, AM-301 nasal spray is forming a thin film barrier on the nasal mucosa to prevent contact with allergens, trap them, and facilitate their discharge. A clinical trial compared the efficacy, safety, and tolerability of AM-301 and saline spray in SAR. METHODS: A total of 100 patients were randomized 1:1 to self-administer AM-301 or saline 3 × daily for 2 weeks. Primary efficacy endpoint: reduction in mean daily reflective Total Nasal Symptom Score (rTNSS). Secondary efficacy endpoints: reduction in mean instantaneous TNSS and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), global impression of efficacy. Safety and tolerability: adverse events, relief medication use, symptom-free days, global impression of tolerability. RESULTS: AM-301-treated patients achieved a significantly lower rTNSS than the saline group (LS square means difference -1.1, 95% CI -1.959 to -0.241, p = .013) with improvement observed across all individual nasal symptoms. Likewise, all secondary endpoints showed statistical significance in favor of AM-301; for example, quality of life was significantly improved overall (p < .001) as well as for each individual RQLQ domain. Both treatments showed similarly good safety and tolerability. With AM-301, fewer patients used relief medication and more enjoyed symptom-free days compared to saline treatment. CONCLUSIONS: AM-301 was more effective than saline in improving SAR nasal symptoms and related quality of life while offering similar tolerability, demonstrating the benefits of a barrier approach.

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.

Immune signatures predict response to house dust mite subcutaneous immunotherapy in patients with allergic rhinitis.

BACKGROUND: Identifying predictive biomarkers for allergen immunotherapy response is crucial for enhancing clinical efficacy. This study aims to identify such biomarkers in patients with allergic rhinitis (AR) undergoing subcutaneous immunotherapy (SCIT) for house dust mite allergy. METHODS: The Tongji (discovery) cohort comprised 72 AR patients who completed 1-year SCIT follow-up. Circulating T and B cell subsets were characterized using multiplexed flow cytometry before SCIT. Serum immunoglobulin levels and combined symptom and medication score (CSMS) were assessed before and after 12-month SCIT. Responders, exhibiting ≥30% CSMS improvement, were identified. The random forest algorithm and logistic regression analysis were used to select biomarkers and establish predictive models for SCIT efficacy in the Tongji cohort, which was validated in another Wisco cohort with 43 AR patients. RESULTS: Positive SCIT response correlated with higher baseline CSMS, allergen-specific IgE (sIgE)/total IgE (tIgE) ratio, and frequencies of Type 2 helper T cells, Type 2 follicular helper T (TFH2) cells, and CD23+ nonswitched memory B (BNSM) and switched memory B (BSM) cells, as well as lower follicular regulatory T (TFR) cell frequency and TFR/TFH2 cell ratio. The random forest algorithm identified sIgE/tIgE ratio, TFR/TFH2 cell ratio, and BNSM frequency as the key biomarkers discriminating responders from nonresponders in the Tongji cohort. Logistic regression analysis confirmed the predictive value of a combination model, including sIgE/tIgE ratio, TFR/TFH2 cell ratio, and CD23+ BSM frequency (AUC = 0.899 in Tongji; validated AUC = 0.893 in Wisco). CONCLUSIONS: A T- and B-cell signature combination efficiently identified SCIT responders before treatment, enabling personalized approaches for AR patients.

Peanut oral immunotherapy using an extensively heated and baked novel composition of peanuts.

BACKGROUND: Oral immunotherapy (OIT) is an increasingly acceptable therapeutic option for peanut-allergic (PA) children, despite significant side effects. Major peanut allergenic proteins are heat-resistant and are not rendered hypoallergenic after baking or cooking. Lyophilized peanut protein-MH (LPP-MH) is a novel composition from developing peanuts, enabling cooking-induced reduction in allergenicity. We aimed to explore the safety and efficacy of OIT, with extensively heated and baked (EHEB) LPP-MH in PA children. METHODS: In a single-arm, single-center, pilot study, PA children with a single highest tolerated dose of <100 mg peanut protein were placed on a 40-week OIT protocol with 300 mg daily of heat-treated LPP-MH. A repeat open peanut food challenge was performed after 40 weeks of treatment and at a 6-12 months of follow-up visit. RESULTS: Thirty-three children with PA were enrolled, with a mean cumulative tolerated dose (MCTD) of 71.2 mg PP (95% CI 45-100 mg). After 40 weeks, 32/33 patients were able to consume more than 300 mg of natural PP, with MCTD of 1709 mg (CI 365-3675 mg). There were no severe allergic reactions requiring epinephrine, during any of the observed LPP-MH challenges or any treatment related doses at home. After 6-12 months on daily maintenance, the MCTD was 8821 mg (95% CI 1930-13,500 mg). This enabled most children age-appropriate dietary inclusion of peanuts. CONCLUSION: An OIT protocol with heat-treated LPP-MH, a novel composition from developing peanuts, seems a potentially safe and efficacious OIT modality for PA children, enabling the introduction of dietary levels of peanut proteins in highly allergic PA children. Validation in randomized controlled studies is mandated.

