D2.09 - Qualitative concordance between two multiplex molecular diagnostic platforms in LTP allergy

Non-specific lipid transfer proteins (nsLTPs) are panallergens widely distributed throughout the plant kingdom. Sensitization to these allergens is associated with an increased risk of severe allergic reactions following the ingestion of plant-derived foods. Pru p 3, the major peach allergen, plays a central role in sensitization to this allergen group and shows cross-reactivity with other nsLTPs. However, cross-reactivity patterns among nsLTP allergens have not yet been fully characterized. At our institution, several LTP sensitization patterns have previously been identified, depending on cross-reactivity among these proteins and the allergen associated with the highest levels of specific IgE (https://doi.org/10.1111/all.16300). The development of new in vitro diagnostic techniques may help to further characterize and confirm these findings.

Objetive: To qualitatively compare the results obtained using ImmunoCAP ISAC112® and the new EUROLINE®LTP technic in the in vitro assessment of nsLTP sensitization.

A prospective study was conducted between August and November 2025, including samples from patients evaluated at the Allergy Department of Hospital La Fe (Valencia, Spain) with a clinical history compatible with nsLTP allergy. Specific IgE determinations were performed in parallel using ImmunoCAP ISAC®112 (Thermo Fisher Scientific) and EUROLINE®LTP (Euroimmun). A qualitative comparison between both techniques was performed using McNemar’s test. Clinical data was obtained from the electronic medical record system (ORION® Clinic).

A total of 36 patients were included. Clinical records were available for 27 patients (Table 1). Complete qualitative agreement between ISAC®112 and EUROLINE®LTP was observed for Pru p 3, with positive results in 100% of patients. For Jug r 3 and Ara h 9, qualitative agreement was 97%, with no statistically significant differences between techniques (exact McNemar test, p = 1.00). For Cor a 8, EUROLINE®LTP identified a higher number of positive results compared with ISAC (34 vs 30), without statistically significant differences between methods with a concordance rato of 88% and p = 0.125.

Both platforms showed a high qualitative concordance in the detection of nsLTP sensitization. EUROLINE®LTP identified a higher number of positive results for Cor a 8, although no statistically significant differences were observed. Larger studies are required to confirm these preliminary findings.