Assessment of the 1,3-β-D-glucan test and the galactomannan antigen test in the detection of invasive fungal infections in patients with hematological diseases.

To evaluate the diagnostic performance of the 1,3-β-D-glucan (BDG) test and the galactomannan (GM) antigen test in invasive fungal infections (IFI) among hematologic patients and to explore an optimized diagnostic approach. A total of 294 consecutive patients with hematological diseases suspected of fungal infections were enrolled at Peking University People's Hospital from January 2020 to October 2023. IFI diagnosis referred to a composite reference standard (CRS), which combined both mycological and clinical evidence. Serum BDG (cut-off: 60 pg/mL) and GM (cut-off: 0.5) tests were analyzed. Of the 294 patients, 122 were classified as IFI-positive, including cases of invasive Aspergillosis (IA, n = 55), invasive Candidiasis (IC, n = 49), and other fungal infections (n = 18). Compared with CRS, the BDG test demonstrated higher sensitivity (64.4% vs 47.5%, P = 0.008), while the GM test showed higher specificity (93.0% vs 83.1%, P = 0.003). The combination of BDG and GM test results generated a Predicted Diagnostic Probability Value (PDPV) and yielded a receiver operating characteristic (ROC) curve with an area under the curve (AUC) of 0.848. At a PDPV threshold of 0.64, the Youden index was maximized (J = 0.60), achieving 73.0% sensitivity and 86.6% specificity. PDPV outperformed both the BDG (P = 0.010) and GM tests (P = 0.002, Z test). In hematologic patients, the composite diagnostic indicator PDPV significantly improved diagnostic performance for IFI, offering higher sensitivity and robust specificity compared to the individual BDG or GM tests. Additionally, the BDG test detected significantly more positive IC cases than the GM test, though no significant difference was observed for IA diagnosis.IMPORTANCEInvasive fungal infections (IFI) remain a common cause of morbidity and mortality in patients with hematologic diseases, and early diagnosis is crucial for improving outcomes. This study systematically evaluated the diagnostic performance of the 1,3-β-D-glucan (BDG) test and the galactomannan (GM) antigen test in a cohort of hematologic patients. Importantly, the study developed a novel composite indicator, the Predicted Diagnostic Probability Value (PDPV), which integrated BDG and GM results to enhance diagnostic performance. PDPV showed improved sensitivity and specificity compared to individual tests, offering a practical and optimized approach for IFI diagnosis in high-risk patients. This diagnostic approach may contribute to improved clinical decisions and earlier initiation of antifungal therapy.