Differentiation of IgE-dependent and IgE-independent reactions in children with bronchial asthma on the basis of TOP CAST Paediatric Allergen Mix test.

PURPOSE

TOP CAST Paediatric Allergen Mix test is a new cellular in vitro test based on evaluation of leukotrienes synthesised by basophils under the influence of specific allergens. The aim of the study was evaluation of applicability of this test as screening examination in diagnosis of atopic asthma in children.

MATERIAL AND METHODS

The study was carried out on a group of 30 children (56.7% boys and 43.3% girls) aged 6-15 yrs (mean age 8 years and 9 months, SD = 2.1) with diagnosed bronchial asthma. In children qualified for the study clinical symptoms, subject examination as well as functional examination of the respiratory system (obturation with positive reversibility test) confirmed the disease. All the children had skin prick tests performed with the most popular aero- and troph-allergens, which results were expressed (+) according to the Skandinavian scale. In 15 cases asthma had atopic origin: in 11 children--mites were responsible for the contraction of bronchi, in 3 cases--tree-pollens allergens and in 1 case--grass pollens. In 15 next cases non-atopic asthma was diagnosed. The control group consisted of 10 children without clinical manifestations of asthma and negative results of the above tests. Test TOP CAST Paediatric Allergen Mix with mixture of 21 inhalatory and food allergens was performed according to the producer's procedure.

RESULTS

Statistically significant differences of the values of released leukotrienes were noted at allergen concentration of both 100 ng/ml and 10 ng/ml in children with diagnosed atopic asthma compared to those with non-atopic asthma and control group. The sensitivity of TOP CAST Paediatric Allergen Mix test was 80% at both allergen concentrations while the specificity was higher (90%) at the lower concentration. There was also correlation between the number of released leukotriens and IgEc in the examined group of children, however, no statistically significant differences were observed between the concentration of the released leukotrienes and the size of the wheal and the number of positive skin prick tests.

CONCLUSIONS

1. TOP CAST Paediatric Allergen Mix test is a good screening method in differentiation of atopic and non-atopic background of bronchial asthma in children. 2. At the present evaluation stage of this test, it may be applied as complementation of routine tests in allergological practice.