Dynamics of 1,3-β-D-Glucan in Invasive Candidiasis: A Narrative Review of Microbiological Aspects and Diagnostic Implications

Invasive candidiasis (IC) remains a significant cause of morbidity and mortality among critically ill, hematologic, and neonatal patients worldwide. Rapid and accurate diagnosis is essential to guide timely antifungal therapy and improve outcomes. Among available diagnostic tools, 1,3-β-D-glucan (BDG), a polysaccharide component of the fungal cell wall, has emerged as a key biomarker. BDG assays allow for early detection of probable IC, often preceding positive blood cultures, and offer prognostic information based on serial measurements. Species-specific differences in Candida cell wall composition influence BDG release and diagnostic sensitivity. Candida albicans generally correlates with high BDG levels, whereas Nakaseomyces glabrata, Candida parapsilosis, and Candida auris exhibit variable or lower glucan exposure, limiting assay sensitivity. BDG performance is affected by patient-specific factors, such as prior surgery, transfusions, or coexisting bacterial infections, which may lead to false-positive results. Molecular techniques, including PCR-based assays, provide complementary diagnostic accuracy and species identification, and their combination with BDG testing enhances sensitivity up to 90%. Serial BDG monitoring supports risk stratification and treatment response assessment, with persistent elevations predicting worse outcomes. In neonatal and pediatric populations, optimal cut-off values remain under investigation, highlighting the need for integration with clinical and microbiological data. Overall, BDG represents a valuable adjunct in a multimodal diagnostic workflow, providing both diagnostic and prognostic insights in invasive candidiasis management.