Are immunoglobulin E levels associated with early wheezing? A prospective study in Brazilian infants.

The relationship between wheezing or asthma and serum immunoglobulin (Ig)E levels in early life is unclear. The aim of this study was to follow-up the IgE immune response in infants that did, or did not, develop recurrent wheezing during their first year of life. One-hundred and two randomised term neonates were included, in which IgE levels were quantified in cord blood samples, at 3, 6, 9 and 12 months of age. Specific IgE levels for food and inhalant allergens and the skin-prick test for inhalant allergens were also assessed at 6 and 12 months. During clinical follow-up, 32 (31%) infants presented with two or more wheezing episodes, while 70 (69%) had no wheezing. Total IgE levels were significantly higher up to 12 months in wheezing infants when compared to nonwheezing group. At 12 months, the specific IgE levels to cow's milk, egg white and mites were higher in infants with recurrent wheezing. There was no influence of family history for atopy on IgE levels. The skin-prick tests were positive in 14% and 23% in wheezing infants at 6 and 12 months, respectively. These results indicate an early allergic sensitisation in wheezing infants, suggesting an altered immunoregulatory T-cell role in immunoglobulin E production.