The development and prediction of atopy in high-risk children: follow-up at age seven years in a prospective randomized study of combined maternal and infant food allergen avoidance

Cost-effectiveness of primary prevention of paediatric asthma: a decision-analytic model

BACKGROUND

Many children stand to benefit from being asthma-free for life with primary (i.e., prenatally started) prevention addressing one environmental exposure in a unifaceted (UF) approach or at least two in a multifaceted (MF) approach. We assessed the cost-effectiveness of primary prevention programmes for Dutch children in a decision-analytic framework.

METHODS

A decision-analytic tree model analysing healthcare costs and asthma cases prevented was developed to compare usual care (UC) with two UF and three MF programmes on the primary prevention of asthma amongst children. Programmes were evaluated through incremental cost-effectiveness ratios and net monetary benefits. Decision and parameter uncertainty were subjected to value-of-information analyses.

RESULTS

The current UC and one of three MF programmes dominated the other alternatives. The MF programme was more costly but also more effective than UC at an incremental cost-effectiveness ratio of <euro>8,209.20/additional asthma case prevented. The value of perfect information to reduce uncertainty was <euro>291.6M at its lowest. Most of the uncertainty in the cost-effectiveness threshold was attributable to the probability and cost estimates for low-risk children.

CONCLUSION

This study supports the feasibility of a structured programme that simultaneously addresses exposure to house dust mites, pet dander, environmental tobacco, and breast-feeding as a cost-effective alternative to UC in the primary prevention of asthma amongst children.

Introduction of gluten, HLA status, and the risk of celiac disease in children

BACKGROUND

The relationship between the risk of celiac disease and both the age at which gluten is introduced to a child's diet and a child's early dietary pattern is unclear.

METHODS

We randomly assigned 832 newborns who had a first-degree relative with celiac disease to the introduction of dietary gluten at 6 months (group A) or 12 months (group B). The HLA genotype was determined at 15 months of age, and serologic screening for celiac disease was evaluated at 15, 24, and 36 months and at 5, 8, and 10 years. Patients with positive serologic findings underwent intestinal biopsies. The primary outcome was the prevalence of celiac disease autoimmunity and of overt celiac disease among the children at 5 years of age.

RESULTS

Of the 707 participants who remained in the trial at 36 months, 553 had a standard-risk or high-risk HLA genotype and completed the study. At 2 years of age, significantly higher proportions of children in group A than in group B had celiac disease autoimmunity (16% vs. 7%, P=0.002) and overt celiac disease (12% vs. 5%, P=0.01). At 5 years of age, the between-group differences were no longer significant for autoimmunity (21% in group A and 20% in group B, P=0.59) or overt disease (16% and 16%, P=0.78 by the log-rank test). At 10 years, the risk of celiac disease autoimmunity was far higher among children with high-risk HLA than among those with standard-risk HLA (38% vs. 19%, P=0.001), as was the risk of overt celiac disease (26% vs. 16%, P=0.05). Other variables, including breast-feeding, were not associated with the development of celiac disease.

CONCLUSIONS

Neither the delayed introduction of gluten nor breast-feeding modified the risk of celiac disease among at-risk infants, although the later introduction of gluten was associated with a delayed onset of disease. A high-risk HLA genotype was an important predictor of disease. (Funded by the Fondazione Celiachia of the Italian Society for Celiac Disease; CELIPREV ClinicalTrials.gov number, NCT00639444.).

Development of β-lactoglobulin-specific chimeric human IgEκ monoclonal antibodies for in vitro safety assessment of whey hydrolysates

Background

Cow’s milk-derived whey hydrolysates are nutritional substitutes for allergic infants. Safety or residual allergenicity assessment of these whey hydrolysates is crucial. Currently, rat basophilic leukemia RBL-2H3 cells expressing the human IgE receptor α-chain (huFcεRIα-RBL-2H3), sensitized with serum IgE from cow’s milk allergic children, are being employed to assess in vitro residual allergenicity of these whey hydrolysates. However, limited availability and inter-lot variation of these allergic sera impede standardization of whey hydrolysate safety testing in degranulation assays.

Objective

An oligoclonal pool of chimeric human (chu)IgE antibodies against bovine β-lactoglobulin (a major allergen in whey) was generated to increase sensitivity, specificity, and reproducibility of existing degranulation assays.

Methods

Mice were immunized with bovine β-lactoglobulin, and subsequently the variable domains of dissimilar anti-β-lactoglobulin mouse IgG antibodies were cloned and sequenced. Six chimeric antibodies were generated comprising mouse variable domains and human constant IgE/κ domains.

Results

After sensitization with this pool of anti-β-lactoglobulin chuIgEs, huFcεRIα-expressing RBL-2H3 cells demonstrated degranulation upon cross-linking with whey, native 18 kDa β-lactoglobulin, and 5–10 kDa whey hydrolysates, whereas a 3 kDa whey hydrolysate and cow’s milk powder (mainly casein) showed no degranulation. In parallel, allergic serum IgEs were less sensitive. In addition, our pool anti-β-lactoglobulin chuIgEs recognized multiple allergenic immunodominant regions on β-lactoglobulin, which were also recognized by serum IgEs from cow’s milk allergic children.

Conclusion

Usage of our ‘unlimited’ source and well-defined pool of β-lactoglobulin-specific recombinant chuIgEs to sensitize huFcεRIα on RBL-2H3 cells showed to be a relevant and sensitive alternative for serum IgEs from cow’s milk allergic patients to assess safety of whey-based non-allergic hydrolyzed formula.

Food hypersensitivity in mexican adults at 18 to 50 years of age: a questionnaire survey

PURPOSE

There is limited epidemiological evidence of food hypersensitivity (FH) in the adult population. We aimed to determine the prevalence of FH in Mexican adults, their clinical features and to establish common food involved in its appearance.

METHODS

We designed a cross-sectional study using a fixed quota sampling; 1,126 subjects answered a structured survey to gather information related to FH.

RESULTS

The prevalence of FH in adults was 16.7% (95% CI, 14.5% to 18.8%), without statistical significant differences related to gender (women, 17.5% and men, 15.9%) or residential location. The most common clinical manifestations in adults with FH were oral allergy syndrome (70 of 1,126) and urticaria (55 of 1,126). According to category, fruits and vegetables were the most frequent foods to trigger FH (6.12%) and were individually related to shrimp (4.0%), and cow milk (1.5%). Adults under age 25 had a higher frequency of FH (OR, 1.39; 95% CI, 1.01 to 1.91, P <0.001). Personal history of any atopic disease was significantly associated with FH (P <0.0001).

CONCLUSIONS

The prevalence of FH is relatively high in Mexican adults, and FH is significantly associated with atopic diseases.

