Food allergy therapy: is a cure within reach?

Current Options for the Treatment of Food Allergy

Food allergy is increasing in prevalence; as a result, there is intense focus on developing safe and effective therapies. Current methods of specific immunotherapy include oral, sublingual, and epicutaneous, while nonspecific methods that have been investigated include: Chinese herbal medicine, probiotics, and anti-IgE antibodies. Although some studies have demonstrated efficacy in inducing desensitization, questions regarding safety and the potential for achieving immune tolerance remain. Although some of these therapies demonstrate promise, further investigation is required before their incorporation into routine clinical practice.

Evaluation of hypoallergenicity of a new, amino acid-based formula

The American Academy of Pediatrics (AAP) defined a formula as hypoallergenic if it ensures with 95% confidence that 90% of infants with confirmed cow's milk allergy (CMA) will not react with defined symptoms under double-blind, placebo-controlled conditions. This study's objective was to determine whether a new amino acid-based formula (AAF) meets the AAP hypoallergenicity criteria.

METHODS

Children with CMA were randomized to double-blind placebo-controlled food challenges (DBPCFC) with a new AAF and a commercial AAF in crossover fashion followed by an at-home open challenge with the new AAF. Allergic reactions were assessed using a scoring system.

RESULTS

Thirty-three subjects completed DBPCFCs with both formulas without acute allergic reactions. The lower bound 95% confidence interval for hypoallergenicity was 91.3%. No unusual stool patterns, allergic symptoms, or signs of intolerance were reported during the open challenge.

CONCLUSION

. The new AAF meets AAP hypoallergenicity criteria and can be recommended for the management of CMA.

Duration of a cow-milk exclusion diet worsens parents' perception of quality of life in children with food allergies

BACKGROUND

In Italy, rigorous studies obtained with specific and validated questionnaires that explore the impact of exclusion diets on health-related quality of life (HRQoL) in children with food allergies are lacking. In this cross-sectional study, we wished to validate the Italian version of a disease-specific quality of life questionnaire, and assess the impact of exclusion diets on the HRQoL in a cohort of Italian children with IgE-mediated food allergies.

METHODS

Children on an exclusion diet for ≥1 food were enrolled consecutively, and their parents completed the validated Italian version of the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) and Food Allergy Independent Measure (FAIM).

RESULTS

Ninety-six parents of children aged 0-12 years answered the FAQLQ-PF. The validity of the construct of the questionnaire was assessed by correlation between the FAQLQ-PF and FAIM-PF (r = 0.85). The Italian version of the FAQLQ had good internal consistency (Cronbach's α >0.70). Factors that mainly influenced the HRQoL were older age, severity of food allergy, and the duration of the cow milk-exclusion diet.

CONCLUSIONS

The FAQLQ-PF, validated in Italian, is a reliable instrument. Worse QoL scores were observed among older children, those with severe systemic reactions, and those with a prolonged cow milk-free diet. It is very important to consider the QoL assessment as an integral part of food-allergy management. These results emphasize the need to administer exclusion diets only for the necessary time and the importance of assessment of the HRQoL in these patients.

Clinical efficacy and mechanism of probiotics in allergic diseases

A complex interplay between genetic and environmental factors partially contributes to the development of allergic diseases by affecting development during prenatal and early life. To explain the dramatic increase in the prevalence of allergic diseases, the hygiene hypothesis proposed that early exposure to infection prevented allergic diseases. The hygiene hypothesis has changed to the microbial hypothesis, in which exposure to microbes is closely linked to the development of the early immune system and allergic diseases. The intestinal flora may contribute to allergic disease through its substantial effect on mucosal immunity. Based on findings that exposure to microbial flora early in life can change the Th1/Th2 balance, thus favoring a Th1 cell response, probiotics may be beneficial in preventing allergic diseases. However, evidence from clinical and basic research to prove the efficacy of probiotics in preventing allergy is lacking. To date, studies have yielded inconsistent findings on the usefulness of probiotics in allergic diseases. It is difficult to demonstrate an exact effect of probiotics on asthma, allergic rhinitis, and food allergy because of study limitations, such as different first supplementation period, duration, different strains, short follow-up period, and host factors. However, many studies have demonstrated a significant clinical improvement in atopic dermatitis with the use of probiotics. An accurate understanding of the development of human immunity, intestinal barrier function, intestinal microbiota, and systemic immunity is required to comprehend the effects of probiotics on allergic diseases.

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.

Oral immunotherapy for milk allergy

BACKGROUND

The mainstay of treatment of IgE-mediated cow milk allergy (IMCMA) is an avoidance diet, which is especially difficult with a ubiquitous food like milk. Milk oral immunotherapy (MOIT) may be an alternative treatment, through desensitization or induction of tolerance.

OBJECTIVES

We aim to assess the clinical efficacy and safety of MOIT in children and adults with IMCMA as compared to a placebo treatment or avoidance strategy.

SEARCH METHODS

We searched 13 databases for journal articles, conference proceedings, theses and unpublished trials, without language or date restrictions, using a combination of subject headings and text words. The search is up-to-date as of October 1, 2012.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were considered for inclusion. Blinded and open trial designs were included. Children and adults with IMCMA were included. MOIT administered by any protocol were included.

