Laboratory performance of two commercially available Aspergillus antigen lateral flow assays compared to Platelia Aspergillus galactomannan antigen assay.

Abstract

Invasive aspergillosis (IA) infections remain a significant threat to immunosuppressed patients, resulting in considerable morbidity and mortality. While newer non-culture-based methods, such as the galactomannan antigen enzyme immunoassay (EIA) and molecular techniques, provide improved sensitivity and faster results, these methods have notable limitations. These include high costs, long turnaround times, and requirement for specialised instrumentation and skilled personnel. Lateral flow assays (LFA) offer a promising alternative for screening of IA, delivering rapid results with enhanced cost-effectiveness. In this study, we compared the clinical performance, precision, and accuracy of two LFAs for detecting Aspergillus antigen: the IMMY sōna Aspergillus Galactomannan Lateral Flow Assay (sōna-LFA) and the OLM Diagnostics Aspergillus-specific lateral flow device (OLM-LFD). These assays were evaluated in serum and bronchoscopy fluid samples against the Bio-Rad Laboratories Platelia Aspergillus Antigen EIA as the reference method. For the 70 clinical samples analysed (38 of which were positive by Platelia assay), the sōna-LFA demonstrated 95% sensitivity and 100% specificity. In comparison, the OLM-LFD showed 100% sensitivity and 81% specificity. Additionally, the quantitative components of the Platelia assay and the sōna-LFA were evaluated using linear regression analysis. The positive index values revealed a strong linear correlation, with a p value ≤0.05 and an r² value of 0.83. The sōna-LFA demonstrated high sensitivity and specificity for detecting Aspergillus antigen with high correlation of the quantitative component of testing when compared to the Platelia assay.