Appearance of atopic disease in relation to serum IgE antibodies in children followed up from birth for 4 to 15 years

The allergy march: from food to pollen

There is epidemiological evidence, especially from longitudinal studies, that clinical manifestations of atopy as well as IgE antibodies against food and aeroallergens show a systematic sequence of events. The atopic march begins with food allergy associated gastrointestinal disorders and atopic dermatitis followed by respiratory allergies, i.e. asthma and atopic rhino-conjunctivitis. Detectable food antibodies, especially against egg and milk proteins, usually precede or accompany the early clinical symptoms and signs. Similarly, aeroallergen sensitization, first against indoor allergen antibodies, succeeded by outdoor allergen antibodies, precede the clinical manifestation of respiratory allergy. Early atopic events, either manifestation or sensitization can be used as risk markers or even predictors of atopic disorders to implement preventive measures. Early atopic dermatitis as well as elevated serum IgE antibodies against food allergens in the first two years of life in combination with a family history can be used as a predictor for aeroallergen sensitization.

Sensitization to hen's egg at the age of twelve months is predictive for allergic sensitization to common indoor and outdoor allergens at the age of three years

BACKGROUND

Specific predictors for atopic sensitization in early infancy are prerequisites for preventive intervention studies.

OBJECTIVE

To identify predictors of allergic sensitization to common aeroallergens in infancy, 1314 children in five German cities were followed up from birth (1990) to the age of 3 years.

METHODS

Blood samples were taken from cord blood and at follow-up visits at the ages of 1, 2, and 3 years. Total serum IgE and specific IgE antibodies to common food and inhalant allergens were determined.

RESULTS

Among our study population, risk factors for sensitization to indoor and/or outdoor allergens at the age of 3 years were a positive family history, the presence of hen's egg-specific IgE antibodies (> or = 0.35 kU/L), and increased log- [total IgE] levels at the age of 12 months. Elevated cord blood IgE was not associated with sensitization to inhalant allergens at the age of 3 years. Egg-specific IgE greater than 2 kU/L in combination with a positive family history of atopy was a highly specific (specificity, 99%) and predictive (positive predictive value, 78%) marker for sensitization to inhalant allergens at 3 years of age.

CONCLUSIONS

Hen's egg-specific IgE at the age of 12 months is a valuable marker for subsequent allergic sensitization to allergens that cause asthma, allergic rhinitis, and atopic dermatitis.

Season of birth as predictor of atopic manifestations

The relation between month of birth, sensitisation, and manifestations of atopy was assessed in 209 children who were followed from birth to 12-15 years. Children born during the tree pollen season were less likely to develop allergic rhinoconjunctivitis, IgE antibodies to pollen, or a positive screening test for IgE antibodies (odds ratio 0.28, 0.41, 0.35, respectively) than children born during the rest of the year. The prevalence of IgE antibodies to food and animal dander at 9 months and to atopic disease was higher in children born in the autumn and winter, that is, September to February, compared to the spring and summer (egg 20% v 6%; milk 10% v 2%). Thus sensitisation to pollen and allergic rhinoconjunctivitis is least common in children born in the spring, while birth in September to February is associated with an increased incidence of sensitisation to food and of atopic disease.

Immunogenicity and antigenicity of a partially hydrolyzed cow's milk infant formula

We evaluated the immunogenicity and antigenicity of a formula based on partially hydrolyzed cow's milk whey protein in infants at risk of atopy and in controls. Total IgE and specific IgE, IgG, and IgG4 subclass antibodies against egg albumin and cow's milk alpha-lactalbumin, casein, and beta-lactoglobulin were measured by radioimmunoassay of cord blood and of peripheral blood at 5 days and 6 months of life in five groups of infants: 16 breast-fed infants at risk of atopy (group 1), 21 partially hydrolyzed whey formula-fed infants at risk of atopy (group 2), 14 formula-fed infants at risk of atopy (group 3), 10 breast-fed control infants (group 4), and 13 formula-fed control infants (group 5). Total IgE concentration was significantly lower in group 2 at 6 months than in groups 3 and 5 infants and similar to that observed in groups 1 and 4 infants. The concentration of specific antiegg and anti-cow's milk protein IgG and of specific anti-cow's milk alpha-lactalbumin and beta-lactoglobulin IgG4 subclass antibodies was significantly reduced in group 2 as compared to group 3 infants and similar to that found in breast-fed infants. In conclusion, the partially hydrolyzed formula was less immunogenic and antigenic than a traditional formula and was as immunogenic and antigenic as breast milk.

