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.     

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.     

The significance of anti-nuclear envelope (gp210) antibody in primary biliary cirrhosis]

Primary biliary cirrhosis (PBC) is considered to be an autoimmune disease selectively targeted for interlobular bile ducts. While anti-mitochondrial antibodies are specifically detected in more than 90% of PBC patients, anti-nuclear envelope-gp210 antibodies are also specifically detected in 20-30% of PBC patients. In this review, we present 1, T cells specific for mitochondrial major epitope, PDC-E2 163-176, cross-react with peptides derived from nuclear envelope-gp210 protein, 2, PBC patients who have sustained high antibody titers to gp210 are at high risk for the progression to end-stage hepatic failure. These evidences may be very important for the epitope spreading of autoantigens from PDC-E2 to nuclear antigens and for the identification of target antigens on biliary epithelial cells which are recognized by cytotoxic T cells in PBC.     

A spectrum of histopathologic findings in autoimmune liver disease

We retrospectively studied 42 liver biopsy specimens from 39 patients who met serologic and histologic criteria of autoimmune liver diseases. We found 10 cases of overlap syndrome (OLS), 10 autoimmune cholangitis (AIC), 10 primary biliary cirrhosis (PBC), and 9 autoimmune hepatitis (AIH) type 1. The following results were obtained: (1) Granulomas and biliary duct lesions were more prominent in PBC and AIC than in OLS and AIH. (2) Bile duct loss was not observed in AIH cases. (3) Features of hepatocellular damage such as piecemeal necrosis, spotty lobular necrosis, and confluent necrosis, were much more prevalent in OLS and AIH than in PBC and AIC. (4) HLA-DR antigen expression by hepatocytes was more frequent in AIH and OLS, whereas the expression of the same antigen by the bile duct epithelium was more frequent in PBC and AIC. We conclude there is a morphologic spectrum in autoimmune liver diseases, in which PBC forms one end of the spectrum, AIH the other, OLS the middle but closer clinically and histologically to AIH than to PBC, and AIC, which seems to be an antimitochondrial antibody-negative subtype of PBC.     

Increase of chemokine interferon-inducible protein-10 (IP-10) in the serum of patients with autoimmune liver diseases and increase of its mRNA expression in hepatocytes

To clarify the role of IP-10 in autoimmune liver diseases, we studied the serum levels of IP-10 in 14 patients with autoimmune hepatitis (AIH), 23 patients with primary biliary cirrhosis (PBC), and 65 patients with chronic viral hepatitis (20 type B and 45 type C). The hepatic expression of IP-10 mRNA and the correlation between the serum levels of IP-10 and clinical parameters were also evaluated. In addition to 20 healthy controls, 16 rheumatoid arthritis (RA) patients were included as an extrahepatic inflammatory disease. The serum level of IP-10 was significantly (P < 0.02) higher in patients with AIH, PBC, and chronic hepatitis B and C than in healthy controls, and it was significantly correlated (P < 0.05) with the serum levels of aspartate aminotransferase and alanine aminotransferase in patients with AIH, PBC, and chronic hepatitis B and C. The serum level of IP-10 was not elevated in RA patients. After successful treatment of AIH and chronic hepatitis C, the serum level of IP-10 decreased to the same level as in healthy volunteers. As we previously showed in cases with chronic hepatitis B or C, in situ hybridization in both AIH and PBC cases demonstrated the expression of IP-10 mRNA in hepatocytes around focal or lobular necrosis surrounded by infiltrating mononuclear cells, whereas IP-10 mRNA was not expressed in areas around the damaged bile ducts in PBC cases. The present results suggest that IP-10 is specifically produced by hepatocytes in inflammatory areas irrespective of the aetiology of hepatitis, and that IP-10 may help to recruit T cells to the hepatic lesions in autoimmune liver diseases as well as in chronic viral hepatitis.     

