Serum cystatin C in advanced liver cirrhosis and different stages of the hepatorenal syndrome

ABSTRACT

The hepatorenal syndrome [HRS] is classified into two types [HRS-2 and HRS-1] based on mild or high serum creatinine elevations. Although it has been identified as an early marker of renal dysfunction, data are lacking about cystatin C across the wide range of renal changes in end-stage liver disease. This study investigates serum cystatin C and creatinine in patients with advanced liver cirrhosis and classic HRS throughout its whole spectrum. Serum cystatin C immunonephelometric measurements were obtained from 65 Child-Pugh C patients 32 with normal creatinine, 17 with HRS-2 and 16 with HRS-1. The glomerular filtration rate [GFR] was estimated according to modification of diet in renal disease [MDRD] and the Hoek formulae [creatinine- and cystatin C-based, respectively] with staging of renal dysfunction severity into an increasing order from 1 to 5. Early HRS was identified by the raised cystatin C in 56.3% of patients having normal creatinine. Cystatin C correlated significantly with creatinine in HRS-2 [r = 0.74; p < 0.001] and showed a significantly lower multiplication ratio [folds of rise] compared to creatinine in HRS-1 patients [p < 0.01]. There was no satisfactory agreement between MDRD and Hoek GFR staging [k = 0.29]. The 'early' HRS identified by a rise in cystatin C in cases with advanced cirrhosis was found to be common and can be added to the already classified two types, as type-3 HRS. Compared to creatinine, cystatin C provides no better information in HRS-2, and underestimates the renal deterioration in HRS-1. Further studies are required to determine the course of the early HRS