Peanut, milk, and wheat intake during pregnancy is associated with reduced allergy and asthma in children

BACKGROUND

Maternal diet during pregnancy may affect childhood allergy and asthma.

OBJECTIVE

We sought to examine the associations between maternal intake of common childhood food allergens during early pregnancy and childhood allergy and asthma.

METHODS

We studied 1277 mother-child pairs from a US prebirth cohort unselected for any disease. Using food frequency questionnaires administered during the first and second trimesters, we assessed maternal intake of common childhood food allergens during pregnancy. In mid-childhood (mean age, 7.9 years), we assessed food allergy, asthma, allergic rhinitis, and atopic dermatitis by questionnaire and serum-specific IgE levels. We examined the associations between maternal diet during pregnancy and childhood allergy and asthma. We also examined the cross-sectional associations between specific food allergies, asthma, and atopic conditions in mid-childhood.

RESULTS

Food allergy was common (5.6%) in mid-childhood, as was sensitization to at least 1 food allergen (28.0%). Higher maternal peanut intake (each additional z score) during the first trimester was associated with 47% reduced odds of peanut allergic reaction (odds ratio [OR], 0.53; 95% CI, 0.30-0.94). Higher milk intake during the first trimester was associated with reduced asthma (OR, 0.83; 95% CI, 0.69-0.99) and allergic rhinitis (OR, 0.85; 95% CI, 0.74-0.97). Higher maternal wheat intake during the second trimester was associated with reduced atopic dermatitis (OR, 0.64; 95% CI, 0.46-0.90). Peanut, wheat, and soy allergy were each cross-sectionally associated with increased childhood asthma, atopic dermatitis, and allergic rhinitis (ORs, 3.6 to 8.1).

CONCLUSION

Higher maternal intake of peanut, milk, and wheat during early pregnancy was associated with reduced odds of mid-childhood allergy and asthma.

EAACI food allergy and anaphylaxis guidelines. Primary prevention of food allergy

Food allergy can have significant effects on morbidity and quality of life and can be costly in terms of medical visits and treatments. There is therefore considerable interest in generating efficient approaches that may reduce the risk of developing food allergy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Prevention and is part of the EAACI Guidelines for Food Allergy and Anaphylaxis. It aims to provide evidence-based recommendations for primary prevention of food allergy. A wide range of antenatal, perinatal, neonatal, and childhood strategies were identified and their effectiveness assessed and synthesized in a systematic review. Based on this evidence, families can be provided with evidence-based advice about preventing food allergy, particularly for infants at high risk for development of allergic disease. The advice for all mothers includes a normal diet without restrictions during pregnancy and lactation. For all infants, exclusive breastfeeding is recommended for at least first 4-6 months of life. If breastfeeding is insufficient or not possible, infants at high-risk can be recommended a hypoallergenic formula with a documented preventive effect for the first 4 months. There is no need to avoid introducing complementary foods beyond 4 months, and currently, the evidence does not justify recommendations about either withholding or encouraging exposure to potentially allergenic foods after 4 months once weaning has commenced, irrespective of atopic heredity. There is no evidence to support the use of prebiotics or probiotics for food allergy prevention.

Does maternal diet during pregnancy and lactation affect outcomes in offspring? A systematic review of food-based approaches

OBJECTIVES

The aim of this study was to investigate the relationship between maternal diet during pregnancy and lactation and development of atopic disorders in childhood.

METHODS

We included studies published up to August 2011 that assessed food-based maternal dietary interventions or that examined associations between maternal dietary intake during pregnancy and/or lactation and allergic outcomes (eczema, asthma, hay fever, and sensitization) in their children.

RESULTS

We included 42 studies (>40 000 children): 11 intervention studies (including 7 randomized control trials), 26 prospective cohort studies, 4 retrospective cohort studies, and 1 case-control study. In the randomized control trials, no significant difference was noted overall in the prevalence of eczema and asthma in the offspring of women on diets free from common food allergens during pregnancy. The prospective cohorts investigated a large number of potential associations, but reported few significant associations between maternal dietary intake and development of allergy. Maternal diets rich in fruits and vegetables, fish, and foods containing vitamin D and Mediterranean dietary patterns were among the few consistent associations with lower risk for allergic disease in their children. Foods associated with higher risk included vegetable oils and margarine, nuts, and fast food.

CONCLUSION

This review did not find widespread or consistent links between mothers' dietary intake and atopic outcomes in their children. However, maternal consumption of Mediterranean dietary patterns, diets rich in fruits and vegetables, fish, and vitamin D-containing foods were suggestive of benefit, requiring further evaluation.

Optimal timing for solids introduction - why are the guidelines always changing?

There have been dramatic changes in timing of first exposure to solid foods for children over the last 40 years, ranging from exposure prior to 4 months of age for most infants in the 1960s, to guidelines recommending delaying solids until after 6 months of age introduced in the 1990s. Infant diet, specifically age of weaning and age at introduction of allergenic foods, has long been thought to play a role food allergy. However, controversy surrounding the relationship between timing of introduction of foods and development of food allergy has lead to a plethora of inconsistent infant feeding guidelines both between and within countries. The aims of this article were to discuss the history of changing guidelines for optimal timing of introduction of solids in general and allergenic solids in particular and the evidence (or lack thereof) underpinning recommendations at each of these time-points. We present the current clinical equipoise with regards to recently revised guidelines published almost simultaneously in the UK, US and Australia and argue that guideline modification about timing of introduction (both for high risk infants but also for the general population) will require careful review of emerging literature to provide a true evidence base to inform public health practice such as infant feeding guidelines.

Active or passive exposure to tobacco smoking and allergic rhinitis, allergic dermatitis, and food allergy in adults and children: a systematic review and meta-analysis

BACKGROUND

Allergic rhinitis, allergic dermatitis, and food allergy are extremely common diseases, especially among children, and are frequently associated to each other and to asthma. Smoking is a potential risk factor for these conditions, but so far, results from individual studies have been conflicting. The objective of this study was to examine the evidence for an association between active smoking (AS) or passive exposure to secondhand smoke and allergic conditions.

