Dietary aspects of food allergy prevention in infants and children

Do Human Milk Oligosaccharides Protect Against Infant Atopic Disorders and Food Allergy?

Atopic disorders (AD), often coexistent with food allergy (FA), start developing in early life and have lifelong health consequences. Breastfeeding is thought to be protective against AD and FA, but the data are controversial, and mechanisms are not well understood. Human milk oligosaccharides (HMOs) are complex carbohydrates that are abundant in human milk. These are thought to contribute to the development of the infant immune system by (i) promoting healthy microbiome, (ii) inhibiting pathogen binding to gut mucosa and (iii) modulating the immune system. Differences in microbiome composition between allergic and healthy infants have been observed, regardless of breastfeeding history. To date, limited studies have examined the preventive effects of HMOs on AD and FA in infants and current data relies on observation studies as trials of varying HMO intake through randomising individuals to breastfeeding are unethical. There is evidence for beneficial effects of breastfeeding on lowering the risks of FA, eczema and asthma but there are inconsistencies amongst studies in the duration of breastfeeding, diagnostic criteria for AD and the age at which the outcome was assessed. Furthermore, current analytical methods primarily used today only allow detection of 16-20 major HMOs while more than 100 types have been identified. More large-scale longitudinal studies are required to investigate the role of HMO composition and the impact of changes over the lactation period in preventing AD and FA later in life.

Stoss therapy using fortified biscuit for vitamin D-deficient children: a novel treatment

BACKGROUND

To evaluate the efficacy of stoss therapy using fortified biscuit for vitamin D-deficient children.

METHODS

A total of 108 children aged 30-72 months with vitamin D deficiency were studied in a randomized single-blind clinical trial. The deficient children were assigned to three groups, namely, vitamin D-fortified biscuit (BG), capsule vitamin D (CG), and ampoule vitamin D (AG). Capsules and biscuits containing 50,000 IU of cholecalciferol were consumed twice per week for 3 consecutive weeks. Ampoules with 300,000 IU of cholecalciferol were injected intramuscularly in a single dose. Three weeks after treatment, serum 25(OH)D concentrations were measured, and the three groups were compared.

RESULTS

Each method of treatment could increase the mean serum 25(OH)D concentration to optimal level. Serum 25(OH)D concentrations ≥100 ng/mL were observed in six children, including four from AG and two from CG (P = 0.09). The comparison of the mean serum 25(OH)D concentrations after treatment showed between ampoule and capsule (P = 0.3) and capsule and biscuit (P = 0.62) were insignificant; however, the ampoule and biscuit groups differed significantly (P = 0.012).

CONCLUSION

Stoss therapy using fortified biscuit may be an effective way to improve compliance in children who cannot take capsules without adverse effects and may also be recommended for prevention purposes.

The challenges of preventing food allergy: Lessons learned from LEAP and EAT

OBJECTIVE

To highlight challenges associated with this novel preventive strategy.

DATA SOURCES

The Learning Early About Peanuts (LEAP) and Enquiring About Tolerance (EAT) Studies, with reference to other oral tolerance induction studies.

STUDY SELECTIONS

Randomized clinial trials seeking to prevent food allergy through allergen introduction in infancy.

RESULTS

Oral tolerance induction programs that use a regimen of consumption of 2 g/week of protein are effective in preventing peanut and egg allergy. LEAP findings suggest oral tolerance induction is allergen specific. Adding peanut and other common food allergens (egg, fish, sesame, milk) to the infant diet has no adverse nutritional or growth effects and does not increase rates of food allergy. Breastfeeding rates are not adversely affected by these interventions. In the Western world, nonwhite children have the highest risk of food allergy, but their families are the least likely to participate in oral tolerance induction programs.

CONCLUSION

Many challenges must be overcome to implement successful food allergy prevention strategies. Allergy testing of high-risk infants (those with moderate to severe eczema and/or egg allergy) before commencing oral tolerance induction is desirable, but access is not universal. Dietary interventions would ideally be implemented in infancy before allergic sensitization and allergy occur, using a program that provides protection against multiple common allergens. Further research and consensus with regard to food preparations, target populations, dosing regimens, and preparations and clearly defined adherence are now required.

Nutrient intakes of infants with atopic dermatitis and relationship with feeding type

BACKGROUND/OBJECTIVES

The prevalence of atopic dermatitis in infants is increasing worldwide. However, the nutrient intake status of infants with atopic dermatitis has not been studied properly. This study was conducted to compare the nutrient intake status of infants in the weaning period with atopic dermatitis by feeding type.

MATERIALS/METHODS

Feeding types, nutrient intake status and growth status of 98 infants with atopic dermatitis from age 6 to 12 months were investigated. Feeding types were surveyed using questionnaires, and daily intakes were recorded by mothers using the 24-hour recall method. Growth and iron status were also measured.

RESULTS

The result showed that breastfed infants consumed less energy and 13 nutrients compared to formula-fed or mixed-fed infants (p < 0.001). The breastfed group showed a significantly lower intake rate to the Dietary Reference Intakes for Koreans than the other two groups (p < 0.001). In addition, they consumed less than 75% of the recommended intakes in all nutrients, except for protein and vitamin A, and in particular, iron intake was very low, showing just 18.7% of the recommended intake. There was no significant difference in growth by feeding type, but breastfed infants showed a significantly higher rate of iron deficiency anemia (p < 0.001).

CONCLUSIONS

Continuous management programs should be prepared for breastfed infants with atopic dermatitis, who are in a period when rapid growth takes place and proper nutrient intake is essential.

