Clinical value of urinary retinol-binding protein in ascites due to cirrhosis.

The aim of the present study was to explore the clinical value of urinary retinol-binding protein (RBP) level in the prognosis of cirrhotic ascites by assessment of the RBP levels prior to and following ascites treatment. The levels of urinary RBP, urinary microalbumin (mAlb), serum urea nitrogen (urea) and serum creatinine (Cr), and the estimated glomerular filtration rate (eGFR) were measured in 90 patients with cirrhosis and ascites hospitalized in a single institution between May 2011 and January 2012, and in 30 healthy controls. The levels of urinary mAlb, serum urea and serum Cr were higher in the cirrhotic patients compared with the healthy controls (P<0.05). Urinary RBP levels were significantly higher and eGFR was significantly lower in the liver cirrhosis group compared with the healthy control group (P<0.01). Urinary RBP, urinary mAlb, serum urea and serum Cr increased and eGFR decreased as the severity of the ascites increased (P<0.05). Urinary RBP was significantly higher in patients whose ascites did not respond or was refractory compared with those in whom it subsided (P<0.05), exhibiting a gradual increase over time in the former and a gradual reduction over time in the latter group (P<0.05). Increased urinary RBP and decreased eGFR in the early stage of cirrhosis ascites suggested impaired renal function, which serves a role in the process of ascites formation. These results indicated that urinary RBP is a sensitive indicator of early renal injury in patients with ascites due to cirrhosis and is closely associated with the progression of cirrhotic ascites.