Association of urinary post-translationally modified fetuin-a and outcomes in acute kidney disease

BACKGROUND: Risk stratification during the acute kidney disease period remains suboptimal with existing staging systems. METHODS: We used prospectively collected clinical data and samples from 130 patients with acute kidney disease to evaluate the association between a novel biomarker, urinary post-translationally modified fetuin-A (uPTM-FetA), and clinical outcomes. Traditional staging systems based on the serum creatinine ratio, estimated glomerular filtration rate, or albuminuria were also compared. The outcome of interest was death or dialysis within 180 days. RESULTS: The level of uPTM-FetA was significantly associated with the outcome in both logistic regression (odds ratio 3.41, 95% confidence interval 1.35-8.62, P = 0.01) and Cox models (hazard ratio 2.91, 95% confidence interval 1.30-6.51, P = 0.009). The crude area under the receiver operating characteristic curve was 0.75. Grouping with tertiles of uPTM-FetA levels showed discrimination between patients with and without the outcome. Furthermore, integrating uPTM-FetA into the traditional staging system of acute kidney disease was associated with improvement in model fit, risk classification, and clinical utility. CONCLUSIONS: uPTM-FetA during the acute kidney disease period offers the potential to provide additional prognostic information. Given the small sample size, the results should be viewed as exploratory. Future studies with independent cohorts are warranted to validate this finding.