The gut as communicator between environment and host: immunological consequences

During human evolution, the mucosal immune system developed two anti-inflammatory mechanisms: immune exclusion by secretory antibodies (SIgA and SIgM) to control epithelial colonization of microorganisms and inhibit penetration of harmful substances; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens such as food proteins. The latter function is referred to as oral tolerance when induced via the gut. Similar mechanisms also control immunity to commensal bacteria. The development of immune homeostasis depends on "windows of opportunity" where adaptive and innate immunities are coordinated by antigen-presenting cells; their function is not only influenced by microbial products but also by dietary constituents, including vitamin A and lipids like polyunsaturated omega-3 fatty acids. These factors can in several ways exert beneficial effects on the immunophenotype of the infant. Also breast milk provides immune-modulating factors and SIgA antibodies - reinforcing the gut barrier. Mucosal immunity is most abundantly expressed in the gut, and the intestinal mucosa of an adult contains at least 80% of the body's activated B cells - terminally differentiated to plasmablasts and plasma cells (PCs). Most mucosal PCs produce dimeric IgA which is exported by secretory epithelia expressing the polymeric Ig receptor (pIgR), also called membrane secretory component (SC). Immune exclusion is therefore performed mainly by SIgA. Notably, pIgR knockout mice which lack SIgs show increased uptake of food and microbial antigens and they have a hyper-reactive immune system with disposition for anaphylaxis; but this untoward development is counteracted by cognate oral tolerance induction as a homeostatic back-up mechanism.

Homeostatic impact of indigenous microbiota and secretory immunity

In the process of evolution, the mucosal immune system has generated two layers of anti-inflammatory defence: (1) immune exclusion performed by secretory IgA (and secretory IgM) antibodies to modulate or inhibit surface colonisation of microorganisms and dampen penetration of potentially dangerous antigens; and (2) suppressive mechanisms to avoid local and peripheral hypersensitivity to innocuous antigens, particularly food proteins and components of commensal bacteria. When induced via the gut, the latter phenomenon is called 'oral tolerance', which mainly depends on the development of regulatory T (Treg) cells in mesenteric lymph nodes to which mucosal dendritic cells (DCs) carry exogenous antigens and become conditioned for induction of Treg cells. Mucosally induced tolerance appears to be a rather robust adaptive immune function in view of the fact that large amounts of food proteins pass through the gut, while overt and persistent food allergy is not so common. DCs are 'decision makers' in the immune system when they perform their antigen-presenting function, thus linking innate and adaptive immunity by sensing the exogenous mucosal impact (e.g. conserved microbial molecular patterns). A balanced indigenous microbiota is required to drive the normal development of both mucosa-associated lymphoid tissue, the epithelial barrier with its secretory IgA (and IgM) system, and mucosally induced tolerance mechanisms including the generation of Treg cells. Notably, polymeric Ig receptor (pIgR/SC) knock-out mice that lack secretory IgA and IgM antibodies show reduced epithelial barrier function and increased uptake of antigens from food and commensal bacteria. They therefore have a hyper-reactive immune system and show predisposition for systemic anaphylaxis after sensitisation; but this development is counteracted by enhanced oral tolerance induction as a homeostatic back-up mechanism.

Food allergy: separating the science from the mythology

Numerous genes are involved in innate and adaptive immunity and these have been modified over millions of years. During this evolution, the mucosal immune system has developed two anti-inflammatory strategies: immune exclusion by the use of secretory antibodies to control epithelial colonization of microorganisms and to inhibit the penetration of potentially harmful agents; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens, such as food proteins. The latter strategy is called oral tolerance when induced via the gut. Homeostatic mechanisms also dampen immune responses to commensal bacteria. The mucosal epithelial barrier and immunoregulatory network are poorly developed in newborns. The perinatal period is, therefore, critical with regard to the induction of food allergy. The development of immune homeostasis depends on windows of opportunity during which innate and adaptive immunity are coordinated by antigen-presenting cells. The function of these cells is not only orchestrated by microbial products but also by dietary constituents, including vitamin A and lipids, such as polyunsaturated omega-3 fatty acids. These factors may in various ways exert beneficial effects on the immunophenotype of the infant. The same is true for breast milk, which provides immune-inducing factors and secretory immunoglobulin A, which reinforces the gut epithelial barrier. It is not easy to dissect the immunoregulatory network and identify variables that lead to food allergy. This Review discusses efforts to this end and outlines the scientific basis for future food allergy prevention.

Fortification of orange juice with vitamin D(2) or vitamin D(3) is as effective as an oral supplement in maintaining vitamin D status in adults

BACKGROUND

Vitamin D has been added to calcium-fortified orange juice. It is unknown whether vitamin D is as bioavailable from orange juice as it is from supplements.

OBJECTIVES

The objective was to compare the bioavailability of vitamin D(2) and vitamin D(3) from orange juice with that from vitamin D(2) and vitamin D(3) supplements. A secondary aim was to determine which form of vitamin D is more bioavailable in orange juice.

DESIGN

A randomized, placebo-controlled, double-blind study was conducted in healthy adults aged 18-84 y (15-20/group) who received 1000 IU vitamin D(3), 1000 IU vitamin D(2), or placebo in orange juice or capsule for 11 wk at the end of winter.

RESULTS

A total of 64% of subjects began the study deficient in vitamin D (ie, 25-hydroxyvitamin D [25(OH)D]) concentrations <20 ng/mL). Analysis of the area under the curve showed no significant difference in serum 25(OH)D between subjects who consumed vitamin D-fortified orange juice and those who consumed vitamin D supplements (P = 0.084). No significant difference in serum 25(OH)D(3) was observed between subjects who consumed vitamin D(3)-fortified orange juice and vitamin D(3) capsules (P > 0.1). Similarly, no significant difference in serum 25(OH)D(2) was observed between subjects who consumed vitamin D(2)-fortified orange juice and vitamin D(2) capsules (P > 0.1). No significant overall difference in parathyroid hormone concentrations was observed between the groups (P = 0.82).

