Diagnostic and Prognostic Role of Biomarkers in Patients with Cirrhosis and AKI

Patients with cirrhosis have a high prevalence of renal dysfunction. The susceptibility to renal dysfunction is due to both the severe splanchnic arterial vasodilation and the systemic inflammation observed in these patients. An accurate assessment of renal function is recommended in all patients with cirrhosis. Meanwhile, despite its limitations, serum creatinine is still the most used biomarker for the estimation of glomerular filtration rate (GFR) and the assessment of acute kidney injury (AKI) in patients with cirrhosis. New renal biomarkers such as cystatin C, NGAL, IL-18, TIMP-2, etc. can improve the assessment of GFR and the prognostic stratification in these patients.

AKI is a life-threatening complication and needs timely management. AKI can be further categorized into four types in patients with cirrhosis and ascites, including: Acute tubular necrosis (ATN-AKI) - 41.7%.;Prerenal failure (Prerenal-AKI) - 38%; Hepatorenal syndrome (HRS-AKI) - 20%; Post-renal failure (Post-renal AKI) - 0.3%.

The differential diagnosis between HRS and ATN is tricky in clinical practice. The nature of HRS can be predominantly functional or associated with some degree of parenchymal damage in a continuum spectrum of kidney injury from prerenal-AKI to ATN-AKI. New biomarkers of kidney injury, such as neutrophil gelatinase-associated lipocalin and IL-18, represent useful tools in refining the discrimination between HRS and ATN. A study has shown that the sensitivity and specificity of IL-18 and NGAL for the diagnosis of ATN were 0.8, 0.86 and 0.88, 0.82, respectively.

Due to its higher sensitivity, NGAL is seen as a promising tool in phenotyping AKI and predicting its evolution in patients with cirrhosis.