IgE and mast cell response on intestinal allergen exposure: a murine model to study the onset of food allergy

OBJECTIVE

Allergic reactions to food are characterized by enhanced allergen-specific IgE serum levels and the activation of intestinal mast cells. Here we describe a murine model for the onset of food allergy and the role of cytokines in the regulation of food-induced IgE responses.

METHODS

Mice were primed systemically with low doses of alum-precipitated ovalbumin. Subsequent intragastric challenge led to enhanced sensitization.

RESULTS

Compared with baseline ovalbumin-specific IgE levels before challenge (0.23 +/- 0.06 optical density [OD] units), ovalbumin-challenged mice showed significantly elevated IgE levels (0.86 +/- 0.23 OD units) after intragastric challenge, which were not observed in control animals (0.29 +/- 0.06 OD units). IgE levels mirrored intestinal mast cell activation, measured by decreased histamine levels in duodenal specimens, in ovalbumin-challenged mice (92.6 +/- 7.9 ng/0.1 gm tissue weight) but not in saline-challenged mice (135.4 +/- 18.3 ng/0.1 gm tissue weight), compared with baseline levels (141.1 +/- 4.1 ng/0.1 gm tissue weight). Changes in IgE and histamine levels after intragastric challenge could be blocked by treating the animals with neutralizing antibodies against IL-4 or IL-10. Although it is generally accepted that ingestion of food allergens leads to a state of immunologic unresponsiveness (i.e., oral tolerance), it is shown here that low-dose systemic priming followed by intragastric challenge leads to sensitization instead of unresponsiveness.

CONCLUSIONS

Our murine model shows an important correlation between TH2 cytokines, IgE production, and histamine release. Hence, this in vivo model provides a useful tool with which the complex mechanism underlying sensitization to food allergens can be studied.

Development of immune functions related to allergic mechanisms in young children

The newborn immune system differs quantitatively and functionally from that of adults. Development of the immune system has important implications for childhood diseases. The immaturity of the immune system in the first years of life may contribute to failure of tolerance induction and in the development of allergic disease. T cell function is diminished, especially the capacity to produce cytokines; production of interferon (IFN)-gamma, and IL-4 is strongly reduced. IFN-gamma has been found to be even lower in cord blood of newborns with a family history of atopy. Differences in other cell types (natural killer cells, antigen-presenting cells, and B cells) could also play a role in the development of allergic disease. Current data suggest that irregularities in IgE synthesis, helper T cell subsets (Th1, Th2, CD45RA, and CD45RO), cytokines (IL-4, IFN-gamma), and possibly other cell types may play a role in the development of allergy in childhood. Moreover, the role of cell surface molecules, like co-stimulatory molecules (CD28, CD40L), activation markers (CD25), and adhesion molecules (LFA-1/ICAM-1, VLA-4/ VCAM-1) is also discussed. These variables are modulated by genetic (relevant loci are identified on chromosome 5q, 11q, and 14) and environmental forces (allergen exposure, viral infections, and smoke). The low sensitivity of current predictive factors for the development of allergic diseases, such as cord blood IgE levels, improves in combination with family history and by measurement of in vitro responses of lymphocytes and skin reactivity to allergens. New therapeutic approaches are being considered on the basis of our current understanding of the immunopathology of allergic disease, for instance cytokine therapy and vaccination with tolerizing doses of allergen or peptides.

Atopic dermatitis: an update

This review focuses on recent literature regarding the following clinical features of atopic dermatitis (AD); diagnostic criteria, epidemiology and genetics, provocative factors, predictors of disease development and markers of disease severity, therapy, and prognosis. For example, the frequency of AD appears to be increasing, perhaps in response to provocative factors such as food allergens and house dust mites. Determination of reliable markers for disease development may identify susceptible newborns and facilitate avoidance of relevant triggers. Immunomodulating therapy holds promise in the treatment of refractory AD, and new investigation has led to refinements in conventional modalities such as antihistamines and phototherapy.