CONCLUSION

Vitamin D(2) and vitamin D(3) are equally bioavailable in orange juice and capsules.

Skin prick test predictive value on the outcome of a first known egg exposure in milk-allergic children

Children with milk allergy have higher incidence of other food allergies, especially egg allergy. The objective of this study was to ascertain the accuracy of the prick test in children with IgE-mediated milk allergy for diagnosing egg allergy. Children under the age of 1 yr who came consecutively to Allergy Department 2003-05, and were diagnosed with IgE-mediated milk allergy were selected for this study. Egg introduction was completely avoided until the age of 14 months when clinical history, skin prick tests (SPT), specific-IgE antibodies determination and egg challenge test were performed. One hundred and four milk-allergic children were included. At least one positive prick test to any egg allergen was found in 65 out of the 104 (62.5%). Thirty-eight (36.5%) were allergic to egg proteins as well. Prick tests with egg white and ovomucoid (OVM) had the best diagnostic performances showing the largest areas under the receiver operating characteristic curve. The optimal diagnosis cut-off point was 6 mm for egg white and 5 mm for OVM. The positive likelihood ratios for these cut-off points were: 2.95 (95% CI: 1.74-4.99) for egg white prick test, and 20 (95% CI: 2.9-143.7) for OVM prick test. Children with specific IgE-mediated cow's milk allergy must be closely followed as a risk group for egg allergy. Early diagnosis is necessary and the SPT has shown itself to be a very useful tool for diagnosing immediate IgE reactions to egg on first known exposure.

Soy protein for infant feeding: what do we know?

PURPOSE OF REVIEW

This review discusses the safety, nutritional adequacy and recommendations for use of soy protein formulae, based mainly on the most relevant reports published during 2005 and 2006.

RECENT FINDINGS

Concerns have recently been raised regarding potential risks with soy protein formulae, in particular regarding their high phytoestrogenic isoflavone content. Recent data are insufficient to draw definitive conclusions on safety, but authorities and paediatric societies from several countries recently advised health professionals to use soy protein formulae only in certain cases. Indications for use of soy protein formulae, mainly for prevention and management of food allergy, have also been better defined.

SUMMARY

Soy protein formulae ensure normal growth and development in healthy term infants but they have no nutritional advantages over cow's milk protein formulae. Main indications include severe lactose intolerance, galactosaemia and need to avoid foods of animal origin. Soy protein formulae have no role in preventing allergy or in management of nonspecific gastrointestinal symptoms (e.g. infantile colic and regurgitation). They should not be used in preterm infants or infants with food allergy before age 6 months. After 6 months, soy protein formulae may be considered if tolerance to soy protein is established.

The impact of diet on anti-social, violent and criminal behaviour

The role of diet in anti-social behaviour was considered, paying particular attention to double-blind placebo-controlled trials. Meta-analysis of five well-designed studies found that elimination diets reduced hyperactivity-related symptoms, producing a summary standardized mean difference (SSMD) of 0.80 (95% CI 0.41-1.19). The picture was of children potentially responding to a wide range of food items although the pattern was individual to the child. Supplementation with poly-unsaturated fatty acids decreased violence (SSMD -0.61, 95% CI -0.83 to -0.39) although there was no evidence of an influence on hyperactivity. Three well-designed studies have reported that vitamin/mineral supplementation reduced anti-social behaviour. There are also findings of an association between a tendency to develop low blood glucose and aggression. Many responses to diet were idiosyncratic and involved a wide range of foods interacting with individual differences in physiology. Reactions were not observed in all members of groups chosen because they share a common behavioural designation or diagnosis.

Relation between the socioeconomic status of the family and primary allergy prevention in infant feeding in Hajdu-Bihar County, Hungary

BACKGROUND

The relationship between socioeconomic status and preventive care is an important issue in public health practice in Hungary. Our aim was to investigate the association between the socioeconomic status and the present practice of primary allergy prevention in infant feeding in Hajdú-Bihar County, Hungary.

METHODS

A questionnaire-based cross-sectional survey was performed among 3076 infants aged 0-6 months. We studied how socioeconomic status, type of settlement, allergic background of the family and skin symptoms indicative for allergy were related to primary allergy prevention in infant feeding. Prevalence odds ratios (ORs) were calculated by multiple logistic regression.

RESULTS

Independent determinants of breast feeding were age [OR corresponding to one month change 0.74; 95% confidence interval (CI) 0.70-0.77], the female gender (OR 1.24; 95% CI 1.06-1.46), the socioeconomic status of the family (OR comparing the worst with the best category 0.63; 95% CI 0.43-0.93), and birth weight (OR comparing <1500 g to >2500 g category 0.17; 95% CI 0.07-0.41). Among supplementary nutrient users independent determinants of the use of hydrolysed infant formulae were the socioeconomic status (OR comparing the worst with the best category 0.06; 95% CI 0.01-0.27), the type of settlement (OR comparing village with town 0.48; 95% CI 0.28-0.80), history of allergy in the family (OR 2.30; 95% CI 1.28-4.11), and skin symptoms indicative of allergy (OR 3.46; 95% CI 1.96-6.14).

CONCLUSION

Socioeconomic status is related to the implementation of primary allergy prevention in infant feeding.

Diet of lactating women and allergic reactions in their infants

PURPOSE OF REVIEW

To evaluate whether the diet of lactating women modulates the development of allergic disease in their children.

