Plasma YAP1 as a biomarker for the prediction of occurrence, progression, and outcomes of sepsis-associated liver injury: a prospective observational study

BACKGROUND: Sepsis-associated liver injury (SALI) is an independent risk factor for multiple organ dysfunction and high mortality in septic patients, which is often associated with a poor prognosis. Currently, there is still a lack of early diagnostic biomarkers of Sepsis-Associated Liver Injury in clinical practice. YAP1 (Yes1 Associated Transcriptional Regulator) has been demonstrated to correlate with hepatic inflammation, nevertheless, its exact function and mechanism in sepsis-associated liver injury have not been conclusively determined. METHODS: Clinical data of septic patients in the ICU of Northern Jiangsu People's Hospital (Oct. 2023 - Dec. 2025) were reviewed. Patients were classified into sepsis non-liver injury (SNLI) and SALI groups according to the presence or absence of liver injury at admission. Logistic regression was used to identify independent risk factors for SALI. Receiver operating characteristic (ROC) analysis assessed predictive performance. Patients were stratified by plasma YAP1 quartiles to evaluate its association with disease progression, and significant variables were further analyzed by logistic regression. Correlations were examined using Spearman analysis. A Cox proportional hazards model was applied to assess the association between YAP1 and 28-day mortality in SALI patients. RESULTS: A total of 199 patients were included (SNLI, n = 121; SALI, n = 78). Plasma YAP1 was an independent protective factor for SALI (OR = 0.97, P < 0.001), while BMI (OR = 1.35, P = 0.015) and day 1 lactate (OR = 1.48, P = 0.002) were independent risk factors. YAP1 showed good predictive performance (AUC = 0.86). Higher YAP1 levels were independently associated with 72-hour SOFA score reduction (OR = 7.55, P = 0.009), indicating improved early organ function. No significant association was found between YAP1 and 28-day mortality. CONCLUSION: Plasma YAP1 is inversely associated with SALI occurrence and demonstrates good predictive performance. Higher YAP1 levels are associated with early organ function improvement but not with 28-day mortality.