Abstract: Objective To evaluate and compare the clinical diagnostic value of five laboratory methods for pulmonary aspergillosis (PA): fungal polymerase chain reaction (PCR) using bronchoalveolar lavage fluid (BALF), BALF galactomannan test (GM test), fungal culture (culture method), serum GM test, and serum (1,3)-β-D-glucan test (G test), and to provide evidence for selecting an efficient diagnostic strategy for PA in clinical practice. Method A retrospective analysis was conducted on 841 hospitalized patients with suspected community-acquired pneumonia admitted to Xi’an Chest Hospital from December 2024 to April 2025. All patients underwent the above five tests. Using clinical diagnosis as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, and Kappa value were calculated for each method. Receiver operating characteristic (ROC) curves were plotted and the area under the curve (AUC) was computed to compare the diagnostic performance comprehensively. Result In single-test analysis, the sensitivities of PCR and BALF-GM were 0.519 and 0.577, respectively, significantly higher than those of serum GM (0.096), G test (0.077), and culture method (0.077). The positive predictive values of culture method (1.000) and PCR (0.750) were significantly higher than those of BALF-GM (0.484), serum GM (0.156), and G test (0.333). ROC curve analysis showed that the AUCs of PCR (0.754) and BALF-GM (0.768) were both significantly greater than those of serum GM (0.531), G test (0.533), and culture method (0.567). In combined testing, when PCR was used as the base test and sequentially combined with BALF-GM and serum GM, the diagnostic sensitivity increased to 0.673 and 0.712, respectively; further addition of G test or culture method did not improve the sensitivity further (both remained 0.712). Conclusion PCR alone demonstrates excellent overall diagnostic performance for PA and has high clinical application value. Compared with single tests, the combination of PCR, BALF-GM, and serum GM effectively improves the diagnostic sensitivity for PA.

Key words: Pulmonary aspergillosis, Bronchoalveolar lavage fluid, Polymerase chain reaction, Galactomannan test, (1,3)-β-D-glucan test, Diagnostic performance, Combined detection