METHODS AND FINDINGS

We retrieved studies published in any language up to June 30th, 2013 by systematically searching Medline, Embase, the five regional bibliographic databases of the World Health Organization, and ISI-Proceedings databases, by manually examining the references of the original articles and reviews retrieved, and by establishing personal contact with clinical researchers. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk (RR) estimates and confidence intervals of smoking and allergic conditions, first among the general population and then among children. We retrieved 97 studies on allergic rhinitis, 91 on allergic dermatitis, and eight on food allergy published in 139 different articles. When all studies were analyzed together (showing random effects model results and pooled ORs expressed as RR), allergic rhinitis was not associated with active smoking (pooled RR, 1.02 [95% CI 0.92-1.15]), but was associated with passive smoking (pooled RR 1.10 [95% CI 1.06-1.15]). Allergic dermatitis was associated with both active (pooled RR, 1.21 [95% CI 1.14-1.29]) and passive smoking (pooled RR, 1.07 [95% CI 1.03-1.12]). In children and adolescent, allergic rhinitis was associated with active (pooled RR, 1.40 (95% CI 1.24-1.59) and passive smoking (pooled RR, 1.09 [95% CI 1.04-1.14]). Allergic dermatitis was associated with active (pooled RR, 1.36 [95% CI 1.17-1.46]) and passive smoking (pooled RR, 1.06 [95% CI 1.01-1.11]). Food allergy was associated with SHS (1.43 [1.12-1.83]) when cohort studies only were examined, but not when all studies were combined. The findings are limited by the potential for confounding and bias given that most of the individual studies used a cross-sectional design. Furthermore, the studies showed a high degree of heterogeneity and the exposure and outcome measures were assessed by self-report, which may increase the potential for misclassification.

CONCLUSIONS

We observed very modest associations between smoking and some allergic diseases among adults. Among children and adolescents, both active and passive exposure to SHS were associated with a modest increased risk for allergic diseases, and passive smoking was associated with an increased risk for food allergy. Additional studies with detailed measurement of exposure and better case definition are needed to further explore the role of smoking in allergic diseases.

Timing of complementary feeding and the risk of atopic eczema

AIM

To find out whether there was an association between when complementary feeding was introduced and the appearance of atopic eczema in children with a family history of allergy.

METHODS

This prospective study followed 256 mother and child pairs until the child was four-years-old. Repeated skin prick testing was performed and a clinical diagnosis of eczema made by a physician. The mothers kept a continuous diary about the introduction of complementary feeding. To control the possible reverse causation of delaying complementary food introduction due to presumed child allergy, parental suspicions of allergic reactions were recorded.

RESULTS

The introduction of cereals and fish after seven-months-of-age was associated with an increased risk of atopic eczema. However, when the parents' suspicions that their child might be exhibiting symptoms of allergic disease were taken into account, this effect was no longer significant.

CONCLUSION

We found no evidence that the timing of the introduction of complementary feeding increased the risk of atopic eczema in a high-risk cohort, when parental suspicions were taken into account. Therefore, it seems that families with a history of allergy can safely comply with current feeding recommendations, although confirmation in further studies is warranted.

The natural history of cow's milk allergy in north-eastern Poland

PURPOSE

The rate of cow's milk allergy diminishes with age. There is not enough information concerning geographical trends in persistent cow's milk allergy in children. The objective of the study was to evaluate the prevalence of persistent cow's milk allergy in children previously diagnosed with IgE-mediated cow's milk allergy (CMA).

MATERIAL/METHODS

Diagnosis of cow's milk allergy was established by a medical history of symptoms associated with exposure to cow's milk, positive skin prick tests with cow's milk, the presence of milk-specific IgE, and by a positive double- or single-blind placebo-controlled food challenge with milk confirmed by a positive open-controlled milk challenge. A second oral challenge was performed after at least one year of a milk-free diet and children with a positive oral milk rechallenge were diagnosed as having a persistent CMA.

RESULTS

Two hundred ninety-one children, 2-14 years of age (mean 5.30±3.16 years, 95% CI, 5.02-5.62 years) completed the study. Persistent CMA was diagnosed in 79 patients (27.1%). Two hundred twelve children (72.9%) outgrew their allergy to cow's milk at a mean age of 5 years after an average time of 16.4±0.8 months on an elimination diet. Eighty percent of children below 3 years of age became milk tolerant. Milk-specific IgE (p=0.018) and history of paternal bronchial asthma and/or rhinitis (p=0.020) were associated with persistence of cow's milk allergy in regression analysis.

CONCLUSIONS

An age above 3 years, as well as features of atopy, individual and familial, may be associated with a risk of delayed tolerance to milk in children.

US perspective on gluten-related diseases

The incidence of allergy and autoimmune disease in the US and other industrialized nations is increasing, and gluten-related disorders are no exception. The US has documented a profound rise in celiac disease that cannot be fully explained by improved serological techniques or better recognition by physicians. Non-celiac gluten sensitivity, a condition only recently recognized by the medical community, has become a commonly diagnosed entity. Proteins, including gluten are increasingly being identified as a source of wheat allergy. Although the gluten free diet represents a safe and effective treatment for these conditions, there is still much to be learned about the development of gluten-related disorders and the apparent increase in incidence within the US. In this article, we present a review of current knowledge on the epidemiology of gluten-related disorders within a global context, with a focus on diagnostic trends and the evaluation of potential risk factors.

Introduction of complementary foods and the relationship to food allergy

OBJECTIVES

To address questions regarding breastfeeding, complementary feeding, allergy development, and current infant-feeding recommendations.

METHODS

This was a nested, case-control within a cohort study in which mothers of 41 infants diagnosed with food allergy by the age of 2 years (according to double-blind, placebo-controlled food challenge) and their 82 age-matched controls kept prospective food diaries of how their infants were fed in the first year of life.

RESULTS

Infants who were diagnosed with food allergy by the time they were 2 years of age were introduced to solids earlier (≤16 weeks of age) and were less likely to be receiving breast milk when cow's milk protein was first introduced into their diet.

CONCLUSIONS

This study supports the current American Academy of Pediatrics' allergy prevention recommendations and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition recommendations on complementary feeding to not introduce solids before 4 to 6 months of age. It also supports the American Academy of Pediatrics' breastfeeding recommendations that breastfeeding should continue while solids are introduced into the diet and that breastfeeding should continue for 1 year, or longer, as mutually desired by mother and infant.

Prevalence of immediate-type food allergy in early childhood in seoul

PURPOSE

There are scanty epidemiologic data on the prevalence of food allergy (FA) among preschool children in Asia. We performed this study to determine the prevalence and causative foods of immediate-type FA in early childhood in Korea.

METHODS

A questionnaire-based, cross-sectional study was performed between September and October 2011. Children aged 0-6 years were recruited from 301 public child care centers in Seoul. Parents were asked to complete a questionnaire on FA. Children with FA were classified into "perceived FA, ever," "immediate-type FA, ever," and "immediate-type FA, current" according to the algorithm.

RESULTS

A total of 16,749 children were included in this study. The prevalence of "perceived FA, ever," "immediate-type FA, ever," and "immediate-type FA, current" was 15.1%, 7.0%, and 3.7%, respectively. "Immediate-type FA, current" was reported by 182 (4.9%) out of 3,738 children aged ≤2 years, 262 (3.4%) of 7,648 children aged 3-4 years, and 177 (3.3%) of 5,363 children aged 5-6 years. Hen's egg (126/621) was the most frequent cause as the individual food item, followed by cow's milk (82/621) and peanut (58/621). Among the food groups, fruits (114/621), tree nuts (90/621) and crustaceans (85/621) were the most common offending foods. The three leading causes of food-induced anaphylaxis were hen's egg (22/47), cow's milk (15/47), and peanut (14/47).