Periductal interleukin-17 production in association with biliary innate immunity contributes to the pathogenesis of cholangiopathy in primary biliary cirrhosis

An innate immune response to bacterial components is speculated to be involved in the pathogenesis of primary biliary cirrhosis (PBC). Recently, CD4-positive T helper type 17 (Th17) cells, characterized by the secretion of interleukin (IL)-17, have been implicated in the pathogenesis of autoimmune diseases. Human Th17 cells are generated from Th0 cells by IL-6 and IL-1β and maintained by IL-23. In this study, the role of IL-17 in PBC and its association with biliary innate immunity were examined. Using cultured human biliary epithelial cells (BECs), the expression of Th17-related cytokines and chemokines and changes therein on treatment with pathogen-associated molecular patterns (PAMPs) and IL-17 were examined. Immunohistochemistry for IL-17 and Th17-related cytokines was performed using tissue samples of human liver. Consequently, the expression of IL-6, IL-1β, IL-23p19 and IL-23/IL-12p40 mRNAs, and their up-regulation by PAMPs, were found in BECs. Moreover, BECs possessed IL-17-receptors and stimulation with IL-17 induced production of IL-6, IL-1β, IL-23p19 and chemokines. Several IL-17-positive cells had infiltrated damaged bile ducts and the expression of IL-6 and IL-1β was enhanced in the bile ducts of PBC patients. In conclusion, IL-17-positive cells are associated with the chronic inflammation of bile ducts in PBC which is associated causally with the biliary innate immune responses to PAMPs.     

Activation of ATM signaling pathway is involved in oxidative stress-induced expression of mito-inhibitory p21WAF1/Cip1 in chronic non-suppurative destructive cholangitis in primary biliary cirrhosis: an immunohistochemical study

Biliary epithelial cells (BECs) of chronic non-suppurative destructive cholangitis (CNSDC) in primary biliary cirrhosis (PBC) reportedly express p21(WAF1/Cip1) and p16(INK4a), which may induce cell cycle arrest and are related to progressive loss of BECs of PBC. Given that the ATM pathway plays a role in the induction of p21(WAF1/Cip1), we examined its possible involvement in bile duct damage of PBC. The expression of phosphorylated-ATM (p-ATM) reflecting the activation of ATM, p21(WAF1/Cip1) and 8-hydroxy-deoxyguanosine (8-OHdG), an oxidative stress marker, was examined immunohistochemically in the liver tissues of 20 cases of stage 1/2 PBC, 9 extrahepatic biliary obstruction (EBO), 35 chronic viral hepatitis (CVH), 17 nonalcoholic steatohepatitis (NASH), and 18 histologically normal liver. p21(WAF1/Cip1), p-ATM and 8-OHdG were frequently and extensively co-expressed in the nuclei of CNSDC in PBC, and their expressions were correlated. In contrast, the expression of these three molecules was absent or faint in small bile ducts in normal livers, CVH, and EBO, and these molecules were clearly expressed in the nuclei of hepatocytes of NASH, in which oxidative stress is involved in hepatocellular damage. In conclusion, oxidative stress-induced p21(WAF1/Cip1) expression in BECs in PBC is closely associated with activation of the ATM pathway and the resultant reduced regeneration or cell cycle arrest of BECs may be related to the progressive loss of small bile ducts of PBC.     

Autoimmune hepatitis associated with bile duct injury resembling chronic non-suppurative destructive cholangitis

Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are representative autoimmune liver diseases in which hepatocytes and intrahepatic bile ducts, respectively, are selectively damaged by autoimmune mechanisms. Bile duct injury and loss is characteristic of PBC and chronic non-suppurative destructive cholangitis (CNSDC), in particular, is a histological hallmark of PBC. In this report, we present an unusual case of AIH accompanied by CNSDC-like bile duct injury in a 46-year-old woman. The patient's serum aminotransferase level was abnormally high. The serum levels of alkaline phosphatase, gamma-GTP and IgG were also elevated, but the IgM level was within normal limits. The titer of antismooth muscle antibody (SMA) was 1:80, while antinuclear autoantibody (ANA) and the M2 fraction of antimitochondrial antibody (AMA) were both negative. Liver biopsy disclosed CNSDC-like bile duct injuries and severe interface hepatitis and lobular hepatitis with perivenular zonal necrosis were observed. The aggregate score of the International Autoimmune Hepatitis Group corresponded to the category of probable AIH. Immunohistochemically, histocompatibility leukocyte antigen-DR, which is aberrantly expressed in the damaged bile ducts of PBC, was not found in the injured bile ducts of this case. Laboratory data were much improved by treatment with prednisone, but ursodeoxycholic acid was not effective. Although the possibility of an overlapping syndrome of AIH- and AMA-negative PBC could not be excluded, this case was diagnosed as AIH with CNSDC-like bile duct lesions.     

