Plasma SCUBE2 as a novel biomarker associates with survival outcomes in patients with sepsis-associated acute kidney injury

Background: The adverse effects of sepsis-associated acute kidney injury (SA-AKI) highlight the need for new biomarkers. Signal Peptide-Complement C1r/C1s, Uegf, Bmp1-Epidermal Growth Factor-like Domain-Containing Protein 2 (SCUBE2), important for angiogenesis and endothelial integrity, has been linked to increased mortality in models of lipopolysaccharide-induced lung injury. This research aimed to assess the utility of plasma SCUBE2 levels as a prognostic indicator for SA-AKI in intensive care unit (ICU) patients. Methods: Between September 2020 and December 2022, our study enrolled ICU patients diagnosed with stage 3 SA-AKI. We collected demographic information, illness severity indices, and laboratory data, including plasma SCUBE2 and sepsis-triggered cytokine levels. We employed receiver operating characteristic curves and DeLong tests to assess the predictive accuracy for survival, Kaplan–Meier curves to evaluate the relative risk of death, and multivariate logistic regression to identify independent mortality predictors. Results: Among the total of 200 participants, the survivors had significantly higher plasma SCUBE2 levels (115.9 ng/mL) compared to those who died (35.6 ng/mL). SCUBE2 levels showed a positive correlation with the anti-inflammatory cytokine IL-10 and a negative correlation with the APACHE II score, SOFA score, C-reactive protein, and monocyte chemoattractant protein-1. Multivariate analysis revealed that elevated SCUBE2 and IL-10 levels were independently protective against mortality, and associated with the most favorable 30-day survival outcomes. Conclusions: In ICU patients with stage 3 SA-AKI, lower plasma levels of SCUBE2 were correlated with elevated pro-inflammatory factors, which impacted survival outcomes. This suggests that SCUBE2 could be a potential biomarker for predicting prognosis in patients with SA-AKI.