Oral Immunotherapy for Children with Cow's Milk Allergy

Lactic acid bacteria and yeast co-fermented milk alleviate cow milk allergy

Cow milk allergy is one of the common food allergies. Our previous study showed that the allergenicity of fermented milk is lower than that of unfermented skimmed milk in vitro, and the antigenicity of β-lactoglobulin and α-lactalbumin in fermented milk was decreased by 67.54% and 80.49%, respectively. To confirm its effects in vivo, allergic BALB/C mice model was used to further study the allergenicity of fermented milk. It was found that compared with the skim milk (SM) group, the intragastrically sensitization with fermented milk had no obvious allergic symptoms and the fingers were more stable: lower levels of IgE, IgG, and IgA in serum, lower levels of plasma histamine and mast cell protein-1, and immune balance of Th1/Th2 and Treg/Th17. At the same time, intragastrically sensitization with fermented milk increased the α diversity of intestinal microbiota and changed the microbiota abundance: the relative abundance of norank-f-Muribaculaceae and Staphylococcus significantly decreased, and the abundance of Lachnospiraceae NK4A136 group, Bacteroides, and Turicibacter increased. In addition, fermented milk can also increase the level of short-chain fatty acids in the intestines of mice. It turns out that fermented milk is much less allergenicity than SM. PRACTICAL APPLICATION: Fermentation provides a theoretical foundation for reducing the allergenicity of milk and dairy products, thereby facilitating the production of low-allergenic dairy products suitable for individuals with milk allergies.

Long-Term Adherence and Risk of Allergic Reactions in Patients Who Attained Milk Oral Immunotherapy Maintenance

BACKGROUND

Oral immunotherapy (OIT) has emerged as the most popular therapy for food allergy. However, data on the long-term adherence and efficacy of this approach are sparse.

OBJECTIVE

We aimed to assess the long-term adherence rates to OIT protocol and the associated risk of allergic reactions.

METHODS

Patients who completed milk OIT and reached a maintenance dose of 200 mL of milk were surveyed biannually on their dairy consumption and occurrence of allergic reactions. A survival analysis was performed to evaluate the association between the risk of reaction and the adherence to OIT maintenance protocol.

RESULTS

The cohort consisted of 50 patients. Only 56% of the cohort adhered to the protocol, which consisted of ingesting a minimum of 200 mL of milk at least 3 times per week. Adherent patients had a significantly reduced risk of allergic reactions as well as a reduced incidence of anaphylaxis, health care/emergency room visits, and epinephrine/antihistamine administration.

CONCLUSIONS

The findings demonstrate the importance of consistent maintenance dose consumption in the management of food allergies, with regular milk consumption contributing to the maintenance of unresponsiveness and decreased risk of allergic symptoms.

Fatal food anaphylaxis in adults and children

Anaphylaxis is a life-threatening reaction characterized by the acute onset of symptoms involving different organ systems and requiring immediate medical intervention. The incidence of fatal food anaphylaxis is 0.03 to 0.3 million/people/year. Most fatal food-induced anaphylaxis occurs in the second and third decades of life. The identified risk factors include the delayed use of epinephrine, the presence of asthma, the use of recreational drugs (alcohol, nicotine, cannabis, etc.), and an upright position. In the United Kingdom (UK) and Canada, the reported leading causal foods are peanuts and tree nuts. In Italy, milk seems to be the most common cause of fatal anaphylaxis in children < 18 years. Fatal food anaphylaxis in Italian children and adolescents almost always occurs outside and is characterized by cardiorespiratory arrest; auto-injectable adrenaline intramuscular was available in few cases. Mortality from food anaphylaxis, especially in children, is a very rare event with stable incidence, but its risk deeply impacts the quality of life of patients with food allergy and their families. Prevention of fatal food anaphylaxis must involve patients and their families, as well as the general public, public authorities, and patients' associations.

Glutamine and lysine as common residues from epitopes on α-lactalbumin and β-lactoglobulin from cow milk identified by phage display technology

Cow milk is an important source of food protein for children; however, it could lead to allergy, especially for infants. α-Lactalbumin (α-LA) and β-lactoglobulin (β-LG) from whey protein make up a relatively high proportion of milk proteins and have received widespread attention as major allergens in milk. However, few studies have identified the epitopes of both proteins simultaneously. In this study, ImmunoCAP and indirect ELISA were first used for detection of sIgE to screen sera from allergic patients with high binding capacity for α-LA and β-LG. Subsequently, the mimotopes was biopanned by phage display technology and bioinformatics and 17 mimic peptide sequences were obtained. Aligned with the sequences of α-LA or β-LG, we identified one linear epitope on α-LA at AA 11-26 and 5 linear epitopes on β-LG at AA 9-29, AA 45-57, AA 77-80, AA 98-101, and AA 121-135, respectively. Meanwhile, the 8 conformational epitopes and their distributions of α-LA and β-LG were located using the Pepitope Server. Finally, glutamine and lysine were determined as common AA residues for the conformational epitopes both on α-LA and β-LG. Moreover, we found the addition of mouse anti-human IgE during the biopanning process did not significantly affect the identification of the epitopes.

