A simple predictor for donor-specific anti-HLA antibody desensitisation in haploidentical haematopoietic stem cell transplantation.

Donor-specific HLA antibody (DSA) has been recognised as an independent risk factor for graft failure in patients undergoing haploidentical haematopoietic stem cell transplantation (HID HSCT). Therapeutic plasma exchange (TPE), as a first-line strategy for DSA desensitisation, can promptly reduce serum DSA levels. This study aimed to investigate DSA characteristics and identify a biomarker predicting the efficacy of DSA desensitisation in patients proceeding to HID HSCT. We retrospectively enrolled 32 patients with DSA from April 2021 to January 2024, and analysed the mean fluorescence intensity (MFI) value of DSA at the different time points of desensitisation treatment. Compared with baseline DSA level before TPE, the median MFI of HLA class I DSA was reduced from 8178.6 to 795.3 (p < 0.001), and HLA class II DSA decreased from 6210.9 to 808.8 (p < 0.001) after TPE. The DSA level in 1:16 diluted pre-TPE serum correlated well with DSA value in post-TPE serum (class I, r = 0.85, p < 0.0001; class II, r = 0.94, p < 0.0001), predicting TPE efficacy in 84.4% of patients. Based on the degree of DSA reduction after TPE, patients were divided into complete responders (decreased by >70%), partial responders (decreased by 30 to 70%) and non-responders (decreased by <30%) and the percentages were 43.8%, 25% and 31.2%, respectively. Non-responders receiving aggressive immunotherapy had longer overall survival compared to those receiving standard strategies (p < 0.05). The 1:16 diluted pre-TPE serum may predict the efficacy of TPE and allow for more rational immunotherapy strategy for patients with DSA proceeding to HID HSCT.

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.

Efficacy and safety of low-dose sesame oral immunotherapy in paediatric patients: a protocol for a single-centre, randomised controlled trial.

INTRODUCTION: Sesame allergy, though with low prevalence, can result in severe, potentially life-threatening reactions and poses challenges in allergen avoidance due to hidden sources. In the majority of patients, sesame allergy persists and there is currently no effective long-term treatment available. Therefore, oral immunotherapy (OIT) is a promising alternative approach to managing sesame allergy. In this study protocol, we present a randomised controlled trial evaluating the efficacy and safety of OIT with low-dose sesame protein in paediatric patients. The study's aim is to compare OIT with a 300 mg maintenance dose of sesame protein against controls. METHODS AND ANALYSIS: 39 participants aged 3-17 with IgE-mediated sesame allergy confirmed by oral food challenge will be enrolled into the study. The trial will be conducted at the Paediatric Hospital of the Medical University of Warsaw, Poland. The study comprises two arms-sesame OIT and control. In the sesame OIT group, interventions will be administered once daily for up to 18 months. During the first phase, the dose will be escalated every 2-4 weeks, and in the second phase, the maintenance dose of 300 mg sesame protein will continue for 3 months. Members of the control group will receive standard treatment, which includes an elimination diet and will remain under observation for 1 year. The primary outcome is the proportion of participants tolerating a single dose of 4000 mg of sesame protein during the final oral food challenge in the experimental group versus the control group. Secondary outcomes assess adverse events, changes in immunological parameters and the maximum tolerated doses of sesame protein in each group. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of the Medical University of Warsaw (approval number: KB/269/2023). Results will be published in peer-reviewed journals and disseminated via presentations at international conferences. TRIAL REGISTRATION NUMBER: NCT06261554.

Impact of COVID-19 on adverse reactions to subcutaneous specific immunotherapy in children:a retrospective cohort study.

