Gene expression profiling in biliary epithelial cells of primary biliary cirrhosis using laser capture microdissection and cDNA microarray

Primary biliary cirrhosis (PBC) is a chronic, cholestatic liver disease characterized by progressive destruction of interlobular bile ducts that leads to biliary cirrhosis. To elucidate the etiology of PBC, the gene expression profile in biliary epithelial cells (BECs) was analyzed. Liver specimens of 5 PBC, 3 chronic hepatitis C (CHC), and 3 normal subjects were obtained. BECs were selectively collected by laser capture microdissection (LCM), RNA were obtained by extraction and amplification with T7 RNA polymerase, and a cDNA microarray analysis was performed. The following genes exhibited increased expression in BEC of PBC, as compared with CHC or normal subjects: human leukocyte antigen DQ alpha 1 (HLA-DQA-1), carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and vascular cell adhesion molecule 1 (VCAM-1). The immunohistochemistry for HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1 confirmed these results. Furthermore, two-way cluster analysis showed that the gene expression profiling in BEC of PBC were categorized into a separate cluster, distinct from CHC or normal subjects. Conclusions: The gene expression profiling in BEC of PBC differed from those of CHC and normal subjects, and the genes concerning local immune response, such as HLA-DQA-1, CEACAM1, TRAIL, and VCAM-1, exhibited increased expression, indicating that they were involved in the development of bile duct injury.     

Propagation and characterization of lymphocytes infiltrating livers of patients with primary biliary cirrhosis and autoimmune hepatitis

Lymphocytes were propagated with interleukin 2 from liver tissue removed at transplantation from patients with primary biliary cirrhosis or autoimmune chronic active hepatitis. Phenotypic analysis of the cultured lymphocytes as well as the infiltrating cells in situ indicated that the culture technique did not select for a particular phenotype. Eight cultures were tested for cell-mediated lympholysis activity against a bile duct tumor line as well as a hepatocellular carcinoma line, but no specific killing was seen. In addition, no natural killer activity was detected. However, the lymphocyte cultures were able to kill the targets in a lectin-dependent cytotoxicity assay, indicating their cytolytic effector activity. Preliminary studies have demonstrated that lymphocytes extracted from hepatic tissue and hilar lymph nodes from a patient with primary biliary cirrhosis proliferated in response to autologous biliary epithelial cells. These methods might be useful in studying the pathogenesis of primary biliary cirrhosis and other liver diseases with autoimmune features.     

Immune response to lipopolysaccharide in primary biliary cirrhosis and autoimmune diseases

A bacteriological aetiology is suspected to be the triggering factor in primary biliary cirrhosis. We studied lipid A, the toxic and immunogenic moiety of gram-negative bacteria lipopolysaccharide, which accumulates abnormally in Kupffer cells, hepatocytes, and biliary epithelial cells in primary biliary cirrhosis patients. Anti-lipid A antibody levels from serum samples from 36 primary biliary cirrhosis patients, drawn before and after ursodeoxycholic acid treatment, were compared to those from patients with other liver diseases (n=236), non-hepatic diseases (n=249), and healthy subjects (n=75). In primary biliary cirrhosis patients, the prevalence of IgM anti-lipid A antibodies was higher before than after ursodeoxycholic acid therapy (64% vs 22%, respectively; P<0.001). Patients with anti-lipid A antibodies had significantly higher IgM levels than those without antibodies (8.7+/-1.1 g/l vs 4.4+/-0.8 g/l, P<0.02). Total IgM levels were correlated with anti-lipid A antibody levels (r=0.65, P<0.02). After therapy, the serum IgM levels decreased significantly (P<0.03). These results indicate that bacterial antigens may participate in the observed increase of serum IgM levels, and support an aetiological role of a gut-derived endotoxin antigen in the pathogenesis of primary biliary cirrhosis.     

Levels of BAFF in serum in primary biliary cirrhosis and autoimmune diabetes

Levels of the B-cell activating cytokine BAFF are increased in serum in various autoimmune disease, and particularly Sj?gren's syndrome in which there is evident B-lymphocyte proliferation. Studies in two autoimmune disease in which B-cell proliferation is less evident, primary biliary cirrhosis (PBC), and adult-onset Type 1 diabetes, showed serum levels of BAFF to be mostly in the normal range. A single raised level among eight sera tested in one patient studied with autoimmune hepatitis (AH) coincided with a relapse of the disease. Increased levels of BAFF in human sera, indexing a potent antigenic drive on B-cell production and survival in some autoimmune diseases, may mark only particular stages in the evolution of such diseases.     

Portal tract eosinophils and hepatocyte cytokeratin 7 immunoreactivity helps distinguish early-stage, mildly active primary biliary cirrhosis and autoimmune hepatitis.

