Prevention and management of food allergy

Cow's Milk Protein Allergy in Term and Preterm Infants: Clinical Manifestations, Immunologic Pathophysiology, and Management Strategies

Cow's milk allergy is a common food allergy among infants. Symptoms of cow's milk allergy are wide-ranging and depend on the mechanism involved. There are immunoglobulin E (IgE)-mediated, non-IgE-mediated, and mixed mechanisms of food allergy. Symptoms of IgE-mediated cow's milk allergy may be mild or may progress to anaphylaxis, which can be life-threatening. Non-IgE-mediated allergy includes food protein-induced allergic proctocolitis (FPIAP), food protein-induced enterocolitis syndrome, food protein-induced enteropathy, and Heiner syndrome (pulmonary hemosiderosis). These diagnoses comprise about half of all cow's milk allergies. The most common manifestation of cow's milk allergy in infants is FPIAP. FPIAP is commonly seen in healthy, full-term infants who present with rectal bleeding and are otherwise well-appearing. This can occur in both formula-fed and exclusively breastfed infants. Food proteins secreted in maternal breast milk can contribute to the development of these symptoms. Maternal cow's milk elimination diet is often successful in helping resolve symptoms. A period of reintroduction of cow's milk resulting in re-emergence of symptoms in stable asymptomatic infants is an excellent diagnostic tool to confirm a cow's milk allergy. Preterm infants are susceptible to food allergy, as demonstrated from several case reports of necrotizing enterocolitis-like illnesses that responded clinically to cow's milk elimination. Further study is needed about food allergy in the preterm infant population.

Reduced IgE and IgG antigenic response to milk proteins hydrolysates obtained with the use of non-commercial serine protease from Yarrowia lipolytica

The aim of the study was to investigate the use of serine protease from Yarrowia lipolytica yeast for reduction of milk proteins allergenicity. Whey protein concentrate (WPC-80), αs-casein and their hydrolysates were analyzed for the capacity to bind IgE and IgG antibodies present in sera from patients with cow milk protein allergy using a competitive ELISA. The hydrolysis of αs-casein and whey protein concentrate contributed to a significant reduction of their immunoreactive epitopes. In case of IgE antibodies, the lowest binding capacity was detected in the 24 h hydrolysates of both proteins in which the inhibition of the reaction was ≤20 and ≤68% for αs-casein and whey protein concentrate respectively. One hour hydrolysis of WPC-80 reduced the protein antigenicity, while the longer time (5 h) might lead to the exposure of new IgE - reactive epitopes.

Hydrolysis with Cucurbita ficifolia serine protease reduces antigenic response to bovine whey protein concentrate and αs-casein

In the present study the effect of hydrolysis with non-commercial Cucurbita ficifolia serine protease on a reduction of the IgE and IgG binding capacity of whey protein concentrate and αs-casein was investigated. The intensity of the protein degradation was analyzed by the degree of hydrolysis, the free amino groups content and RP-HPLC. The ability to bind the antibodies by native proteins and their hydrolysates was determined using a competitive ELISA test. Deep hydrolysis contributed to a significant reduction of immunoreactive epitopes present in WPC. In the case of IgE and IgG present in the serum pool of children with CMA, the lowest binding capacity was detected in the 24 h WPC hydrolysate, where the inhibition of the reaction with native WPC was ≤23 and ≤60 %, respectively. The analysis of the IgG reactivity in the antiserum of the immunized goat showed that the lowest antibody binding capacity was exhibited also by 24 h WPC hydrolysate at a concentration of 1000 μg/ml where the inhibition of the reaction with nWPC was ≤47 %. One-hour hydrolysis of α-casein was sufficient to significant reduction of the protein antigenicity, while the longer time (5 h) of hydrolysis probably lead to the appearance of new epitopes reactive with polyclonal.

