Diagnostic Value of Plasma Cystatin C as a Glomerular Filtration Marker in Decompensated Liver Cirrhosis

Abstract

Background: Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. Methods: We studied 36 patients with decompensated liver cirrhosis and 56 noncirrhotic controls, both groups including individuals with normal and impaired renal function. GFR was measured in all individuals by inulin clearance, with values <72 mL · min−1 · 1.73 m−2 considered decreased. We measured cystatin C and creatinine in plasma and calculated (from plasma concentrations) and measured creatinine clearances, using for them decision points of 1.25 mg/L, 115 μmol/L, and 72 and 72 mL · min−1 · 1.73 m−2, respectively. Results: Plasma cystatin C concentrations were similar in controls and cirrhotics and, at the usual cutpoint, could detect decreased GFR with similar sensitivities in the two groups (73% and 88%, respectively). Serum creatinine was markedly lower in cirrhotics and remained mostly within the reference interval at all GFR values; the diagnostic sensitivity of creatinine was much lower in cirrhotics than in controls (23% vs 64%). Lower diagnostic sensitivity was also observed for calculated creatinine clearance (53% vs 100% in controls), whereas similar sensitivities were found for measured creatinine clearance (86% and 81%) in controls and cirrhotics, respectively. ROC analysis showed that all four variables had similar diagnostic accuracies in cirrhotic patients. However, it also revealed that good diagnostic accuracies for plasma creatinine and calculated creatinine clearance can be obtained only if reference intervals different from those used for the general population are adopted. Conclusions: Plasma cystatin C concentration is an accurate GFR marker in cirrhotic patients. Plasma creatinine concentration and calculated creatinine clearance are of no practical value, as their reference values vary with the severity of the liver disease.

Novel approaches to assessing renal function in cirrhotic liver disease

“…8 © 2007 The Japan Society of Hepatology Orlando et al compared cystatin C with serum creatinine in decompensated cirrhotic patients and used inulin clearance to measure GFR. 9 In 36 decompensated post-viral cirrhotic patients, cystatin C was the most sensitive indicator of a low GFR in cirrhotic patients. There were no differences between the reciprocals of cystatin C and serum creatinine and it was suggested that this may relate to the methodology of creatinine measurement; enzymatic PAP method as opposed to the less accurate Jaffe reaction.…”

Glomerular filtration rate is an independent factor of mortality in patients with decompensated cirrhosis

“…32 Based on the inaccuracy of serum Cr, different Cr-based mathematical equations have been used, particularly the MDRD formula. Serum CysC has been considered a more sensitive indicator of renal function, compared to serum Cr, in cirrhosis, [33][34][35] and thus cystatin-based GFR formulae (e.g. Hoek and Larsson) have been proposed.…”

Review article: renal function assessment in cirrhosis – difficulties and alternative measurements

“…Indeed, cystatin C may give similar or more information, compared to Cr. 54,55 In cirrhotics with HRS, cystatin C is at least as accurate as Cr. 56 In a recent study, Gerbes et al evaluated 97 patients and concluded that cystatin C is a useful tool for renal function assessment, especially in patients with endstage liver disease, in women and for earlier diagnosis of renal impairment, compared to enzymatic Cr and C-G formula.…”