DATA COLLECTION AND ANALYSIS

A total of 2111 unique records were identified and screened for potential inclusion. Studies were selected, data extracted and methodological quality assessed independently by two reviewers. We attempted to contact the study investigators to inquire about data not published that was required for the analysis. Statistical heterogeneity was assessed using the I² test. We estimated a pooled risk ratio (RR) for each outcome using a Mantel-Haenzel fixed-effect model if statistical heterogeneity was low as evaluated by an I² value less than 50%.

MAIN RESULTS

Of 157 records reviewed, 16 were included, representing five trials. In general, the studies were small and had inconsistent methodological rigor. Overall, the quality of evidence was rated as low. Each study used a different MOIT protocol. A total of 196 patients were studied (106 MOIT, 90 control) and all were children. Three studies were blinded and two used an avoidance diet control.  Sixty-six patients (62%) in the MOIT group were able to tolerate a full serving of milk (about 200 mL) compared to seven (8%) of the control group (RR 6.61, 95% CI 3.51 to 12.44). In addition, 27 (25%) in the MOIT group could ingest a partial serving of milk (10 to 184 mL) while none could in the control group (RR 9.34, 95% CI 2.72 to 32.09). None of the studies assessed the patients following a period off immunotherapy. Adverse reactions were common (97 of 106 MOIT patients had at least one symptom), although most were local and mild. Because of variability in reporting methods, adverse effects could not be combined quantitatively. For every 11 patients receiving MOIT, one required intramuscular epinephrine. One patient required it on two occasions.

AUTHORS' CONCLUSIONS

Studies to date have involved small numbers of patients and the quality of evidence is generally low. The current evidence shows that MOIT can lead to desensitization in the majority of individuals with IMCMA although the development of long-term tolerance has not been established. A major drawback of MOIT is the frequency of adverse effects, although most are mild and self-limited. The use of parenteral epinephrine is not infrequent. Because there are no standardized protocols, guidelines would be required prior to incorporating desensitization into clinical practice.

Clinical Use of Probiotics in Pediatric Allergy (CUPPA): A World Allergy Organization Position Paper

BACKGROUND

: Probiotic administration has been proposed for the prevention and treatment of specific allergic manifestations such as eczema, rhinitis, gastrointestinal allergy, food allergy, and asthma. However, published statements and scientific opinions disagree about the clinical usefulness.

OBJECTIVE

: A World Allergy Organization Special Committee on Food Allergy and Nutrition review of the evidence regarding the use of probiotics for the prevention and treatment of allergy.

METHODS

: A qualitative and narrative review of the literature on probiotic treatment of allergic disease was carried out to address the diversity and variable quality of relevant studies. This variability precluded systematization, and an expert panel group discussion method was used to evaluate the literature. In the absence of systematic reviews of treatment, meta-analyses of prevention studies were used to provide data in support of probiotic applications.

RESULTS

: Despite the plethora of literature, probiotic research is still in its infancy. There is a need for basic microbiology research on the resident human microbiota. Mechanistic studies from biology, immunology, and genetics are needed before we can claim to harness the potential of immune modulatory effects of microbiota. Meanwhile, clinicians must take a step back and try to link disease state with alterations of the microbiota through well-controlled long-term studies to identify clinical indications.

CONCLUSIONS

: Probiotics do not have an established role in the prevention or treatment of allergy. No single probiotic supplement or class of supplements has been demonstrated to efficiently influence the course of any allergic manifestation or long-term disease or to be sufficient to do so. Further epidemiologic, immunologic, microbiologic, genetic, and clinical studies are necessary to determine whether probiotic supplements will be useful in preventing allergy. Until then, supplementation with probiotics remains empirical in allergy medicine. In the future, basic research should focus on homoeostatic studies, and clinical research should focus on preventive medicine applications, not only in allergy. Collaborations between allergo-immunologists and microbiologists in basic research and a multidisciplinary approach in clinical research are likely to be the most fruitful.

Food-induced anaphylaxis

Food-induced anaphylaxis (FIA) is a serious allergic reaction that may cause death rapidly in otherwise healthy individuals. There is no universal agreement on its definition or criteria for diagnosis. Hospital admissions for FIA have more than doubled in the last decade. Food is one of the most common causes of anaphylaxis, with most surveys indicating that food-induced reactions account for 30% to 50% of cases. The most commonly implicated foods are peanut, tree nuts, milk, eggs, sesame seeds, fish, and shellfish. The only life-saving treatment for anaphylaxis is allergen avoidance, and epinephrine injection if an anaphylactic event occurs.

Alternative and complementary treatment for food allergy

Despite increased consumer interest in complementary and alternative medicine (CAM) for the treatment of food allergy, there remains a relative paucity of knowledge regarding the clinical efficacy, mechanisms of action, and safety of most CAM treatments available to consumers. This article focuses on recent advances in CAM for food allergy, including acupuncture, herbal medicine, probiotics, and alternative approaches to allergen immunotherapy. The mechanism of action of several novel approaches to treatment of food allergy is reviewed, but FAHF-2 is the only investigational herbal formulation currently validated for use in human clinical trials.