A randomized trial of oral immunotherapy for pediatric cow's milk-induced anaphylaxis: Heated vs unheated milk

A Review of Shared Decision-Making, Published Protocols, and Post-desensitization Strategies in Oral Immunotherapy (OIT)

PURPOSE OF REVIEW

The aim of this review is to highlight key published oral immunotherapy (OIT) protocols and post-desensitization strategies for the major food allergens and to cover important concepts to consider when evaluating OIT for food-allergic patients. Shared decision-making should help identify patient and family values which will help influence the type of evidence-based protocol and maintenance strategy to use.

RECENT FINDINGS

With food OIT emerging as a treatment option, there is a pressing need for patients, physicians, and other providers to have a nuanced understanding of the management choices available to them. There are now randomized controlled trials (RCT) of OIT for peanut, egg, milk, and wheat, and reports of cohorts of patients who have undergone OIT for tree nuts and sesame clinically. The current published protocols contain significant diversity in terms of starting dose, build-up schedule, maintenance dose, and even the product used for desensitization. Emerging data can help direct the long-term maintenance strategy for patients on OIT. Based on patient and family values elicited through the shared decision-making process, an OIT protocol may be selected that balances the level of desensitization, potential side effects, frequency of clinic visits, and potential to induce sustained unresponsiveness, among other factors. Once maintenance dosing is reached, most patients will need to maintain regular exposure to the food allergen to remain desensitized. The option to transition to commercial food products with equivalent amounts of food protein as the OIT maintenance dose would simplify the dosing process and perhaps improve palatability as well. Less frequent or decreased OIT dosing can provide practical benefits but may affect the level of desensitization and safety for some patients.

Baked milk and egg diets revisited

Most children with milk and egg allergy are nonreactive to modified forms of milk and egg in bakery products such as muffins because of conformational changes in proteins. These baked milk (BM) and baked egg (BE) diets have become commonplace in the management of milk and egg allergy, respectively. Current laboratory- and skin test-based diagnostic approaches remain limited in their ability to predict BM/BE tolerance, resulting in various approaches to introduce these foods. One approach to introduce BM/BE is to offer a medically supervised oral food challenge and then advise dietary introduction of baked products for children who have tolerance. Another approach is adapted from a home-based protocol of graded ingestion of BM or BE originally intended for non-IgE mediated allergy, often referred to as a "ladder." The ladder advises home ingestion of increasing amounts of BM or BE. For children who have allergy to BM or BE, the ladder is essentially oral immunotherapy, although not always labeled or recognized as such. Risk assessment and education of patients suitable for home introduction are essential. A home approach that may be called a ladder can also be used to escalate diets after demonstrated tolerance of baked forms by introducing lesser cooked forms of milk or egg after tolerating BM or BE. A randomized controlled trial provided clear evidence that baked diets can hasten the resolution of IgE-mediated milk allergy. Moreover, BM/BE foods have an emerging role in the treatment of non-IgE-mediated allergy. There is tangential evidence for BM and BE diets in the prevention of IgE-mediated allergy.

Low-dose oral immunotherapy in immunoglobulin E-mediated food allergies

Nowadays, the management of food allergies has increasingly moved from conventional oral immunotherapy (OIT) to low-dose OIT or low-dose OIT utilizing hypoallergenic foods. This shift is largely because the latter appears to induce oral tolerance with fewer adverse effects than the former. However, the mechanisms underpinning such differences remain unclear. To better understand these mechanisms, we conducted a comparative study scrutinizing the mechanisms of OIT, especially those of low-dose desensitization. We also summarized articles on low-dose OIT and low-dose OIT using hypoallergenic foods. We examined the efficacy, safety, and immunological parameters of low-dose OIT and those of low-dose OIT with hypoallergenic foods with the aim of shedding some light on low-dose OIT and its therapeutic application in inducing oral tolerance for individuals with food allergies.