BACKGROUND: COVID-19 is a new infectious disease. To investigate whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection increases the adverse reactions of subcutaneous specific immunotherapy (SCIT) in children. METHODS: This study was conducted by collecting relevant data from children who underwent house dust mite SCIT from April 3, 2021, to March 18, 2023, including information on the time of COVID-19 infection, symptoms, and adverse reactions after each allergen injection. A mixed effects model was used to analyze the changes in adverse reactions before and after the COVID-19 infection. RESULTS: Among the records of adverse reactions from 2658 injections in 123 children who underwent SCIT, the overall adverse reaction rate before COVID-19 infection was 39.8% and 30.0% after COVID-19 infection. Compared with pre-infection with COVID-19, the risks of overall adverse reactions, local adverse reactions, and systemic adverse reactions of immunotherapy after COVID-19 infection were reduced (odds ratio [OR] = 0.24, 0.31, and 0.28, all P < 0.05). Among the local adverse reactions, the incidence of the unvaccinated group was the highest (15.3% vs. 7.1%). The incidence of overall and local adverse reactions to SCIT decreased in 2-vaccinated COVID-19 recipients (OR = 0.29-0.31, P < 0.05). CONCLUSIONS: In children, SARS-CoV-2 infection does not increase the incidence of adverse reactions to SCIT. This finding can provide a basis for the implementation of allergen-specific immunotherapy (AIT) during the COVID-19 pandemic.

Intranasal administration of a synthetic TLR4 agonist INI-2004 significantly reduces allergy symptoms following therapeutic administration in a murine model of allergic sensitization.

Introduction: Atopic diseases have been steadily increasing over the past decades and effective disease-modifying treatment options are urgently needed. These studies introduce a novel synthetic Toll-like receptor 4 (TLR4) agonist, INI-2004, with remarkable efficacy as a therapeutic intranasal treatment for seasonal allergic rhinitis. Methods: Using a murine airway allergic sensitization model, the impact of INI-2004 on allergic responses was assessed. Results: One or two intranasal doses of INI-2004 significantly reduced airway resistance, eosinophil influx, and Th2 cytokine production - providing strong evidence of allergic desensitization. Further investigations revealed that a liposomal formulation of INI-2004 exhibited better safety and efficacy profiles compared to aqueous formulations. Importantly, the liposomal formulation demonstrated a 1000-fold increase in the maximum tolerated intravenous dose in pigs. Pre-clinical GLP toxicology studies in rats and pigs confirmed the safety of liposomal INI-2004, supporting its selection for human clinical trials. Discussion: These findings lay the groundwork for the ongoing clinical evaluation of INI-2004 in allergic rhinitis as a stand-alone therapy for individuals poly-sensitized to multiple seasonal allergens. The study underscores the significance of innovative immunotherapy approaches in reshaping the landscape of allergic rhinitis management.

Grass pollen allergoids conjugated with mannan for subcutaneous and sublingual immunotherapy: a dose-finding study.

Background: Polymerized allergoids conjugated with mannan represent a novel approach of allergen immunotherapy targeting dendritic cells. In this study, we aimed to determine the optimal dose of mannan-allergoid conjugates derived from grass pollen (Phleum pratense and Dactylis glomerata) administered via either the subcutaneous or sublingual route. Methods: A randomized, double-blind, placebo-controlled trial with a double-dummy design was conducted, involving 162 participants across 12 centers in Spain. Subjects were randomly allocated to one of nine different treatment groups, each receiving either placebo or active treatment at doses of 500, 1,000, 3,000, or 5,000 mTU/mL over four months. Each participant received five subcutaneous (SC) doses of 0.5 mL each, every 30 days, and a daily sublingual (SL) dose of 0.2 mL. Participants who received active treatment through SC, received placebo through SL. Participants who received active treatment through SL, received placebo SC. One Group, as control, received bot SC and SL placebo. The primary efficacy outcome was the improvement in titrated nasal provocation tests (NPT) at the end of the study compared to baseline. Secondary outcomes included specific antibody (IgG4, IgE) and cellular (IL-10 producing and regulatory T cell) responses. All adverse events and side reactions were recorded and assessed. Results: Post-treatment, the active groups showed improvements in NPT ranging from 33% to 53%, with the highest doses showing the greatest improvements regardless of the administration route. In comparison, the placebo group showed a 12% improvement. Significant differences over placebo were observed at doses of 3,000 mTU/mL (p=0.049 for SL, p=0.015 for SC) and 5,000 mTU/mL (p=0.011 for SL, p=0.015 for SC). A dose-dependent increase in IgG4 was observed following SC administration, and an increase in IL-10 producing cells for both routes of administration. No serious systemic or local adverse reactions were recorded, and no adrenaline was required. Conclusion: Grass pollen immunotherapy with mannan-allergoid conjugates was found to be safe and efficacious in achieving the primary outcome, whether administered via the subcutaneous or sublingual routes, at doses of 3,000 and 5,000 mTU/mL. Clinical trial registration: https://www.clinicaltrialsregister.eu/ctr-search (EudraCT), identifier 2014-005471-88; https://www.clinicaltrials.gov, identifier NCT02654223.

