介绍
过去十年中,乙肝治疗进展飞快。药物的抗病毒效显明显且右安全用于肝硬化病人这一有效特性拓宽了乙肝治疗的适应人群。然而,现在的治疗手段并不能彻底消除病毒。抗病毒治疗价格昂贵,可能伴发耐药性及不良反应,再加上并不是所有慢性乙肝病毒感染者都会发展成肝硬化、肝衰竭或肝癌,对乙肝治疗手段仍有许多疑问。首先,哪些人应该接受治疗?其次,以何种药物开始?再次,什么时候可以终止治疗?最后,若治疗失败,如何处理?解决这些问题前先回顾讨论下慢性乙肝病毒感染的自然史,及已准许许治疗手段的安全性和有效性。
慢性乙肝病毒感染的自然史
感染乙肝病毒的阶段
慢性乙肝病毒感染的自然史分为四个阶段,但并非所有病人都会经历全部阶段(表1) [1,2]
免疫耐受期
免疫耐受期的特点是出现乙肝e抗原(HBeAg),血清中乙肝病毒DNA数量多, (ALT)常常正常。处于免疫耐受期的多数病人有轻微的肝脏损伤,随后复查结果预后非常好持续达10年。[3]
免疫清除期
免疫清除期(或者称乙肝e抗原阳性的慢性肝炎) 的特点是出现乙肝e抗原(HBeAg), 血清中乙肝病毒DNA数量多,持续或间歇性升高,并常常伴随有肝脏炎症。这个阶段内,率在每年10–20%。E抗原转阴经常发生但并不总是伴随谷丙转氨酶数量突增发生。[4,5]病人在40岁之前e抗原自然转阴的预后良好。[6]
非活动期
非活动(携带者)期的特点是e抗原消失,e抗体(anti-HBe)出现,数量持续正常,血清中乙肝病毒DNA数量少或检测不到。这个阶段的病人预后非常好。[7]
复发期
复发期(也称作e抗原阴性的慢性乙肝)的特点是e抗原消失,e抗体出现,血清中病毒DNA数量和谷丙转氨酶(ALT)数量持续或间歇性升高,
并伴有肝脏炎症。 这个阶段的病人通常已年老,且比期他阶段
的病人有更严重的肝脏疾病。另外,这些病人多数有前核心或
核心突变的乙肝病毒变体,这样的突变病毒可以阻止或减少e抗原的产生。[8]
Natural history of chronic HBV infection
Phases of HBVinfection
The natural course of chronicHBV infection consists of four phases, although not all patients go through allphases (Figure 1).1,2
Immune tolerant phase
The immune tolerant phase ischaracterized by the presence of hepatitis B e antigen (HBeAg), high serum HBVDNA levels and persistently normal levels of alanine aminotransferase (ALT).Most patients in the immune tolerant phase have minimal liver injury andprognosis is favorable during follow-up of up to 10 years.3
Immuneclearance phase
The immune clearance phase (orHBeAg-positive chronic hepatitis) is characterized by the presence ofHBeAg, high serum HBV DNA levels, persistently or intermittently increased ALTlevels and active inflammation in the liver. During this phase, spontaneousHBeAg seroconversion occurs at a rate of 10–20% per year. HBeAg seroconversionis frequently but not always accompanied by a sudden increase in ALT levels.4,5 Patients who undergo spontaneous HBeAg seroconversion before theage of 40 have a good prognosis.6
Inactive phase
The inactive (carrier) phase ischaracterized by the absence of HBeAg, presence of HBe antibody (anti-HBe),persistently normal ALT levels and low or undetectable levels of serum HBV DNA.Patients in this phase have a favorable prognosis.7
Reactivationphase
The reactivation phase (alsoknown as HBeAg-negative chronic hepatitis B) is characterized by the absence ofHBeAg, presence of anti-HBe, intermittently or
persistently elevated serum HBVDNA and ALT levels, and active inflammation in the liver. Patients in this phaseare usually older and have more advanced liver disease than patients in theother phases of the disease. In addition, most of these patients have precoreor core promoter HBV variants that prevent or decrease the production of HBeAg.8
欢迎光临 肝胆相照论坛 (http://hbvhbv.info/forum/) | Powered by Discuz! X1.5 |