Food Allergen Immunotherapy in the Treatment of Patients with IgE-Mediated Food Allergy

The prevalence of allergic diseases, including food allergy, is increasing, especially in developed countries. Implementation of an elimination diet is not a sufficient therapeutic strategy in patients with food allergy, whose quality of life is significantly impaired. In recent years, new effective therapeutic strategies have been developed, such as the application of oral, sublingual, and epicutaneous immunotherapy. Oral immunotherapy is the most often applied strategy because of its effectiveness and ease of application, with an acceptable safety profile. The effectiveness of oral immunotherapy in patients with egg, cow's milk, and peanut allergy has been proven both in terms of raising of the threshold and the development of tolerance, and in some patients, the development of sustainable unresponsiveness. Although oral immunotherapy is an effective treatment for food allergy, several limitations, including a long duration and a significant rate of reported adverse events, reduces its success. Therefore, new therapeutic options, such as treatment with biologicals, either as combinations with food allergen immunotherapy or as monotherapy with the aim of improving the efficacy and safety of treatment, are being investigated.

Natural history of cow's milk allergy in children aged 6-12 years

BACKGROUND

Approximately 50%-90% of children with immediate-type cow's milk allergy (CMA) acquire tolerance by pre-school age. We aimed to investigate the acquisition rate of CMA tolerance in children aged 6-12 years.

METHODS

We included children with CMA who persisted until the age of 6. Tolerance was defined as passing an oral food challenge with 200 mL of unheated cow's milk (CM) or consuming 200 mL of CM without symptoms, whereas persistent CMA was defined as fulfilling neither of these criteria by 12 years old. Children receiving oral immunotherapy (OIT) were excluded from the primary analysis. Risk factors associated with persistent CMA were assessed using Cox regression analysis.

RESULTS

Of 80 included children, 30 (38%) had previous CM anaphylaxis, and 40 (50%) had eliminated CM completely from their diet. The median CM-specific immunoglobulin E (sIgE) level at 6 years old was 12.0 kUA /L. Tolerance was acquired by 25 (31%) and 46 (58%) children by the age of 9 and 12 years, respectively. At baseline, persistent CMA was associated with higher CM-sIgE levels (hazard ratio 2.29, 95% confidence interval 1.41-3.73, optimal cutoff level 12.7 kUA /L), previous CM anaphylaxis (2.07, 1.06-4.02), and complete CM elimination (3.12, 1.46-6.67). No children with CMA who had all three risk factors (n = 14) acquired tolerance.

CONCLUSION

Except for OIT patients, more than half of children with CMA at 6 years old acquired tolerance by 12 years old. Children with CMA who have the risk factors are less likely to acquire tolerance.

Combination of heat-killed Lactiplantibacillus plantarum YIT 0132 (LP0132) and oral immunotherapy in cow's milk allergy: a randomised controlled trial

Safer and more effective cow milk (CM)-oral immunotherapy that does not induce allergic reactions has not yet been standardised. We sought to explore the efficacy and feasibility of a combination of heat-killed Lactiplantibacillus plantarum YIT 0132 (LP0132) and oral immunotherapy for treating IgE-mediated cow milk allergy (CMA). We conducted a 24-week, double-blind, randomised (1:1), two-arm, parallel-group, placebo-controlled, phase 2 trial of LP0132 intervention for treating IgE-mediated CMA in children aged 1-18 years (n=60) from January 29, 2018 to July 12, 2019 in Tokyo, Japan. Participants were randomly assigned to the LP0132 group receiving citrus juice fermented with LP0132 or to the control group receiving citrus juice without. Both groups received low-dose slow oral immunotherapy with CM. The primary outcome was improved tolerance to CM, proven by the CM challenge test at 24 weeks. Secondary outcomes were changes in serum biomarkers of serum-specific β-lactoglobulin-IgE (sIgE) and β-lactoglobulin-IgG4 (sIgG4). Exploratory outcomes included changes in serum cytokine levels and gut microbiota composition. A total of 61 participants were included. Finally, 31 children were assigned to the LP0132 group and 30 to the control group, respectively. After the intervention, 41.4 and 37.9% of the participants in the LP0132 and control groups, respectively, showed improved tolerance to CM. In serum biomarkers after the intervention, the sIgG4 level was significantly higher, and interleukin (IL)-5 and IL-9 were significantly lower, in the LP0132 group than in the control group. In the gut microbiome, the α-diversity and Lachnospiraceae increased significantly in the LP0132 group, and Lachnospiraceae after the intervention was significantly higher in the LP0132 group than in the control group. In conclusion, low-dose oral immunotherapy with modulating gut microbiota might be a safer and more effective approach for treating cow's milk allergy.

