Septal Bile Ducts Research Articles

Primary biliary cirrhosis: seeking the silent partner of autoimmunity.

Primary biliary cirrhosis is a disorder characterised by an intense inflammatory response in the septal and interlobular bile ducts and is considered to be an autoimmune disease. Evidence to suggest that chronic viral infection could be a crucial element in the development of biliary epithelial cell damage and activation of the associated autoimmune response is reviewed

Immunoglobulin gene usage and immunohistochemical characteristics of human monoclonal antibodies to the mitochondrial autoantigens of primary biliary cirrhosis induced in the XenoMouse.

The immunodominant antimitochondrial antibody (AMA) response in primary biliary cirrhosis (PBC) is directed against the E2 component of pyruvate dehydrogenase (PDC-E2). The nature of the clonal selection process is unclear, and to address this issue, we took advantage of a transgenic technology, XenoMouse, that contains 80% of the human immunoglobulin (Ig) variable gene repertoire and can produce high-affinity human antibodies to virtually any immunogen without evidence of clonal bias. We immunized mice with PDC-E2 to obtain 13 HmAbs, including 4 IgG(2) and 9 IgM isotypes. Immunoglobulin gene analysis was unique and demonstrated a clonal bias; the immunoglobulin gene usage was considerably different from other antibody responses analyzed in XenoMouse systems. Four of the 13 mAbs recognized the inner lipoyl domain of PDC-E2, 2 of 13 recognized the entire PDC-E2 molecule, 4 of 13 recognized PDC-E2 and OGDC-E2, 1 of 13 recognized OGDC only, 1 recognized BCOADC-E2 only, and 1 recognized an unidentified 100-kd mitochondrial protein. Immunohistochemical staining using these HmAbs produced mitochondrial staining of septal bile ducts in both PBC and control livers. Ig gene analysis showed that 7 of 13 HmAbs used the V(H)3 and 4 of 13 used VH4 gene repertoire, respectively. Three of 7 V(H)3 antibodies used the same Ig VH3-21 gene family found in human AMA from patients with PBC. The CDRs of these autoantibodies were slightly mutated when compared with the sequences present within the Ig germline genes. In conclusion, the XenoMouse not only recapitulates the unique specificity and restriction of PBC patients, but indicates that the autoantibodies are derived from a restricted clonal selection process. Such data suggest that the original immunogen leads to somatic mutation without subsequent development of determinant spreading.

Distribution of apoptotic cells and expression of apoptosis-related proteins along the intrahepatic biliary tree in normal and non-biliary diseased liver.

The cell kinetics and homeostasis of biliary epithelial cells may be maintained differently along the biliary tree. In this study, the role of apoptosis in the maintenance and homeostasis of the intrahepatic biliary tree was evaluated. By counting apoptotic biliary cells and by immunostaining apoptosis-related proteins in normal liver, fatty liver, and those with acute viral hepatitis, chronic viral hepatitis, and hepatitis virus-related cirrhosis, it was found that the larger the intrahepatic bile ducts became, the more biliary epithelial cells underwent apoptosis. bcl-2, an inhibitor of apoptosis, was diffusely expressed in the interlobular bile ducts, but rarely detectable in the large and septal bile ducts. bcl-XL and mcl-1, inhibitors of apoptosis, and bax, a promoter of apoptosis, were diffusely expressed along the intrahepatic biliary tree. CD95, a direct inducer of apoptosis, was present in the large and septal bile ducts, but rarely in the interlobular bile ducts. The ratio of bax to bcl-2, as well as the expression of CD95 which differed at the interlobular versus large and septal bile ducts, may be responsible for the unique distribution of apoptotic biliary cells and involved in the homeostasis of the intrahepatic biliary tree.