RECENT FINDINGS

Although maternal avoidance of common food protein allergens was previously recommended for lactating women with infants predisposed to allergic disease, recent expert reviews have concluded that there is no strong evidence to support this position. A recent well-controlled study, using egg as an allergen, confirmed that the appearance of food proteins in human milk is common, but this can be highly variable between women even after consuming the same challenge (dose) food. On the other hand, preliminary data suggest that increasing dietary n-3 fatty acids may offer protection from the development of some childhood allergies. A recent animal study offers mechanistic support, indicating that perinatal diets high in n-3 fatty acids can induce oral neonatal tolerance more effectively compared with diets predominating in n-6 fatty acids.

SUMMARY

Current data do not support the use of maternal antigen-avoidance diets during lactation as a strategy to prevent childhood allergies. Controlled trials are required to evaluate the efficacy of maternal dietary n-3 fatty acid interventions in preventing allergic disease in at-risk infants.

Soy protein infant formulae and follow-on formulae: a commentary by the ESPGHAN Committee on Nutrition

This comment by the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) Committee on Nutrition summarizes available information on the composition and use of soy protein formulae as substitutes for breastfeeding and cows' milk protein formulae as well as on their suitability and safety for supporting adequate growth and development in infants. Soy is a source of protein that is inferior to cows' milk, with a lower digestibility and bioavailability as well as a lower methionine content. For soy protein infant formulae, only protein isolates can be used, and minimum protein content required in the current European Union legislation is higher than that of cows' milk protein infant formulae (2.25 g/100 kcal vs. 1.8 g/100kcal). Soy protein formulae can be used for feeding term infants, but they have no nutritional advantage over cows' milk protein formulae and contain high concentrations of phytate, aluminum, and phytoestrogens (isoflavones), which might have untoward effects. There are no data to support the use of soy protein formulae in preterm infants. Indications for soy protein formulae include severe persistent lactose intolerance, galactosemia, and ethical considerations (e.g., vegan concepts). Soy protein formulae have no role in the prevention of allergic diseases and should not be used in infants with food allergy during the first 6 months of life. If soy protein formulae are considered for therapeutic use in food allergy after the age of 6 months because of their lower cost and better acceptance, tolerance to soy protein should first be established byclinical challenge. There is no evidence supporting the use of soy protein formulae for the prevention or management of infantile colic, regurgitation, or prolonged crying.

Intervention during pregnancy and allergic disease in the offspring

The etiology of allergy is multifactorial, with many variables contributing to the final expression of atopic disease. Three breeding grounds are needed to develop allergic disease: the appropriate genetic background, contact with the allergen(s) and environmental factors. Timing and dosing of allergen(s) are of major importance. Contact with (dietary) allergens and various agents such as tobacco smoke and infections occur not only during post-natal life, but also perinatally and even pre-natally. A critical review of published evidence regarding the impact of maternal exposure to antigens during pregnancy on later development of allergy in the offspring can only conclude that more research is urgently needed. Contact with multiple dietary allergens should be in general of benefit to the fetus to develop tolerance. Current knowledge suggests that pregnant women should have a normal diversified diet, avoiding toxic agents such as tobacco and alcohol. The role of maternal intake of poly-unsaturated fatty acids on the development of atopy in the infants needs to be further evaluated. If parental history would be insufficient to determine the fetal risk, preventive measurements would be advisable for all fetuses.

Effect of cooked and raw egg consumption on ovalbumin content of human milk: a randomized, double-blind, cross-over trial

BACKGROUND

Maternal avoidance of egg intake has been recommended to treat egg allergy in breastfed infants.

OBJECTIVE

To determine if the concentration of ovalbumin (OVA) in human milk is directly related to the quantity and form of egg consumed by breastfeeding mothers.

METHODS

Randomized, blinded, cross-over, intervention trial. Breastfeeding women (n = 41) attended four clinic days between 11 and 14 weeks of lactation and on each day were randomly allocated to receive a test breakfast, identical except for the egg content (no egg, one raw egg, half a cooked egg or one cooked egg). Breast milk samples were collected at two hourly intervals for 8 h and their OVA concentration measured by ELISA.

RESULTS

There was a direct, dose-response between the amount of cooked egg ingested and the peak OVA concentration (no egg 0.05 ng/mL [95% confidence interval (CI), 0.01-0.11], half a cooked egg 2.24 ng/mL [95% CI, 0.57-3.91], one cooked egg 3.16 ng/mL [95% CI, 1.41-4.91], n = 41, P<0.05) as well as the total OVA excretion (no egg 0.18 ng/mL/h [95% CI, 0.04-0.39], half a cooked egg 4.93 ng/mL/h [95% CI, 1.40-8.46], one cooked egg 9.14 ng/mL/h [95% CI, 4.25-14.03], n = 41, P<0.05). The peak concentration and total OVA excretion in response to one raw egg did not differ from ingesting half a cooked egg. There was no detectable OVA in the breast milk of 24% (10/41) women up to 8 h after any egg challenge.

CONCLUSION

OVA was detected in the breast milk of lactating women up to 8 h after a controlled intake of egg. A dose-response correlation was indicated. As excretion of OVA in human milk appears to be a normal phenomenon, further studies need to determine the threshold of OVA excretion that leads to symptoms in egg-allergic breastfed infants.

Maternal consumption of dairy products during pregnancy and lactation, and the development of cow's milk antibodies in the offspring

OBJECTIVE

To assess whether the maternal consumption of milk and milk products affects development of cow's milk (CM) antibodies in infants.

DESIGN

A randomized pilot trial using food frequency questionnaires (mothers) and food records (infants).

SETTING

Families with a newborn infant with increased HLA-DQB1-conferred risk of type 1 diabetes and at least one first-degree relative affected by type 1 diabetes from 16 hospitals in Finland between April 1995 and November 1997.

SUBJECTS AND INTERVENTION

Infants randomized to receive a hydrolysed formula when breast milk was not available during their first 6-8 mo (n=112). Of these, 13 dropped out by the age of 3 mo and two were excluded due to incomplete CM antibody data.

