Establishment of sensitive sandwich-type chemiluminescence immunoassay for Aspergillus galactomannan antigen.

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) poses significant diagnostic challenges in immunocompromised patients, with galactomannan (GM) detection serving as a key biomarker. Existing Platelia™ GM enzyme-linked immunosorbent assay (ELISA) faces limitations in throughput and turnaround time.

METHODS

We developed a magnetic bead-based chemiluminescent enzyme immunoassay (CLEIA) for GM detection in serum/bronchoalveolar lavage fluid (BALF).

RESULTS

Optimized CLEIA parameters enabled 30-min analysis versus 120-min for ELISA. Validation with 241 clinical specimens demonstrated robust analytical performance: diagnostic thresholds of ≥ 0.20 CLEIA Units for serum and BALF matrices (ROC-AUC 0.87, p<0.0001), analytical sensitivity of 0.50 ng/mL, and precision with ≤14.40% total CV, and no hook effect ≤200 ng/mL. Method comparison against the Platelia ELISA revealed 86.72% overall diagnostic agreement (Cohen's k=0.72), while cross-reactivity analyses indicated specificity limitations exclusively with Histoplasma-positive specimens, consistent with parallel GM ELISA results.

DISCUSSION: This assay enables 75% processing time reduction with uncompromised diagnostic accuracy, positioning it as a high-throughput alternative for rapid IA screening in high-risk cohorts.