自身免疫性肝病中的重叠综合征

自身免疫性肝病是一组具有一定自身免疫基础的炎症性肝病,包括自身免疫性肝炎(autoimmune hepatitis,AIH)、原发性胆汁性肝硬化(primary biliary cirrhosis,PBC)、原发性硬化性胆管炎(primary sclerosing cholangitis,PSC)等,其共同特点是在肝脏出现病理性炎症损伤的同时、血清中可发     

自身免疫性肝病与其重叠综合征

自身免疫性肝病(autoimmune liver disease,AILD)是一组由异常自身免疫介导的肝、胆损伤性疾病。根据其临床表现、生化、免疫学、影像学和组织病理学特点,可分为以肝炎为主型,即自身免疫性肝炎(AIH)和以胆系损害及胆汁     

自身免疫性肝病重叠综合征诊治进展

自身免疫性肝病包括自身免疫性肝炎(AIH)、原发性胆汁性胆管炎(PBC)、原发性硬化性胆管炎(PSC)等。同时存在AIH、PBC或PSC特征者称为重叠综合征,若不及时接受治疗常可迅速进展至肝硬化和肝功能衰竭。早期诊断和治疗可显著改善预后。本文就近年自身免疫性肝病重叠综合征的诊治进展作一阐述。     

自身免疫性肝病重叠综合征的现状

自身免疫性肝病(autoimmune liver disease,A I L D)包括自身免疫性肝炎(a u t o i m m u n e hepatitis,AIH)、原发性胆汁性肝硬化(primary biliary cirrhosis,PBC)和原发性硬化性胆管炎(primary sclerosing cholangitis,PSC).AILD重叠综合征(overlap syndrome,OS)是指患者同时兼具AIH和PBC或PSC两种疾病的临床表现、生物化学、血清学、组织学以及影像学特征的一种罕见疾病状态.AILD OS主要分为AIH-PBC OS和AIH-PSC OS.前者多见于成人,后者多见于儿童.OS若无治疗,最终可致肝硬化或肝衰竭.高剂量熊去氧胆酸(ursodeoxycholic acid)与免疫抑制剂类固醇和/或硫唑嘌呤(azathioprine)联合使用通常被用于治疗AIH-PBC OS和AIH-PSC OS.目前,肝移植仍是治疗终末期OS患者的唯一有效方法.     

自身免疫性肝病重叠综合征的研究现状

自身免疫性肝病主要包括原发性胆汁性胆管炎(PBC)、自身免疫性肝炎(AIH)和原发性硬化性胆管炎(PSC)。同时或相继出现以上任意两种单独自身免疫性肝病特征者称为重叠综合征。其中,以PBC重叠AIH(PBC-AIH)相对最为常见。若不及时接受治疗可迅速进展至肝硬化和肝衰竭。就近年自身免疫性肝病重叠综合征的研究进展进行了总结。     

自身免疫性肝病重叠综合征的诊断和治疗

自身免疫性肝病重叠综合征是肝脏自身免疫性疾病的一种,肝硬化相关并发症发生率高、预后差。本文从流行病学、临床特点、诊断、治疗和预后等方面阐述了自身免疫性肝病重叠综合征的最新研究进展,重点总结了如何诊断并使用有效的方案治疗不同的重叠综合征,以期提高临床工作者对该类疾病的认识,及早的诊断和治疗该疾病。     

自身免疫性肝病重叠综合征的临床治疗探讨

目的探讨自身免疫性肝病重叠综合征的治疗方法,提高治疗的有效性与安全性。方法 32例自身免疫性肝炎（AIH）-原发性胆汁性肝硬化（PBC）重叠综合征患者,均给予强的松（0.5mg.kg-1.d-1）联合熊去氧胆酸（UDCA,15 mg.kg-1.d-1）治疗,回顾性分析治疗前、后不同时段患者疾病状态的变化,评价临床疗效。结果所有患者症状、体征明显减轻,生化指标、肝脏病理损害均明显改善,与入院前比较差异有统计学意义（P〈0.01或P〈0.05）。IgG、IgM、抗平滑肌抗体（SMA）、抗线粒体抗体（AMA）治疗前后无明显变化,差异无统计学意义（P〉0.05）。结论强的松联合UDCA短期内能明显减轻AIH-PBC患者的临床症状、体征,改善生化学和肝组织学指标,提高患者生存质量,治疗安全有效。     