RESULTS

Maternal milk protein intake from cheese during pregnancy was inversely related to IgA-class antibody titres to beta-lactoglobulin (BLG) and casein (CAS) at 3 mo, and to IgA antibody titres to BLG at 6 mo. Maternal consumption of raw milk products during lactation was positively related to the development of IgA antibody titres to CAS at 6 mo, and inversely correlated to IgG antibody titres to bovine serum albumin (BSA) and IgA antibody titres to CAS at 2 y. Maternal cheese consumption was inversely related to the IgG antibody titres to CM formula and CAS and to the IgA antibody titres to CAS in early infancy.

CONCLUSIONS

Few associations were established between maternal CM protein intake and CM protein antibody levels in the infants. The milk and milk products taken by the mother differed in their impact on the emerging CM antibody response in the offspring.

What do midwives and nurses in Turkey know about nutrition in the first six months of life

OBJECTIVE

to discover what midwives and nurses in Turkey know and advise about nutrition in the first 6 months of life.

DESIGN

a descriptive, cross-sectional study.

SETTING

health clinics and mother and baby health and family planning centres in the municipality of Ankara.

PARTICIPANTS

301 midwives and nurses selected by stratified, random sampling.

FINDINGS

nine questions related to the features and benefits of breast milk. The mean number of questions answered correctly was 7.55 (standard deviation [SD]=1.25). Participants agreed that the babies should be breast fed for the first 6 months of life (n=184; 61.1%) and that complementary food could be introduced at 6 months of age (n=291; 96.7%). Most participants (n=223; 74.1%) recommended that mothers who have to resume work should express and store breast milk, and their babies should be fed with it. Many participants noted that there may be one or more situations when artificial milk should be given in the first 6 months of life (n=286; 95.0%). Almost all of the participants (n=292; 97.0%) gave one or more suggestions of when breast milk was sufficient or insufficient.

CONCLUSIONS

most midwives and nurses in this research had adequate knowledge related to babies in the first 6 months of life. However, with continuing education, knowledge deficits can be corrected, and awareness of their roles and responsibilities can be increased in achieving one of Turkey's priority goals for the 21st Century, that of decreasing the baby death rate.

Low levels of immunoglobulin A in children with intrinsic asthma: a possible protection against atopy

Immunoglobulin A and G (IgA, IgG) serum concentrations were detected in children with nonallergic/intrinsic (36 children) or allergic/extrinsic asthma (43 children) and in age-matching control children (40 children). Asthmatic children with allergic asthma had lower IgA (1.36+/-0.54 g/L) and higher IgG (10.48+/-2.77 g/L) levels than the age-matching control children group (1.63+/-0.69 vs. 9.01+/-2.32 g/L). Children with nonallergic/intrinsic asthma had lower IgA (1.03+/-0.41 g/L) ( p = 0.004) and IgG (8.38+/-1.93 g/L) (p = 0.001) levels than the allergic/extrinsic asthma group (1.36+/-0.54 vs. 10.48+/-2.77 g/L). Low IgA levels were found in children with nonallergic/intrinsic asthma and high IgG levels were found in those children with allergic/extrinsic childhood asthma. The hypothesis is that the increased incidence of asthma in the population may be caused by a decrease in childhood infections (hygiene hypothesis). Frequent infections in early life boost the immune system, stimulating Th1-type response in young children and reducing the risk of atopic diseases. Our hypothesis is that low IgA (and/or IgG) levels in our patients might be responsible for infection development among those children with nonallergic/intrinsic asthma. These infections stimulate the normal development of immune system in young children, reducing risk of atopy, so that those children do not get allergic/extrinsic childhood asthma. Intrinsic childhood asthma=nonallergic (nonatopic) childhood asthma. Extrinsic childhood asthma=allergic (atopic) childhood asthma.

Infant diet and type 1 diabetes in China

Infant milk and food introduction may be linked to type 1 diabetes risk in high incidence populations. Dietary data through age 12 months was collected for 247 type 1 diabetic cases and 443 controls in China, a low incidence population, to determine if milk and solid food intake differed. Age range at introduction to milk and formulas was similar in cases and controls but solid food introduction more often occurred before age 3 months in cases. Logistic regression analyses showed soy milk formula consumption at 4-6 (OR = 2.0; 95% CI: 1.1-3.4) and 7-12 months of age (OR = 1.5; 95% CI: 1.0-2.1) was associated with a twofold higher risk of type 1 diabetes, while steamed bread consumption (4-6 months, OR = 0.44; 95% CI: 0.28-0.68; 7-12 months, OR = 0.48; 95% CI: 0.34-0.69) and higher SES (4-6 months, OR = 0.55; 95% CI: 0.39-0.78; 7-12 months, OR = 0.57; 95% CI: 0.40-0.83) were negatively associated. Drinking cow's milk at 7-12 months (OR = 0.60; 95% CI: 0.43-0.85) was negatively associated with type 1 diabetes while consuming vegetables at 4-6 months (OR = 1.5; 95% CI: 1.0-2.2) was positively associated. Results suggest that infant milk and solid food intake are associated with type 1 diabetes in China. Prospective studies may determine how these dietary factors impact disease etiology, particularly for at-risk-populations.

Therapeutic modalities for cow's milk allergy

OBJECTIVE

To discuss current therapeutic modalities for cow's milk allergy and its prevention.

DATA SOURCES AND STUDY SELECTION

The sources of data include original clinical studies carried out at Ste. Justine Hospital, as well as a systematic search of the published English and French language scientific literature restricted to human subjects using computerized searches (National Public Library of Medicine, Cochrane Database Systems Review) from 1997 to 2002. Search terms for article retrieval included food allergy, milk allergy, therapy, and prevention.