Hepatic expression of toll-like receptor 4 in primary biliary cirrhosis

Toll-like receptor 4 (TLR4) is a receptor for bacterial lipopolysaccharide, which is suggested to be involved in the pathogenesis of disease of hepatobiliary tracts. To explore a possible role for this receptor in primary biliary cirrhosis (PBC), we investigated the expression of TLR4 in liver tissues from PBC patients. We studied liver biopsy sections from 62 PBC patients and 41 patients with chronic hepatitis C (CHC). Expression of TLR4 in paraffin-embedded sections was analyzed by immunohistochemistry. The bile duct epithelial cells (BECs) of PBC liver tissues markedly expressed TLR4, whereas BECs of CHC liver tissues barely expressed TLR4. The TLR4 expression was also observed in periportal hepatocytes of PBC liver tissues and its expression was extended to interlobular hepatocytes in advanced stage PBC. Although periportal hepatocytes of CHC liver tissues expressed TLR4, its expression levels were not correlated with the fibrosis stage. Our data demonstrated that TLR4 was expressed in BECs and periportal hepatocytes in PBC livers, suggesting the possible involvement of bacterial pathogens and TLR4 in the inflammatory processes of PBC.     

cDNA microarray analysis of autoimmune hepatitis, primary biliary cirrhosis and consecutive disease manifestation

While autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) usually have distinct clinical manifestations, some patients present with features of both conditions. Using cDNA microarrays, we analyzed and compared gene expression profiles in 8 patients with AIH, 9 with PBC, 8 with chronic hepatitis C (CHC), 8 with non-alcoholic steatohepatitis (NASH) and 9 with normal livers. We subsequently applied this method to a tissue sample from a 61-year-old woman with overlapping features of both AIH and PBC. A 61-year-old woman was admitted to our hospital for evaluation of elevated serum alkaline phosphatase. A liver biopsy showed accumulation of mononuclear cells around the bile duct cells, a feature characteristic of chronic non-suppurative destructive cholangitis (CNSDC). Three years later, her serum alanine aminotransferase (ALT) level had increased, and a liver biopsy demonstrated evidence of a severe form of hepatitis. A cDNA microarray analysis of both biopsies identified the molecular events associated with her altered histology. The expression profile of this patient, which was originally different from that of the other PBC patients, changed to an AIH pattern. Our results suggest that this patient has characteristics of both AIH and PBC.     

Histological grading and staging in chronic hepatitis: its practical correlation

Although the histological features of various causes of chronic liver disease have been well described, usually the inflammatory activity of the disease is important after the cause has been established. Some patients have co-infection or concomitant liver disease and on occasion it is difficult to decide the treatment. In order to clarify the histological differences, we investigated the inflammatory activity among autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), chronic hepatitis C (CHC) and chronic hepatitis B (CHB) in a standardized way using the modified histological activity index (HAI). According to the modified HAI, inflammatory activity is divided into four categories; categories A/D explains portal/periportal inflammation and categories B/C explains lobular activity. The inflammatory score of AIH tended to be greater in all categories from the early stage of fibrosis, whereas scores of PBC were lower, except for portal inflammation. Chronic hepatitis C patients had portal or periportal inflammation, and their inflammatory scores were linked to the development of fibrosis. Chronic hepatitis B patients tended to have severe lobular injury, but did not have a relationship between the inflammatory score and their stage. To know the distribution of inflammation using the modified HAI scoring system may be helpful and convenient in evaluating patients with chronic inflammatory liver disease.     

