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.

Omalizumab withdrawal outcomes in chronic spontaneous urticaria are linked with baseline IgE and eosinophil levels.

Background: Chronic Spontaneous Urticaria (CSU) is an immune-mediated skin disease that may require prolonged treatments. Currently, there are no recommendations for treatment discontinuation once CSU symptoms are controlled, particularly among patients primarily diagnosed with severe CSU. Objective: In this real-life study we aimed to describe our experience of omalizumab (Oma) treatment withdrawal in CSU and define biomarkers related to these outcomes. Methods: CSU patients followed at our allergy clinic from January 2016 to December 2022 were included. Response to Oma therapy, and Oma-withdrawal outcomes among patients who reached complete remission for >6 months were analyzed. Results: During the study period 192/335(%) CSU patients were categorized as severe-CSU and entitled to receive Oma according to our country's regulations. Of them, 131/192(68%) were considered "Oma-responders", and 95/131(72.5%) patients underwent gradual treatment withdrawal. Successful Oma-withdrawal was documented in 47/95(49.5%) whereas 48/95(50.5%) patients experienced flare and were defined as unsuccessful OMA-withdrawal. The first was associated with shorter disease duration 7.1 ± 7.4 years vs. 10.7 ± 9.4 (P = 0.042), lower baseline-IgE 81.6 ± 84.1IU/ml vs. 324.7 ± 555.9 (P = 0.005), and lower baseline-eosinophils count 131.4 ± 110.5 vs. 195.6 ± 98.4 (P = 0.043) in comparison to failure of Oma-withdrawal group. Conclusion: OMA may be successfully withdrawn in up to 50% of severe CSU patients following complete remission of disease symptoms, utilizing a gradual withdrawal protocol. Oma-withdrawal failure was linked with longer duration of disease as well as high IgE and eosinophil counts prior to initiation of Oma therapy. These parameters may enable the design of a treatment withdrawal algorithm.

Drug fever-an immune-mediated delayed type hypersensitivity reaction to Vinca alkaloids in pediatric oncology patients, possibly mediated by cysteinyl leukotrienes.

Background: Drug hypersensitivity reactions are common in pediatric hemato-oncology patients due to multiple factors including immune compromise and pharmacological complexities. Fever can signify severe delayed-type hypersensitivity reactions such as drug reaction with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS). The etiology of fever as an isolated hypersensitivity reaction to chemotherapeutic agents not fully understood. Here, we report three children with intracranial neoplasms experiencing recurrent febrile reactions following Vinca alkaloid-based chemotherapy, mitigated by cysteinyl leukotriene receptor antagonist therapy. Methods: We present a series of pediatric patients with diverse intracranial neoplasms who developed recurrent fever episodes after multiple courses of Vinca alkaloid-based chemotherapy. Treatment involved prophylactic and post-chemotherapy administration of a cysteinyl leukotriene receptor antagonist to prevent fever episodes and enable completion of chemotherapy regimens without protocol modifications or desensitization. Results: All three patients experienced fever consistent with delayed-type hypersensitivity reactions to Vinca alkaloids. Prophylactic use of the leukotriene antagonist Montelukast successfully prevented fever recurrence, allowing uninterrupted completion of chemotherapy courses. Conclusion: Our findings suggest that Montelukast, a leukotriene antagonist, may be beneficial in managing fever as a delayed-type hypersensitivity reaction to Vinca alkaloids in pediatric patients. Further research is warranted to elucidate the underlying mechanisms and leukotriene pathways involved in drug-induced fever reactions.