CONCLUSIONS

The prevalence of immediate-type FA in early childhood is 3.7%, and is higher in younger children. The most common offending foods differed with age.

Increased cow's milk protein-specific IgG4 levels after oral desensitization in 7- to 12-month-old infants

BACKGROUND

Cow's milk protein (CMP)-specific IgG4 responses and the efficacy of oral desensitization in infants with cow's milk allergy (CMA) warrant more clarification.

OBJECTIVE

To explore whether CMP-specific IgG4 responses develop during infancy and whether regular CM exposure is efficacious for inducing a CMP-specific IgG4 response accompanying CM desensitization in 7- to 12-month-old infants.

METHODS

CM-specific IgE and CMP (α-lactalbumin, β-lactoglobulin, and casein)-specific IgG4 levels were measured in 262 CM-sensitized children. Of these, 31 infants 7 to 12 months old with challenge-proved CMA were randomly assigned to oral desensitization or an elimination diet and evaluated 6 months later.

RESULTS

CMP-specific IgG4 levels in 7- to 12-month-old infants were higher than in those younger than 6 months but comparable to those in children older than 12 months. CMP-specific IgG4 levels in 7- to 12-month-old infants with CMA were significantly lower than in those without CMA. Fourteen of 16 patients receiving oral desensitization could accept daily doses of 200 mL of CM, whereas all but 3 dropout patients receiving the elimination diet still showed allergic symptoms at the follow-up food challenge. In patients who became desensitized, CM-specific IgE levels were lower than at baseline, whereas CMP-specific IgG4 levels were significantly increased. In patients receiving the elimination diet, CM-specific IgE and CMP-specific IgG4 levels remained unchanged.

CONCLUSION

CMP-specific IgG4 responses did not develop sufficiently in 7- to 12-month-old infants with CMA. Oral desensitization in 7- to 12-month-old infants with CMA was associated with the upregulation of CMP-specific IgG4 responses accompanying the alleviation of CMA symptoms.

Timing of introduction of solid food and risk of allergic disease development: understanding the evidence

Strategies to prevent or reduce the risk of allergic diseases are needed. The time of exclusive breastfeeding and introduction of solid foods is a key factor that may influence the development of allergy. For this reason, the aim of this review was to examine the association between exposure to solid foods in the infant's diet and the development of allergic diseases in children. Classical prophylactic feeding guidelines recommended a delayed introduction of solids for the prevention of atopic diseases. Is it really true that a delayed introduction of solids (after the 4th or 6th month) is protective against the development of eczema, asthma, allergic rhinitis and food or inhalant sensitisation? In recent years, many authors have found that there is no statistically significant association between delayed introduction of solids and protection for the development of allergic diseases. Furthermore, late introduction of solid foods could be associated with increased risk of allergic sensitisation to foods, inhalant allergens and celiac disease in children. Tolerance may be driven by the contact of the mucosal immune system with the allergen at the right time of life; the protective effects seem to be enhanced by the practice of the breastfeeding at the same time when weaning is started. Therefore, recent guidelines propose a "window" approach for weaning practice starting at the 17th week and introducing almost all foods within the 27th week of life to reduce the risk of chronic diseases such as allergic ones and the celiac disease. Guidelines emphasize the role of breastfeeding during the weaning practice.

Position document: IgE-mediated allergy to egg protein

Egg is the food that most often causes allergy in young Spanish children, with an incidence of 2.4-2.6% in the first 2 years of life. The prevalence of sensitisation and allergy to egg is greater in children with allergy to cow's milk and in those suffering atopic dermatitis. The protein component from egg white is the cause of the allergic response in child. The major allergens in egg white are ovomucoid and ovalbumin. Most of the allergic reactions affect the skin, followed by gastrointestinal and respiratory systems. Egg allergy is one of the most common causes of severe anaphylaxis. The diagnosis of egg allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which represents the gold standard for confirming the diagnosis. The treatment of egg allergy is based on the avoidance of egg protein intake. A subgroup of egg-allergic patients are tolerant to cooked egg. In these cases, only uncooked egg must necessarily be avoided. Maintaining a diet with strict egg avoidance is difficult, and transgressions are relatively common. The patient, family, and school environment should receive education and training in the avoidance of egg and in the management of possible allergic reactions. With an avoidance diet, up to 15-20% of children will remain allergic and the severity of the reactions will increase over the years. In these more severe cases of egg-allergy, it becomes more difficult to adhere to the avoidance diet over the years, with a significant decrease in patient quality of life. Oral tolerance induction can be regarded as a therapeutic option for IgE-mediated egg allergy. The anti-IgE, omalizumab, might become another genuine therapeutic option for food allergy, not only to prevent allergic reactions after a contact with egg, but also as a complementary treatment to oral tolerance induction for egg allergy, with the purpose of reducing adverse reactions. The administration of influenza vaccine to children with egg allergy is safe in children that do not manifest severe reactions after egg intake, and in children who tolerate cooked egg. The triple viral vaccine (MMR) can be given to egg-allergic children in their usual vaccination centre, with no added risk. Different medicinal products can be formulated with egg proteins, and therefore should be avoided in children with egg allergy.

Local atopy is more relevant than serum sIgE in reflecting allergy in childhood adenotonsillar hypertrophy

BACKGROUND

There was a lack of convincing evidence supporting the influence of allergy on the adenotonsillar hypertrophy (ATH). We investigated the presence of specific IgE (sIgE) in the serum and adenotonsillar tissues in children with ATH.

METHODS

A Pharmacia ImmunoCAP system was used to test sIgE against 31 allergens in the serum in 83 children with ATH before adenotonsillectomy. sIgE against 15 representative allergens were detected in adenotonsillar tissues from 20 of those children.

RESULTS

A total of 51 (61.45%) children had positive serum sIgE. 20 children with ATH had positive sIgE to more than two allergens at both tonsils and adenoids, although half of them were serum sIgE negative. The percentage of subjects with positive sIgE expression in adenoids and tonsils was 50.0% and 42.9%, respectively, among the subjects with positive serum sIgE expression. Of subjects with negative serum sIgE expression, local sIgE was detected in 36.0% of adenoids and 43.8% of tonsils, respectively. The rate of sIgE presence in local tissue (adenoids or tonsils) was significantly higher than that seen in the serum.

CONCLUSION

This study provided evidence that there was an important role for allergic inflammation in the ATH. The inconsistency in sIgE expression between adenotonsillar and serum suggests a role of local atopy in childhood ATH.