Immunohistochemical analysis of adhesion molecules in the micro-environment of portal tracts in relation to aberrant expression of PDC-E2 and HLA-DR on the bile ducts in primary biliary cirrhosis

We have examined immunohistochemically the expression of adhesion molecules in the micro-environment of portal tracts and their relationship to the expression of the pyruvate dehydrogenase E2 complex (PDC-E2) and HLA-DR in liver biopsy specimens. Ten cases of primary biliary cirrhosis (PBC) and 19 controls were examined, including four cases of extrahepatic biliary obstruction, six of chronic viral hepatitis, and nine normal livers. In PBC, the damaged small bile ducts demonstrated an increased expression of PDC-E2 and an aberrant expression of HLA-DR; about half of these damaged bile ducts also expressed intercellular adhesion molecules (ICAM)-1 and a few expressed vascular adhesion molecule (VCAM)-1. In addition, lymphocyte function-associated antigen (LFA)-1 and very late antigen (VLA)-4 were expressed on infiltrating lymphocytes around these bile ducts. In contrst, in control livers, these alterations in antigen expression on the bile ducts were either not observed or were only focal and weak, when present. These findings suggest that ICAM-1/LFA-1 and also VCAM-1/VLA-4 linkages between the damaged bile ducts and lymphocytes may facilitate antigen-specific reactions such as the presentation of antigens, possibly PDC-E2, to the periductal lymphocytes in PBC. ICAM-1, VCAM-1, and E-selectin were strongly expressed on the endothelial cells of some vessels in the portal tracts in PBC, suggesting the facilitation of the recruitment of lymphocytes around the of some vessels in the portal tracts in PBC, suggesting the facilitation of the recruitment of lymphocytes around the bile ducts of PBC. VCAM-1, a member of the immunoglobulin superfamily, has not hitherto been reported on bile ducts.     

The Immunophysiology and Apoptosis of Biliary Epithelial Cells: Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis

Biliary epithelial cells (BECs) provide the first line of defense against lumenal microbes in the biliary system. BECs express a variety of pathogen recognition receptors and can activate several intracellular signaling cascades to initiate antimicrobial defenses, including production of several anti-microbial peptides, cytokines, chemokines, and adhesion molecules. BECs also secrete immunoglobulin A and interact with other cells through expression and release of adhesion molecules and immune mediators. Recently, several reports suggest a correlation between apoptosis and autoimmunity through ineffective clearance of self-antigens. Primary biliary cirrhosis (PBC) is a slowly progressive, autoimmune cholestatic liver disease characterized by highly specific antimitochondrial antibodies (AMAs) and the specific immune-mediated destruction of BECs. We have demonstrated that the AMA self-antigen, namely the E2 subunit of the pyruvate dehydrogenase complex, is detectable in its antigenically reactive form within apoptotic blebs from human intrahepatic biliary epithelial cells and activates innate immune responses. Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and the presence of concentric fibrosis of intrahepatic and/or extrahepatic bile ducts, eventually leading to cirrhosis. However, apoptosis does not appear to play a central role in PSC. Despite both diseases involving immune-mediated injury to bile ducts, apoptosis occurs more commonly overall in PBC where it likely plays a unique role.     

Peribiliary capillary plexus around interlobular bile ducts in various chronic liver diseases: An immunohistochemical and morphometric study

