Immunogenicity of a so-called hypoallergenic formula in at-risk babies: two case reports

Large molecule protein feeding during the suckling period is required for the development of pancreatic digestive functions in rats

We examined if large molecule protein feeding during the suckling period is prerequisite for the proper development of pancreatic digestive functions. Most amino acids in breast milk exist as the constituent of large proteins and not as oligopeptides or free amino acids. Accumulating evidence indicates the nutritional importance of large protein feeding for suckling infants; however, evidence on the physiological significance remains small. We thus artificially reared rat pups on a standard rat formula with milk protein or a formula with milk protein hydrolysate from 7 to 21 days of age, and thereafter, fed a standard solid diet until 42 days of age. Pancreas weight and the stock of pancreatic digestive enzymes in the hydrolysate-fed rats were significantly lower than those in the protein-fed rats during and also after the suckling period. Plasma insulin, a stimulator of amylase synthesis, was also significantly low in the hydrolysate-fed rats compared with the protein-fed rats. At 28 days of age, we evaluated the pancreatic secretory ability in response to dietary protein and cholecystokinin (CCK) by means of pancreatic duct cannulation. Pancreatic secretion stimulated by dietary protein in the hydrolysate-fed rats was significantly weaker than that in the protein-fed rats. No significant difference was observed in the increasing rate of pancreatic enzyme secretion in response to CCK between the two groups. These results suggest that the presence of large proteins in breast milk is significant for the development of pancreatic digestive functions and the outcomes could remain even later on in life.

Approach to suspected food allergy in atopic dermatitis. Guideline of the Task Force on Food Allergy of the German Society of Allergology and Clinical Immunology (DGAKI) and the Medical Association of German Allergologists (ADA) and the German Society of Pediatric Allergology (GPA)

The following guideline of the "Arbeitsgruppe Nahrungsmittelallergie der DGAKI" (Task Force on Food Allergy of the German Society of Allergology and Clinical Immunology) and the ADA ("Arzteverband Deutscher Allergologen", Medical Association of German Allergologists) and the GPA (German Society of Pediatric Allergology) summarizes the approach to be taken when food allergy is suspected in patients with atopic dermatitis (neurodermatitis, atopic eczema). The problem is clinically relevant because many patients assume that allergic reactions against foods are responsible for triggering or worsening their eczema. It is important to identify those patients who will benefit from an elimination diet but also to avoid unnecessary diets. Elimination diets (especially in early childhood) are associated with the risk of malnutrition and additional emotional stress for the patients. The gold standard for the diagnosis of food-dependent reactions is to perform placebo-controlled, double-blind oral food challenges because specific IgE, prick tests and history often do not correlate with clinical reactivity. This is particularly true in the case of delayed eczematous skin reactions. Diagnostic elimination diets should be used before an oral provocation test. If multiple sensitizations against foods are discovered in a patient, an oligoallergenic diet and a subsequent stepwise supplementation of the nutrition should be performed. If a specific food is suspected of triggering food allergy, oral provocation should be performed after a diagnostic elimination diet. As eczema-tous skin reactions may develop slowly (i. e. within one or two day), the skin be inspected the day after the provocation test and that a repetitive test be performed if the patient has not reacted to a given food on the first day of oral provocation. The guideline discusses various clinical situations for patients with atopic dermatitis to facilitate differentiated diagnostic procedures.

A method for in vitro evaluation of protein hydrolysates for potential inclusion in veterinary diets

A candidate chicken-protein hydrolysate was subjected to high-performance size-exclusion chromatography to characterize its molecular weight profile. An inhibition ELISA assay was developed to assess the residual antigenicity, using canine serum IgG produced by dogs sensitized to the intact protein. Finally, the hydrolysate was compared to the intact protein through electrophoresis and immunoblotting. The chicken hydrolysate had a suitable molecular weight profile with 96.9% reduced to less than 10 kDa peptides. The inhibition ELISA demonstrated a residual antigenic mass of 1.5% compared with the intact protein. Immunoblotting demonstrated a strong immunoreactive band at 68-70 kDa consistent with chicken serum albumin in the intact protein, which was absent in the hydrolysate. These results demonstrate the suitability of the chicken hydrolysate for use in a protein hydrolysate diet, and provide a basis for the future comparisons of the peptide components of hydrolyzed protein diets so that veterinarians may make more informed decisions in their dietary prescriptions.