Risk factors for discontinuing oral immunotherapy in children with persistent cow milk allergy

Background

There are no universally accepted criteria for discontinuing milk oral immunotherapy (MOIT) in patients with persistent cow milk allergy (CMA) and little data are available on predictive risk factors for dropping out from oral immunotherapy (OIT), due to allergic reactions or other reasons.

Methods

We retrospectively reviewed clinical records of patients with persistent severe CMA undergoing MOIT in a tertiary care center hospital to investigate risk factors associated with discontinuation of OIT. Persistent and severe allergy was defined as the history of systemic reactions and any milk protein‐specific IgE level >85 kU/ml. All patients were first admitted for an in‐hospital rush phase eventually followed by an at‐home dose increase. We evaluated the effect of various factors on two primary outcomes: the highest dose of milk ingested during the in‐hospital rush phase and during the home OIT phase.

Results

We identified 391 patients, of whom 131 met the inclusion criteria for the retrospective study, 54 females and 77 males. Data of the home OIT phase were available for 104 patients (27%).

Regarding the home OIT outcome, an association for having a cow milk avoiding diet was found with reaching a dose below 10 ml during the in‐hospital rush phase (relative risks [RR]: 2.33, confidence interval [CI]: 0.85; 6.42), an age above than 10 years from the time of admission (RR: 3.29, CI: 0.85; 12.73), and a higher total number of reactions occurred during the hospitalization (RR: 1.54, CI: 1.02; 2.32), whereas the presence of respiratory reactions with wheezing (RR: 1.93, CI: 0.49; 7.61) and an IM adrenaline use was related to a higher risk of having an OIT still in progress (RR: 5.47, CI: 0.33; 7.73).

Conclusions

In this cohort of children with persistent CMA undergoing OIT who presented with respiratory reactions with wheezing, the development of anaphylaxis with the need for IM adrenaline, and age above 10 years were predictors of poor long‐term outcome.

This study shows that wheezing reactions during the in‐hospital phase admission, discharge with a dose below 10 ml, use of IM epinephrine, and older age (over 10 years) were all risk factors for OIT discontinuation.

The provided phenotype of patients with a severe milk allergy who are more likely to fail OIT can help pediatricians to provide to their parents the elements to properly decide the most appropriate approach.

Could Age and Oral Challenge Outcomes Identify High-Risk Patients During Cow's Milk Oral Immunotherapy?

Objective: Severe immunglobuline E (IgE)-mediated reactions during oral immunotherapy (OIT) are major obstacles to treatment. The present study aimed to evaluate and identify clinical and laboratory biomarkers of adverse events during OIT among children with cow's milk (CM) allergy. Study Design: Eighty-six children older than 36 months who had undergone OIT with milk were enrolled. Clinical data, oral food challenge (OFC) test results, and laboratory data were recorded retrospectively. Results: The median duration of the build-up phase of OIT was 19 weeks (min 10-max 40) and the duration of the maintenance phase was 86.5 (min 1-max 132) months. A total of 11,767 CM doses were administered during the build-up phase and adverse reactions were seen in 62 (73.8%) patients with reactions registered for 157 doses among 11,767 (1/75 doses). The number of reactions during the maintenance phase was 41 (47.6%) in 24 (27.9%) patients. There was a significant reduction in the number of reactions (P = 0.000) between the build-up phase and maintenance phase. Adverse reactions and anaphylaxis were higher for patients who had cough during OFC (P = 0.003, P = 0.002, respectively) during the build-up phase and also during the maintenance phase too (P = 0.000). Evaluation for all reactions and anaphylaxis (during build-up and maintenance) with Kaplan-Meier and Cox regression analysis showed class IV-VI of CM-specific immunoglobulin E (sIgE), casein-sIgE and cough during OFC were significantly associated with increased probability of reaction and anaphylaxis. Younger age at onset of OIT was associated with risk reduction (0.017). Conclusion: Laboratory data and reactions during the OFC (especially cough) can help to identify high-risk patients during OIT.

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.