CD4~+CD25~+调节性T细胞在自身免疫性肝炎发病机制中的作用

自身免疫性肝炎( autoimmune hepatitis,AIH)是一种免疫介导的、慢性肝脏炎症性疾病,以高y球蛋白血症、自身抗体阳性、肝组织学界面炎和免疫抑制治疗有效为特征[1].尽管AIH的发病机制尚未完全阐明,但多项证据表明,遗传易感性、分子模拟学说及调节性T细胞(regulatory T cells,Treg)缺陷参与了自身免疫性肝损伤.免疫系统本身具有区分自己与非己的功能,并可建立及维持自身免疫耐受,以抑制自身抗原的免疫反应,进而预防自身免疫[2].CD4+ CD25+ Treg细胞在维持机体内环境稳定和维持自身免疫耐受方面起重要作用[3].而自身免疫性疾病的发生正是这种免疫耐受被打破,机体不能维持内环境稳定的结果.近年来的研究表明,Treg细胞功能缺陷可能是AIH发病的基础之一[4].本文就CD4+ CD25+ Treg细胞在AIH发病机制中的作用综述如下.     

Overlap syndromes with autoimmune hepatitis in chronic cholestatic liver diseases

Conditions exhibiting features of two different autoimmune liver diseases are commonly designated overlap syndromes, although there is no current agreement on what constitutes an overlap syndrome or specific diagnostic criteria. As in the classic autoimmune liver diseases, such as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), the etiology is unknown but presumed to be related to alterations of immune regulation. Distinction of these clinical entities is important for management as outcomes may differ from outcomes of patients with diagnosis of classic autoimmune liver diseases. Due to their presumed rarity, no large therapeutic trials are available and treatment of overlap conditions is empirical and based upon extrapolation of data from the primary autoimmune liver diseases. PBC–AIH overlap is the most frequently described overlap syndrome and may be associated with a poor prognosis. This may represent an important and unrecognized cause of resistance to ursodeoxycholic acid in patients with PBC. PSC–AIH overlap is less commonly reported. Prognosis may be better than in patients with PSC alone; however, worse than in patients with AIH alone. Further studies are needed for determining diagnosis, natural history and optimal therapeutic strategies of overlap syndromes of autoimmune liver disease.     

自身免疫性肝病与慢性乙型病毒性肝病超声影像对比分析

探讨自身免疫性肝病与慢性乙型肝病的超声表现的异同点,通过单因素、非条件Logistic回归测得AIH与CHB在性别、肝脏大小方面,存在明显差别(P<0.001);中晚期PBC与乙肝肝硬化超声表现在肝脏大小、肝脏回声(P<0.001、P=0.047)方面存在明显差异。AIH与CHB,PBC与乙肝肝硬化超声表现不同。     

The future of autoimmune liver diseases – Understanding pathogenesis and improving morbidity and mortality

Autoimmune liver diseases (AILD), namely autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), are rare diseases. These days, patients with PBC almost never require liver transplantation. When treated early with ursodeoxycholic acid patients have a normal life expectancy if the disease is diagnosed at an early stage and the patients respond to treatment. Patients with AIH often go into remission with first‐line therapy including corticosteroids alone or in combination with azathioprine. Nevertheless, about one quarter of patients already developed cirrhosis at diagnosis. Those who do not respond to first line standard of care (SOC) have significant liver‐related morbidity and mortality. No approved second‐ or third‐line treatments are available and the drugs are selected based on limited case series and personal experience. Larger trials are needed to develop efficient therapies for difficult‐to‐treat AIH patients. No treatment has been found to alter the natural course of disease in patients with PSC except for liver transplantation. Identifying PSC patients at risk of developing cholangiocarcinoma (CCA) is another unmet need. Current research in all AILD including AIH, PBC and PSC, focuses on improving our understanding of the underlying disease process and identifying new therapeutic targets to decrease morbidity and mortality.     

Epidemiology of autoimmune liver disease

Primary biliary cirrhosis (PBC), autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC) are chronic liver diseases that likely have an autoimmune basis to their pathogenesis. Although significant strides have been made in the clinical management of these conditions, their pathogenesis remains obscure. Understanding of various epidemiological factors may shed light on predisposing or causative factors for these diseases. Most is known about the epidemiology of PBC, with only minimal information on that of PSC and AIH. In this review, the current data on the epidemiology of PBC, AIH and PSC are summarized and suggestions are made for future work in this important area.     

