血浆胱抑素C作为失代偿期肝硬化肾小球滤过标志物的诊断价值

Diagnostic value of plasma cystatin C as a glomerular filtration marker in decompensated liver cirrhosis.

作者信息

Orlando Rocco, Mussap Michele, Plebani Mario, Piccoli Pierpaolo, De Martin Sara, Floreani Maura, Padrini Roberto, Palatini Pietro

机构信息

Department of Medical and Surgical Sciences, University of Padua, Largo E. Meneghetti 2, 35131 Padua, Italy.

出版信息

Clin Chem. 2002 Jun;48(6 Pt 1):850-8.

PMID:12029000

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 x min(-1) x 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 micromol/L, and 72 and 72 mL x min(-1) x 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.

摘要

背景

在失代偿期肝硬化患者中，血浆肌酐浓度及计算得出的肌酐清除率作为肾小球滤过率（GFR）指标，其价值有限。我们评估了血浆胱抑素C作为此类患者GFR指标的情况。

方法

我们研究了36例失代偿期肝硬化患者和56例非肝硬化对照者，两组均包括肾功能正常和受损的个体。所有个体均通过菊粉清除率测定GFR，GFR值<72 mL·min⁻¹·1.73 m⁻²被视为降低。我们测定了血浆中的胱抑素C和肌酐，并计算（根据血浆浓度）和测定肌酐清除率，其判断标准分别为1.25 mg/L、115 μmol/L以及72和72 mL·min⁻¹·1.73 m⁻²。

结果

对照组和肝硬化患者的血浆胱抑素C浓度相似，在常用切点时，两组检测降低GFR的敏感性相似（分别为73%和88%）。肝硬化患者的血清肌酐明显较低，在所有GFR值时大多仍在参考区间内；肌酐在肝硬化患者中的诊断敏感性远低于对照组（23%对64%）。计算得出的肌酐清除率的诊断敏感性也较低（对照组为53%对100%），而测定的肌酐清除率在对照组和肝硬化患者中的敏感性相似（分别为86%和81%）。ROC分析显示，这四个变量在肝硬化患者中的诊断准确性相似。然而，分析还表明，只有采用与一般人群不同的参考区间，血浆肌酐和计算得出的肌酐清除率才能获得较好的诊断准确性。