The pathology of primary biliary cirrhosis and autoimmune cholangitis

Primary biliary cirrhosis is the prototype of the small-duct biliary diseases which are characterized by damage or destruction of interlobular and proximal septal bile ducts. Autoimmune cholangitis differs serologically from primary biliary cirrhosis but, by current consensus, has the same pathological features. The histological findings in primary biliary cirrhosis and the staging criteria of that disease are well described and at this point can be applied to autoimmune cholangitis also. Diagnostic difficulties arise either because other small-duct biliary diseases are not considered or because tell-tale histological signs, particularly ductopenia, are not recognized. Review of all small-duct biliary diseases suggests that interlobular and adjacent septal bile ducts (1st and 2nd generation ducts) represent an immunosensitive portion of the biliary tree. Comparative studies of these unique segments may have important implications for our understanding of primary biliary cirrhosis and autoimmune cholangitis and possibly for future treatment options for these conditions.

Expression of Bcl-2 familial proteins is reduced in small bile duct lesions of primary biliary cirrhosis

In primary biliary cirrhosis, biliary epithelial cell death by apoptosis results in progressive bile duct loss. We examined immunohistochemically 4 apoptosis-regulating bcl-2 familial proteins (bcl-2, mcl-1, bcl-X, and bax) in the biliary epithelium in 19 cases of primary biliary cirrhosis. Ten cases of chronic hepatitis C, 9 cases of extrahepatic biliary obstruction, and 10 cases of normal liver were used as a control. Bcl-2 and mcl-1 are inhibitors of apoptosis, bcl-X, probably bcl-XL in biliary epithelial cells, an inhibitor, and bax, a promoter of apoptosis. First, we clarified the distribution of bcl-2 familial proteins on the intrahepatic biliary tree in normal livers. Bcl-2 was detected in the interlobular bile ducts and bile ductules, but not in the large and septal bile ducts in all cases examined. Mcl-1, bcl-X, and bax were diffusely detectable at the any level of the intrahepatic biliary tree, with a staining pattern that was diffuse and cytoplasmic. This distribution pattern was preserved in extrahepatic biliary obstruction. Bcl-2 expression was lost or markedly reduced in the damaged interlobular bile ducts in primary biliary cirrhosis, whereas the reduction was only focal or mild in the bile ducts with hepatitis-associated damage in chronic hepatitis C. Expression levels of mcl-1, bcl-X, and bax were similarly reduced to that of bcl-2 in these 2 diseases. These findings suggest that bax is not important as a proapoptotic factor in the damaged bile ducts and that downregulation of bcl-2 and mcl-1, and probably that of bcl-XL, leads to a decrease in the threshold of apoptosis and increase in the vulnerability to apoptotic stimuli in these bile ducts, followed by the progressive apoptotic loss of interlobular bile ducts, in primary biliary cirrhosis.

The variant forms of cholestatic diseases involving small bile ducts in adults

SEASES of the biliary system can be subdivided into small-duct diseases which require liver biopsy to establish the diagnosis and large-duct diseases which are diagnosed by cholangiography or other imaging studies. The term “small-ducts” refers to interlobular and proximal septal bile ducts. Small-duct diseases in adults can be classified according to etiology: 1) part of a systemic condition, including sarcoidosis, cystic fibrosis, graft-versus-host disease and malignancy (e.g. Hodgkin’s disease); 2) specific etiology including toxic or ischemic damage and rejection of transplant liver; and 3) primary diseases including primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and idiopathic adulthood ductopenia. The majority of adult patients with chronic cholestasis have PBC or PSC. These diseases have been extensively described in their typical forms. However, recent data indicate that subsets of patients must be individualized in terms of diagnostic criteria or management. In this paper, we review the variants forms of the primary small-duct diseases in adults (Table 1).

Familial Primary Biliary Cirrhosis in Hiroshima

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the presence of anti-mitochondrial antibodies and chronic inflammatory destruction of septal and intrahepatic bile ducts. Although there are no obvious associations of PBC with MHC class I or class II genes, there appears to be a significant increased risk of developing disease within families. Clearly, a combination of genetic and environmental factors play a role in disease pathogenesis, although the relative contributions of each are unclear. In this study, we have taken advantage of the well-defined health-care system in Hiroshima prefecture, where PBC is a reportable disease. In the period 1988–1997, 156 new patients with PBC in a total population of 2,873,000 were diagnosed. These patients included 18 subjects that were derived from eight different families in which more than one family member had a history of PBC; this reflects a frequency of 5.1% and further shows that the prevalence of PBC is greatly increased in family members. Of interest, the median age of onset of PBC in second generation patients was much younger (33.4±10.8 years) compared to median disease onset in general patients with PBC in Hiroshima (55.6±12 years). In fact, it was striking that the onset of disease in family members often occurred within a few years of each other. We also noted that sera of affected members had similar AMA reactive profiles against recombinant PDC-E2, BCKD-E2 and OGDC-E2; the major autoantigens of PBC. Similar HLA types were found within affected members of a pedigree but the data is limited because of absence of similar typing of unaffected members. The increased family history of PBC, and the earlier onset of disease in second generation members, suggests that environmental agents are an important risk factor for the development of disease. We suggest that genomic analysis in familial PBC will be important to identify the mechanisms of genetic susceptibility.