自身免疫性肝炎患者肝内调节性T细胞的数量变化及其意义

目的 研究自身免疫性肝炎(AIH)患者外周血及肝内CD4+ CD25+调节性T细胞（Treg细胞）数量和功能变化.方法 应用流式细胞技术,比较正常人（25例）、慢性乙型肝炎(CHB)患者（18例）和AIH患者（25例）外周血中Treg细胞的变化;应用免疫组织化学染色方法进行Foxp3染色,比较CHB患者（15例）和AI...     

自身免疫性肝病诊断与治疗进展

自身免疫性肝病是一组由自身免疫介导的慢性肝胆系统损伤性疾病,主要包括自身免疫性肝炎、原发性胆汁性肝硬化及原发性硬化性胆管炎.本文就自身免疫性肝病的诊断与治疗进展进行综述.     

Spectrum of autoimmune liver diseases in western India

BACKGROUND AND AIM: The prevalence and spectrum of autoimmune liver diseases (AILDs) in India are rarely reported in comparison to the West. METHOD: During a study period of 7 years, all patients with chronic liver diseases (CLDs) were evaluated for the presence of AILDs on the basis of clinical, biochemical, imaging, serological, and histological characteristics. RESULTS: Of a total of 1760 CLD patients (38.1% females), 102 patients (5.7%) had an AILD. A total of 75 (11.2%) female patients had an AILD. Among males, 27 (2.4%) had an AILD. The prevalence of AILDs in women increased from 11.2% to 45.7% and in men from 2.4% to 10.3%, after excluding alcohol, hepatitis B virus, and hepatitis C virus as a cause of CLD. Of the AILDs, autoimmune hepatitis (AIH) was present in 79 patients (77.4%), followed in descending order by primary biliary cirrhosis (PBC) in 10 patients (9.8%), PBC/AIH true overlap syndrome in six patients (5.8%), primary sclerosing cholangitis (PSC) in five patients (4.9%), and PBC/AIH switchover syndrome in two patients (1.9%). None had PSC/AIH or PBC/PSC overlap syndrome. Associated known autoimmune diseases were found in 40 (39.2%) patients. CONCLUSIONS: AILDs are not uncommon in India. They should be suspected in all cases of CLDs, especially in middle-aged women who do not have problems with alcoholism and who are without viral etiology, as well as in all patients with known autoimmune diseases.     

Occult hepatitis B virus infection in patients with autoimmune liver diseases

Background: Occult hepatitis B virus (HBV) infection is characterized by undetectable serum HBV surface antigen (HBsAg) but detectable HBV‐DNA in serum or liver. Aims: To determine the prevalence and clinical impact of occult HBV in autoimmune liver diseases as similar data are missing. Methods: One hundred and ninety‐six sera samples from HBsAg‐negative patients, including 66 autoimmune hepatitis (AIH), 93 primary biliary cirrhosis (PBC) and 37 primary sclerosing cholangitis (PSC), were investigated for HBV‐DNA using the polymerase chain reaction (PCR) before treatment initiation. One hundred and three serial samples from 38 AIH patients under immunosuppression and 282 selected blood donors (HBsAg negative; antibodies to HBV‐core antigen positive) were also investigated. Fourteen available paraffin‐embedded AIH liver samples were also investigated for HBV‐DNA by nested‐PCR. Results: Hepatitis B virus DNA was detected in the serum of 24/196 patients (12.2%) and 0/282 donors (P=0.0000). Nine patients had AIH (13.6%), eight had PBC (8.6%) and seven had PSC (18.9%) (P=0.0000 vs healthy). HBV‐DNA detection in AIH livers was higher than in serum. HBV‐DNA was associated neither with HBV markers nor with epidemiological, laboratory and clinical data. Serial testing of AIH patients revealed two HBV‐DNA‐negative patients before treatment becoming positive during treatment, while all HBV‐DNA‐positive patients before immunosuppression became negative. Conclusion: Based mainly on serum HBV‐DNA, we found a significant proportion of autoimmune liver disease patients with occult HBV compared with donors. However, taking into account our results in a small number of liver tissues, it should be emphasized that occult HBV could be even higher when both serum and liver specimens are investigated. Occult HBV does not seem to affect the clinical and laboratory features of the diseases, while AIH patients with occult HBV under immunosuppression do not deteriorate during follow‐up.     

New insights into autoimmune liver diseases.

