BACKGROUND: Multiple allergen simultaneous test (MAST) is a convenient, cost-effective, semi-quantitative immunoassay widely used for allergy screening. However, cross-reactions, such as those caused by IgE against Bet v 1 or cross-reactive carbohydrate determinants, should be considered when interpreting MAST results. This study aimed to compare two MASTs, Advansure AlloScreen Max108 (AlloScreen assay
LG Chem Ltd., Seoul, Korea) and PROTIA Allergy-Q 128M (Allergy-Q assay
ProteomeTech Inc., Seoul, Korea). METHODS: A total of 89 serum samples (56 positive and 33 negative) were analyzed through AlloScreen and Allergy-Q assays for 104 common allergens. Discrepant results were confirmed using the ImmunoCAP assay (Phadia AB, Uppsala, Sweden). In addition, concomitant sIgE reactivity to plant-derived food allergens related to Bet v 1 was assessed in birch pollen-positive samples. RESULTS: The total agreement between the two MASTs was 94.4% (kappa = 0.661), and class consistency was 0.878 (p <
0.002). Among the 78 discrepancies assessable by ImmunoCAP, Allergy-Q showed an agreement of 51.3%, while AlloScreen showed 48.7%. In birch pollen-positive samples, Allergy-Q demonstrated a higher positivity for concomitant sIgE reactions to plant-derived food allergens (46.9%) compared to AlloScreen (23.4%). CONCLUSIONS: The AlloScreen and Allergy-Q assays showed good overall agreement and class consistency. However, differences were observed in their detection of concomitant sIgE reactivity to plant-derived food allergens in birch pollen-positive samples. Further studies, incorporating clinical symptom evaluation, are needed to establish the clinical utility and reliability of these assays.