编者按：今年的第68届美国肝病研究学会年会特别设置了 “State-of-the-Art Lecture”专题，邀请在慢加急性肝衰竭、肠道微生态与肝脏、器官移植和药物性肝损伤这四大研究领域的顶级大师分享最新学术动态，为与会医生和研究者们指点江山。

 

《国际肝病》有幸采访到来自美国梅奥诊所胃肠病学和肝病科的Patrick S. Kamath教授，他在“Leon Schiff State-of-the-Art Lecture”专题中介绍了慢加急性肝衰竭（ACLF）不同亚型的病理生理差异、如何量化多器官功能衰竭风险，以及如何识别可能受益于肝移植的患者。

 

一、不同亚型ACLF的治疗和转归差异？

 

慢加急性肝衰竭（ACLF）的定义为在慢性肝病、代偿期或失代偿期肝硬化基础上的肝功能突然恶化，特征为肝衰竭和肝外器官衰竭。

 

根据慢加急性肝衰竭的诱发因素和基础疾病不同，进一步分为三个亚型：A型是叠加于慢性肝病基础上，常见如HBV再激活，其表现与暴发性肝衰竭更为相似；第二种亚型为B型，诸如饮酒、病毒感染或药物性肝损伤等诱发事件，导致代偿期肝硬化患者发生慢加急性肝衰竭；第三种亚型为C型，这些诱发事件导致失代偿期肝硬化患者发生慢加急性肝衰竭。

 

每种亚型的治疗和转归不同，肝支持系统可能对B型最有效，也可能对A型有效，但是，可能对C型无效，因为失代偿期肝硬化患者的肝脏再生能力减弱。

 

二、如何量化多器官功能衰竭的风险？

 

慢加急性肝衰竭的严重度取决于基础肝病的严重度和诱发事件，此外，还取决于机体的炎症反应以及肝外器官的应答情况，这四种因素可影响患者的转归。目前，主要应用多器官衰竭评分对患者的转归进行预测，应用这些评分识别的患者处于疾病的较晚阶段，所以预测性能并不理想，迄今为止，这些评分对患者的治疗并无影响。

 

三、如何识别可能受益于肝移植的患者？

 

慢加急性肝衰竭患者发生肝脏和肝外器官衰竭，病情极其危重，大多数患者可以从肝移植受益。关键是确定是否有一组患者可以从肝支持系统受益，从而不需要接受肝移植，更重要的是需要考虑是否有一组患者病情过重，接受肝移植后也不能挽救生命的问题。当然，患者的器官衰竭数目越多，难以从肝移植受益的可能性就越大，对于这部分患者不应该考虑肝移植治疗。

 

Acute on chronic liver failure is defined as a sudden deterioration in liver function with underlying chronic liver disease, cirrhosis (either compensated or decompensated), and characterized by liver failure and extrahepatic organ failure. Because each one of the precipitating factors and the underlying conditions are different, we have tried to subclassify acute on chronic liver failure. Type A is when it is superimposed on chronic liver disease, and typically acute hepatitis B virus reactivation. This presents more like fundamental liver failure. The second variety, type B, is when precipitating events like alcohol, viruses or drugs cause compensated cirrhosis. The third type C is when these precipitating events are over decompensated cirrhosis. Each one of these is likely to have a different outcome and different management. Liver support systems would probably work best for type B, perhaps for type A, but probably not for type C, because in decompensated cirrhosis, the regenerative capacity of the liver is going to be reduced.

 

The severity of acute on chronic liver failure depends on the underlying severity of liver disease. It depends on the precipitating event. Thirdly, it depends on the inflammatory reaction. And the fourth is the extrahepatic organ response. Each one of these is likely to impact on the outcomes for the patient. Currently, we use scores of multiple organ failure, and these are really suboptimal, because they are identifying patients far too late. Thus far, we don’t think they impact management.

 

Because these patients are extremely sick with liver and extrahepatic organ failure, I think the majority would benefit from liver transplantation. The key here is trying to identify whether there is a group of patients who might benefit from liver support systems and would not require liver transplant. Probably more important is whether there is a group of patients who are too sick to transplant raising the question of futility. Certainly, the more organ failures you have, the less likely the patient is going to benefit from liver transplant and should be excluded from that option.