Autoinflammatory liver disease represents an important aspect of global hepatological practice. The three principal disease divisions recognized are autoimmune hepatitis, primary sclerosing cholangitis and primary biliary cirrhosis. Largely, but not exclusively, these diseases are considered to be autoimmune in origin. Increased recognition of outlier and overlap syndromes, changes in presentation and natural history, as well as the increased awareness of IgG4-associated sclerosing cholangitis, all highlight the limitations of the classic terminology. New insights continue to improve the care given to patients, and have arisen from carefully conducted clinical studies, therapeutic trials, as well as genetic and laboratory investigations. The challenges remain to treat patients before liver injury becomes permanent and to prevent the development of organ failure.     

Diagnostic and therapeutic implications of bile duct injury in autoimmune hepatitis.

BACKGROUND: Bile duct injury is not a feature of classical autoimmune hepatitis (AIH), but it has been described in variant forms of the disease. AIMS: Our goals were to assess the similarity of AIH with bile duct injury to classical disease and to evaluate the possibility of concurrent primary biliary cirrhosis (PBC). METHODS: Fifteen patients with bile duct injury were compared with 151 patients with classical AIH. Patterns of nuclear immunofluorescence and the frequency and nature of autoantibodies associated with AIH and PBC were determined. RESULTS: Patients with bile duct injury had the same nuclear-staining patterns, frequency and nature of autoantibodies, and genetic risk factors as the comparison group. Features specific for PBC, including the multiple nuclear dot pattern of immunofluorescence and antibodies to the M2 antigens, Sp100 and nuclear pore complex antigen, gp210, did not distinguish them from classical disease. Remission and treatment failure occurred with similar frequencies in both groups. CONCLUSIONS: Patients with AIH and bile duct injury lack features of PBC, and they respond as well to corticosteroid therapy as patients with classical disease. Background bile duct changes should not alter the diagnosis or treatment of AIH.     

Deficiency of forkhead box P3 and cytotoxic T-lymphocyte-associated antigen-4 gene expressions and impaired suppressor function of CD4+CD25+ T cells in patients with autoimmune hepatitis

Aim:  Recently, forkhead box P3 (Foxp3), cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR), and CD28 were identified as the key molecules that control the development and activation of CD4+CD25+ regulatory T cells (T-reg). We investigated the expression pattern of these molecules on T-reg, and investigated the ability of T-reg to produce cytokines in patients with autoimmune hepatitis (AIH).
Methods:  Fifteen patients with AIH and nine healthy patients were included. To determine the frequency of T-reg, a two-color flow cytometry analysis was performed. T-reg were isolated using immunomagnetic beads, and the mRNA levels of Foxp3 , CTLA-4, GITR , and CD28 were quantified by real-time polymerase chain reaction (PCR). The ability of T-reg to produce interferon-γ, interleukin (IL)-10, transforming growth factor-β, and tumor necrosis factor-α after stimulation by OKT3 was evaluated by measuring the levels of mRNA in T-reg by real-time PCR.
Results:  The frequency of T-reg was increased in AIH. The mRNA levels of Foxp3 and CTLA-4 were significantly lower in AIH. The ability of T-reg to produce IL-10 was impaired in AIH.
Conclusion:  We speculate that the inferiority of the Foxp3 and CTLA-4 gene expressions on T-reg results in the impaired suppressor function of T-reg, and eventually in the breakdown of self-tolerance.     

187例自身免疫性肝病的临床特点分析

目的分析自身免疫性肝病（AILD）的临床、生化及免疫学特点。方法分析北京大学人民医院2001年1月～2010年12月187例自身免疫性肝病患者的临床表现、生化及免疫学特点。结果 AILD的发病以40岁以上女性多见,30.5%（57/187）的患者确诊时已进展为肝硬化失代偿期。临床症状无特异性,自身免疫性肝炎（AIH）以ALT、IgG及γ球蛋白升高更为明显（P〈0.05）,而PBC以ALP、GGT、IgM升高更为明显（P〈0.05）。AILD患者常合并一种或多种肝外自身免疫病,AILD合并干燥综合症最为常见,AIH组及PBC组合并干燥综合症的发生率均达30%以上。AILD患者均有一种或多种自身抗体阳性,其中AIH组ANA阳性率为88.3%,AMA阳性率为7.5%（3/40）,AMA-M2阳性3.7%（2/54）;PBC组ANA阳性率为88.2%（97/110）,AMA阳性率为96.4%（81/84）,AMA-M2阳性率为94.4%（85/90）。AIH患者主要应用糖皮质激素治疗,其中共46例（59.7%）患者单用或联用UDCA治疗后肝脏酶学指标改善。结论生化、免疫学、自身抗体等检查对诊断与鉴别诊断具有重要意义。UDCA在AIH的治疗中有一定的作用。     

Thiopurine S-methyltransferase gene polymorphism in Japanese patients with autoimmune liver diseases.