CONCLUSIONS

The therapy of food allergies depends upon an accurate diagnosis, which remains a challenge in non--IgE-mediated cases. Dietary exclusion remains the mainstay of therapy, with medications reserved for exceptional patients. Preliminary evidence suggests that pancreatic enzyme supplementation may be of benefit for cases with multiple food allergies and severe eczema. Hydrolysate formula use is currently recommended for dietary allergy prevention in infants at an increased risk when maternal milk is insufficient or unavailable. The use of partially hydrolyzed formulas to prevent allergic disorders, including atopic dermatitis, is supported by clinical studies, but cannot be used in the already sensitized, milk-allergic child. Probiotics show enormous potential in preventing food allergic disorders as well.

Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health

BACKGROUND

Fortification of milk with vitamin D may not be adequate for satisfying the vitamin D requirement because of variability in vitamin D content after fortification and because many persons have milk allergy or lactose intolerance. Additional foods need to be fortified with vitamin D.

OBJECTIVE

We determined whether vitamin D, a fat-soluble vitamin, is bioavailable in orange juice and skim milk, 2 nonfat beverages.

DESIGN

On 3 separate occasions, 18 adults ingested 25 000 IU vitamin D(2) in 240 mL whole milk or skim milk or in 0.1 mL corn oil applied to toast. A separate, double-blind, randomized, controlled trial investigated whether the consumption of orange juice fortified with vitamin D(3) would increase serum 25-hydroxyvitamin D [25(OH)D] concentrations: 14 subjects ingested 240 mL orange juice fortified with 1000 IU vitamin D, and 12 subjects ingested a control orange juice daily for 12 wk.

RESULTS

Peak serum vitamin D(2) concentrations did not differ significantly after the ingestion of vitamin D(2) in whole milk, skim milk, or corn oil on toast. After subjects consumed orange juice fortified with 1000 IU vitamin D(3) daily for 12 wk, serum 25(OH)D(3) concentrations increased by 150%, and serum parathyroid hormone concentrations decreased by 25% compared with baseline; control subjects had a seasonal increase of 45% in 25(OH)D and no significant change in serum parathyroid hormone.

CONCLUSIONS

The fat content of milk does not affect vitamin D bioavailability. Vitamin D fortification at 1000 IU/240 mL orange juice for 12 wk safely increased 25(OH)D(3) concentrations in adults.

Early origins of allergic disease: a review of processes and influences during early immune development

PURPOSE OF REVIEW

With the disturbing increase in allergic disease, there is a pressing need to determine the causes, pathogenesis and safe avenues for disease prevention. Although events in early life appear important, no causal pathways have been identified. This review examines new developments in the area of foetal and early postnatal immune maturation. It secondly addresses early predisposing influences and protective factors that may have a future role in allergy prevention.

RECENT FINDINGS

New developments in the understanding of the ontogeny of allergen-specific immune responses in atopic infants are discussed, including the role of early type 1 and 2 immune responses, and how these are influenced by perinatal antigen presenting cell and T-cell immaturity. The controversial role of early dietary exposures including breastfeeding, food allergens, hydrolyzed formulae and other dietary factors including omega-3 fatty acids are discussed in the context of the most recent literature. Equally contentious, the role of early house dust and pet allergen exposure is discussed in light of new epidemiological studies and disappointing early results of multicentre allergen avoidance studies. Finally, a number of studies in animals and humans suggest that bacterial products can influence early immune development, providing a new potential therapeutic avenue for disease treatment and prevention.

SUMMARY

Complex multifactorial genetic and environmental interactions make research in this area difficult and apparent associations with allergic disease may not be causal in nature. Many current targets for prevention, such as early allergen exposure and infant feeding practices, are proving to be ineffective and may not be directly implicated in rising rates of disease.

A new oligomeric parvalbumin allergen of Atlantic cod (Gad mI) encoded by a gene distinct from that of Gad cI

BACKGROUND

The major allergen of Baltic cod (Gadus callarias) is a 12.3-kDa parvalbumin with two calcium-binding sites corresponding to EF-hand motifs. Our group found a 24-kDa IgE-reactive band that was also recognized by a monoclonal antiparvalbumin antibody in Atlantic cod (Gadus morhua). Our purpose was to purify and to determine the cDNA deduced sequence of this new cod allergen.

METHODS

Proteins from pre rigor mortis Atlantic cod were separated by gel filtration and the eluted peaks were analysed by SDS-PAGE and Western blotting with sera of sensitized patients and with antiparvalbumin. Protein bands were microsequenced, RNA transcripts were amplified by reverse transcription and polymerase chain reaction (RT-PCR) using primer combinations overlapping the open reading frame.

RESULTS

Four IgE and antiparvalbumin reactive proteins(12.5, 24, 38 and 51 kDa) were detected in gel filtration eluate. The cDNA deduced sequence of the 24 kDa protein had 109 amino acid residues with a molecular weight of 11.5 kDa and a theoretical pI of 4.34. The 24 kDa band corresponded therefore to a dimer of a beta-parvalbumin. Its homology was higher with Sal sI than with Gad cI. This new allergen was named Gad mI.

CONCLUSION

We have characterized a new parvalbumin allergen in Gadus morhua. This protein formed oligomers in native and in reducing conditions. Gad mI and Gad cI may correspond to two distinct genes of Gadus species.

IgE-binding and cross-reactivity of a new 41 kDa allergen of codfish

BACKGROUND

A 41-kDa IgE-reactive protein (p41) was purified from raw cod extract. This protein is homologous to an aldehyde phosphate dehydrogenase (APDH). The present study aims to evaluate the IgE-binding and the cross-reactivity of this protein in 13 patients allergic to codfish.

METHODS

IgE binding of sera from 13 patients allergic to codfish was tested by Sepharose RIA and by Western blot.