Population-based efficacy modeling of omalizumab in patients with severe allergic asthma inadequately controlled with standard therapy

Omalizumab, a recombinant humanized monoclonal antibody, is the first approved anti-immunoglobulin E (IgE) agent for the treatment of subjects with moderate to severe persistent allergic asthma that are inadequately controlled by the standard of care. The objective of this study was to quantitatively characterize relationships between serum free IgE and pulmonary function (as measured by forced expiratory volume in 1 s [FEV1]) as well as serum free IgE and airway inflammation (as measured by fractional exhaled nitric oxide [FeNO]) using population-based efficacy models. Data were collected from patients in the EXTRA trial who received omalizumab or placebo 150 to 375 mg subcutaneously every 2 or 4 weeks from week 0 to 48 with constant standard of care as background therapy. None of the covariates evaluated, including demographics, disease status, and baseline pharmacodynamic biomarkers, were significant in explaining the variability in the FEV1 or FeNO response to omalizumab. Results from the efficacy models further confirmed the current omalizumab dosing rationale based on the mean target free IgE level of 25 ng/ml and quantified the variability for the target. In addition, the resulting population models could be used to predict population FEV1 or FeNO response for omalizumab and/or other anti-IgE therapeutics for which PK-IgE models are constructed.

Role of parental atopy in cow's milk allergy: a population-based study

BACKGROUND

A family history of atopy has been considered an independent risk factor for atopic diseases in children.

OBJECTIVE

To relate the risk of an infant developing IgE-mediated cow's milk allergy (IgE-CMA) to the atopic status of parents.

METHODS

Assessment of the parental atopic status of children with IgE-CMA (n = 66) previously identified in a large-scale prospective study was compared with the parental atopic status of a control group of healthy infants (n = 156). The atopic status was identified both by self-reporting and skin prick tests (SPTs).

RESULTS

Analysis for the risk for infants to develop IgE-CMA depended on the assessment method used. No significant differences were noted in self-reported parental atopic status between the IgE-CMA patients and the control group. However, among the subgroup of infants with persistent IgE-CMA (n = 25), maternal but not paternal self-reporting for atopy was more likely compared with parents of the control group (P = .04). In contrast, when analyzed by SPT, in both this persistent subgroup and the total allergic cohort, no significant differences were noted whether analyzed by single parent or both parents and whether the parent tested singly or multiply positive on the SPT.

CONCLUSION

In families with children with persistent IgE-CMA, self-reporting of atopy by parents may be biased. Furthermore, the demonstration of IgE-mediated responses to allergens in parents is insufficient by itself, in a general population cohort, to predict which infants are at greatest risk of developing IgE-CMA.

Identifying infants at high risk of peanut allergy: the Learning Early About Peanut Allergy (LEAP) screening study

BACKGROUND

Peanut allergy (PA) is rare in countries in which peanuts are introduced early into infants' diets. Learning Early About Peanut Allergy (LEAP) is an interventional study aiming to assess whether PA can be prevented by oral tolerance induction.

OBJECTIVE

We sought to characterize a population screened for the risk of PA.

METHODS

Subjects screened for the LEAP interventional trial comprise the LEAP screening study cohort. Infants were aged 4 to 10 months and passed a prescreening questionnaire.

RESULTS

This analysis includes 834 infants (mean age, 7.8 months). They were split into the following: group I, patients with mild eczema and no egg allergy (n = 118); group II, patients with severe eczema, egg allergy, or both but 0-mm peanut skin prick test (SPT) wheal responses (n = 542); group III, patients with severe eczema, egg allergy, or both and 1- to 4-mm peanut wheal responses (n = 98); and group IV, patients with greater than 4-mm peanut wheal responses (n = 76). Unexpectedly, many (17%) in group II had peanut-specific IgE sensitization (≥ 0.35 kU/L); 56% of group III were similarly sensitized. In contrast, none of the patients in group I and 91% of those in group IV had peanut-specific IgE sensitization. Sensitization on skin testing to peanut (SPT response of 1-4 mm vs 0 mm) was associated with egg allergy and severe eczema (odds ratio [OR], 2.31 [95% CI, 1.39-3.86] and 2.47 [95% CI, 1.14-5.34], respectively). Similar associations were observed with specific IgE sensitization. Black race was associated with a significantly higher risk of peanut-specific IgE sensitization (OR, 5.30 [95% CI, 2.85-9.86]). Paradoxically, for a given specific IgE level, black race was protective against cutaneous sensitization (OR, 0.15 [95% CI, 0.04-0.61]).

CONCLUSION

Egg allergy, severe eczema, or both appear to be useful criteria for identifying high-risk infants with an intermediate level of peanut sensitization for entry into a PA prevention study. The relationship between specific IgE level and SPT sensitization needs to be considered within the context of race.

Interaction between IL13 genotype and environmental factors in the risk for allergic rhinitis in Korean children

BACKGROUND

The prevalence of allergic rhinitis (AR) is increasing worldwide. Allergic diseases develop in susceptible subjects when they are exposed to specific environmental factors.

OBJECTIVE

We analyzed changes in the prevalence of AR and identified genetic and environmental factors in early childhood that affect risk.

METHODS

We used the International Study of Asthma and Allergies in Childhood questionnaire to collect data on AR, allergies, and environmental exposures from 4554 elementary school students from 5 areas of Seoul, Korea, in 2008. We also obtained DNA from 1050 subjects from 1 area of Seoul for genotype analysis of IL13.

RESULTS

We identified genetic and environmental factors during infancy and early childhood that increased the risk for current AR (resulting in a diagnosis of AR and AR symptoms in the past 12 months) in elementary school-aged children. These included allergic disease in parents and antibiotic use in infants, allergic disease in parents and exposure of infants to mold, and allergic disease in parents and moving an infant to a newly built house. The risk of current AR also increased in subjects with GA or AA at nucleotide 2044 in IL13 who had been exposed to mold in the home during infancy (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11) compared with subjects who had GG at this position and had not been exposed to mold (adjusted odds ratio, 3.27; 95% CI, 1.75-6.11).

CONCLUSION

The prevalence of AR is increasing in Korean children. Children with a family history of allergic disease and exposure to specific environmental risk factors during infancy are more likely to have AR. Children with GA or AA at IL13(+2044) are at increased risk for AR when exposed to mold in the home during the first year of life.

Maternal dietary antigen avoidance during pregnancy or lactation, or both, for preventing or treating atopic disease in the child

BACKGROUND

Some breastfed infants with atopic eczema benefit from elimination of cow milk, egg, or other antigens from their mother's diet. Maternal dietary antigens are also known to cross the placenta.

OBJECTIVES

To assess the effects of prescribing an antigen avoidance diet during pregnancy or lactation, or both, on maternal and infant nutrition and on the prevention or treatment of atopic disease in the child.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 July 2012).