Viral Vector Based Immunotherapy for Peanut Allergy.

Food allergy (FA) is estimated to impact up to 10% of the population and is a growing health concern. FA results from a failure in the mucosal immune system to establish or maintain immunological tolerance to innocuous dietary antigens, IgE production, and the release of histamine and other mediators upon exposure to a food allergen. Of the different FAs, peanut allergy has the highest incidence of severe allergic responses, including systemic anaphylaxis. Despite the recent FDA approval of peanut oral immunotherapy and other investigational immunotherapies, a loss of protection following cessation of therapy can occur, suggesting that these therapies do not address the underlying immune response driving FA. Our lab has shown that liver-directed gene therapy with an adeno-associated virus (AAV) vector induces transgene product-specific regulatory T cells (Tregs), eradicates pre-existing pathogenic antibodies, and protects against anaphylaxis in several models, including ovalbumin induced FA. In an epicutaneous peanut allergy mouse model, the hepatic AAV co-expression of four peanut antigens Ara h1, Ara h2, Ara h3, and Ara h6 together or the single expression of Ara h3 prevented the development of a peanut allergy. Since FA patients show a reduction in Treg numbers and/or function, we believe our approach may address this unmet need.

Single-Domain Antibodies-Novel Tools to Study and Treat Allergies.

IgE-mediated allergies represent a major health problem in the modern world. Apart from allergen-specific immunotherapy (AIT), the only disease-modifying treatment, researchers focus on biologics that target different key molecules such as allergens, IgE, or type 2 cytokines to ameliorate allergic symptoms. Single-domain antibodies, or nanobodies, are the newcomers in biotherapeutics, and their huge potential is being investigated in various research fields since their discovery 30 years ago. While they are dominantly applied for theranostics of cancer and treatment of infectious diseases, nanobodies have become increasingly substantial in allergology over the last decade. In this review, we discuss the prerequisites that we consider to be important for generating useful nanobody-based drug candidates for treating allergies. We further summarize the available research data on nanobodies used as allergen monitoring and detection probes and for therapeutic approaches. We reflect on the limitations that have to be addressed during the development process, such as in vivo half-life and immunogenicity. Finally, we speculate about novel application formats for allergy treatment that might be available in the future.

Glycolysis Changes in Alloreactive Memory B Cells in Highly Sensitized Kidney Transplant Recipients Undergonig Desensitization Therapy.

Despite the growing use of desensitization strategies, hyperimmune patients remain at high risk of antibody-mediated rejection suggesting that, even when donor-specific antibodies (DSA) are effectively depleted, anti-donor specific B cells persist. We included 10 highly sensitized recipients that underwent desensitization with plasmapheresis and B cell depletion prior to kidney transplantation. We quantified changes in DSA (luminex), total B-cell subsets (flow cytometry), anti-donor HLA B cells (fluorospot), and single-cell metabolism in serially collected samples before desensitization, at the time of transplant, and at 6 and 12 months thereafter. Desensitization was associated with a decrease in DSA and total memory B cell and naive B cell percentage, while plasma cells and memory anti-donor HLA circulating B cells persisted up to 12 months after transplant. At 12-month post-transplantation, memory B cells increased their glycolytic capacity, while proliferative KI67+ plasma cells modified their metabolism by increasing fatty acid and amino acid oxidation capacity and decreasing their glucose dependence. Despite effective DSA depletion, anti-donor B cells persist in kidney transplant recipients. Due to the reliance of these cells on glycolysis, glycolysis-targeting therapies might represent a valuable treatment strategy.