RESULTS

Among the 13 patients, only 4 had specific IgE to APDH detected by APDH-Sepharose RIA. The two patients who had the highest level of specific IgE to human APDH also had a class 5-6 CAP-RAST IgE level to codfish, but two other patients with a class 5 had a negative APDH-Sepharose IgE-RIA. Relative content of APDH was higher in extracts of commercial nonfrozen fish, compared to pre rigor mortis, post rigor mortis and frozen commercial codfish. A high homology of codfish APDH was found with the corresponding human enzyme. A significant inhibition of APDH-Sepharose by human and, to a lesser extent, by rabbit APDH was observed. Western blot of APDH codfish extract showed two bands at 41 and 36 kDa, respectively.

CONCLUSIONS

We have characterized a new allergen from codfish, which had a high level of homology in different species. The p41 relative content of extracts from nonfrozen codfish was higher than in the other samples assessed.

High incidence of adverse reactions to egg challenge on first known exposure in young atopic dermatitis children: predictive value of skin prick test and radioallergosorbent test to egg proteins

BACKGROUND

Egg skin prick test (SPT) and/or radioallergosorbent test (RAST) positivity has been described in infants and children with a food allergy, or in infants at high risk of atopy who have never eaten eggs. Clinical reactions are also observed when some of these children or infants eat eggs for the first time.

OBJECTIVE AND METHOD

A prospective study was made of 107 atopic dermatitis (AD) children (66 boys, 41 girls) aged 1-19 months (median 5 months) who had never ingested egg, to compare the outcome of a first oral egg challenge and the results of albumen and yolk SPTs and RASTs.

RESULTS

The egg challenge (conducted at age 12-24 months: mean 16 months, median 15 months) was positive in 72/107 children (67.3%). The reactions were immediate or early (first 6 h) in 56/72 (77.8%). The most severe (all within the first 6 h) were one case of anaphylactic shock (1.4%), three cases of laryngeal oedema (4.1%) and one serious attack of asthma (1.4%). The skin weal diameter at and above which reactions always occurred was 5 mm for both albumen and yolk. They were, however, also observed in the complete absence of a weal. The outcome of the challenge was always positive when the specific IgEs (sIgE) for albumen and yolk were > 99 KU/L and > or = 17.5 KU/L, respectively. Here, too, reactions were noted even when sIgE levels were < 0.35 KU/L.

CONCLUSION

AD children who have never eaten eggs may be sensitized and display reactions at the first ingestion. The percentage of reactions in this series was by no means negligible. These findings were observed in children with mild as well as moderate-severe AD when first examined. SPT for albumen and yolk diameter > or = 5 mm, and sIgE for albumen > 99 KU/L and for yolk > or = 17.5 KU/L were 100% specific in predicting the outcome of the challenge. It may thus be concluded that children with AD whose SPT and/or RAST for albumen and/or yolk are equal to or higher than these cut-off values should not be subjected to the oral challenge when consideration is given to the introduction of egg in their diet. Even when these cut-offs are not reached, however, clinical reactions to the challenge cannot be ruled out a priori, and it should be preferably performed in a protected environment, such as a hospital.

Current understanding of gastrointestinal immunoregulation and its relation to food allergy

Tolerance to food antigens induced via the gut ("oral tolerance") appears to be a rather robust adaptive immune mechanism. However, the neonatal period is particularly critical in terms of mucosal defense, with regard to infections and priming for allergic disease. This is so because the intestinal barrier function provided by secretory antibodies, as well as the immunoregulatory network, is poorly developed for a variable period after birth. Notably, the postnatal development of mucosal immune homeostasis depends on the establishment of a normal commensal microbial flora and also on adequate timing and dose of dietary antigens when first introduced. In this context, breastfeeding appears to exert both shielding and positive regulatory effects. Altogether, the intestinal immune system normally seems rather fit for tolerance induction against innocuous antigens because most children with food allergy "outgrow" their problems, whereas airway allergy tends to persist.

Antineutrophil cytoplasmic antibodies, anti-Saccharomyces cerevisiae antibodies, and specific IgE to food allergens in children with inflammatory bowel diseases

Differential diagnosis between ulcerative colitis (UC) and Crohn's disease (CD) is difficult in the initial phases in pediatric patients with inflammatory bowel diseases (IBD). This study was performed to determine the significance of anti-neutrophil cytoplasmic antibodies (ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) in IBD. ANCA were specified with regard to their antigenic specifity, significance to the diagnosis, and correlation of titer with the disease activity. The occurrence of food allergy was questioned, too. Serum samples from 44 children with UC (n = 23) or CD (n = 21) and from disease-control children (coeliac disease, n = 21) were analyzed for IgG ANCA, ANCA target antigens, IgA and IgG ASCA, and IgE to food allergens. Results show that ANCA occur more frequently in UC than in CD and disease-control (74, 24, and 10%, respectively). The presence of ANCA does not reflect disease activity. Antigenic specificity does not differ in any group. IgA-ASCA are found more often in patients with CD (76% versus 17% in UC). The testing for both ANCA and ASCA enabled clear-cut differential diagnosis between UC and CD based on the high specificity (ANCA+ ASCA- 92.5% for UC, ANCA- ASCA+ 93.2% for CD). Specific IgE to food allergens were found in 8.7, 14.3, and 23.8% of patients with UC, CD, and coeliac disease, respectively. We conclude that combined testing of ANCA and ASCA represents a valuable tool in the differential diagnosis between UC and CD in pediatric patients, minimizing invasive diagnostic procedures. Monitoring of ANCA, its specificity, and titer determination does not bring more information. Testing for specific IgE to food allergens may be considered in individual patients.

