Abstract / Summary
Background: /Objectives: Diagnosing invasive pulmonary aspergillosis (IPA) in critically ill patients remains challenging, as classic host factors and clinical signs are often absent in this population. Lateral flow assays for galactomannan (LF-GM) offer a rapid and cost-effective alternative to conventional enzyme immunoassay (EIA-GM) and fungal culture, but their diagnostic performance and clinical impact on antifungal prescribing in the ICU setting remain incompletely characterized. This study aimed to evaluate the diagnostic performance of LF-GM on bronchoalveolar lavage (BAL) samples for IPA diagnosis according to BM-AspICU criteria and its impact on antifungal therapy decisions.
Methods: We retrospectively analyzed 244 BAL samples from 195 patients admitted to two university-hospital ICUs in Seville, Spain (July 2022–December 2024) with suspected lower respiratory tract infection. Sensitivity, specificity, predictive values, and Cohen's kappa were calculated for LF-GM against probable IPA (BM-AspICU), EIA-GM, and fungal culture, with exact Clopper-Pearson 95% confidence intervals. Subgroup analyses assessed the influence of neutropenia and prior antifungal exposure. The effect of LF-GM results on antifungal prescribing was also evaluated.
Results: Probable IPA was identified in 32/244 samples (13%). LF-GM showed 81% sensitivity, 92% specificity, and 97% negative predictive value for probable IPA, with moderate agreement with EIA-GM (κ = 0.58) and fungal culture (κ = 0.50). Neither neutropenia nor prior antifungal exposure significantly altered LF-GM performance. A positive LF-GM result prompted antifungal initiation or maintenance in most cases, while a negative result was associated with withholding or discontinuing therapy; discordant LF-GM-positive/EIA-GM-negative results led to discontinuation in 83% of cases.
Conclusions: LF-GM is a reliable, rapid tool for ruling out IPA in critically ill patients, with high specificity and negative predictive value, and meaningfully influences antifungal prescribing. Combined with confirmatory EIA-GM testing, it may support a safe rule-in/rule-out strategy for antifungal stewardship in the ICU, though prospective validation is warranted.