The Aspergillus galactomannan Ag VIRCLIA® Monotest and the sõna Aspergillus galactomannan lateral flow assay show comparable performance for the diagnosis of invasive aspergillosis.

BACKGROUND

Rapid galactomannan tests, such as the sõna Aspergillus GM Lateral Flow Assay (GM-LFA) and the Aspergillus Galactomannan Ag VIRCLIA® Monotest (GM-Monotest), which are suitable for the analysis of single samples, have the potential to accelerate diagnosis of invasive aspergillosis (IA).

OBJECTIVES

To compare the performance of the GM-Monotest and the GM-LFA for the diagnosis of IA.

PATIENTS/METHODS: Two patient cohorts were analysed: adults who had received an allogeneic haematopoietic stem-cell transplant (alloHSCT-cohort) and patients with proven/probable IA from a 5-year period (cross-sectional IA-cohort). In the alloHSCT-cohort, weekly serum samples were tested, whereas in the cross-sectional IA-cohort sera and bronchoalveolar lavage fluids were analysed. The diagnostic performance was calculated using two definitions for positivity: (1) a single positive GM result and (2) at least two positive GM results from consecutive samples. IA classification followed EORTC/MSG 2019.

RESULTS

The alloHSCT-cohort included 101 patients. Four had proven/probable IA, 26 possible IA and 71 no IA. The specificity for one positive serum and two consecutively positive sera was 88.7% and 100% (GM-Monotest) and 85.9% and 98.6% (GM-LFA). Comparison of ROC curves in the alloHSCT-cohort showed no significant difference. The cross-sectional IA-cohort included 59 patients with proven/probable IA. The sensitivity for one positive sample and two consecutively positive samples was 83.1% and 55.1% (GM-Monotest) and 86.4% and 71.4% (GM-LFA).

CONCLUSIONS

Both assays showed comparable diagnostic performance with a higher sensitivity for the GM-LFA if two consecutive positive samples were required for positivity. However, due to poor reproducibility, positive GM-LFA results should always be confirmed.