SELECTION CRITERIA

All randomized or quasi-randomized comparisons of maternal dietary antigen avoidance prescribed to pregnant or lactating women. We excluded trials of multimodal interventions that included manipulation of the infant's diet other than breast milk or of non-dietary aspects of the infant's environment.

DATA COLLECTION AND ANALYSIS

We extracted data from published reports, supplemented by additional information received from the trialists we contacted.

MAIN RESULTS

The evidence from five trials, involving 952 participants, does not suggest a protective effect of maternal dietary antigen avoidance during pregnancy on the incidence of atopic eczema during the first 18 months of life. Data on allergic rhinitis or conjunctivitis, or both, and urticaria are limited to a single trial each and are insufficient to draw meaningful inferences. Longer-term atopic outcomes have not been reported. The restricted diet during pregnancy was associated with a slightly but statistically significantly lower mean gestational weight gain, a non-significantly higher risk of preterm birth, and a non-significant reduction in mean birthweight.The evidence from two trials, involving 523 participants, did not observe a significant protective effect of maternal antigen avoidance during lactation on the incidence of atopic eczema during the first 18 months or on positive skin-prick tests to cow milk, egg, or peanut antigen at one, two, or seven years.One crossover trial involving 17 lactating mothers of infants with established atopic eczema found that maternal dietary antigen avoidance was associated with a non-significant reduction in eczema severity.

AUTHORS' CONCLUSIONS

Prescription of an antigen avoidance diet to a high-risk woman during pregnancy is unlikely to reduce substantially her child's risk of atopic diseases, and such a diet may adversely affect maternal or fetal nutrition, or both. Prescription of an antigen avoidance diet to a high-risk woman during lactation may reduce her child's risk of developing atopic eczema, but better trials are needed.Dietary antigen avoidance by lactating mothers of infants with atopic eczema may reduce the severity of the eczema, but larger trials are needed.

Peanut and tree nut consumption during pregnancy and allergic disease in children-should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort

BACKGROUND

The relation between maternal peanut intake during pregnancy and allergic disease development in children has been controversial.

OBJECTIVE

We used data from the Danish National Birth Cohort to examine associations between maternal peanut and tree nut intake during pregnancy and allergic outcomes in children at 18 months and 7 years of age.

METHODS

We estimated maternal peanut and tree nut intake (n = 61,908) using a validated midpregnancy food frequency questionnaire. At 18 months, we used parental report of childhood asthma diagnosis, wheeze symptoms, and recurrent wheeze (>3 episodes). We defined current asthma at 7 years as doctor-diagnosed asthma plus wheeze in the past 12 months and allergic rhinitis as a self-reported doctor's diagnosis. We also used alternative classifications based on registry-based International Classification of Diseases, Tenth Revision, codes and drug dispensary data. We report here odds ratios (ORs) comparing intake of 1 or more times per week versus no intake.

RESULTS

We found that maternal intake of peanuts (OR, 0.79; 95% CI, 0.65-0.97) and tree nuts (OR, 0.75; 95% CI, 0.67-0.84) was inversely associated with asthma in children at 18 months of age. Compared with mothers consuming no peanuts, children whose mothers reported eating peanuts 1 or more times per week were 0.66 (95% CI, 0.44-0.98) and 0.83 (95% CI, 0.70-1.00) times as likely to have a registry-based and medication-related asthma diagnosis, respectively. Higher tree nut intake was inversely associated with a medication-related asthma diagnosis (OR, 0.81; 95% CI, 0.73-0.90) and self-reported allergic rhinitis (OR, 0.80; 95% CI, 0.64-1.01).

CONCLUSIONS

Our results do not suggest that women should decrease peanut and tree nut intake during pregnancy; instead, consumption of peanuts and tree nuts during pregnancy might even decrease the risk of allergic disease development in children.

Strategies to prevent or reduce allergic disease

The need for allergy prevention strategies has never been greater. Surging rates of food allergy and eczema are now adding to the already substantial burden of asthma and respiratory allergic diseases. The parallel rise in many other immune diseases suggests that the developing immune system is highly vulnerable to modern environmental changes. These strong environmental pressures may be one reason why simple allergen avoidance strategies have not been successful. Another more recent strategy to curtail the allergy epidemic has been to identify factors associated with modern lifestyle that may be causally linked with allergic disease, in an attempt to restore more favourable conditions for immune tolerance during early development. More hygienic conditions and disruption of microbial exposure have prompted strategies to restore this balance using probiotic and prebiotic supplements. Modern dietary changes linked with allergic diseases have prompted supplementation studies to assess the preventive merits of specific immunomodulatory dietary nutrients such as polyunsaturated fatty acids. Other nutrients such as antioxidants, folate, and vitamin D are also currently under investigation. Modern environmental pollutants have also been associated with adverse effects on immune development and the risk of disease. While many of these avenues have provided some promise, they have not yet translated into specific recommendations. Current evidence-based guidelines for allergy prevention remain limited to avoidance of cigarette smoke, promotion of breastfeeding and the use of hydrolysed formula when breastfeeding is not possible. Allergen avoidance strategies have been largely removed from most guidelines. It is hoped that a number of ongoing studies will help provide clearer recommendations around the use of probiotics, prebiotics, specific dietary nutrients and the role of early introduction of allergenic foods for the promotion of tolerance. Despite the current uncertainties, prevention remains the best long-term strategy to reduce the growing burden of allergic disease.

Can we prevent food allergy by manipulating the timing of food exposure?

Prevention of food allergies by maternal and infant feeding practices serves as a simple, inexpensive approach to address the growing number of subjects with food allergies in comparison with any emerging interventional therapies for existing food allergies, such as oral immunotherapy. This article provides a careful evaluation of the rationale and existing data on the effect of timing of the introduction of food allergens (during pregnancy, lactation, and early childhood) on the development of specific food allergies.

Prevention of asthma in genetically susceptible children: a multifaceted intervention trial focussed on feasibility in general practice

BACKGROUND

Although the effectiveness of the multifaceted allergen-reducing interventions for the prevention of asthma in susceptible children was showed to be proven, the feasibility was not clear.

METHODS

The research question of the PREVention of asthma in susceptible children (PREVASC) trial was focused on the assessment of the effectiveness and feasibility of a multifaceted intervention on the prevention of allergic asthma in general practice. The effectiveness and feasibility of an intervention aimed at the simultaneous reduction in the environmental exposures to inhalant- and food allergens in susceptible children was investigated. A total of 476 children susceptible for developing asthma were initially included during pregnancy and were randomly divided over an intervention group of n = 222 children whose parents were offered a multifaceted environmental exposure-reducing intervention. Controls (n = 221) received usual care. The main outcome was 'diagnosis of allergic asthma at age 6'.