Early detection of specific IgE antibody against house dust mite in children at risk of allergic disease

OBJECTIVES

House dust mite (HDM) is a representative inhalant allergen that triggers allergic disease in childhood. The aim of this study is early detection of HDM-specific IgE antibody and prediction of the risk of a positive reaction to this antibody by in vitro parameters in infants with allergic manifestations.

STUDY DESIGN

Levels of HDM IgE in a range below the standard cutoff point of 0.35 U/ml, serum concentrations of IgE, and specific IgE antibodies against egg white, cow milk, and soybeans were determined in 108 infants with allergic manifestations at 6 months of age, and these infants were monitored for conversion of HDM IgE to positive levels greater than 0.35 U/ml up to 5 years of age. The presence of active allergic disease at 5 years of age in relation to HDM-specific IgE was also examined.

RESULTS

We were able to determine reliably the HDM IgE values between 0.23 and 0.35 U/ml, using a fluorescent enzyme immunoassay that measured the intensity of fluorescence. The HDM IgE levels increased, resulting in positive values, in 54 of 108 subjects during the first 5 years of life. In multiple regression analysis, an HDM IgE value between 0.23 and 0.35 U/ml, a high serum IgE level, and a positive reaction to specific IgE antibody against egg white in infants at 6 months of age proved to be significant predictors of the future positive reaction to HDM IgE (p = 0.0006, 0.0043, and 0.0001). In particular, the sensitivity and specificity of specific IgE antibody against egg white for the conversion of HDM IgE to positive values were the best among these indicators. Moreover, active allergic diseases were observed significantly more often in children with positive HDM IgE values than in children with negative HDM IgE values at 5 years of age (p < 0.001 for each).

CONCLUSIONS

A determination of these predictors in infants at 6 months of age can be used for early detection of HDM IgE and would be valuable in a screening test for later allergic disease among infants with allergic manifestations.

Intestinal inflammation in children with atopic eczema: faecal eosinophil cationic protein and tumour necrosis factor-alpha as non-invasive indicators of food allergy

BACKGROUND

Food allergy is contemplated in atopic eczema. Early recognition of food allergies is difficult and the diagnosis is often missed because of the non-specificity of symptoms. New non-invasive tests are clearly needed.

OBJECTIVE AND METHODS

We measured the concentrations of tumour necrosis factor-alpha, eosinophil cationic protein and alpha-1 antitrypsin in faeces as indicators of intestinal inflammation induced by double-blind placebo-controlled oral cow's milk challenge in infants and young children with atopic eczema.

RESULTS

An increased alpha-1 antitrypsin concentration (> 2 mg/g) after cow's milk challenge was detected in 43% of the infants positive as compared with 11% of the infants negative to challenge, P = 0.02. The concentration of eosinophil cationic protein in faeces increased after cow's milk challenge in patients positive to challenge (P = 0.02) but not in those negative to challenge (P = 0.79). The concentration of eosinophil cationic protein was enhanced particularly in patients manifesting immediate-type reactions to the cow's milk challenge. The concentration of tumour necrosis factor-alpha increased after cow's milk challenge in patients positive to challenge (P = 0.005) but not in those negative to challenge (P = 0.25). The concentration of tumour necrosis factor-alpha in faeces was enhanced particularly in patients manifesting delayed-type reactions to the cow's milk challenge.

CONCLUSION

We conclude that in children with atopic eczema food allergy is associated with intestinal inflammation indicating that more general immunologic disturbances than previously thought take place in these patients. We further suggest that faecal eosinophil cationic protein, tumour necrosis factor-alpha and alpha-1 antitrypsin distinctly indicate various reaction types of food allergy. Parallel testing with eosinophil cationic protein and tumour necrosis factor-alpha may significantly enhance the accuracy in diagnosis of food allergy in patients with atopic eczema.