Cow's milk-specific immunoglobulin E levels as predictors of clinical reactivity in the follow-up of the cow's milk allergy infants.

BACKGROUND: IgE-mediated cow's milk proteins (CMPs) allergy shows a tendency to disappear with age. The sooner tolerance is detected, the earlier the substitute diets can be suspended and the quicker family emotional hardship is alleviated. OBJECTIVE: To analyse the specific IgE levels to cow's milk and its proteins, which help to separate tolerant from no tolerant children in the follow-up of infants with allergy to cow's milk. PATIENTS AND METHODS: Sixty-six infants diagnosed with IgE-mediated allergy to CMPs were included in this prospective follow-up study. Periodic reassessments were carried out every 6 months until they were 2-years old and then, annually, until tolerance arose or until the last reassessment in which tolerance had not been achieved. Non-tolerant infants were followed, at least, for a period of 3 years. In each visit, the same skin tests and determination of specific IgE (CAP System FEIA) for milk and its proteins were carried out. The open challenge test was repeated unless a clear transgression to milk, which came to be positive, had taken place within the previous 3 months in each of the follow-up visits. Specific IgE levels to milk and its proteins, in different moments of the follow-up were analysed by means of the receiver-operating characteristic curve to predict clinical reactivity. RESULTS: Throughout the follow-up 45 (68%) infants became tolerant. The follow-up mean for tolerant infants was 21.2 months whereas for non-tolerant infants it was 58 months. The specific IgE levels which were predictors of the clinical reactivity (positive predictive value (PPV)> or =90%), grew as the age of the infants increased: 1.5, 6 and 14 kU(A)/L for milk in the age range 13-18 and 19-24 months and in the third year, respectively. Specific IgE levels to casein: 0.6, 3 and 5 kU(A)/L, respectively, predicted clinical reactivity (PPV> or =90%) in the different analysed moments of the follow-up. The cut-off points: 2.7, 9 and 24 kU(A)/L for milk and 2, 4.2 and 9 kU(A)/L for casein, respectively, predicted clinical reactivity with an accuracy > or =95% corresponding to a specificity of 90%. CONCLUSIONS: Monitorization of specific IgE concentration for milk and casein by means of the CAP system in allergic children to CMPs allows us to predict, to a high degree of probability, clinical reactivity. Age factor must be taken into account to evaluate the specific IgE levels which are predictors of tolerance or clinical reactivity.

[Incidence of allergy to cow's milk protein in the first year of life and its effect on consumption of hydrolyzed formulae]. / Incidencia de alergia a proteínas de leche de vaca en el primer año de vida y su repercusión en el consumo de hidrolizados.

OBJECTIVES: The aims of this study were to determine the incidence of allergy to cow's milk protein in infants and the cost of treatment with hydrolyzed formulae in the Autonomous Community of Madrid. PATIENTS AND METHODS: Infants with suspected adverse reaction to cow's milk protein born between March 1, 2000 and February 28, 2001 within the catchment area covered by the pediatric services of Hospital La Paz were studied. The diagnostic algorithm of allergy to cow's milk protein of our department was used. The theoretical consumption of hydrolyzed formulae in the treatment of allergic infants was calculated and extrapolated to the Community of Madrid. RESULTS: There were 5367 live births in the above-mentioned catchment area. Adverse reaction to cow's milk protein was suspected in 185 infants. Allergy to cow's milk protein was confirmed in 101 (54 %). The incidence of allergy to cow's milk protein was 101/5356 (1.9 %). In the same period there were 57 078 live births in the Autonomous Community of Madrid. The number of infants that might be allergic in one year would be 1084. The cost of hydrolyzed formulae per infant and year would be 1,585.72 Euros. Thus, the cost of hydrolyzed formulae in the 1084 allergic infants would be 1,718,922.9 Euros; in the 923 in whom allergy was ruled out, the cost would be 1,463,621.8 Euros. CONCLUSIONS: The incidence of allergy to cow's milk protein in the first year of life is at least 1.9 %. The correct diagnosis allows us to rule out allergy to cow's milk protein in almost half of the cases, thus avoiding the use of unnecessary substitutive diets involving a high cost.

Incidencia de alergia a proteínas de leche de vaca en el primer año de vida y su repercusión en el consumo de hidrolizados / Iincidence of allergy to cow's milk protein in the first year of life and its effect on consumption of hydrolyzed formulae

Objetivos: Cálculo de la incidencia de alergia a proteínas de leche de vaca (APLV) en el lactante y coste del tratamiento con hidrolizados de leche de vaca en la comunidad de Madrid. Pacientes y métodos Lactantes con sospecha de APLV nacidos entre el 1 de marzo de 2000 y el 28 de febrero de 2001 en el Hospital La Paz pertenecientes a las áreas que atiende el Hospital Infantil. Se les aplicó el algoritmo diagnóstico de APLV del servicio. Se realizó el cálculo teórico del consumo de hidrolizados utilizados en el tratamiento de los APLV y se extrapoló a la comunidad de Madrid. Resultados Nacidos vivos en el Hospital La Paz pertenecientes a las áreas citadas: 5.356 niños. Consultaron por sospecha fundada de APLV: 185 niños. Se diagnosticaron como alérgicos a PLV a 101 (54 per cent). La incidencia calculada de APLV fue de: 101/5.356: 1,9 per cent. Nacidos en la comunidad de Madrid en el mismo período: 57.078 niños. El número de posibles APLV en un año sería de 1.084. El cálculo aproximado de consumo de hidrolizados en el primer año de vida por niño, supone un coste de 1.585,72 3. El gasto de hidrolizados en los 1.084 alérgicos en la comunidad de Madrid sería de 1.718.922,9 3. El gasto de los 923 niños en los que se descartó alergia supondría 1.463.621,8 3.Conclusiones La incidencia de APLV en el primer año de vida en nuestro medio es de, al menos, 1,9 per cent. El diagnóstico correcto permite descartar APLV en casi la mitad de los casos, evitando someter al lactante a dietas innecesarias y que suponen un elevado coste (AU)

Evaluation of an extensively hydrolyzed casein-whey protein formula in immediate cow's milk protein hypersensitivity.

BACKGROUND: Hydrolysate formulas are safe for most infants who are allergic to cow's milk. The purpose of this study was to assess the clinical tolerance and safety of an extensively hydrolyzed casein-whey protein formula in a homogeneous group of patients with immediate cow's milk hypersensitivity. METHODS: The study population consisted of 33 infants in whom immediate cow's milk protein allergy had been diagnosed by clinical data, evidence of specific immunoglobulin E antibodies, and positive results in a controlled challenge test with cow's milk proteins. RESULTS: The hydrolysate was well tolerated in 31 of the 33 patients, which represented a 94% effectiveness. Using 95% confidence intervals generated for a binomial outcome (reaction-no reaction), the casein-whey protein formula is tolerated by 84.4% to 99% of infants with immediate immunoglobulinE-mediated cow's milk protein allergy. These figures are in the range of values recommended for this type of product. CONCLUSIONS: This extensively hydrolyzed casein-whey protein formula is generally safe to feed children with immediate hypersensitivity to cow's milk. However. it is advisable that the first intakes be given under direct medical supervision, in that the occurrence of adverse reactions in highly sensitive infants cannot be unequivocally excluded.