Outcome of oral food challenges in children in relation to symptom-eliciting allergen dose and allergen-specific IgE

Food allergy population thresholds: an evaluation of the number of oral food challenges and dosing schemes on the accuracy of threshold dose distribution modeling

For most allergenic foods, limited availability of threshold dose information within the population restricts the advice on action levels of unintended allergenic foods which should trigger advisory labeling on packaged foods. The objective of this paper is to provide guidance for selecting an optimal sample size for threshold dosing studies for major allergenic foods and to identify factors influencing the accuracy of estimation. A simulation study was performed to evaluate the effects of sample size and dosing schemes on the accuracy of the threshold distribution curve. The relationships between sample size, dosing scheme and the employed statistical distribution on the one hand and accuracy of estimation on the other hand were obtained. It showed that the largest relative gains in accuracy are obtained when sample size increases from N=20 to N=60. Moreover, it showed that the EuroPrevall dosing scheme is a useful start, but that it may need revision for a specific allergen as more data become available, because a proper allocation of the dosing steps is important. The results may guide risk assessors in minimum sample sizes for new studies and in the allocation of proper dosing schemes for allergens in provocation studies.

Clinical predictors for favorable outcomes in an oral immunotherapy program for IgE-mediated cow's milk allergy

BACKGROUND

Avoidance strategies in patients with cow's milk allergy occasionally fail to protect these patients from inadvertent exposures, leading to life-threatening reactions.

OBJECTIVE

To assess the safety and efficacy of milk oral immunotherapy as an alternative therapeutic strategy.

METHODS

Patients (n = 280, >4 years old) with IgE-mediated cow's milk allergy were enrolled into a milk oral immunotherapy program at a single hospital center. High-risk patients were not excluded. The treatment protocol consisted of 3 rounds of oral induction performed every 4 weeks. On day 1, a patient's reaction threshold was determined. On days 2 and 3, a tolerated starting dose below the threshold was confirmed. Day 4 mimicked the home treatment, which continued until the next induction.

RESULTS

The median initial starting dose was 52.5 mg of cow's milk protein. Excluding those whose treatment failed in the first week (n = 5) or are still undergoing treatment (n = 15), 61.5% (160 of 260 patients) achieved 7,200 mg and 85.4% of patients were consuming at least 180 mg of milk protein. Reactions at home requiring the use of injectable epinephrine occurred in 15.7% of patients (44 of 280) and in 0.075% (58 of 77,098) of doses administered. Predictors for achieving a full dose in multivariate analysis included a starting dose higher than 30 mg of milk protein (odds ratio 4.6, P < .001), not requiring epinephrine during induction (odds ratio 5.2, P < .001) or home treatment (odds ratio 2.6, P = .037), and the lack of nonanaphylactic type symptoms (odds ratio 15.6, P < .001).

CONCLUSION

Milk oral immunotherapy, carried out in a highly controlled setting, is successful in protecting the overwhelming majority of patients from accidental exposures to cow's milk protein.

Monitoring immune modulation by nutrition in the general population: identifying and substantiating effects on human health

Optimal functioning of the immune system is crucial to human health, and nutrition is one of the major exogenous factors modulating different aspects of immune function. Currently, no single marker is available to predict the effect of a dietary intervention on different aspects of immune function. To provide further guidance on the assessment and interpretation of the modulation of immune functions due to nutrition in the general population, International Life Sciences Institute Europe commissioned a group of experts from academia, government and the food industry to prepare a guidance document. A draft of this paper was refined at a workshop involving additional experts. First, the expert group defined criteria to evaluate the usefulness of immune function markers. Over seventy-five markers were scored within the context of three distinct immune system functions: defence against pathogens; avoidance or mitigation of allergy; control of low-grade (metabolic) inflammation. The most useful markers were subsequently classified depending on whether they by themselves signify clinical relevance and/or involvement of immune function. Next, five theoretical scenarios were drafted describing potential changes in the values of markers compared with a relevant reference range. Finally, all elements were combined, providing a framework to aid the design and interpretation of studies assessing the effects of nutrition on immune function. This stepwise approach offers a clear rationale for selecting markers for future trials and provides a framework for the interpretation of outcomes. A similar stepwise approach may also be useful to rationalise the selection and interpretation of markers for other physiological processes critical to the maintenance of health and well-being.

Cow's milk allergy: from allergens to new forms of diagnosis, therapy and prevention

The first adverse reactions to cow's milk were already described 2,000 years ago. However, it was only 50 years ago that several groups started with the analysis of cow's milk allergens. Meanwhile the spectrum of allergy eliciting proteins within cow's milk is identified and several cow's milk allergens have been characterized regarding their biochemical properties, fold and IgE binding epitopes. The diagnosis of cow's milk allergy is diverse ranging from fast and cheap in vitro assays to elaborate in vivo assays. Considerable effort was spent to improve the diagnosis from an extract-based into a component resolved concept. There is still no suitable therapy available against cow's milk allergy except avoidance. Therefore research needs to focus on the development of suitable and safe immunotherapies that do not elicit severe side effect.