[The advances on oral tolerance induction for prevention of egg allergy in infants].

The prevalence of food allergy is increasing worldwide and seriously affects the living quality of patients and their families. Egg allergy is one of the commonest forms of food allergy. The traditional regimen is to delay the introduction of eggs to infant complementary foods, which is not able to reduce the prevalence of egg allergies and causes negative effects on infants' physical and psychological conditions. Oral tolerance therapy is an approach to establish immune tolerance by the active suppression of specific immune responses to antigens in the gastrointestinal tract. The development of oral tolerance through early introduction of eggs to infant complementary has proven effective in randomized controlled trials, which has been incorporated into infant feeding guidelines in many countries. This article focuses on the mechanism, efficacy and safety of oral tolerance induction in the prevention of egg allergy.

Drug Reactions and Desensitization to Chemotherapeutic Agents: An Overview and Case Study.

Certain chemotherapy agents have an increased potential to cause allergic reactions. These reactions can vary in severity from mild to severe, and a change in treatment may be suggested for the patient to avoid the causative.

Selection of allergen extract for immunotherapy in polysensitized allergic rhinitis patients.

Aim: To evaluate the criteria used by allergists in selecting an immunotherapy extract (allergen immunotherapy [AIT]-extract) in rhinitis patients with polysensitization. Methods: First, a cross-sectional study was carried out by evaluating different factors that influence the medical choice of AIT-extract. Second, a literature review was performed by evaluating the diagnostic performance of atopy tests. Results: A total of 419 patients were included (84 children, 149 adolescents and 186 adults). Anamnesis, atopy tests and exposure to pets were the main factors for choosing the AIT extract. The sensitivity and specificity of atopy tests were high for Dermatophagoides spp., (>80%), moderate for pets (60%) and indeterminate for Blomia tropicalis. Conclusion: NCTs could be necessary for AIT-extract selection in polysensitized allergic rhinitis patients.

Allergen immunotherapy is an effective treatment for patients with allergic rhinitis. Atopy tests are used to identify possible substances in the environment that cause symptoms. A patient may sometimes have multiple substances which could be causing their allergic reactions, which makes it difficult to choose the appropriate immunotherapy for the patient. In this study, we identified some factors that might help to guide the criteria used by allergists when selecting the extract for immunotherapy.

[Basics in diagnostics and therapy of allergic diseases for ENT consultations]. / Grundlagen der Allergologie für die HNO-Sprechstunde.

Allergies play a pivotal role in the daily practice of ENT specialists. Allergic symptoms induced by inhalant allergens are widespread in the population and can manifest through a wide range of symptoms, including rhinorrhea, sneezing, conjunctival redness, cough and dyspnea. Inconsistent diagnosis and treatment of allergic conditions can lead to reduced quality of life, decreased work performance, and socioeconomically significant secondary diseases. In addition to the medical history, the skin prick test and serological IgE diagnostics are the most important diagnostic procedure for detecting type-I allergies. To clarify clinical relevance, molecular diagnostics and nasal provocation testing may be employed. The key to effective treatment lies in a comprehensive allergological diagnosis coupled with a detailed patient history. General treatment recommendations such as allergen avoidance and nasal irrigation should complement pharmacological therapy. In the treatment of allergic rhinitis topical steroids are first line treatment options. The primary goal of treatment is symptom control, and if control is insufficient, causal therapy through specific allergen immunotherapy is recommended. Challenges in the ENT clinic involve selecting the necessary diagnostics and appropriate, effective treatments. Hence, using diagnostic and treatment algorithms, as well as standardized patient history questionnaires, can serve as invaluable tools in daily patient interactions, especially considering limited time availability.