CONCOMITANT ACTIVATION OF THE TRANSCRIPTION FACTOR NF-κB & NF-κB-RESPONSIVE INFLAMMATORY GENES IN HUMAN LIVER ALLOGRAFTS DURING CHRONIC DUCTOPENIC REJECTION

1012 The transcription factor NF-κB is central to the induction of inflammatory and immune-response genes that play an important role in the pathogenesis of chronic transplant allograft rejection. The relevance of in situ NF-κB activation and active gene transcription of the NF-κB-inducible pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, GM-CSF) and the chemokine IL-8 was assessed in human liver allografts during chronic ductopenic rejection [CR]. Methods: NF-κB activation and immunophenotypic analyses were assessed by immunohistochemistry. The active transcription of the NF-κB-inducible genes was analyzed by RT-PCR. Results: Activated NF-κB was detected on Kupffer cells and macrophages in CR specimens (n=8) which were shown to be CD68+ following immunohistochemical analysis of serial sections with α-CD68 mAb. The mean intensity of Kupffer cell and macrophage NF-κB immunoreactivity was greater (P=0.002) than that of the controls (n=11) consisting of stable allografts and normal liver tissue. The zonal distribution of NF-κB+ Kupffer cell/macrophage was most prominent in the centrilobular areas. Occasional NF-κB immunostaining was noted in the portal infiltrates of some CR and control specimens. Minimal NF-κB activation was detected on cytokeratin 19+ biliary epithelial cells of septal and interlobular bile ducts of controls and CR. Weak NF-κB immunoreactivity was detected on hepatocytes in three isolated cases of CR but in none of the controls. Semi-quantitative RT-PCR analysis revealed induction of IL-1β, IL-6, TNF-α, GM-CSF and IL-8 mRNA transcripts in virtually all of CR specimens. Conclusion: These data provide evidence for local induction of NF-κB activation and concomitant active transcription of NF-κB-inducible proinflammatory cytokine and chemokine genes in human liver allografts during CR. These data implicate NF-κB-active Kupffer cells and macrophages as important sources of these inflammatory mediators in the pathogenesis of chronic rejection.

Laparoscopic Findings in Primary Sclerosing Cholangitis

Abstract: The laparoscopic appearance of the liver surface in patients with primary sclerosing cholangitis (PSC) has not been fully delineated. We examined 5 patients with PSC and reviewed 35 previously reported cases. Intense white markings in a mesh‐like pattern were characteristic of PSC. The findings varied depending on the histologic stage and affected site. Red patches which have also been seen in primary biliary cirrhosis (PBC), green patches indicating cholestasis, and dilatation of the terminal bile ducts were also observed. The red patches were wider than those in PBC. The white markings were less well defined in the red patches than in other areas. The severity of the fibrosis and histologic damage was judged to be mild at the red sites. The green patches were caused by localized cholestasis. This indicated that PSC unevenly affects the liver. Severe obstruction may be present between the interlobular bile ducts and the septal bile ducts in anicteric stages. (Dig Endosc 1999; 10: 37–41)