We studied nondiagnostic liver biopsy specimens from 20 patients with definite primary biliary cirrhosis (PBC) and 18 with definite autoimmune hepatitis (AIH) to identify distinguishing features. All patients had early-stage disease; biopsy specimens were devoid of granulomas or diagnostic features of PBC or AIH. Diagnoses were based on serologic and clinical variables. Sixteen specimens from each group were immunostained with cytokeratin 7. The density of portal tract eosinophils and number with cytokeratin 7-reactive periportal hepatocytes were quantified. Sixteen of 18 patients with AIH and 13 of 20 with PBC had no or minimal bile duct injury. Histologic activity index scores were 5.8 in AIH and 5.7 in PBC. The mean portal eosinophil score was greater in PBC than in AIH. Cytokeratin 7 identified many central bile ducts that were obscured by portal inflammation. The mean periportal cytokeratin 7-reactive hepatocyte score was greater in PBC than in AIH. Portal eosinophils and cytokeratin 7 reactivity in periportal hepatocytes are supportive of PBC rather than AIH. No morphologic features were supportive of AIH. Cytokeratin 7 reactivity in periportal hepatocytes may be an early response to PBC-induced biliary obstruction in other regions of the liver.     

Diversity of autoantibodies in primary biliary cirrhosis and chronic active hepatitis

The presence of autoantibodies in the serum of 110 patients with primary biliary cirrhosis (PBC), 50 with HBsAg negative chronic active hepatitis (HBsAg- CAH) and 30 with HBsAg positive chronic active hepatitis (HBsAg+ CAH) was assessed using two methods: indirect immunofluorescence on cells grown in tissue culture (HEp-2 cell line) or standard mouse tissue sections, and counter immunoelectrophoresis (CIE) with soluble tissue extracts. Anti-nuclear antibodies (ANA) were found in 38% of sera from patients with PBC using HEp-2 cells compared with 10% using mouse tissue. A variety of staining patterns were detected including a pattern of multiple nuclear dots. In contrast, ANA was detected in 70% of sera from patients with HBsAg- CAH and 27% with HBsAg+ CAH. Using CIE four distinct antibody antigen systems were detected: Ro (SS-A), La (SS-B) and two new systems, designated XH and XR, reacting with extracts of human spleen and rabbit thymus, respectively. Correlation of the presence of antibody with clinical conditions confirmed the close association between anti-centromere antibody and sclerodactyly in patients with PBC and indicated an association between 'multiple nuclear dot' staining and the sicca syndrome in PBC. No association was found between the presence of either Ro or La antibody and the sicca syndrome in patients with PBC.     

Progression of autoimmune damage in primary biliary cirrhosis: an immunohistochemical study

Aberrant MHC Class II antigen expression and the nature of the infiltrating lymphoid cells were studied by immunohistochemical techniques in liver biopsies from 37 patients with Primary biliary cirrhosis (PBC) (11 histological stage I, 13 stage II-III, 13 stage IV) and 15 patients with chronic non autoimmune liver disease. Bile duct epithelial cells expressed HLA-DR, DP and DQ antigens in biopsies from patients with early (Stage I) PBC and less frequently in the late cirrhotic phases of the disease (Stage IV); these observations support the hypothesis that induction of Class II antigens on epithelial cells may be involved in initiating autoimmune responses towards bile duct components. The presence of cytotoxic/suppressor T cells around the bile ducts in Stage I suggests a role for cell mediated destruction of the ducts at this early stage. The nature of the chronic inflammatory cell infiltrate in the portal tracts, periportal areas and lobular parenchyma does not establish the mechanism(s) involved in disease progression. However, the lack of Class II antigen expression on hepatocytes is compatible with the hypothesis that hepatocellular damage is non-specific and may be secondary to the initial bile duct injury.     

Pseudohyponatraemia, hypercholesterolaemia, and primary biliary cirrhosis.

A 62 year old woman with primary biliary cirrhosis was found to have a plasma sodium concentration of 115 mmol/l. Follow up showed this to be a "pseudohyponatraemia" due to a massively raised serum cholesterol concentration of 78 mmol/l. Electrophoresis of serum lipoproteins and of the lipoproteins and apolipoproteins in fractions isolated on density-gradient ultracentrifugation showed that the major portion of the serum cholesterol was being transported with lipoprotein-X. Low density lipoprotein-cholesterol concentration was also raised. Lipoprotein-X contained, in addition to albumin and apolipoprotein C, apolipoprotein E. This case is of interest because of the degree of hypercholesterolaemia, its association with pseudohyponatraemia, and the unequivocal demonstration of apolipoprotein E associated with lipoprotein-X.     