[Protein hydrolysates: hypoallergenic milks and extensively hydrolyzed formulas. Immuno-allergic basis for their use in prevention and treatment of milk allergy]

Allergy to milk has an estimated incidence of 2.5%. Hypoallergenic milks are partial hydrolysates of proteins with lactose. Extensive hydrolysates of casein are mainly small peptides and do not include lactose in their formula. A primary allergenicity as well as a cross-sensitivity are shown for all partial hydrolysates. Even extensive hydrolysates have a weak potential of cross-allergy. The prevention of cow's milk allergy in infants at peculiar risk, born from atopic parents, is based on breast-feeding and/or partial or extensive hydrolysates. There is no conclusive evidence for the usefulness of eviction of dairy products during pregnancy or during the period of breast-feeding. The treatment needs exclusively extensive casein hydrolysates ensuring a 90% protection with 95% confidence intervals. Predictive prick tests in certain cases may help the choice of another hydrolysate. Severe cases with failure to thrive or multiple food intolerance require an amino-acid based formula (Neocate). A rational diversification of the diet is advised in order to prevent the onset of a multiple food intolerance syndrome which could avert from the recovery of cow milk allergy.

Detection of potentially allergenic material in 12 hydrolyzed milk formulas

Hypoallergenic milk formulas are used as an alternative diet for infants who have allergies to cow's milk when breast-feeding is not possible. These products are based on proteins, which have been heat-treated and hydrolyzed to a different degree in order to cleave antibody-binding structures. Even extensively hydrolyzed products have occasionally been observed to elicit allergic reactions in sensitized infants, however. Therefore, the parameters of relevance to allergenic potential require more investigation. The objective of the present study was to investigate 12 different hydrolyzed milk formulas for their contents of potentially allergenic protein material, i.e. material that may induce allergenicity or elicit allergic responses in already sensitized individuals. Analytical methods applied were gel filtration, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), native PAGE, immunoblotting, dot-immunobinding, and ELISA. Care was taken to assure that all protein fractions were investigated, including supernatants and precipitates following centrifugation of the milk formulas. By gel filtration, protein material with apparent molecular masses of 7 to >30 kDa was detected. Analysis by SDS-PAGE of formula precipitates showed that proteins with a molecular mass above 20 kDa were present even in some of the extensively hydrolyzed formulas. Residual antigenic beta-lactoglobulin was found by ELISA in all products. By immunoblotting and dot-immunobinding with antibodies against total whey, caseins, or Kunitz soybean trypsin inhibitor, we observed antigenic material mainly in partially hydrolyzed products. We concluded that SDS-PAGE of formula supernatants and precipitates gave the most differentiated profile of hydrolyzed formulas and that this method is well suited for screening potential allergenicity.

Prevention and management of food allergy

The phenotypic expression and natural history of food allergy vary widely according to the patient's age, disease presentation and type of offending food. Prevention of food allergy might be achieved by altering the dietary factors responsible for the sensitization and phenotypic expression of the disease. Owing to the peculiarity of the atopic status, a minute amount of allergens can trigger both sensitization and symptoms in atopic individuals. The oral dose of beta-lactoglobulin causing sensitization can be estimated to be between 1 ng and several milligrams. In food allergy, sensitization and treatment are allergen specific; therefore, for primary prevention (avoiding sensitization) and secondary prevention of food allergy (avoiding symptoms in an already sensitized subject), a product without immunogenic and allergenic epitopes should be given in each case. Babies of atopic parents are particularly prone to develop food allergy and for this reason they are called high-risk babies. Cow's milk is the most commonly offending food in both gastrointestinal and cutaneous manifestations. Cow's milk proteins are potent allergens and around 2.5% of infants experience cow's milk allergy in the first years of life. The major risk factors for cow's milk allergy are positive family history of atopy and early exposure to cow's milk proteins. Hydrolysate formulae have been developed for the purpose of reducing the allergenicity of cow's milk proteins. More recently, partially and extensively hydrolysed formulae have also been used for feeding babies with a high risk of atopy for the prevention of cow's milk allergy. However, according to the results of a recent randomized controlled study, only an extensively hydrolysated formula, and not a partially hydrolysated formula, significantly decreased the prevalence of cow's milk allergy.