中老年自身免疫性肝炎重叠综合征14例临床分析

目的探讨中老年自身免疫性肝炎(AIH)与慢性乙型病毒性肝炎重叠综合征患者的临床特征。方法采用国际自身免疫性肝炎小组新修订的描述性诊断标准,从确诊的50例中老年AIH患者中筛选出14例AIH/乙肝重叠综合征患者,分析比较中老年人AIH/乙肝重叠综合征和单纯AIH患者的生化和免疫学指标的特点。结果50例中老年AIH患者中,AIH/乙肝重叠综合征14例(占28%),单纯AIH36例(占72%)。AIH/乙肝重叠综合征患者丙氨酸氨基转氨酶(ALT)、天门冬氨酸氨基转氨酶(AST)、γ-球蛋白、ALT/ALP(碱性磷酸酶)、SMA、ANA效价明显高于单纯AIH患者;AIH/乙肝重叠综合症患者兼有AIH和乙肝的双重组织学特点。结论中老年人中单纯AIH与AIH/乙肝重叠综合征患者的生化检查、免疫学及肝组织病理学特征有差异,临床治疗选择药物时应区别对待。     

加强对自身免疫性肝病重叠综合征的认识

随着自身免疫性肝病研究的不断深入,发现许多自身免疫性肝病同时具有或随后表现出其他自身免疫性肝病的特征,临床上称为自身免疫性肝病重叠综合征.由于发病率越来越高以及本组疾病的病因不明、临床表现多样、诊断标准及治疗终点等诸多方面均有待于进一步探讨,因而加强对本组疾病的探索具有重要的意义.     

Autoimmune hepatitis and overlap syndromes

Autoimmune hepatitis (AIH) is an immune-mediated, autodestructive liver disease with hepatocytes as target cells, mostly affecting young women. Primary biliary cirrhosis (PBC) is also regarded as an autoimmune liver disease with bile duct epithelia as the target cells, resulting in a continuous loss of bile ducts. Both diseases may occur simultaneously in their full manifestations in about 10% to 20% of cases, thus constituting an overlap syndrome with PBC directing the course of the disease. AIH may also occur simultaneously with primary sclerosing cholangitis (PSC), with a frequency of between 2% and 8% of patients with PSC. In most cases, AIH precedes manifestation of PSC. In children, the overlap syndrome of AIH and PSC seems to make up an entity of its own: autoimmune sclerosing cholangitis.     

Autoimmune hepatitis and overlap syndromes

Autoimmune hepatitis is a well-established chronic liver disease. It primarily affects women, is characterized by circulating autoantibodies and elevated gammaglobulins and is associated with extrahepatic immune-mediated syndromes. Treatment regimens have remained unchanged for a number of years because of the high efficacy of steroid monotherapy, or combination therapy of azathioprine and steroids. In approximately 90% of patients remission of the disease is reached by medical therapy, which is usually administered lifelong because long-term remission after drug withdrawal is achieved in only 17% of patients. In 10% of patients treatment failure is observed. The challenge of remission induction involves the use of transplant immunosuppressants such as cyclosporine, mycophenolate moffetil, and tacrolimus. The challenge of maintenance therapy minimizing steroid side-effects involves the evaluation of topical steroids and the use of azathioprine monotherapy. Overlap syndromes occur in approximately 20% of autoimmune liver diseases. The diagnosis is broadly based on serological, biochemical, clinical and histological parameters. Most common are the overlap of autoimmune hepatitis and primary biliary cirrhosis, as well as autoimmune hepatitis with primary sclerosing cholangitis. These yet incompletely defined syndromes are an important differential diagnosis in the difficult-to-treat patient with autoimmune hepatitis.     

