A comparison of specific IgE and skin prick test results to common environmental allergens using the HYTEC (TM) 288

Although skin-prick testing (SPT) is commonly used by allergists in the evaluation of allergy, in-vitro testing for specific IgE (sIgE) is an attractive alternate because it can be performed remotely and is of utility when SPT is contraindicated, as in patients on anti-histamines, or with dermatitis or severe eczema. It is, however, necessary to determine the extent of correlation between the in-vitro and in-vivo methods. In this study, we examined the qualitative concordance between SPT and sIgE as measured on the HYTEC (TM) 288 platform for 10 commonly encountered inhalant allergens in 232 subjects, and analysed the performance characteristics for the HYTEC (TM) 288. Overall concordance between SPT and sIgE was > 70% for all allergens tested. Sensitivity ranged from 25% to 95%, depending on the allergen, while specificity was significantly higher for all allergens (78-97%). NPV was > 85% for all allergens tested, while PPV was more variable, ranging from 22% to 88%. These results are similar to findings in other studies comparing SPT with sIgE. Lack of concordance in a percentage of samples might be partly attributed to differences in allergen preparations for SPT and HYTEC (TM) 288. Follow-up studies utilizing identical allergen preparations for both in-vivo and in-vitro testing may address these discrepancies.