Contribution of molecular diagnosis of allergy to the management of pediatric patients with allergy to pollen.

BACKGROUND Component-resolved diagnosis based on recombinant allergens facilitates treatment of multiple sensitization and/or crossreactivity in allergic patients. OBJECTIVE To assess the usefulness of molecular diagnosis in childhood allergies. METHODS A total of 162 children aged 4-16 years diagnosed with allergic rhinitis or asthma/rhinitis caused by pollen were referred for recombinant allergen-based diagnosis in 2006. Specific immunoglobulin (Ig) E against pollen allergens and purified recombinant Phleum pratense pollen allergens were measured using an in vitro quantitative assay, and considering the recombinant allergens Phl p 1+Phl p 5 as P pratense--specific allergens and Phl p 7+Phl p 12 as cross-reacting allergens. Conditional probability was calculated to determine the relationship between values for specific IgE against major allergens and those for cross-reacting allergens. RESULTS Specific IgE antibodies against P pratense were detected in 99.4% of serum samples, and cross-reacting allergens in 46%. Multiple sensitization to pollen was documented in 38% of patients, with Plantago lanceolata as the main cause. Conditional probability calculations showed that patients with specific IgE values of 75-80 kU(A)/L to Phl p 1+Phl p 5 were 75% (95% confidence interval) more likely to present values > or = 2 kUA/L to Phl p 7+Phl p 12. CONCLUSIONS Our results show that recombinant DNA technology can help diagnose allergy in cases of multiple sensitization and crossreactivity, and is therefore a promising option for improving prognosis and management of allergic pediatric populations.