Scleroderma overlap syndromes

Scleroderma is a connective tissue disease that causes fibrosis and vascular abnormalities, but that also has an autoimmune component. Many patients with scleroderma have a positive antinuclear antibody, and there can be family histories of other connective tissue diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Some patients have features of scleroderma and other autoimmune conditions. This article will review recent literature to help in the understanding of scleroderma with overlap features. Recent reports of scleroderma overlap with rheumatoid arthritis suggest distinct features of diffuse scleroderma with positive Scl-70, pulmonary fibrosis, and later seropositive erosive rheumatoid arthritis. SLE rarely occurs with scleroderma. Sj?gren syndrome symptoms are common in scleroderma. In primary Sj?gren syndrome, anticentromere antibody positive patients have more Raynaud phenomenon. Antibodies that occur in scleroderma that are thought to be specific are present in other connective tissue diseases. For instance, Scl-70 antibody is reported in as many as 35% of patients with scleroderma but can be present in 25% of patients with SLE. Myositis or myopathy can be features of scleroderma. Scleroderma overlap with polymyositis is frequently anti-PM Scl antibody positive, whereas anti-Jo-1 does not normally occur in the overlap of scleroderma and polymyositis but is usually exclusively positive in polymyositis with arthritis and alveolitis. A better prognosis is found with PM Scl antibody in myositis. Vasculitis is not a typical feature of scleroderma, but has been reported. Eosinophilic fasciitis is rare, and the onset could be associated with simvastatin.     

Scleroderma overlap syndromes

Overlap features with diffuse scleroderma are rare. More commonly, other connective tissue diseases have features usually seen in the systemic involvement of scleroderma. The limited form of scleroderma (CREST) has interesting associations with primary biliary cirrhosis, whereas mixed connective tissue disease evolves toward a scleroderma-like picture with advancing years.     

Autoimmune overlapping syndromes

The overlap syndrome raises several questions. First could these patients have two coincident autoimmune diseases? Such possibility cannot be discarded in particular in the setting of consecutive occurrence of the two conditions (eg, PBC followed by AIH) and this is consistent with the fact that autoimmune diseases are associated with one another in about 5% to 10% of cases. Furthermore, it is presumed that they share similar genetic susceptibility. A second possibility could be that overlap syndrome represents the middle of a continuous spectrum of two autoimmune liver diseases. The systematic study of the relationships between elementary histologic lesions and biochemistries in "pure" PBC patients pleads strongly for such a hypothesis. Pure PBC is characterized by 2 different groups of elementary lesions that are not interrelated: first, florid bile duct lesions and bile duct paucity and second, lymphocytic piecemeal necrosis and lobular necro-inflammatory changes. Furthermore, the first set of lesions is selectively associated with biochemical cholestasis and IgM levels, whereas the second set of lesions is selectively associated with serum transaminase activities and IgG levels. These observations are consistent with the assumption that two main mechanisms are involved in the progression of liver injury in PBC. The first is bile duct destruction leading to chronic cholestasis and fibrosis of biliary pattern. The second is lymphocytic piecemeal necrosis of hepatocytes, which tends to lead to cirrhosis, the pattern of which resembles cirrhosis following various forms of chronic active hepatitis. The author has therefore speculated that the picture of pure PBC results always forms the clinical and biochemical expression of the two main histologic lesions, and combination of these processes might explain why the spectrum of PBC varies from typical PBC to AIH or PBC overlap. A third hypothesis is that an exaggerated hepatitic response in PBC is associated with the HLA haplotype commonly seen in AIH, eg, B8, DR3, DR4. Further studies are obviously needed to confirm such an attractive hypothesis. Other possible explanation for the concurrent occurrence of features of both conditions in the same individual includes the selective modulation of HLA class 1, class 2 expression and Rantes by cholestasis itself and in particular bile acids. It is conceivable that the degree of interface and lobular inflammation in PBC and PSC may be modulated by chemokines, their receptors, and the parenchymal concentrations of individual bile acids that are all, at least in part, genetically determined.     

Myositis overlap syndromes.

Myositis-overlap syndromes are characterized by a heterogeneous group of clinical syndromes of which many are closely linked with specific autoantibodies. Clinical and laboratory-based research into this fascinating group of syndromes have given us clues in elucidating the role of immunogenetic, environmental influences on the etiopathogenesis of autoimmune disease. Patients positive for anti-snU1 RNP antibody often present with a constellation of "autoimmune-related" clinical features, often not fulfilling the diagnostic criteria for a single disease entity. Controversy remains as to whether this represents a single disease entity, namely mixed connective tissue disease, or an undifferentiated autoimmune rheumatic/overlap syndrome. Anti-PM-Scl antibodies are linked with myositis-scleroderma overlap and generally tend to follow a benign course, often responding well to minimal immunosuppression. More recently the number of anti-tRNA synthetase antibody-associated overlap syndromes has expanded; antibodies to the autoantigen histidyl-tRNA synthetase (Jo1) being the commonest and best characterized. Patients with these antibodies often have severe interstitial lung disease and the poorest prognosis, often necessitating aggressive immunosuppressive therapy.