Peribiliary capillary plexus (PCP) is a network of capillaries which arise from the hepatic artery surrounding the intrahepatic bile ducts. We immunohistochemically investigated the density of PCP around interlobular bile ducts in various chronic liver diseases including primary biliary cirrhosis (PBC) (n = 47), autoimmune hepatitis (AIH) (n = 12), chronic hepatitis B (n = 16), chronic hepatitis C (n = 19), liver cirrhosis due to hepatitis B virus (n = 13), liver cirrhosis due to hepatitis C virus (n = 20), alcoholic hepatitis (n = 20), alcoholic liver cirrhosis (n = 17), using human liver biopsies fixed in formalin and embedded in paraffin wax. PCP was immunohistochemically detected by an endothelial marker, the CD34 antigen. The number of PCP per duct was 1.21 +/- 0.18 in normal livers. Compared with normal liver, vasopenia was observed in PBC and AIH, the number in which was 0.93 +/- 0.34 (P < 0.0001) and 0.82 +/- 0.38 (P < 0.005) per duct, respectively. In contrast, increased number of PCP was observed in liver cirrhosis due to hepatitis B or C virus, alcoholic hepatitis, and alcoholic liver cirrhosis, the number in which were 1.59 +/- 0.37 (P < 0.005), 1.55 +/- 0.52 (P < 0. 02), 1.38 +/- 0.23 (P < 0.02) and 1.61 +/- 0.33 (P < 0.002) per duct, respectively. These data suggest that PCP may be destroyed in autoimmune liver diseases, including PBC and AIH, but PCP may proliferate in other inflammatory and alcoholic liver diseases.     

In situ mass spectrometry of autoimmune liver diseases

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) are the major forms of autoimmune liver diseases each characterized by the destruction of a specific liver cell type and the presence of differing auto-antibodies. We took a proteomic approach utilizing in situ matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) to obtain profiles directly from liver samples of patients with PBC, PSC, AIH and controls. The ability to precisely localize the region for acquisition of MALDI MS allowed us to obtain profiles from bile ducts, inflammatory infiltrates and hepatocytes from each biopsy sample. Analysis tools developed to identify peaks and compare peaks across diseases and cell types were used to develop models to classify the samples. Using an initial set of testing samples from PBC patients and controls, we identified unique peaks present in bile ducts, inflammatory infiltrates and hepatocytes that could classify samples in a validation cohort with 88-91% accuracy. Interestingly, profiles of PSC and AIH did not differ significantly from PBC. Identification of proteins in these peaks may represent novel autoantigens or effector molecules. These findings illustrate the potential of a proteomic approach to autoimmune diseases with in situ MALDI MS.     

Expression of co-stimulatory factor B7-2 on the intrahepatic bile ducts in primary biliary cirrhosis and primary sclerosing cholangitis: an immunohistochemical study

Co-stimulatory factors B7-1 (CD80) and B7-2 (CD86) and their ligands, including CD28, are important for the efficient presentation and persistence of an antigen-specific immune reaction. Hitherto, there has been a paucity of data on the roles of such co-stimulatory factors in immune-mediated biliary diseases. In this investigation, the hepatic immunohistochemical expression of B7-1 and B7-2 has been studied, with emphasis on intrahepatic biliary epithelia, using wedge biopsies from 22 patients with primary biliary cirrhosis (PBC), seven with primary sclerosing cholagitis (PSC), and, as controls, eight cases of extrahepatic biliary obstruction, eight of chronic viral hepatitis C, and three histologically normal livers. In 10/22 (45 per cent) patients with PBC and 3/7 (43 per cent) patients with PSC, B7-2, but not B7-1, was expressed on the epithelial cells of small intrahepatic bile ducts and bile ductules. This expression was manifest as diffuse but variable cytoplasmic staining. Such B7-2-positive bile ducts were not seen in controls. Positive staining was found only in the early stage of PBC and PSC. In PBC and PSC, almost all lymphocytes in the portal tracts, including those around the damaged bile ducts, were positive for CD28, a ligand of B7-2. These results suggest that B7-2 expression on biliary epithelial cells is involved in antigen presentation and perhaps in bile duct destruction in PSC and PBC. Copyright © 1998 John Wiley & Sons, Ltd.     

