Comparison of the Performance of Skin Prick and ISAC Tests in the Diagnosis of Allergy

Abstract

The recent European Union and Italian regulations in the matter of in vivo test could strongly impact on current diagnostic approach, increasing the usage of in vitro tests in daily clinical practice. We evaluated 506 patients with both skin prick test and a microarray system (ImmunoCAP ISAC 112). The overall evaluation between ImmunoCAP® ISAC vs SPT showed a moderate agreement (k=0.509, 95% C.I. 0.480-0.540, SE: 0.016) considering both aeroallergens and food allergens. When we considered the concordant results (double-positive plus double-negatives), the agreement ranged from 69% to 80% for pollen allergens, between 74% and 76% for dust mites, and between 74% and 93% for animal epithelia. In the case of food allergens, the accordance was pretty lower, accounting values ranging from 67% to 86%. ISAC testing identified from 22% to 26% more cases than SPTs in peach and nuts hyper-sensitivity. In 2.8% of the control group, the ISAC-test failed to detect an allergy sensitization caused by dust mite, shrimp, Anisakis, or seed storage proteins. Multiplex testing is more than a promising tool for more precise and comprehensive profiling of allergic patients and can be considered as a second-line approach, after the anamnesis, in the diagnosis of allergic diseases.

Real‐life evaluation of molecular multiplex IgE test methods in the diagnosis of pollen associated food allergy

“…Comparison of the molecular test results with SPT results confirmed that for most PFS allergens a positive SPT correlates with sIgE detected in ISAC and/or ALEX 2 , which was not the case in a previous study comparing SPT test results with sIgE levels detected by ISAC. 26 …”

Mollusk allergy in shrimp-allergic patients: Still a complex diagnosis. An Italian real-life cross-sectional multicenter study

“…We confirmed once more that the diagnostics with both extracts and the currently available molecules are inadequate to detect properly patients hypersensitive to crustaceans and mollusks. 15 We observed a great heterogeneity of results from one patient to another using the routine diagnostic approaches, including SPT with commercial extracts, PTP with fresh material, and specific IgE measurements. We previously showed the unreliability of commercial extracts for SPT available on the market due to differences in allergenic protein concentrations, thus potentially leading to confounding results.…”

“…19 In addition, geographical differences could also underlie different sensitization mechanisms according to different environmental exposure. 15 Furthermore, possible occupational exposure should be considered. 20,21 These points need to be addressed in future studies.…”

Allergy screening with extract‐based skin prick tests demonstrates higher sensitivity over in vitro molecular allergy testing

“…In another much smaller study from Italy, SPTs were compared with the ISAC112 platform from the same manufacturer as in our study using a different technical platform but the same molecular allergens. 23 The patients differed from our study as the Italian cohort also contained a lot of food allergic and urticaria patients that had been excluded in our study focusing on inhalant allergy. Also, Der p23 was missing in their 2019 version of the ISAC.…”