Comparative analysis of the clarus Aspergillus Galactomannan Enzyme Immunoassay for the Diagnosis of Invasive Pulmonary Aspergillosis in Bronchoalveolar Lavage Fluid

Abstract Background: Galactomannan (GM) testing using Platelia Aspergillus enzyme immunoassay (Platelia GM) from bronchoalveolar lavage fluid (BALF) aids in early diagnosis of invasive pulmonary aspergillosis (IPA). Globally, only a minority of laboratories have the capability to perform on-site GM testing, necessitating accessible and affordable alternatives. Hence, we conducted a comparative evaluation of the new clarus Aspergillus GM enzyme immunoassay (clarus GM) with Platelia GM using BALF samples. Methods: This is a single-center, prospective, cross-sectional study, where Platelia GM testing was routinely performed followed by clarus GM testing in those with true positive or true negative GM test results according to the 2020 EORTC/MSG and the 2024 FUNDICU consensus definitions. Descriptive statistics, ROC curve analysis, and Spearman’s correlation analysis were used to evaluate analytical performance of the clarus GM assay. Results: This study enrolled 259 adult patients, of which 53 (20%) were classified as probable IPA, while 206 did not fulfill IPA criteria. Spearman's correlation analysis revealed a strong correlation between the two assays (rho = 0.727, p < 0.001). The clarus GM had a sensitivity of 96% (51/53) and a specificity of 74% (153/206) for differentiating probable versus no IPA when using the manufacturer recommended cut-off. ROC curve analysis showed an AUC of 0.936 (95% CI: 0.901-0.971) for the clarus GM, while the Platelia GM yielded an AUC of 0.918 (95% CI: 0.876-0.959). Conclusions: Clarus GM demonstrated a strong correlation and promising test performance, comparable to Platelia GM, rendering it a viable alternative in patients at risk of IPA.