Skin-centered strategies in food allergy prevention.

While the early introduction of food allergens in the infant diet has been shown to be effective at preventing the development of food allergy (FA), its implementation in real life has been associated with various challenges. Interventions aimed at correcting skin barrier dysfunction have been explored in recent decades as a distinct or complementary mean to prevent allergic sensitization through the skin and subsequent development of FA. Studies assessing the application of emollient from birth have yielded conflicting results, and meta-analyses have demonstrated either no effect or only a slight positive effect on FA prevention. However, a careful review of the clinical trials reveals that different emollients were used, which may have explained some of the discrepancies between study results. Emollient application protocols also varied widely between studies. While firm conclusions cannot be drawn with regard to their overall efficacy at preventing FA, the available data provide valuable insight into the characteristics that could be associated with a more effective intervention. Namely, successful trials tended to use emollients with an acidic pH of 5.5, applied over the entire body, and combined with topical corticosteroids in affected areas. Consensus on the optimal strategy to restore skin barrier function could help improve the homogeneity and clinical relevance of future trials on this topic. In the meantime, clinicians should avoid products associated with worse outcomes.

Current state and advances in desensitization for peanut allergy in pediatric age.

Peanut allergy affects about 1%-3% of the pediatric population in the world, with an important increase in the last decades. Nowadays, international guidelines recommend the early introduction of peanuts in the infant diet, with poor information about the quantity and the frequency of the intake. Allergen immunotherapy may represent the only therapeutic strategy able to modify the natural history of peanut allergy. In particular, oral immunotherapy showed the most promising results in terms of efficacy, but with significant rates of adverse reactions, mostly gastrointestinal. In 2020, the Food and Drug Administration and the European Medicines Agency approved Palforzia®, an oral drug for patients aged 4-17 years. Several studies are ongoing to improve the tolerability of oral immunotherapy and standardize the desensitization protocols. Sublingual immunotherapy permits to offer much lower doses than oral immunotherapy, but fewer adverse events are shown. Subcutaneous immunotherapy is associated with the greatest systemic adverse effects. Epicutaneous immunotherapy, for which Viaskin® patch was approved, has the highest safety profile. Innovative studies are evaluating the use of biological drugs, such as omalizumab or dupilumab, and probiotics, such as Lactobacillus rhamnosus, in monotherapy or associated with oral immunotherapy. Therapy for peanut allergy is constantly evolving, and new perspectives are ongoing to develop.

A retrospective comparison of IgE-mediated cow's milk protein allergy management strategies in pediatric cohorts.

BACKGROUND: Complete avoidance of milk is the usual management for IgE-mediated cow's milk protein allergy (CMPA). A baked milk ladder is a method of dietary advancement therapy in IgE-mediated CMPA in Ireland, while in Spain, avoidance of milk awaiting natural tolerance acquisition through an oral food challenge (OFC) is employed. The aim of this study was to evaluate the use of dietary advancement therapy using a milk ladder compared with complete avoidance of milk for managing IgE-mediated CMPA. METHODS: This is a retrospective chart review of 371 pediatric patients from the population who have been treated for IgE-mediated CMPA between 2011 and 2020, with the milk ladder (Ireland) or complete avoidance followed by an OFC (Spain). The main outcome was the introduction of cow's milk. RESULTS: Milk ladder patients were 3.67 times more likely to succeed in comparison with milk avoidance (p < .001). Anaphylaxis during the treatment period occurred in 34 patients in the milk avoidance groups, while three patients in the milk ladder group experienced anaphylaxis due to accidental exposure to milk (p < .001). Failure to complete treatment was associated with a higher skin prick test in the milk avoidance group and a raised specific IgE in the milk ladder group. CONCLUSION: This is the first study that compares outcomes of dietary advancement therapy to complete avoidance for CMPA management, demonstrating that cow's milk can be successfully and safely reintroduced using dietary advancement therapy using a milk ladder.