中国人自身免疫性肝病相关性 CTLA-4基因多态性研究

目的　探讨细胞毒性 T细胞相关抗原 - 4 (cytotoxic T lymphocyte- associated antigen- 4 ,CTL A- 4 )基因启动子 - 318和第 1外显子区第 4 9位基因多态性与中国人自身免疫性肝炎 (autoimmunehepatitis,AIH)、原发性胆汁性肝硬化 (primary biliary cirrhosis,PBC)发病的相关性。方法　应用限制性片段长度多态性方法分析 6 2例 AIH和 77例 PBC患者外周血单核细胞基因组 DNA CTL A- 4启动子 -318T/ C、第 1外显子区第 4 9位基因 A/ G多态性 ,并与 16 0名正常对照比较。结果　 AIH组 CTL A- 4启动子 - 318位 T/ C基因型分布与对照组比较差异无显著性 ,但 C等位基因频率明显高于正常对照组 (P=0 .0 2 ,OR=2 .4 3)。 PBC患者 CTL A- 4第 1外显子区第 4 9等位基因分布与正常对照组比较差异非常显著(P=0 .0 0 6 ) ,PBC患者 G等位基因频率明显高于正常组 (P=0 .0 0 4 6 ,OR=1.8)。联合分析 CTL A- 4启动子与第 1外显子的基因多态性分布 ,虽然 AIH组和 PBC组 GG- CC型携带率均比正常人高 (AIH组 :32 .3% ,PBC组 :37.7% ,对照组 :2 2 .5 % ) ,但是统计学分析结果均显示两组患者与正常人差异无显著性。结论　 CTL A- 4启动子 - 318和第 1外显子区第 4 9位基因多态性可能与中国人 AIH、PBC易感性相关。     

Histopathological features in mixed types of chronic aggressive hepatitis and primary biliary cirrhosis

Summary A histopathological study was carried out on 27 patients with chronic inflammatory liver disease and clinical and/or biochemical evidence of cholestasis who had either mitochondrial antibodies against mitochondrial antigen fractions of 1.19 density (PBC antigen; 14 cases) or of 1.13 density (CAH-PBC mixed-type antigen; 13 cases). For comparison, the liver biopsies of 17 patients with chronic-aggressive hepatitis (CAH) and antinuclear and/or anti-smooth muscle antibodies but without cholestasis and mitochondrial antibodies, were evaluated. The 14 patients with mitochondrial antibodies against the PBC antigen showed the typical histological features of primary biliary cirrhosis (PBC). The 13 patients with mitochondrial antibodies against the CAH-PBC mixed-type antigen had heterogenous liver alterations. In 11 cases highly active CAH and/or active postnecrotic cirrhosis (AC) were found both with augmented ductular proliferation. Some of these cases showed distinct criteria of PBC as early bile duct lesions or absence of regular bile ducts. The liver histology of one case corresponded to classical PBC; another case to chronic persistent hepatitis. The CAH-patients without cholestasis and mitochondrial antibodies only occasionally showed bile duct proliferation. In conclusion, a high correlation was found between mitochondrial antibodies against the CAH-PBC mixed-type antigen and highly active CAH or early AC with augmented ductular proliferation. This represents an overlapping of CAH and PBC. In contrast, the cases with antibodies reacting to the PBC antigen showed the slowly progressive liver changes of typical PBC.     

Liver schistosomiasis and primary biliary cirrhosis

Summary The case of a patient suffering from liver schistosomiasis diagnosed by liver biopsies is presented. There were also lesions in the liver suggestive of non-suppurative destructive cholangitis and the serum-immunological studies strengthened the diagnosis of primary biliary cirrhosis. The eo-existence of these two affections and their possible interrelationship are discussed. The authors further discussed some clinical, biochemical, immunological and pathological aspects of these two conditions and evoked the eventuality of an auto-immune type of hepatic affection triggered by the presence of the schistosome eggs.The authors are grateful to Dr. A. Cruchaud for the immunological studies, to Mrs. M. Loup and Miss C. L. Seignemartin for secretarial services, and Mr. E. Denkinger for the photographs.     

Environmental pathways to autoimmune diseases: the cases of primary biliary cirrhosis and multiple sclerosis

The pathways leading to autoimmunity remain enigmatic despite numerous lines of experimental inquiry and epidemiological evidence. The mechanisms leading to the initiation and perpetuation of specific diseases such as primary biliary cirrhosis (PBC) or multiple sclerosis (MS) remain largely enigmatic, although it is established that a combination of genetic predisposition and environmental stimulation is required. The growing number of genome-wide association studies and the largely incomplete concordance for autoimmune diseases in monozygotic twins concur to support the role of the environment (including infectious agents and chemicals) in the breakdown of tolerance leading to autoimmunity through different mechanisms. In the present article we illustrate the current hypotheses related to an environmental impact on the onset of PBC and MS as two representative conditions investigated with complementary approaches. Indeed, while a role of post-translational antigen modifications has been proposed for MS, this field remain unexplored in PBC where, conversely, most evidence is gathered from geoepidemiology and experimental data on xenobiotics or infectious agents.