BACKGROUND AND AIM: Thiopurine S-methyltransferase (TPMT) genotypes or phenotypes may be a predictive factor for azathioprine-induced toxicities. We investigated the genotypic status of TPMT to evaluate the risk of azathioprine-related adverse effects in Japanese patients with different liver diseases, including autoimmune hepatitis (AIH). METHODS: 49 patients with AIH, 67 with primary biliary cirrhosis (PBC), and 120 with hepatitis C virus (HCV) were examined. TPMT genotypes were determined by PCR-restriction fragment length polymorphism-based assays. RESULTS: The distribution of TPMT genotypes was 90% TPMT*1/TPMT*1, 8% TPMT*1/TPMT*3C, and 2% TPMT*3C/TPMT*3C in AIH, and 94% TPMT*1/TPMT*1, 4.5% TPMT*1/TPMT*3C, and 1.5% TPMT*3C/TPMT*3C in PBC. All except 1 patient with HCV had the TPMT*1/TPMT*1 genotype. Severe myelosuppression occurred in two of nine patients with AIH who received azathioprine, one of whom was homozygous for TPMT*3C. CONCLUSIONS: TPMT*3C variants are more frequent in patients with AIH or PBC than in patients with viral hepatitis or healthy volunteers in Japan. Pharmacogenetic screening for TPMT polymorphisms before commencing azathioprine therapy may help to prevent severe hematotoxicity in patients with TPMT deficiency.     

Celiac disease autoantibodies in severe autoimmune liver disease and the effect of liver transplantation

Background/aims: Celiac disease (CD) is associated with primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune hepatitis. We investigated the following: (i) the prevalence of tissue transglutaminase antibodies (tTGAs) and endomysial antibodies (EMAs) in end‐stage autoimmune liver disease (ESALD), (ii) the correlation among auto‐antibodies and the human leucocyte antigen (HLA) haplotype, and (iii) the effect of liver transplantation on antibody kinetics. Methods: Pretransplantation sera from 488 patients (310 with ESALD, and 178 with non‐autoimmune disease) were tested for tTGAs. Positive samples were also tested for EMAs, and retested 6–12 and ≥24 months post‐transplantation. Results were correlated with the HLA type of the recipient. Results: Serological evidence of CD was found in 3% (ESALD) vs. 0.6% (non‐autoimmune) of the patients (five‐fold increased risk in ESALD). The prevalence of tTGAs (14.2 vs. 5.4%, P=0.0001) and EMAs (4.3 vs. 0.78%, P=0.01) was significantly higher in patients with the HLA‐DQ2 or HLA‐DQ8 haplotypes. tTGAs and EMAs normalized in 94 and 100%, respectively, without gluten exclusion post‐transplantation. Post‐transplantation, of the five patients with symptoms of ‘classical’ CD, three improved. Intestinal lymphoma was diagnosed in another two cases with clinically ‘silent’ CD. Conclusions: Patients with ESALD, especially those who are HLA‐DQ2 or HLA‐DQ8 positive had a high prevalence of CD‐associated antibodies. Both tTGAs and EMAs decreased post‐transplantation without gluten withdrawal. Immunosuppression may improve symptoms of CD, but might not prevent progression to intestinal lymphoma.     

Autoimmune diseases of the liver, autoimmune hepatitis and primary biliary cirrhosis: Unfinished business

Autoimmune liver diseases (AILD) including autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) have attracted much attention since their discovery 50 years ago, but there remain items of unfinished business. These relate to disease susceptibility including genetic influences (HLA and non-HLA genes, genes associated with female predisposition, and others) and environmental influences (infections, chemicals, xenobiotics and medications). Also needed is better characterization of autoantigenic molecules, particularly the anti-F-actin specificity characteristic of AIH, shown here to have functional effects in vitro . Deeper analysis of T-lymphocyte function in AILD should reveal relative contributions of eachof the multiple subsets of T cells now being defined in studies on laboratory animals, CD4⁺, CD8⁺, Th1, Th2, Th17, memory subsets and regulatory subsets. Diagnostic immunology providers now offer high-performance assay formats that call for systematic clinical assessments to achieve standardization, calibration and optimal information.