RESULTS

A significant reduction in inhalant allergen exposure levels of house dust mite [(Der p1), p = 0.043], cat [(Fel d1), p = 0.037], and dog [(Can f1), p = 0.012] was reached. Significantly more intervention group children started using cow's milk and solids after the age of 6 months (p ≤ 0.001). No statistical difference, however, was reached between groups on the duration of breast-feeding (p = 0.635) and the reduction in smoke exposure (p = 0829). At age 6, the intervention had no influence on the development of main outcome allergic asthma (OR = 1.010 (CI 0.580-1.758).

CONCLUSION

Other primary preventive asthma-reducing interventions were shown to be effective in reducing the occurrence of asthma for at least the first 7-8 yr of life. The multifaceted PREVASC allergic asthma primary preventive intervention was effective in reducing the exposure to inhalant and food allergens, but was not feasible for the parents. A lack of sufficient room for improvement focus on stimulating adherence seemed to be involved. It is suggested that a multifaceted environmental exposure-reducing intervention may have to be adapted to the personal circumstances of patients at baseline.

The incidence and risk factors of immediate type food allergy during the first year of life in Korean infants: a birth cohort study

OBJECTIVES

We conducted this study to determine the incidence of food allergy (FA) in Korean infants and identify the risk factors of FAs during the first year of life in a birth cohort study.

METHODS

Pregnant women ≥34 weeks of gestation were enrolled in this study. Participants were asked to complete questionnaires describing basic demographic information including family history of allergic diseases. Since birth, all the babies were regularly followed up for FA symptoms through telephone interviews at 4, 8, and 12 months of age. FA was defined as a repetitive convincing history of immediate allergic reactions following the ingestion of offending food.

RESULTS & CONCLUSIONS

A total of 1177 infants and their parents completed this study. The prevalence of FA was 5.3% in infants. The three leading food allergens were hen's eggs (33/62), cow's milk (20/62) and peanut/nuts (8/62). Children with a history of maternal AD showed a significantly higher prevalence of FA (P = 0.012) [aRR = 3.17]. In addition, children who were born during autumn had a higher prevalence than those born during spring (p = 0.005) [aRR = 3.48]. In conclusion, we identified several characteristics that may influence the development of FA in the next generation, including maternal AD and autumn birth.

Dietary counseling to improve fat quality during pregnancy alters maternal fat intake and infant essential fatty acid status

To explore the effect of maternal dietary intervention on infant essential fatty acid (FA) status, we conducted a prospective, single-blind, randomized nutrition intervention study. At the first trimester of pregnancy, 90 women from families with a history of allergy were randomized either to receive intensive dietary counseling to modify dietary intake according to current recommendations or as controls. Infants' cord and 1-mo isolated serum phospholipid FA were identified and quantified by GC. Detectable levels of eicosatrienoic acid [ETA, 20:3(n-9)] were taken as a biochemical marker for essential FA deficiency, and the DHA sufficiency index [22:6(n-3):22:5(n-6)] and the DHA deficiency index [22:5(n-6):22:4(n-6)] were taken as markers for DHA [22:6(n-3)] status. The concentration of ETA was lower in cord blood in the intervention (I) group [median 0.64 (IQR 0.40-0.78) mg/L; 2.09 (1.31-2.54) μmol/L] than in the control (C) group [0.92 (0.54-1.20) mg/L; 3.00 (1.76-3.92) μmol/L] (P = 0.048). The proportion of ETA in total FA in the I group [0.73% (0.48-0.85%)] was lower than in the C group [0.93% (0.78-1.22%)] (P = 0.003). A higher DHA sufficiency index and lower DHA deficiency index were detected in cord blood in the I group than in the C group, although the groups did not differ in the DHA concentration or proportion of the total FA. There were no differences among groups at 1 mo for any of the variables measured. Our findings suggest a better supply of essential FA, particularly important during the period of rapid development, in infants whose mothers received dietary counseling. The results thus highlight the importance of maternal diet for child health, calling for dietary counseling for pregnant women in primary health care.

Can food allergy be prevented? The current evidence

Food allergy is a recognized public health concern, for which preventative strategies are required. Although an intervention that adequately protects against the development of food allergy has still to be identified, limited benefits have been shown for the prevention of related allergic conditions such as eczema, and to a lesser extent asthma and rhinitis; these benefits are usually limited to at-risk populations. Prevention strategies need to be tested using randomized controlled study designs that account for the numerous methodological challenges, safety concerns, and necessary ethical limitations.

Infant feeding practices and physician diagnosed atopic dermatitis: a prospective cohort study in Taiwan

It is common to recommend breastfeeding and a delayed introduction of solids to prevent atopic dermatitis (AD). However, the scientific evidence for this is inconclusive. The aim of this study was to explore the effect of breastfeeding and solids on AD, when taking account of reverse causality. This on-going birth cohort study was designed to sample 24,200 representative post-partum women and their babies from the Taiwan National Birth Registration database. Using two home interviews at 6 and 18 months after birth, with structured questionnaires about diet and physician's diagnosis of AD by parental reports, a total of 20,172 pairs (83.4%) were reviewed completely. Considering reverse causality, we excluded 2399 children with AD in the first 6 months of life and 18,733 were finally recruited. All study participants provided informed consent as approved by the Ethics Review Board of the National Taiwan College of Public Health. After adjustment for potential confounders, the overall results showed that the increased duration of breastfeeding seemed to increase the risk of AD at 18 months in children. However, no significant effect was found for the delayed introduction of solids on the risk of AD. There is no evidence of a protective effect of prolonged breastfeeding and a delayed introduction of solids against AD among children at age 18 months, and may even be a risk factor of AD.

The role of the gut mucosal immunity in the development of tolerance against allergy to food

PURPOSE OF REVIEW

To provide an overview on the role of gut mucosal immunity in the development of tolerance against allergy to food.

RECENT FINDINGS

The gastrointestinal tract, through innate and specific immunologic factors, acts as a defense against ingested antigens. In addition to the mucous membrane integrity and digestion, numerous specific immunologic cells and mediators orchestrate such defensive mechanisms. In case of food antigens, the outcome is usually in favor of tolerance. Defects in that barrier, however, can lead to the development of aberrant immunologic responses, including hypersensitivity reactions.

SUMMARY

The prevailing evidence is that healthy mucosal immunity plus appropriate feeding regimen during early infancy are in favor of food tolerance. However, in addition to genetic predisposition, development of allergy is facilitated by defects in the gut barrier (immune or nonimmune) and the food allergen load.

Are peanut allergies a concern for using peanut-based formulated foods in developing countries?

BACKGROUND

Peanut allergy is relatively common among children in developed countries and may have severe outcomes, including anaphylaxis. However, few data about peanut allergy in developing countries are available. Meanwhile, formulated foods with peanuts as a major ingredient are being promoted to prevent and control malnutrition in developing countries.

