The clinical and immune outcomes after food allergen immunotherapy emphasizing the development of tolerance

Maximum Dose Food Challenges Reveal Transient Sustained Unresponsiveness in Peanut Oral Immunotherapy (POIMD Study)

BACKGROUND

The maximum tolerated dose of peanut protein following peanut oral immunotherapy (POIT) is unknown because most research studies have not examined very high thresholds.

OBJECTIVE

To define the maximum dose tolerated by patients on POIT and severity of allergic reactions after a 1-month period of treatment discontinuation.

METHODS

In a phase 2 3-year POIT open-label study, we enrolled participants age 5 to 13 years with a 1-year build-up period followed by a 2-year daily maintenance dose of 3900 mg with assessment of the maximum tolerated dose using double-blind placebo-controlled food challenges (DBPCFCs) of 26,225 mg cumulative dose of peanut protein. The DBPCFC was performed at baseline, after 12-month build-up, at 2 year of maintenance, and after a 1-month period of treatment discontinuation. Biomarkers were assessed every 6 weeks for the first 6 months of therapy. A general linear mixed model was used for analysis.

RESULTS

The mean maximum cumulative tolerated dose after 12 months increased by 12,063 mg (P < .001) (n = 12), slightly decreased during maintenance (n = 11), and significantly decreased by 7593 mg after avoidance for 1 month (P = .03) (n = 6). Biomarker analysis revealed decreases in cytokine expression within the first 6 weeks of initiation of POIT and decreased peanut-IgG₄ and increased cytokine expression after 1 month of discontinuation. The DBPCFC reaction severity, examined through a symptom score with 1 point for each defined symptom, decreased after 12 months, but did not significantly change after 1 month of POIT discontinuation.

CONCLUSIONS

The evaluation of POIT and sustained unresponsiveness by maximum tolerated dose by DBPCFCs in this small phase 2 trial showed that desensitization is diminished, with 100% loss of tolerated dose after 1 month of avoidance following 3 years of treatment.

Oral immunotherapy in children with a food allergy-Where do we stand? - Review

The number of hospitalisations due to an anaphylactic reaction to food is continuously increasing. Therefore, there is an urgent need to seek effective therapy. Currently, the only way to treat food allergies is to avoid allergens and to administer intramuscular adrenaline if an accidental allergen intake occurs. The only causal therapeutic strategy is specific oral immunotherapy. An increasing amount of data confirms this therapy's effectiveness and safety, but the results remain inconclusive due to the lack of long-term follow-up. In this state-of-the-art review, we briefly summarise the latest placebo-controlled randomised controlled trials on oral immunotherapy (OIT) to treat food allergy. During the paper's review, we asked the following questions: does the therapy permanently increase the amount of allergen consumed without symptoms? Does it significantly increase or decrease the occurrence of severe systemic reactions - requiring the administration of adrenaline or hospitalisation? Many authors describe outcomes such as an increase in the amount of allergen that can be safely ingested; however, significant clinical benefits such as decreased hospitalisations or anaphylaxis incidence are rarely included in the results. To date, there is no unified protocol of therapy, which makes comparisons between studies difficult because of significant differences in types, doses, and routes of administration of the allergen, timeline for up-dosing and maintenance, duration of the therapy, and primary outcomes of OIT.

Biomarkers for diagnosis and prediction of therapy responses in allergic diseases and asthma

Modern health care requires a proactive and individualized response to diseases, combining precision diagnosis and personalized treatment. Accordingly, the approach to patients with allergic diseases encompasses novel developments in the area of personalized medicine, disease phenotyping and endotyping, and the development and application of reliable biomarkers. A detailed clinical history and physical examination followed by the detection of IgE immunoreactivity against specific allergens still represents the state of the art. However, nowadays, further emphasis focuses on the optimization of diagnostic and therapeutic standards and a large number of studies have been investigating the biomarkers of allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, food allergy, urticaria and anaphylaxis. Various biomarkers have been developed by omics technologies, some of which lead to a better classification of distinct phenotypes or endotypes. The introduction of biologicals to clinical practice increases the need for biomarkers for patient selection, prediction of outcomes and monitoring, to allow for an adequate choice of the duration of these costly and long‐lasting therapies. Escalating healthcare costs together with questions about the efficacy of the current management of allergic diseases require further development of a biomarker‐driven approach. Here, we review biomarkers in diagnosis and treatment of asthma, atopic dermatitis, allergic rhinitis, viral infections, chronic rhinosinusitis, food allergy, drug hypersensitivity and allergen immunotherapy with a special emphasis on specific IgE, the microbiome and the epithelial barrier. In addition, EAACI guidelines on biologicals are discussed within the perspective of biomarkers.