Milk processing as a tool to reduce cow's milk allergenicity: a mini-review

Milk processing technologies for the control of cow’s milk protein allergens are reviewed in this paper. Cow’s milk is a high nutritious food; however, it is also one of the most common food allergens. The major allergens from cow’s milk have been found to be β-lactoglobulin, α-lactalbumin and caseins. Strategies for destroying or modifying these allergens to eliminate milk allergy are being sought by scientists all over the world. In this paper, the main processing technologies used to prevent and eliminate cow’s milk allergy are presented and discussed, including heat treatment, glycation reaction, high pressure, enzymatic hydrolysis and lactic acid fermentation. Additionally, how regulating and optimizing the processing conditions can help reduce cow’s milk protein allergenicity is being investigated. These strategies should provide valuable support for the development of hypoallergenic milk products in the future.

Effect of ingestion of cow's milk protein hydrolysate formulas on alpha-casein-specific immunoglobulin E and G1 antibody responses in naïve and sensitized mice

OBJECTIVES

Cow's milk protein hydrolysate formulas are widely used for genetically predisposed atopic infants. Whether hydrolysate formulas can induce oral tolerance to alpha-casein was studied for the first time in naive and sensitized mice.

METHODS

Using immunoblotting, residual antigenicity to alpha-casein was examined for in animals fed hydrolysate formulas. Naïve mice fed hydrolysate formulas for 1 to 4 weeks were later sensitized with alpha-casein. Another group of mice sensitized first with alpha-casein were then fed hydrolysate formulas continually for 12 weeks.

RESULTS

Oral tolerance measured by immunoglobulin (Ig)E and IgG1 antibody responses to alpha-casein was induced in naïve mice fed NAN for 1 week or NAN-HA for 4 weeks. IgE responses to alpha-casein were suppressed in mice fed NAN-HA for 1 week or Neoangelac FL for 4 weeks. In contrast, mice fed Alfare, Pepti-Junior, or Pregestimil for 1 to 4 weeks did not develop tolerance to alpha-casein. Antibody responses to alpha-casein were not significantly suppressed in sensitized mice fed NAN or hydrolysate formulas for 12 weeks.

CONCLUSIONS

Primary IgE responses to alpha-casein are readily suppressed in naïve mice first fed cow's milk formula or partially hydrolyzed formula for 1 week. Conversely, ongoing IgE, IgG1, and IgG antibody responses to alpha-casein are poorly suppressed in previously sensitized mice even after prolonged feeding of cow's milk formula or hydrolysate formulas.

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.

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.

Primary dietary prevention of food allergy

OBJECTIVE

To present research and clinical evidence on the use of primary dietary prevention in food allergy management.

DATA SOURCES

We conducted MEDLINE searches for pertinent articles published between January 1986 and October 2001 with use of the following keywords or phrases: prevention and diet and allergy, food allergy and prevention, and dietary prevention and food allergy or allergens. Also included are information and commentary reflecting the authors' cumulative clinical experience in an allergy unit of a city hospital.

RESULTS

We define as "proactive" those strategies centered on "success factors," such as the early postnatal environment, prolonged breast-feeding, and use of formula and probiotic supplementation, in contrast to earlier "prohibitionist" approaches to prevention of food allergy. These two approaches are not antagonistic and may even be synergistic. We introduce this distinction in light of epidemiologic evidence and out of concern about compliance and the quality of life for patients.

CONCLUSIONS

Inasmuch as nutritional and immune maturation are implicated, the prohibitionist measures that are most effective in primary prevention of food allergy are exclusive breast-feeding for at least 6 months (for lifelong immunity and other benefits), delayed (after the sixth month) introduction of solid foods, and on-indication use of "hypoallergenic" formulas. Whether proactive strategies can be contemplated remains a debatable issue. Evidence for and against the scientific use of probiotics as well as microbiologic, epidemiologic, and clinical data are discussed. Review of published epidemiologic studies and randomized clinical trials is essential before planning dietary intervention or prevention.

[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.