Evidence for Involvement of IL-9 and IL-22 in Cows' Milk Allergy in Infants.

Although allergic inflammation is characterized by a T helper (Th) 2-dominant immune response, the discovery of a role for new T cell subsets in inflammatory diseases has added an additional layer of complexity to the understanding of the pathogeneses of allergic diseases. We evaluated plasma cytokine profiles in infants with cows' milk allergy (CMA), who were being treated with an elimination diet. In a prospective, randomized and controlled study, infants (aged 8.4 ± 3.9 months) with CMA were treated with an elimination diet for 120 days, which replaced cows' milk with a hydrolysed soy protein formula (n = 26) or a free amino acid formula (n = 20). Blood samples were collected before treatment during active disease (T0) and after 120 days, when symptoms were absent (T1). Plasma cytokine concentrations were measured. Infants with CMA had higher plasma concentrations of interleukin (IL)-4 and IL-13 and lower concentrations of IL-9, IL-17A and interferon-γ, compared with healthy breast-fed infants. At T0, there was a positive correlation between blood eosinophil numbers and plasma concentrations of IL-4, IL-9, IL-17A and IL-22. Treatment with a cows' milk elimination diet resulted in a decrease in plasma IL-4, IL-9, IL-13 and IL-22 and an increase in plasma IL-17A. We conclude that IL-4 and IL-13 are elevated in active CMA. The association of IL-9 and IL-22 with eosinophilia, and the decrease in these two cytokines with cows' milk elimination, suggests that they both play a role in the symptoms observed in CMA and may be important targets for future interventions.

Response of specific immunoglobulin E to foods in children with atopic dermatitis.

Food allergy is a common condition that plays an important role in the pathogenicity and maintenance of atopic dermatitis (AD), however, must be carefully investigated before imposing a restrictive diet. The aim of this study was to evaluate the sensitivity to foods in patients with AD, correlating it with the severity of the disease and other possible associated factors. One hundred and eleven children (6-180 months of age) with AD were evaluated and later followed up at the Allergy and Clinical Immunology Division, Department of Pediatrics at FMABC. The serum concentrations of specific IgE to cow's milk (CM), egg, soy, wheat, corn, peanut and fish were measured using an enzymatic fluorescence method (ImmunoCAP™). In order to identify the clinical reactivity, the open oral provocation test was performed when specific IgE was positive to CM, egg and wheat and in all those who related symptoms after the intake of such foods regardless of the presence or absence of sensitization. In total, 40.5 % of the studied population was sensitized to at least one food allergen, especially those between 73 and 180 months of age. There was a higher prevalence of sensitization in children with more severe AD, and foods like CM, egg and wheat were the most involved, but with low clinical reactivity. We observed increased severity of AD in cases that initiated symptoms earlier and who had shorter duration of exclusive breastfeeding as well as a linear increase in sensitization in the most serious cases. Serum-specific immunoglobulin E was the only factor associated with the relationship that showed sensitization. The occurrence of sensitization to foods was frequent, mainly in the age group of 6-9 years and in patients with severe AD; however, the validation of the clinical reactivity was negative in most of the provocations performed, which agrees with the need to prove the same before the imposition of restrictive diets, often unnecessary and complex.