Augmented type 2 inflammatory response in allergic rhinitis patients experiencing systemic reactions to house dust mite subcutaneous immunotherapy.

BACKGROUND: Subcutaneous immunotherapy (SCIT) can induce systemic reactions (SRs) in certain patients, but the underlying mechanisms remain to be fully elucidated. METHODS: AR patients who were undergoing standardized HDM SCIT (Alutard, ALK) between 2018 and 2022 were screened. Those who experienced two consecutive SRs were included in the study group. A control group was established, matched 1:1 by gender, age, and disease duration with the study group, who did not experience SRs during SCIT. Clinical and immunological parameters were recorded and analyzed both before SCIT and after 1 year of treatment. RESULTS: A total of 161 patients were included, with 79 (49.07%) in the study group. The study group had a higher proportion of AR combined asthma (26.8% vs. 51.8%, p < 0.001) and higher levels of sIgE to HDM and HDM components (all p < .001). Serum IL-4 and IL-13 levels in the study group were higher than those in the control group (p < .05). The study group received a lower maintenance dosage of HDM extracts injections than control group due to SRs (50000SQ vs. 100000SQ, p < .05). After 1 year of SCIT, the VAS score, the lung function parameters of asthmatic patients over 14 years old significantly improved in both groups (all p < .05). After a 7-day exposure to 20 µg/mL HDM extracts, the percentages of Th1, Th17, Tfh10, and Th17.1 in PBMCs decreased, while the Tfh13 cells significantly increased in the study group (p < .05). CONCLUSION: The type 2 inflammatory response is augmented in HDM-induced AR patients who experienced SRs during SCIT. Despite this, SCIT remains effective in these patients when administered with low-dosage allergen extracts.

A retrospective study of a novel 3-session rush venom immunotherapy protocol.

BACKGROUND: Venom immunotherapy (VIT) is an effective treatment for life-threatening stinging-insect hypersensitivity. Rush VIT protocols allow patients to reach maintenance dosing faster, thus conferring protection sooner. The published protocols vary in dosing regimens, monitoring parameters, and safety profiles. OBJECTIVE: To describe a novel 3-session outpatient rush VIT protocol with full therapeutic dosing achieved at the end of session 3. METHODS: We conducted a retrospective chart review of adult patients treated with rush VIT in an outpatient university allergy/immunology clinic. Demographic and clinical data, including the type of sting reaction, the number of venom allergens, and any systemic reactions (SRs) during VIT, were analyzed. RESULTS: Over a 14-year period, 55 patients (28 females and 27 males) with a median age of 47 years underwent our VIT protocol. A total of 46 patients (84%) tolerated the procedure without SR, and 53 (96%) attained full maintenance dosing. All reactions during rush were Brown anaphylaxis criteria grade 1 or 2. Although the most common venom allergy was yellow jacket, most patients had multiple venom allergies and received therapy with more than 1 venom. Furthermore, 10 patients were re-stung while on maintenance with only 1 patient having a mild SR. CONCLUSION: Our 3-session outpatient rush VIT protocol is effective and safe. Most patients had no SR and attained maintenance dosing. Compared with other 3-session rush protocols, our protocol requires non-invasive monitoring, and patients achieved monthly maintenance dosing immediately on completion.

Oral food immunotherapy in patients with atopic dermatitis.