Oral Immunotherapy in Food Allergy: Where Are We Now?

Food allergy (FA) has become more prevalent and problematic in the last 2 decades, and it poses important individual, social, and economic burdens. Besides treating reactions induced by accidental exposure and periodic evaluation for acquiring natural tolerance, the primary management approach is still allergen avoidance as a global standard. However, an active therapeutic approach that can raise the reaction threshold or accelerate tolerance is needed. This review aimed to provide an overview and the latest evidence of oral immunotherapy (OIT), which has recently been used in the active treatment of FA. FA immunotherapy, particularly OIT, is gaining considerable interest, and substantial effort has been made to integrate this active treatment into clinical practice. Consequently, growing evidence has been obtained regarding the efficacy and safety of OIT, particularly for allergens such as peanuts, eggs, and milk. However, several issues need to be addressed regarding the availability, safety, and long-term effects of this intervention. In this review, we summarize currently available information regarding tolerance-inducing immune mechanisms of OIT, data on efficacy and safety, gaps in current evidence, and ongoing research to develop new therapeutic molecules in order to enhance safety.

Oral immunotherapy for Immunoglobulin E‐mediated cow's milk allergy in children: A systematic review and meta analysis

Backgound

Cow's milk allergy (CMA) is the most common allergy in infants that decreases the quality of life of patients and their families. Standard treatment for CMA is the strict avoidance of milk; new treatment strategies such as oral immunotherapy (OIT) have been sought for patients with CMA. We aimed to assess the clinical efficacy and safety of OIT in the treatment of children with immunoglobulin E‐mediated CMA (IMCMA).

Methods

We searched all randomized controlled trials in which OIT is used to treat children with IMCMA from five international electronic databases. We estimated a pooled risk ratio (RR) for each outcome using a Mantel–Haenzel fixed‐effects model if statistical heterogeneity was low.

Results

Eleven studies were chosen for meta‐analysis, including a total of 469 children (242 OITs, 227 controls). One hundred and seventy‐six patients (72.7%) in the OIT were desensitized compared with 49 patients (21.6%) in the control group (RR: 7.35, 95% confidence interval (CI): 2.82–19.13, p < .0001). The desensitization effect of OIT was particularly significant in children over 3 years old (RR: 18.05, 95% CI: 6.48–50.26, p < .00001). Although adverse effects were common, they usually involved mild reactions, but epinephrine use was more common in the OIT group (RR: 7.69, 95% CI: 2.16–27.33, p < .002).

Conclusion

OIT can lead to desensitization in the majority of individuals with IMCMA, especially in patients over 3 years old. A major problem of OIT is the frequency of adverse events, although most are mild. OIT may be an alternative treatment in the future.

Biomarkers in oral immunotherapy

Food allergy (FA) is a global health problem that affects a large population, and thus effective treatment is highly desirable. Oral immunotherapy (OIT) has been showing reasonable efficacy and favorable safety in most FA subjects. Dependable biomarkers are needed for treatment assessment and outcome prediction during OIT. Several immunological indicators have been used as biomarkers in OIT, such as skin prick tests, basophil and mast cell reactivity, T cell and B cell responses, allergen-specific antibody levels, and cytokines. Other novel indicators also could be potential biomarkers. In this review, we discuss and assess the application of various immunological indicators as biomarkers for OIT.

World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) guideline update - XIII - Oral immunotherapy for CMA - Systematic review

Background

Allergy to cow's milk is the most common food allergy in infants and it is usually outgrown by 5 years of age. In some individuals it persists beyond early childhood. Oral immunotherapy (OIT, oral desensitization, specific oral tolerance induction) has been proposed as a promising therapeutic strategy for persistent IgE-mediated cow's milk allergy. We previously published the systematic review of OIT for cow's milk allergy (CMA) in 2010 as part of the World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines.

Objective

To systematically synthesize the currently available evidence about OIT for IgE-mediated CMA and to inform the updated 2022 WAO guidelines.