[Infant formulas and soy protein-based formulas: current data]

For many years soy bean-based formulas (SBBF) were the only dietary product used for infants with cow's milk intolerance. At the present time, their place in infant nutrition is reduced as a result of the availability of new dietary products without lactose and/or cow's milk proteins and the recognition of soy bean protein allergy. There is no evidence that SBBF have any efficiency in infant colic. SBBF have no indication in the prevention of allergy, nor in premature infants' nutrition. Their main indication is the feeding of infants of vegetarian parents who do not want to use cow's milk products. Studies have shown that SBBF contain large quantities of phytoestrogens, particularly isoflavone. Because of experimental data suggesting a possible deleterious effect of phytoestrogens on the neuroendocrine maturation, the reduction of their content in SBBF must be considered.

Intolerance to an extensively hydrolysed formula mistaken for postoperative diarrhoea in a child with neuroblastoma

BACKGROUND

Persistent diarrhoea has recently been reported as a common problem following surgical resection for advanced abdominal neuroblastoma.

CASE STUDY

A 10-month-old child, who had previously had no nutritional problems whilst undergoing chemotherapy treatment for a stage IV neuroblastoma, developed severe diarrhoea following tumour resection. He required nutritional support and was commenced on a continuous overnight nasogastric feed of a non-milk protein hydrolysate feed (MCT Pepdite 0-2, S.H.S. International Ltd, UK) His diarrhoea persisted and it was assumed that this was a postoperative problem which in time would regress. Two months later the child was admitted with a rectal prolapse, and a colonoscopy and biopsy suggested allergic protocolitis. The diarrhoea resolved rapidly on stopping the feed.

CONCLUSION

Although he was never re-challenged with the non-milk protein hydrolysate, it appears that he had a rare intolerance to an extensively hydrolysed protein formula which was masked by the assumption that his diarrhoea was a postoperative problem.

Nutritional and health benefits of soy proteins

Soy protein is a major component of the diet of food-producing animals and is increasingly important in the human diet. However, soy protein is not an ideal protein because it is deficient in the essential amino acid methionine. Methionine supplementation benefits soy infant formulas, but apparently not food intended for adults with an adequate nitrogen intake. Soy protein content of another essential amino acid, lysine, although higher than that of wheat proteins, is still lower than that of the milk protein casein. Adverse nutritional and other effects following consumption of raw soybean meal have been attributed to the presence of endogenous inhibitors of digestive enzymes and lectins and to poor digestibility. To improve the nutritional quality of soy foods, inhibitors and lectins are generally inactivated by heat treatment or eliminated by fractionation during food processing. Although lectins are heat-labile, the inhibitors are more heat-stable than the lectins. Most commercially heated meals retain up to 20% of the Bowman-Birk (BBI) inhibitor of chymotrypsin and trypsin and the Kunitz inhibitor of trypsin (KTI). To enhance the value of soybeans in human nutrition and health, a better understanding is needed of the factors that impact the nutrition and health-promoting aspects of soy proteins. This paper discusses the composition in relation to properties of soy proteins. Also described are possible beneficial and adverse effects of soy-containing diets. The former include soy-induced lowering of cholesterol, anticarcinogenic effects of BBI, and protective effects against obesity, diabetes, irritants of the digestive tract, bone, and kidney diseases, whereas the latter include poor digestibility and allergy to soy proteins. Approaches to reduce the concentration of soybean inhibitors by rearrangement of protein disulfide bonds, immunoassays of inhibitors in processed soy foods and soybean germplasm, the roles of phytoestrogenic isoflavones and lectins, and research needs in all of these areas are also discussed. This integrated overview of the widely scattered literature emphasizes general concepts based on our own studies as well as recent studies by others. It is intended to stimulate interest in further research to optimize beneficial effects of soy proteins. The payoff will be healthier humans and improved animal feeds.

Effect of allergist intervention on patient-centered and societal outcomes: allergists as leaders, innovators, and educators

Atopic disorders, which afflict millions of Americans and hundreds of millions worldwide, are at epidemic levels with concomitant increases in morbidity and mortality. Environmental and lifestyle changes over the past three to five decades are proposed causes for this pandemic and as such present major burdens to reverse. The scope of allergy practice bridges directly on this challenge. Allergy as a specialty is a major leader in developing effective strategies to confront this epidemic. Allergists have made major contributions to the understanding of the risk factors, immunology, pathophysiology, immunomodulation, and prevention of atopic and immunologic disorders. Allergist epidemiologists and clinicians have helped develop and implement national and international guidelines in the recognition, management, and prevention of asthma and rhinitis. Allergist clinical researchers are active in (1) outcomes research that demonstrates convincingly the value of allergy as a specialty in asthma, allergic rhinitis, anaphylaxis, drug and food allergy, and other atopic disorders, (2) National Institutes of Health clinical trials that will form the basis for the future treatment of asthma and allergic disease, and (3) pharmaceutical trials that evaluate new, effective, and safe medication to treat atopic disease. Allergist educators, comprising academic and practicing allergists, supported by allied health professionals, national associations, and affiliated lay organizations, provide comprehensive education to fellows, residents, colleague physicians, media, the public, and patients. Documentation of the value of allergists in improving patient-centered and societal outcomes in their core domain, allergy, is the appropriate final topic contribution in the important series "New millennium: The conquest of allergy."

Update in gastrointestinal allergic diseases

Food allergy or hypersensitivity is defined as an adverse reaction to food protein which is immune mediated. Without standard definitions and reliable tests for many forms of allergic disease of the bowel, studies are difficult to interpret. The proceedings of a recent workshop on the classification of adverse immunologic reactions to foods provide the framework for this review. Recent studies have helped define the clinical spectrum and natural history of IgE and non-IgE-mediated food allergy, and provide insight into underlying pathophysiology and dietary management.