Serum GSDMD for Early Diagnosis of Bloodstream Infection and Differentiating Bacterial from Fungal Infections.

BACKGROUND: The role of Gasdermin D (GSDMD) in bloodstream infection (BSI) diagnosis is unknown.

METHODS: Serum GSDMD levels were measured in BSI patients. Endothelial cells and PBMCs were isolated, infected with bacteria/fungi, and intracellular/extracellular GSDMD concentrations were measured. An animal model was established to investigate the association between serum GSDMD levels and BSI incidence/progression.

RESULTS: ROC curve analysis indicated that GSDMD could be a potential early diagnostic biomarker for BSI (AUC = 0.9885). Combining GSDMD with procalcitonin (PCT) improved the differential diagnosis of Gram-positive and Gram-negative bacteria (AUC = 0.6699, 66.15% specificity), and early diagnosis of Gram-positive bacteria (98.46% sensitivity), while PCT was not significantly elevated. The combined GSDMD and G-test had higher sensitivity (AUC = 0.7174) for differential diagnosis of bacterial and fungal infections, and early detection of fungal infections (98.44% sensitivity). In vitro and in vivo experiments confirmed that GSDMD levels increased significantly within 2 hours, peaked at 16 hours, and exhibited a time-dependent upward trend.

CONCLUSIONS: Serum GSDMD, alone or combined with other biomarkers, has potential for early diagnosis and differential diagnosis of BSI caused by various pathogens. This finding offers a new strategy for early detection and treatment of BSI.