Methods

We searched the electronic databases including PubMed, Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and the websites of selected allergy organizations. We included all studies irrespective of the language of the original publication. The last search was conducted in February 2021. We registered the protocol on Open Science Framework (10.17605/OSF.IO/AH2DT).

Results

We identified 2147 unique records published between 2010 and 2021, including 13 randomized trials and 109 observational studies addressing cow's milk OIT. We found low-certainty evidence that OIT with unheated cow's milk, compared to elimination diet alone, increased the likelihood of being able to consume ≥150 ml of cow's milk in controlled settings (risk ratio (RR): 12.3, 95% CI: 5.9 to 26.0; risk difference (RD): 25 more per 100, 95% CI 11 to 56) as well as accidently ingest a small amount (≥5 ml) of cow's milk (RR: 8.7, 95% CI: 4.7 to 16.1; RD: 25 more per 100, 95% CI 12 to 50). However, 2–8 weeks after discontinuation of a successful OIT, tolerance of cow's milk persisted in only 36% (range: 20%–91%) of patients. OIT increased the frequency of anaphylaxis (rate ratio: 60.0, 95% CI 15 to 244; rate difference 5 more anaphylactic reactions per 1 person per year, 95% CI: 4 to 6; moderate evidence) and the frequency of epinephrine use (rate ratio: 35.2, 95% CI: 9 to 136.5; rate difference 268 more events per 100 person-years, 95% CI: 203 to 333; high certainty). OIT also increased the risk of gastrointestinal symptoms (RR 6.9, 95% CI 1.6–30.9; RD 28 more per 100, CI 3 to 100) and respiratory symptoms (RR 49.0, 95% CI 3.12–770.6; RD 77 more per 100, CI 62 to 92), compared with avoidance diet alone. Single-arm observational studies showed that on average 6.9% of OIT patients (95% CI: 3.8%–10%) developed eosinophilic esophagitis (very low certainty evidence). We found 1 trial and 2 small case series of OIT with baked milk.

Conclusions

Moderate certainty evidence shows that OIT with unheated cow's milk in patients with IgE-mediated CMA is associated with an increased probability of being able to drink milk and, at the same time, an increased risk of serious adverse effects.

Oral Immunotherapy in Food Allergy: A Critical Pediatric Perspective

There is evidence that in children with persistent IgE-mediated food allergy (FA) to cow's milk, hen's egg, and peanut, oral allergen-specific immunotherapy (OIT) may increase the reaction threshold to the culprit food allergen(s). OIT may protect patients from the occurrence of severe reactions in case of accidental ingestion of the culprit food during treatment. Notwithstanding, many gaps are still unsolved, including safety issues, identification of predictive biomarkers, and post-desensitization efficacy. In this perspective, the use of omalizumab (Anti-IgE monoclonal antibody) has been proposed as an adjunctive treatment to OIT in order to reduce the risk of allergic reactions related to OIT. This review aims to summarize the current evidence and unmet needs on OIT in children with FA to enhance the development of longitudinal, prospective, and well-designed studies able to fill the current gaps soon.

Precision medicine for cow's milk immunotherapy in clinical practice

PURPOSE OF REVIEW

Several novel immunotherapies have recently been reported for the treatment of cow's milk allergy (CMA). However, systematic methods for the selection of immunotherapy in clinical practice have not been investigated. In this review, we have provided suggestions for safe and effective immunotherapy for patients with CMA.

RECENT FINDINGS

Recent studies on cow's milk immunotherapy, using lower target doses, heated or baked cow's milk, combination treatment with adjuvants, or various routes of immunotherapy, included school-aged children with severe allergies, infants, and patients with mild CMA. These patients were administered various maintenance doses for various time periods. In the selection of immunotherapy, it would be useful to consider the patient's age and CMA severity at baseline: threshold dose, history of cow's milk anaphylaxis, and cow's milk-specific IgE levels.

SUMMARY

Considering the risks and benefits for patients with CMA, appropriate treatment should be selected based on the current evidence. Low-dose oral immunotherapy may be useful in clinical practice for school-aged children with severe CMA. Additional studies are needed to assess the indications for immunotherapy to select appropriate treatments in real-life settings.