自身免疫性肝炎合并自身免疫性疾病的特征研究

目的 比较自身免疫性肝炎（AIH）合并原发性胆汁性胆管炎（PBC）或部分肝外自身免疫性疾病（autoimmune disease）患者与单纯AIH患者临床特点及并发症,为改善AIH患者的诊治提供参考。方法 收集1999年8月~2019年8月我院收治的AIH患者149例,根据合并症分为无合并病的AIH组（68例）、AIH合并PBC组（AIH-PBC 组,41例）及AIH合并肝外自身免疫性疾病组（AIH-肝外组,40例）,比较三组临床特点、并发症、肝纤维化/肝硬化进展情况。结果 ①AIH-PBC 组及AIH-肝外组年龄低于AIH组,差异有统计学意义（P＜0.05）;三组性别比较,差异无统计学意义（P＞0.05）。②三组共有的临床症状为瘙痒、黄疸、乏力、食欲不振及腹部不适,其中AIH-PBC组瘙痒症状患者多于AIH组、AIH-肝外组,差异有统计学意义（P＜0.05）;三组黄疸、乏力、食欲不振及腹部不适比较,差异无统计学意义（P＞0.05）。③AIH-PBC 组ALT低于AIH组及AIH-肝外组,ALP、GGT高于AIH组及AIH-肝外组,差异有统计学意义（P＜0.05）;AIH-肝外组的AST、DBIL高于AIH组及AIH-PBC 组,差异有统计学意义（P＜0.05）;AIH-肝外组IgG水平高于AIH组及AIH-PBC 组,差异有统计学意义（P＜0.05）。④三组ANA、ASMA、SLA、LKM-1阳性率比较,差异无统计学意义（P＞0.05）;AIH-PBC组AMA、AMA-M2 阳性率高于AIH组、AIH-肝外组,差异有统计学意义（P＜0.05）。⑤三组均以界面性肝炎和淋巴细胞浸润表现居多,其中AIH-PBC组胆管病变、胆汁淤积高于AIH组,差异有统计学意义（P＜0.05）。⑥三组并发症主要包括食管胃底静脉曲张/破裂出血、腹水、肝性脑病、肝癌、肝移植,组间比较,差异无统计学意义（P＞0.05）。⑦三组肝纤维化/肝硬化发生率比较,差异无统计学意义（P＞0.05）;但AIH-PBC组2~5年肝纤维化/肝硬化进展率高于AIH组及AIH-肝外组,差异有统计学意义（P＜0.05）。结论 合并PBC的AIH患者比单纯AIH患者诊断年龄早,肝脏炎症反应轻、胆管病变重;比AIH及合并肝外自身免疫性疾病更易出现瘙痒、胆汁淤积更重、胆管损伤更严重,且肝纤维化/肝硬化速度更快。AMA、AMA-M2可作为AIH合并PBC的鉴别指标。另外,AIH合并肝外自身免疫性疾病常存在肝功能损害,IgG对其具有提示意义。     

Enhanced expression of Bcl-2 in lymphocytes infiltrating into the liver of patients with primary biliary cirrhosis

The Bcl-2 family proteins are important regulators of apoptosis and have been implicated in the occurrence of autoimmune diseases. There have been reports that Bcl-2-positive lymphocytes play important roles in pathogenesis of at least some types of autoimmune diseases, including autoimmune hepatitis. In this study, we examined the role of Bcl-2-positive lymphocytes in the development of primary biliary cirrhosis (PBC). The expression of Bcl-2 in lymphocytes infiltrating into the liver was evaluated from liver biopsy specimens of 25 patients with PBC (stage I/II/III/IV, 11/3/8/3) and 24 controls with chronic hepatitis B (CH-B) or chronic hepatitis C (CH-C). Bcl-2 expression in lymphocytes infiltrating into the liver was investigated by immunohistochemistry using a monoclonal antibody to Bcl-2 with an avidin-biotin complex system. Significant overexpression of Bcl-2 in lymphocytes infiltrating into the liver was observed in the early stage of PBC, especially in areas of destructed bile ducts. Most of Bcl-2-positive cells were CD45RO-positive helper T-cells visualized by the double staining method. These results suggest that Bcl-2-positive helper T-cells may have important roles in the pathogenesis of PBC.