Evaluation of the impact of food technology on the allergenicity of cow's milk proteins

The quantitative evaluation of the allergenicity of food proteins and the clinical tolerance towards antigens are problems the food industry and the clinicians have to face. The allergenicity of a protein depends on multiple factors, including the stability to digestion and the interaction with the intestinal environment. In addition to the possible reduction in allergenicity by technological treatments such as heat and enzymic hydrolysis, the complex interactions existing between the antigens, the intestinal epithelium and the underlying immune system, as well as the individual susceptibility to the sensitizing epitopes, have to be taken into account. Indeed, the intestinal cells are able to take up and process proteins, and possibly to present them directly to mucosal lymphocytes. On the other hand, pathophysiological conditions can modify the interactions between food antigens and the immune system. A large number of methods has been developed to assess the residual antigenicity of food proteins, based on the various immune responses leading to intestinal or extradigestive pathologies. Thus, the difficulty in measuring the residual allergenicity of hypoallergenic formulas is partly due to the physiology of the gastrointestinal tract, since an intricate network of interactions between enterocytes and immune cells governs the development of the immune response to food antigens.

Special formulas in infant nutrition: a review

Special formulas should only be used by medical prescription and for those lactating infants with diagnosed nutritional problems. Lactose-free formulas or those based on soy are the logical choice when the exclusion of lactose from the diet is considered necessary. At present, there is no concensus on the appropriateness of soy formulas for the treatment and prevention of nutritional allergies and current opinion seems to favour hydrolyzed protein formulas. High-degree protein hydrolysate formulas are used to treat lactating infants with an allergy to cow milk proteins or with serious nutritional problems. These formulas are not without risk, as they may contain residual epitopes capable of provoking a severe allergic reaction. Before using these formulas, allergenicity tests should be performed, particularly for highly sensitive infants. The unpleasant taste and high cost of these formulas, in addition to possible nutritional problems, limit their use in the prevention of atopic disease, although their efficacy is well established. Partially protein hydrolysate formulas are only used for preventive purposes and are not suitable for lactating infants with a proven allergy to cow milk. Although these formulas can reduce the incidence or delay the appearance of certain atopic symptoms, they have not been shown to prevent IgE-mediated allergic reactions to cow's milk and so their effectiveness is open to question.

[Nutritional physiology of whey and whey components]

Deriving from positive effects of whey drinking cures in antiquity, the Middle Ages and modern time, a review is given on nutritional significance of whey. The proteins are essential components of whey and belong to the proteins with highest biological value because of their amino acid composition. Besides, they show fundamental functional properties, which enable a varied application in foods, dietetic foods and beverages in form of different whey products (powder, protein concentrates and isolates). Whey proteins have found considerable usage in infant's nutrition as whey predominant formulas as well as whey protein hydrolysates in case of cow's milk protein intolerances. A recent field of research are biological active peptide sequences which become effective during digestion and are of importance for secretion of entero hormones as well as for immune enhancing effects. They may contribute to assess the biological value of whey proteins under enlarged points of view and to develop new application forms and areas. It is pointed to further fields of application (e.g. adipositas, gout, kidney insufficiency). Concerning the quantitatively most dominant lactose in whey, it is dealt with its importance for the healthy development of infants (adaptation to the increased lactose content of mother's milk) as well as with lactose intolerance and galactosaemia. In case of mineral salts of whey it is emphasized the high nutrient density of calcium (prophylaxis for osteoporosis), the beneficial Ca:P and Na:K proportions (antihypertensive in case of the last one), the promotion of absorption of mineral salts by lactose, and the high content of iodine. The whey is rich in B-vitamins, which contribute essentially for their satisfaction or requirement in case of a corresponding consumption. To be emphasized is the vitamin B12 in milk and whey, which is the sole source of this indispensable nutrient for blood-formation and cell division in lacto-ovo-vegetarian nutrition. In conclusion, a summarizing dietetics valuation of whey is performed.

