BACKGROUND/AIMS: Levels of serum apelin (s-apelin), an endogenous ligand for angiotensin-like receptor 1, have been shown to be related to hepatic fibrosis and hemodynamic abnormalities in preclinical studies. We investigated the clinical implications of s-apelin as a noninvasive prognostic biomarker for chronic liver disease (CLD). METHODS: From January 2009 to December 2012, 215 CLD patients were enrolled and underwent clinical data collection, hepatic venous pressure gradient (HVPG) measurement, and liver biopsy. s-apelin was detected with a human total apelin enzyme-linked immunosorbent assay kit. All patients were prospectively observed during the median follow-up period of 23.0±12.9 months for decompensation and mortality. RESULTS: A total of 42 patients (19.5%) died during the follow-up period. s-apelin was significantly correlated with measurements of liver stiffness (R2=0.263, p<0.001) and collagen proportional area (R2=0.213, p<0.001) measured from liver biopsy tissue and HVPG (R2=0.356, p<0.001). In a multivariate analysis using a Cox regression hazard model, s-apelin was a weakly significant predictor of decompensation (hazard ratio [HR], 1.002; p<0.001) and mortality (HR, 1.003; p<0.001). CONCLUSIONS: s-apelin showed a significant relationship with CLD severity. However, its significance as a noninvasive biomarker for disease severity and prognosis was weak.
Adult ; Biomarkers/blood ; Biopsy ; Enzyme-Linked Immunosorbent Assay ; Female ; Follow-Up Studies ; Humans ; Hypertension, Portal/*blood/complications/mortality ; Intercellular Signaling Peptides and Proteins/*blood ; Liver/blood supply/pathology ; Liver Cirrhosis/*blood/etiology/mortality/pathology ; Male ; Middle Aged ; Portal Pressure ; Prognosis ; Proportional Hazards Models ; Prospective Studies