Assessment of glomerular filtration rate in patients with cirrhosis: available tools and perspectives

: Renal dysfunction often complicates the course of liver disease, resulting in higher morbidity and mortality. The accurate assessment of kidney function in these patients is essential to early identify, stage and treat renal impairment, as well as to better predict the prognosis, to prioritize the patients for liver transplantation and to decide whether to opt for simultaneous liver-kidney transplant. This review analyzes the available tools for direct or indirect assessment of glomerular filtration rate, focusing on flaws and strengths of each method in the specific setting of cirrhosis. The aim is to deliver a clear-cut view on this complex issue, trying to point out which strategies to prefer in this context, especially in the peculiar setting of liver transplantation. Moreover, a glance is given on future promising tools for glomerular filtration rate assessment, including new biomarkers and new equations specifically modeled for the cirrhotic population.