Dipartimento di Medicina Interna, Viale G.B. Morgagni, 85, 50134 Firenze, Italy.
Best Pract Res Clin Gastroenterol. 2011 Apr;25(2):281-90. doi: 10.1016/j.bpg.2011.02.009.
Liver cirrhosis is a frequent consequence of the long clinical course of all chronic liver diseases and is characterized by tissue fibrosis and the conversion of normal liver architecture into structurally abnormal nodules. Portal hypertension is the earliest and most important consequence of cirrhosis and underlies most of the clinical complications of the disease. Portal hypertension results from an increased intrahepatic resistance combined with increased portal (and hepatic arterial) blood flow. The fibrotic and angio-architectural modifications of liver tissue leading to increased intrahepatic resistance and the degree of portal hypertension seem to be highly correlated until HVPG values of 10-12 mmHg are reached. At this stage, which broadly represents the turning point between 'compensated' and 'decompensated' cirrhosis, additional extra-hepatic factors condition the further worsening of PH. Indeed, a HVPG ≥10-12 mmHg represents a critical threshold beyond which chronic liver disease becomes a systemic disorder with the involvement of other organs and systems. The progressive failure of one of the fundamental functions of the liver, i.e. the detoxification of potentially harmful substances received from the splanchnic circulation and particularly bacterial end-products, is responsible for the establishment of a systemic pro-inflammatory state further accelerating disease progression. The biology of liver cirrhosis is characterized by a constant stimulus for hepatocellular regeneration in a microenvironment characterized by chronic inflammation and tissue fibrosis, thus representing an ideal condition predisposing to the development of hepatocellular carcinoma (HCC). In reason of the significant improvements in the management of the complications of cirrhosis occurred in the past 20 years, HCC is becoming the most common clinical event leading to patient death. Whereas evidence clearly indicates reversibility of fibrosis in pre-cirrhotic disease, the determinants of fibrosis regression in cirrhosis are not sufficiently clear, and the point at which cirrhosis is truly irreversible is not established, either in morphologic or functional terms. Accordingly, the primary end-point of antifibrotic therapy in cirrhotic patients should be the reduction of fibrosis in the context of cirrhosis with a beneficial impact on portal hypertension and the emergence of HCC.
肝硬化是所有慢性肝病长期临床过程中的常见后果,其特征是组织纤维化和正常肝结构转化为结构异常的结节。门脉高压是肝硬化最早和最重要的后果,是该疾病大多数临床并发症的基础。门脉高压是由于肝内阻力增加和门脉(和肝动脉)血流量增加引起的。导致肝内阻力增加和门脉高压程度的肝组织纤维化和血管结构改变似乎与 HVPG 值达到 10-12mmHg 之前高度相关。在这个阶段,广泛代表“代偿”和“失代偿”肝硬化之间的转折点,肝外因素进一步加重 PH。事实上,HVPG≥10-12mmHg 代表一个关键的阈值,超过这个阈值,慢性肝病就会成为一种系统性疾病,涉及其他器官和系统。肝脏的基本功能之一(即从肠循环中接收的潜在有害物质解毒,特别是细菌终产物)的逐渐衰竭,导致全身炎症状态的建立,进一步加速疾病的进展。肝硬化的生物学特征是在慢性炎症和组织纤维化的微环境中,肝细胞持续再生的刺激,因此代表了易于发展肝细胞癌(HCC)的理想条件。由于过去 20 年来肝硬化并发症管理的显著改善,HCC 正在成为导致患者死亡的最常见临床事件。尽管明确的证据表明,在肝硬化前疾病中纤维化是可逆的,但肝硬化中纤维化消退的决定因素尚不清楚,也没有确定肝硬化在形态学或功能上是否真正不可逆。因此,肝硬化患者抗纤维化治疗的主要终点应该是在肝硬化背景下减少纤维化,对门脉高压和 HCC 的发生有有益影响。