Concordance between different methods of detecting fungal-specific IgE antibody in asthma

Documenting fungal sensitization plays a pivotal diagnostic role in asthma endotypes. Diagnosis relies heavily on detecting fungal-specific immunoglobulin E (sIgE), yet variability in allergen representation, cross-reactivity, and assay performance complicates standardization. Although ImmunoCAP is regarded as the reference method, many commercial kits are available worldwide, with varying accuracy. A scoping review was conducted using Arksey and O'Malley's five-stage framework. Literature searches in PubMed, Scopus, and ProQuest MEDLINE identified studies comparing fungal sIgE detection kits. Inclusion criteria required human studies evaluating fungal allergens in asthma-related diseases. Data from 16 eligible studies and 32 diagnostic kits were analyzed, focusing on assay characteristics, concordance, sensitivity, and specificity. There are 32 commercial kits available, which vary in detection principles, including enzyme immunoassays, immunoblots, and microarrays, with positivity thresholds ranging from 0.1 to 0.35 kUA/L. Most assays identified Aspergillus and Alternaria-specific IgE, while fewer detected Cladosporium, Candida, or Trichophyton. Concordance with ImmunoCAP ranged from moderate to substantial, with the strongest agreement reported for Alternaria. ImmunoCAP demonstrated the highest sensitivity and specificity; however, emerging systems, such as the GOLD chip and MeDALL microarray, showed promising improvements in multiplex capacity and detection limits. Meanwhile, several commercial assays have no publications documenting their diagnostic performance. Fungal sIgE detection remains heterogeneous. Newer microarray-based assays offer enhanced sensitivity and broader allergen profiling. Standardizing cutoff thresholds and incorporating recombinant fungal allergens are crucial for strengthening diagnostic precision and improving the clinical management of fungal asthma.