Management of Patients with Primary Biliary Cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease that predominantly occurs in middle-aged women. It is characterised by inflammatory destruction of interlobular and septal bile ducts, subsequent fibrosis, and finally liver cirrhosis. The disease slowly progresses over decades and may lead to liver failure. It is more frequently diagnosed now than it was in the past probably because of a greater awareness of the disease. Liver function tests reveal an elevation of serum alkaline phosphatase and micro-glutamyltransferase levels with or without elevated aminotransferase levels. Antimitochondrial antibodies (AMAs) are found in 95% of patients with PBC. AMAs have been shown to be directed against the 2-oxo-acid dehydrogenase complexes located on the inner membrane of the mitochondria. However, AMA titres do not correlate with disease severity or progression, and the role of AMAs in the pathogenesis of primary biliary cirrhosis is not yet known. The disease is frequently associated with other autoimmune disease, including Sjogren's syndrome, thyroid disorders and scleroderma. Most therapeutic efforts have been directed at altering the immune response. Ursodeoxycholic acid (UDCA) appears to be effective therapy in preventing or delaying the need for liver transplantation and improving survival. However, a number of patients receiving UDCA still develop progressive disease and go on to transplantation, which is an effective therapy at the end stage of the disease. Various prognostic models have been proposed to assist in the determination of the optimum timing of liver transplantation.

Distribution of intrahepatic mast cells in various hepatobiliary disorders. An immunohistochemical study.

There is evidence that mast cells are involved in a number of pathophysiological processes. The significance of mast cells in hepatic fibrosis was examined in 28 patients with histologically normal livers, 34 with acute liver diseases, 51 with chronic liver diseases, and 59 with cholestatic biliary diseases, using immunostaining of the mast cell-specific proteinase, tryptase. Mast cells that were positive for tryptase and for chymase were significantly increased in frequency in fibrotic portal tracts and fibrous septa, particularly in cholestatic/biliary diseases. Mast cells were also increased in frequency around the fibrotic septal and intrahepatic large bile ducts and peribiliary glands of biliary diseases. However, they were less common or even rare in the sclerotic bile ducts and in scarred portal or septal fibrosis. More than half of these more numerous mast cells were positive for histamine, and some were also positive for basic fibroblast growth factor. These two substances were detectable by immunoelectron microscopic in the cytoplasmic granules of mast cells. In contrast, mast cell numbers were not significantly increased in acute viral or drug-induced hepatitis, or in zones 2 and 3 of the hepatic acinus with respect to pericellular and perivenular fibrosis in chronic liver diseases. These findings suggest that mast cells increase in number in cholestatic/biliary diseases, and to a lesser degree in chronic liver diseases, and are involved in the active fibrous enlargement of portal tract and fibrous septa formation and also in the fibrosis of the intrahepatic bile ducts as they display fibrosis-promoting factors such as tryptase, fibroblast growth factor and histamine.

Primary biliary cirrhosis in patients with breast cancer: studying the link

Primary biliary cirrhosis (PBC) is a liver disease of unknown etiology characterized by chronic nonsuppurative destructive cholangitis (CNSDC) of intrahepatic septal and interlobular bile ducts. It is generally defined as an autoimmune disease. Characteristically, patients with PBC have a cholestatic serum hepatic profile and circulating antimitochondrial antibodies (AMA). PBC is progressive and ultimately leads to biliary cirrhosis and liver failure. It occurs at least three times more often in women than in men and it is the most common indication for liver transplantation in women around the world. There is no known cure for PBC. Despite the remarkable progress elucidating the genetics of breast cancer, and the effort placed on breast cancer education and screening methods, the mortality of breast cancer remains unacceptably high. In this essay, we describe the similarities between breast cancer and PBC and how their pathogenesis may be related. The hypothesis stated herein has evolved from reports from the early 1980s that linked an increased risk for breast cancer with PBC, and from the author's clinical experience with patients who suffer from both diseases. The association between these two diseases in the USA merits further investigation. If it is confirmed, risk factors involved in their pathogenesis will be identified.

Increased MUC6 apomucin expression is a characteristic of reactive biliary epithelium in chronic viral hepatitis.