Ten steps to successful breastfeeding: a summary of the rationale and scientific evidence

Ample evidence is available on the impact of health care practices and hospital routines and procedures on breastfeeding. Good practices enhance successful initiation and establishment of breastfeeding and contribute to increased duration, just as inappropriate practices, and failure to support and encourage mothers, have the opposite effect. In 1991 the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) jointly launched the Baby-Friendly Hospital Initiative, which aims to give every baby the best start in life by ensuring a health care environment where breastfeeding is the norm. The initiative is based on the principles summarized in a joint statement issued by the two organizations in 1989 on the role of maternity services in protecting, promoting, and supporting breastfeeding. To become truly baby-friendly, hospitals and maternity wards around the world are giving practical effect to the principles described in the joint WHO/UNICEF statement that have been synthesized into Ten Steps To Successful Breastfeeding. This summary of the rationale and scientific basis for the Ten Steps is presented in the light of cumulative experience demonstrating the crucial importance of these principles for the successful initiation and establishment of breastfeeding.

Effects of a dietary and environmental prevention programme on the incidence of allergic symptoms in high atopic risk infants: three years' follow-up

A prospective case-control study is presented to assess an allergy prevention programme in children up to 36 months of age. Infants born at three maternity hospitals were followed from birth: 279 infants with high atopic risk (intervention group) were compared with 80 infants with similar atopic risk but no intervention (non-intervention group). The intervention programme included dietary measures (exclusive and prolonged milk feeding diet followed by a hypoantigenic weaning diet) and environmental measures (avoidance of parental smoking in the presence of the babies, day care > 2 years of life). Mothers in this group who had insufficient breast milk were randomly assigned to one of two coded formulas: either a hydrolysed milk formula (Nidina HA, Nestlé) or a conventional adapted formula (Nan, Nestlé). Other environmental measures remained the same as for the breastfeeding mothers. The non-intervention group were either breastfed or received the usual Italian milk feeding and weaning diet, without environmental advice. The main outcome measures were anthropometric measurements and allergic disease manifestations. Normal anthropometric data were observed both in the intervention group and in the non-intervention group. The incidence of allergic manifestations was much lower in the intervention group than in the non-intervention group at 1 year (11.5 versus 54.4%, respectively) and at 2 years (14.9 versus 65.6%) and 3 years (20.6 versus 74.1%). Atopic dermatitis and recurrent wheezing were found in both the intervention group and the non-intervention group from birth up to the second year of life, while urticaria and gastrointestinal disorders were only present in the non-intervention group in the first year of life. Conjunctivitis and rhinitis were present after the second year in both the intervention group and the non-intervention group. Relapse of the same allergic symptom was less in the intervention group (13.0%) than in the non-intervention group (36.9%). In comparison to the non-intervention group, there were fewer intervention group cases with two or more different allergic symptoms (8.7 versus 32.6%), and they were more likely to avoid steroid treatment (0 versus 10.8%) and hospital admission (0 versus 6.5%). Babies in the non-intervention group fed with adapted formula were more likely to develop allergies than breastfed babies in the same group. In the intervention group the breastfed infants had the lowest incidence of allergic symptoms, followed by the infants fed the hydrolysed formula (ns). Infants in the intervention group fed the adapted formula had significantly more allergies than the breastfed and hydrolysed milk fed infants, although less than their counterparts in the non-intervention group. Of the affected subjects in the intervention group, 80.4% were RAST and/or Prick positive to food or inhalant allergens. Total serum IgE values detected at birth in the intervention group were not predictive, but at 1 and 2 years of age, IgE values more than 2 SD above the mean in asymptomatic babies were found to predictive for later allergy. In breastfed babies the total IgE level at 1 and 2 years of age was lower than in the other two feeding groups. Of the various factors tested in the non-intervention group, the following were the most important in the pathogenesis of allergic symptoms: (i) formula implementation begun in the first week of life; (ii) early weaning (< 4 months); (iii) feeding beef (< 6 months); (iv) early introduction of cow's milk (< 6 months); and (v) parental smoking in the presence of the babies and early day care admission (< 2 years of life). All the preventive measures used in this study (exclusive breastfeeding and/or hydrolysed milk feeding, delayed and selective introduction of solid foods, and environmental advice) were effective at the third year of follow-up, greatly reducing allergic manifestations in high atopic risk babies in comparison with those not receiving these interventions