Phosphorylation reduces the allergenicity of cow casein in children with selective allergy to goat and sheep milk.

This study aimed to characterize the role of phosphorylation of caseins in selective allergy to goat milk (GM) and sheep milk (SM) in patients with good tolerance to cow milk (CM). We performed skin prick tests with milk and caseins from CM, GM, and SM and immunoblotting and specific immunoglobulin (Ig) E determinations with milk and casein from cow and GM and SM. Sensitization to milk and caseins from goat and sheep was demonstrated in all 3 patients by skin tests, determination of specific IgE, or both. Immunoblotting confirmed that GM/SM proteins but not CM proteins were involved in the allergic symptoms. IgE reacted with several protein bands from the caseins and milk extracts of both sheep and goat. Phosphorylation was involved in the different allergenicity of CM caseins. We report the implication of phosphorylation in the allergenicity of caseins involved in selective allergy to GM and SM.

Eliciting doses of positive challenge test in cow's milk allergy are related to cow's milk specific IgE levels.

BACKGROUND: Ingestion of small amounts of cow's milk (CM) can elicit adverse reactions in patients with IgE-mediated CM allergy. Knowing the dose eliciting allergic reactions and the factors affecting it can be of great help in avoiding these reactions. OBJECTIVE: To analyse the eliciting doses of positive challenge test in patients with CM allergy and to determine its association with the level of CM specific IgE. METHODS: Ninety-eight positive challenge tests in 56 children, median age of 11 months (3-80) with IgE-mediated CM allergy were retrospectively analysed. Open oral challenge tests were carried out by gradually increasing doses of milk (2-100 ml). The relationship between challenge test doses and CM specific IgE levels were studied. RESULTS: 18 % of the challenge tests were positive with 2 ml, 24 % with doses between 5 and 10 ml, and the other 58 % with doses between 25 and 100 ml. An inverse association between the doses of the positive challenge test and the level of CM specific- IgE was found, 13.9 kU/L (0.54-> 100 kU/L) when the challenge test was positive with the smaller dose (2 ml); and 1.73 kU/L (< 0.35-76.4 kU/L) with doses above 2 ml (p = 0.0001). The median age of the patients was 13 months (6-49) when the challenge test was positive with 2 ml vs 9 months (3-80) with doses above 2 ml (p = 0.048). CONCLUSION: The CM specific IgE level and patient's age should be considered in the assessment of the eliciting doses of positive challenge test in CM allergy.

[Food allergy in children. II. Prognostic factors and long-term development]. / Alergia a alimentos en el niño. II. Factores pronósticos y evolución a largo plazo.

The evolution of 109 allergic children with 129 IgE-mediated food sensitizations has been evaluated. The follow-up period was from nine months to 14 years. The period up to clinical tolerance was analyzed, together with the influence of two possible prognostic factors: specific IgE antibody levels at the beginning of symptomatology and the sensitizing food. Moreover, when clinical tolerance was achieved, the presence of specific IgE antibodies was again assessed. Probability estimations indicated that 30% of food-allergic children become clinically tolerant before 3 years of evolution, 40% before 6 years, 50% before 9 years and 53% before 12 years. Onset of clinical tolerance varies in dependence with the offending food: clinical tolerance to cow's milk seems to be far earlier and easier to reach than those to egg and fish (p less than 0.001, at 9 years' evolution); allergy to egg disappears also earlier and easier than fish allergy (p less than 0.01). Levels of specific IgE antibodies at the onset of the disease show significant difference (p less than 0.01) between the patients which will become tolerant and those with persistence of clinical sensitivity, being higher in the last group. However, a high number of patients who become clinically tolerant (67.5%) remained positive at skin prick testing or had elevated specific IgE serum antibodies against the offending food.

[Food allergy in children. I. Clinical aspects and diagnosis]. / Alergia a alimentos en el niño. I. Clínica y diagnóstico.

Two hundred and thirty children with suspected food allergy have been reviewed retrospectively. One hundred and nine fulfilled the following three selection criteria: suggestive anamnesis, presence of specific IgE antibodies (in serum or by skin prick test), and having been reassessed at least once. The major clinical data analyzed were: age of onset, sensitising foods, symptomatology and diagnostic procedures. The results show a mean age of onset for food allergy of 11.5 months, with variations related to the sensitizing food, cow's milk allergy being the earliest in onset time. The most frequent sensitizing foods in this group of patients were eggs, fish and cow's milk. The skin and the gastrointestinal tract have been the most affected shock organs, both together or isolated; respiratory symptoms were an uncommon finding and their isolated presentation as the sole manifestation of food allergy exceptional. The skin prick tests were positive in 99.2 percent of the sensitizations and in 84 percent high levels of specific IgE antibodies were found. Food allergy seems to be a common situation in children, clinical symptomatology is similar to that of the other atopic diseases and the diagnosis is based on the demonstration of specific IgE antibodies against the sensitizing foods.