The significance of bile ductular proliferation in the progression of various hepatobiliary diseases remains unclear. Increased expression of MUC6 apomucin, a major gastric mucin, has previously been noticed in proliferating bile ductules in chronic viral hepatitis. The purpose of the present study was to characterize MUC6 apomucin and mRNA expression in 35 histologically 'normal livers', 47 livers with chronic viral hepatitis, 28 with primary biliary cirrhosis, and seven with extrahepatic biliary obstruction. MUC6 protein was expressed focally in cytoplasm and/or on the luminal surface of septal and interlobular bile ducts in normal and diseased livers. Bile ductules in normal livers rarely expressed MUC6 protein. The MUC6 expression intensified and spread in proliferating bile ductules and small bile ducts in chronic viral hepatitis and to a lesser degree in other diseases. In the former, the extent and degree of MUC6 expression paralleled the degree of active necroinflammation. MUC6 mRNA expression resembled MUC6 protein expression in proliferating bile ductules and intralobular small biliary cells, suggesting increased transcription and synthesis of MUC6. In conclusion, proliferating bile ductular cells express MUC6 apomucin in diseased liver, especially in chronic viral hepatitis with active necroinflammation. This secreted mucin may act as a cytoprotective agent and represent a phenotype of reactive biliary epithelium in chronic viral hepatitis.

PREDICTIVE MODELS OF NATURAL HISTORY IN PRIMARY BILIARY CIRRHOSIS

Primary biliary cirrhosis is a slow, progressive disease. Although many years may elapse before asymptomatic primary biliary cirrhosis patients begin experiencing symptoms of liver disease, their overall survival is significantly lower than the normal population. The Mayo natural history model has been developed to depict patient survival in the absence of effective therapeutic intervention. Although there are a number of caveats in applying this model, it has been validated using external data sets and established as an accepted tool for clinical or research purposes. Furthermore, recent data suggest that the Mayo natural history model continues to provide useful, predictive information in the presence of ursodeoxycholic acid therapy, which has been shown to lower the serum bilirubin to the natural history model for patient survival. In addition to the natural history model for patient survival, mathematical models have been developed to describe histologic progression and development of esophageal varices.

Immunohistochemical demonstration of MET overexpression in human intrahepatic cholangiocarcinoma and in hepatolithiasis

Expression of MET, the c- met-encoded receptor for hepatocyte growth factor, has not been investigated in proliferative biliary diseases of human liver, including hepatolithiasis and cholangiocarcinoma. Comparatively, we analyzed by immunohistochemistry the expression of MET in normal adult human livers (n = 20), normal postnatal preadult livers (n = 21), fetal livers (n = 36), hepatolithiatic livers (n = 32), and intrahepatic cholangiocarcinomas (n = 26). In normal adult livers, obvious MET immunoreactivity was not found in any cell types. In fetal liver, MET was weakly expressed in primitive biliary cells (ductal plate and immature bile ducts) and immature hepatocytes during 8 to 30 gestational weeks but was essentially negative thereafter. In hepatolithiasis, a condition of risk for cholangiocarcinoma development, MET was overexpressed in proliferated biliary cells in 26 of 32 cases (81%). In this nonneoplastic proliferative biliary condition, MET immunoreactivity was observed to be most prominent in the hyperplastic septal and large bile ducts of liver, and in the proliferated peribiliary glands associated with intrahepatic large bile ducts. In intrahepatic cholangiocarcinoma, MET overexpression in neoplastic biliary epithelium was observed in 15 of 26 cases (58%) and correlated with the degree of tumor differentiation, being highest in well-differentiated tumors and relatively low in poorly differentiated tumors. These data show for the first time that overexpression of MET is a common feature of hyperplastic and neoplastic biliary epithelial cells in human liver and suggest that MET/hepatocyte growth factor may be playing an important role in human biliary hyperplasia and in cholangiocarcinogenesis in vivo.

Microstructure and development of the normal and pathologic biliary tract in humans, including blood supply.

