Hepatology and Liver Intensive Care Unit, Hospital Beaujon, Clichy, France.
J Hepatol. 2010 Apr;52(4):605-13. doi: 10.1016/j.jhep.2009.11.025. Epub 2010 Jan 7.
The MELD score has shown that, besides markers of liver function, serum creatinine has a strong prognostic value in cirrhosis. However, even though creatinine has a good prognostic value, it is an inaccurate marker of renal function in cirrhosis. Creatinine and creatinine-based equations tend to overestimate glomerular filtration rate (GFR), and creatinine clearance from timed urine collection also overestimates GFR. Hence, clearance of exogenous markers such as iohexol remains the only reliable method for assessing precisely GFR in cirrhosis. Whereas these investigations are limited by their costs and complexity, and they can hardly be repeated at short intervals, serum cystatin C could be an alternative, although it needs further validation. Accurate markers and/or specific equations are therefore still needed to assess GFR in cirrhotic patients. Pre-renal failure and hepatorenal syndrome (HRS) are the main causes of acute renal failure in cirrhosis. Both result from decreased renal blood flow and both can result in acute tubular necrosis. HRS is not always fully reversible with liver transplantation possibly due to underlying chronic kidney damage. A number of cirrhotic patients with acute renal failure may also have chronic kidney damage ("acute-on-chronic renal failure"); furthermore, cirrhotic patients frequently have co-morbidities such as diabetes that may result in chronic impairment in renal function. Since conventional urinary markers are biased in cirrhosis, a biopsy is the only way to document and quantify renal lesions; moreover, transvenous route should be preferred to percutaneous route. In candidates for transplantation, attention should therefore be focused on vascular lesions which may represent a risk factor for nephrotoxicities induced by calcineurin-inhibitors.
MELD 评分表明，除了肝功能标志物外，血清肌酐在肝硬化中具有很强的预后价值。然而，尽管肌酐具有良好的预后价值，但它在肝硬化中是肾功能的一个不准确标志物。肌酐和基于肌酐的公式往往高估肾小球滤过率（GFR），而计时尿液采集的肌酐清除率也高估了 GFR。因此，清除外源性标志物如碘海醇仍然是评估肝硬化中 GFR 的唯一可靠方法。虽然这些检查受到其成本和复杂性的限制，并且很难在短时间内重复进行，但血清胱抑素 C 可能是一种替代方法，尽管它需要进一步验证。因此，仍然需要准确的标志物和/或特定的公式来评估肝硬化患者的 GFR。急性肾损伤的主要原因是前肾性衰竭和肝肾综合征（HRS）。两者均源于肾血流量减少，均可导致急性肾小管坏死。HRS 可能由于潜在的慢性肾损伤而并非总是完全可逆的，这可能与肝移植有关。许多急性肾损伤的肝硬化患者也可能存在慢性肾损伤（“急性肾损伤慢性化”）；此外，肝硬化患者经常患有合并症，如糖尿病，这可能导致肾功能慢性损害。由于常规尿液标志物在肝硬化中存在偏差，因此活检是唯一能够记录和量化肾脏病变的方法；此外，应优先选择经静脉途径而不是经皮途径。因此，在移植候选者中，应注意血管病变，这可能是钙调神经磷酸酶抑制剂引起的肾毒性的一个危险因素。
