[Comparison of study results for levels of specific antibodies using the RAST-IgE method and specific bronchial...

The aim of the study was to evaluate the diagnostic power of specific-IgE evaluation in diagnosis of allergy to house dust mite (Dermatophagoides pteronyssinus, D.pt.), in relation to specific bronchial challenge. In a group of 99 children with perennial asthma, specific-IgE evaluation and bronchial challenge were performed with D.pt. allergens. The bronchial challenge was positive in 52 cases (53%). RAST results were concordant with bronchial challenge from 61% (for classes > or = 1) to 75% (for specific-IgE level > 9.5 PRU/ml). The sensitivity for RAST class 1 was 88%, but its specificity did not exceed 30% as opposed to 54% and 91%, respectively for class 4. The best overall concordance would be obtained with RAST class 3-4 or a specific IgE level of at least 9.5 PRU/ml but 25% would still be discordant and distributed among false-negatives and false-positives, for whom outside bronchial challenges, a sure diagnosis cannot be guaranteed.