Atopic dermatitis (AD) is one of the main risk factors for infants in the development of food allergy. Oral immunotherapy (OIT) in early childhood has been found to be highly effective and safe in preschoolers with and without AD, especially in young infants. Delays in initiation of OIT in infants and children due to uncontrolled AD risk expansion of the number of foods children develop allergy to through unnecessary avoidance of multiple foods. Parents and caregivers may attribute eczema flares to OIT doses, which physicians usually ascribe to non-food triggers such as weather changes, psychological stress, and infection. There is a lack of published literature confirming OIT as a trigger of AD flares, and the degree to which OIT may be associated with AD flares needs to be further studied. We describe 8 case scenarios with varying degrees of AD flare before and during OIT. We propose management algorithms for children with preexisting concurrent AD and food allergy who are being considered for starting OIT and children with AD flares during OIT. Optimizing AD control strategies and providing adequate AD care education before starting OIT can reduce confusion for both parents and allergists if rashes arise during OIT, thus improving adherence to OIT.

The riddle of response to cutaneous allergen exposure in patients with atopic dermatitis.

The skin is the largest immunologic organ in the body and contains immune cells that play a role in both food allergen sensitization and desensitization. The dual allergen exposure hypothesis posits that sensitization to food allergens may occur with cutaneous exposure on inflamed skin, eg, atopic dermatitis, but early oral consumption generally leads to tolerance. However, only one-third of children with atopic dermatitis develop a food allergy, suggesting that there is a more complex mechanism for allergen sensitization. Emerging evidence suggests that the outcome of cutaneous allergen exposure is context-dependent and largely influenced by the state of the skin barrier with healthy skin promoting natural tolerance. Current research supports the ability to induce desensitization through repeated application of allergens to the skin, known as epicutaneous immunotherapy. Preclinical research with an occlusive patch has demonstrated a significantly reduced T-helper cell type 2-driven immunologic response when applied to intact, uninflamed skin and induction of a unique population of regulatory T cells that express a broader range of homing receptors, which may be able to maintain sustained protection. In clinical studies of children aged 1 through 11 years with a peanut allergy, epicutaneous immunotherapy with an occlusive patch led to significant desensitization with no major differences in efficacy or safety between children with and without atopic dermatitis. These data begin to answer the conundrum of how allergens that are applied to the skin can lead to both sensitization and desensitization, and future studies should enable us to optimize the power of the skin as a complex immunologic organ to treat allergic, autoimmune, and autoinflammatory disorders.

Randomized trial of pharmacokinetic and pharmacodynamic effects of 13.2 mg intranasal epinephrine treatment in congestion.

BACKGROUND: Nasal congestion could affect the absorption of an epinephrine nasal spray (ENS). OBJECTIVE: To compare the pharmacokinetics of 13.2 mg ENS with nasal congestion vs without congestion and vs intramuscular (IM) treatments. METHODS: This phase I, open-label, 4-period randomized crossover study enrolled 51 healthy adults with seasonal allergies into cohorts that received a single dose of 13.2 mg ENS (NDS1C; Bryn Pharma, Lebanon, New Jersey) administered as 2 consecutive sprays in either opposite nostrils (cohort 1) or the same nostril (cohort 2). Both cohorts received 13.2 mg ENS with and without nasal allergen challenge (NAC), 0.3 mg IM epinephrine by autoinjector, and 0.5 mg IM epinephrine by manual syringe (MS). RESULTS: The ENS after NAC resulted in higher extent and peak exposures and more rapid time to maximum plasma concentration vs ENS without NAC and IM treatments. In cohort 1, the maximum observed baseline-adjusted epinephrine plasma concentration (pg/mL) of ENS with NAC, IM autoinjector, IM MS, or ENS without NAC was 458.0, 279.0, 364.2, and 270.1, respectively, and in cohort 2 was 436.3, 228.2, 322.3, and 250.8, respectively. The maximum observed baseline-adjusted epinephrine plasma concentration geometric mean ratio (90% CI) for ENS with NAC vs without NAC in cohort 1 was 170% (123%-234%), and in cohort 2 was 174% (115%-263%). In cohort 1, the time to maximum plasma concentration was 15, 21, 45, and 25 minutes, respectively, and in cohort 2 was 18, 20, 45, and 20 minutes, respectively (P < .01 for ENS with NAC vs IM MS). The postdose mean heart rate and blood pressure remained stable and relatively similar to predose values regardless of plasma epinephrine concentration. Mild nausea and headache were the most common adverse events with ENS. CONCLUSION: The 13.2 mg ENS with congestion exhibited enhanced absorption vs IM treatments and ENS without congestion and seemed to be well tolerated. There was no clinically impactful relationship between pharmacodynamic effects and plasma epinephrine concentration.