Low specificity of Aspergillus spp. ELITe MGB assay, and potential risks in management of invasive aspergillosis

Objectives: In recent years, commercial molecular tools for diagnosis of invasive aspergillosis have emerged, requiring evaluation to ensure quality. Here we assessed the specificity of Aspergillus spp.-ELITe MGB Assay a commercial assay tergeting 18S gene of Aspergillus spp. Design and methods: As part of a method validation, we evaluate the specificity of the Aspergillus spp.-ELITe MGB Assay by testing fourteen culture based samples of sequenced non-Aspergillus fungal species. The benefits of a pre-lysis treatment was evaluated in parallel on serial dilutions of an Aspergillus fumigatus strain. Results: Our findings revealed cross-reactivity in five strains using the 50 copies/mL cut-off recommended by the manufacturer, suggesting potential diagnostic errors and inappropriate management of patients. Pre-lysis treatment does not affect the limit of detection at serial dilution. Conclusions: In conclusion, the Aspergillus spp. ELITe MGB Assay exhibits limited specificity in culture-based samples, underscoring the importance of careful utilization in laboratories. Further studies are warranted to better comprehend of the impact of this cross-reactivity on clinical samples.