Evaluation of PERFORMANCE of the IMMY and Dynamiker Aspergillus Galactomannan lateral flow assays for the diagnosis of invasive Aspergillosis

Abstract

Current laboratory diagnostic techniques for invasive aspergillosis (IA), such as fungal cultures and enzyme immunoassay (EIA) for the galactomannan antigen (GM), are limited by their low sensitivity, labor-intensive nature, and prolonged processing times. Some lateral flow assays (LFAs) have been developed for the diagnosis of IA; however, clinical validation and comparative studies are lacking. This study assessed the diagnostic performance of two CE-marked GM-LFAs, IMMY-GM-LFA and QuicGM-LFA. This retrospective study comprised 44 bronchoalveolar lavage fluid (BALF) and 127 serum samples obtained from 137 patients, 17 (9.9 %) of whom had proven or probable IA categorized using the revised EORTC/MSG criteria, between September 2020 and March 2021. The correlation coefficient between the IMMY-GM-LFA and GM-EIA was 0.95, while that between the QuicGM-LFA and GM-EIA was 0.90. Both LFAs GM indexes were significantly higher among those with proven/probable IA versus those with no IA and possible IA cases (BALF: 7.92 vs 0.18 and 14.05 vs 0.33; serum: 1.86 vs 0.26 and 5.75 vs 0.38 by IMMY and QuicGM-LFA, respectively. All p<0.05). In BALF samples, the area under the curve (AUC) for IMMY-GM-LFA and QuicGM-LFA were 0.93 and 0.96, respectively, with optimized GM cut-offs established at 1.2 for IMMY-GM-LFA and 0.78 for QuicGM-LFA. In serum samples, the AUC for IMMY-GM-LFA was 1.0, and for QuicGM-LFA was 0.9, with optimized cut-offs of 0.7 and 0.76, respectively. In conclusion, this study demonstrated that IMMY-GM and QuicGM-LFAs offer comparable alternatives to the Bio-Rad GM-EIA when testing BALF and serum samples with optimized thresholds.