OBJECTIVE

The objectives of the paper are to review the existing epidemiologic data about peanut allergy, to determine whether the prevalence of peanut allergy is lower in developing countries, and to explore the possible reasons for onset of peanut allergy.

METHODS

Publications relevant to peanut allergy were searched via Pubmed, and prevalence and etiological factors of peanut allergy were reviewed.

RESULTS

Data about peanut allergy were scarce in most developing countries. The existing data support the conclusion that peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, plans for treatment of individuals with peanut allergy could be incorporated into these formulated food supplementation programs. A few risk factors (late introduction of peanuts to children, peanut processing technology, non-oral peanut exposure, and maternal peanut exposure during pregnancy and lactation) have been hypothesized to be associated with peanut allergy. However, more conclusive data are needed to verify or disprove these hypotheses.

CONCLUSIONS

Peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, more research about prevalence of peanut allergy is warranted in developing countries.

The impact of food allergy on asthma

Food allergy is a potentially severe immune response to a food or food additive. Although a majority of children will outgrow their food allergies, some may have lifelong issues. Food allergies and other atopic conditions, such as asthma, are increasing in prevalence in Western countries. As such, it is not uncommon to note the co-existence of food allergy and asthma in the same patient. As part of the atopic march, many food allergic patients may develop asthma later in life. Each can adversely affect the other. Food allergic patients with asthma have a higher risk of developing life-threatening food-induced reactions. Although food allergy is not typically an etiology of asthma, an asthmatic patient with food allergy may have higher rates of morbidity and mortality associated with the asthma. Asthma is rarely a manifestation of food allergy alone, but the symptoms can be seen with allergic reactions to foods. There may be evidence to suggest that early childhood environmental factors, such as the mother's and child's diets, factor in the development of asthma; however, the evidence continues to be conflicting. All food allergic patients and their families should be counseled on the management of food allergy and the risk of developing co-morbid asthma.

The Asthma Predictive Index: a very useful tool for predicting asthma in young children

Recurrent wheezing is a common problem in young children: approximately 40% of children wheeze in their first year of life. However, only 30% of preschoolers with recurrent wheezing still have asthma at the age of 6 years. Nevertheless, asthma, the most prevalent chronic disease in children, is difficult to diagnose in infants and preschoolers. This article reviews the importance of determining at an early age which infants/preschoolers will have asthma later in life, analyzes the pros and cons of different predictive indices, and discusses the efficacy of the Asthma Predictive Index.

Long-term health outcomes and mechanisms associated with breastfeeding

Breastfeeding is superior to formula feeding because it has factors that have long term consequences for early metabolism and disease later in life. In this paper, the scientific evidence in support of why breast milk is beneficial for infants is summarized and the mechanisms in which breastfeeding impacts on disease are explored. Human milk may show a reduced occurrence of disease because mammalian evolution promotes survival, and because of specific factors in milk that promote active stimulation of the infant's immune system and gastrointestinal mucosal maturation decrease the incidence of infection and alter the gut microflora. Bioactive factors, including: hormones, growth factors, colony-stimulating factors and specific nutrients, may have such far-reaching effects on the infant's immune response that normal development depends heavily on its provision. All mothers should be encouraged and supported to continue breastfeeding for 6 months and beyond in order to promote the good health of their infants.

Acute allergic skin response as a new tool to evaluate the allergenicity of whey hydrolysates in a mouse model of orally induced cow's milk allergy

Hypoallergenic milk formulae are used for cow's milk allergic infants and may be a good option for infants at risk. Clinical studies have shown that the protein source or the hydrolysis methodology used may influence the effectiveness in infants stressing the importance of adequate pre-clinical testing of hypoallergenic formulae in an in vivo model of orally induced cow's milk allergy. This study was undertaken to introduce a new read-out system to measure the residual allergenicity of whey hydrolysates on both the sensitization and challenge phase of orally induced cow's milk allergy in mice. Mice were sensitized orally to whey or a partial whey hydrolysate (pWH) to measure the residual sensitizing capacity. To predict the residual allergenicity of hydrolysates, whey allergic mice were challenged in the ear with pWH, extensive whey hydrolysate or an amino acid-based formula. An acute allergic skin response (ear swelling at 1 h), whey-specific serum antibodies, and local MCP-1 concentrations were measured. In contrast to whey, oral sensitization with pWH did not result in the induction of whey-specific antibodies, although a minor residual skin response to whey was observed after challenge. Skin exposure to whey hydrolysates showed a hydrolysation dependent reduction of the acute allergic skin response in whey allergic mice. In contrast to whey, skin exposure to pWH did not enhance tissue MCP-1 levels. The acute allergic skin response in mice orally sensitized to cow's milk proteins reveals a new pre-clinical tool which might provide information about the residual sensitizing capacity of hydrolysates supporting the discussion on the use of hypoallergenic formulae in high risk children. This mouse model might be a relevant model for the screening of new hypoallergenic formulae aimed to prevent or treat cow's milk allergy.

Breast-feeding, aeroallergen sensitization, and environmental exposures during infancy are determinants of childhood allergic rhinitis

BACKGROUND

Infant predictors of early childhood allergic rhinitis (AR) are poorly understood.

OBJECTIVE

We sought to identify environmental exposures and host factors during infancy that predict AR at age 3 years.

METHODS

High-risk children from greater Cincinnati were followed annually from ages 1 to 3 years. AR was defined as sneezing, runny, or blocked nose in the prior 12 months and a positive skin prick test (SPT) response to 1 or more aeroallergens. Environmental and standardized medical questionnaires determined exposures and clinical outcomes. Primary activity area dust samples were analyzed for house dust endotoxin (HDE) and (1-3)-beta-D-glucan. Fine particulate matter sampled at 27 monitoring stations was used to estimate personal elemental carbon attributable to traffic exposure by using a land-use regression model.

RESULTS

Of 361 children in this analysis, 116 had AR, and 245 were nonatopic and nonsymptomatic. Prolonged breast-feeding in African American children (adjusted odds ratio [aOR], 0.8; 95% CI, 0.6-0.9) and multiple children in the home during infancy was protective against AR (aOR, 0.4; 95% CI, 0.2-0.8). Food SPT response positivity and tree SPT response positivity in infancy increased the risk of AR at age 3 years (aOR of 4.4 [95% CI, 2.1-9.2] and aOR of 6.8 [95% CI, 2.5-18.7], respectively). HDE exposure was associated with AR; the effect was dependent on exposure level. Elemental carbon attributable to traffic and environmental tobacco smoke exposure showed no effect on AR.

CONCLUSION

Prolonged breast-feeding in African American subjects and multiple children in the home during infancy reduced the risk of AR at age 3 years. SPT response positivity to food and tree allergens enhanced risk. The HDE effect on AR was related to exposure.