Microstructure and development of the normal biliary tract and the pathologies of several biliary tract diseases in humans are reviewed. The biliary tract, comprising the bile duct and peribiliary glands, is anatomically divided into the extrahepatic and intrahepatic biliary tree. The intrahepatic biliary tree is further divided into large bile ducts, corresponding to the right and left hepatic ducts and their first to third order branches, and into septal and interlobular bile ducts and bile ductules according to their size and location relative to the hepatic lobules and surrounding structures. The right and left hepatic ducts and the extrahepatic bile ducts are composed of dense fibrous duct walls lined by a layer of columnar biliary epithelium. The peribiliary glands, which may secrete mucinous and serous substances into the bile, are found along the extrahepatic and large intrahepatic bile ducts. They are divided in glands within and outside the duct wall. The former (intramural glands) drain directly into the lumen of the bile duct, while the latter (extramural glands) are composed of several lobules and drain into the ductal lumen via their own conduits. The biliary tract is supplied by a complex vasculature called the peribiliary vascular plexus. Afferent vessels of this plexus derive from hepatic arterial branches, and this plexus drains into the portal venous system or directly hepatic sinusoids. The development of the intrahepatic biliary tract is divided into three stages: the stage of the ductal plate, the stage of biliary cell migration into the mesenchyme, and the stage of bile duct formation in the portal tract. It remains unclear how the extrahepatic and intrahepatic biliary tract integrate. Along with these developmental changes in the biliary tract, the peribiliary glands and the vascular plexus also develop in a step-wise manner and their maturation is completed after birth. Pathologies of various biliary diseases are briefly reviewed noting their relevance to several histologic elements and the microenvironment of the biliary tract and the developmental anomalies of the biliary tract including ductal plate malformation.

In situ nucleic acid hybridization of pyruvate dehydrogenase complex-E2 in primary biliary cirrhosis: pyruvate dehydrogenase complex-E2 messenger RNA is expressed in hepatocytes but not in biliary epithelium.

Pyruvate dehydrogenase-E2, or a cross-reactive molecule, has been shown by a variety of immunohistochemical methods to be present in increased amounts in biliary epithelial cells (BEC) in primary biliary cirrhosis (PBC). In this study, to further understand the nature of the immunoreactive molecule in BEC, we examined the expression of pyruvate dehydrogenase complex-E2 (PDC-E2) messenger RNA (mRNA) and PDC-E2 protein in sections of livers from patients and controls to help identify the molecule found in BEC. We performed in situ hybridization using an antisense probe against the major epitope of PDC-E2. The data were very striking and suggested that there was no increased production of PDC-E2 in BEC. For example, in livers from patients with PBC, PDC-E2 mRNA was found in periportal hepatocytes in 16 of 17 cases (94%). In contrast, interlobular bile ducts and septal bile ducts had detectable levels of PDC-E2 mRNA in only 1 of 17 (6%) and 3 of 8 (38%) cases, respectively. Interestingly, proliferating bile ductules contained detectable levels of mRNA in 12 of 15 cases (80%). In control liver, periportal hepatocytes were positive in 15 of 17 cases (88%). Interlobular bile ducts, septal bile ducts, and proliferating bile ductules expressed mRNA signals in 4 of 17 (24%), 2 of 10 (20%), and 14 of 16 (88%), respectively. When formalin-fixed, paraffin-embedded sections were examined by immunohistochemical staining with anti-PDC-E2 monoclonal antibody (mAb) C355.1, the interlobular bile ducts showed typical aberrant apical staining in all 10 PBC cases, but 0 of 9 liver controls. Periportal hepatocytes, proliferating bile ductules and infiltrating mononuclear cells stained with C355.1 but in a characteristic mitochondrial staining pattern. The presence of a PDC-E2-like molecule recognized by C355.1 is not reflected by the expression levels of PDC-E2 mRNA in the BEC of patients with PBC.

In situ nucleic acid hybridization of pyruvate dehydrogenase complex-E2 in primary biliary cirrhosis: Pyruvate dehydrogenase complex-E2 messenger RNA is expressed in hepatocytes but not in biliary epithelium

Pyruvate dehydrogenase-E2, or a cross-reactive molecule, has been shown by a variety of immunohistochemical methods to be present in increased amounts in biliary epithelial cells (BEC) in primary biliary cirrhosis (PBC). In this study, to further understand the nature of the immunoreactive molecule in BEC, we examined the expression of pyruvate dehydrogenase complex-E2 (PDC-E2) messenger RNA (mRNA) and PDC-E2 protein in sections of livers from patients and controls to help identify the molecule found in BEC. We performed in situ hybridization using an antisense probe against the major epitope of PDC-E2. The data were very striking and suggested that there was no increased production of PDC-E2 in BEC. For example, in livers from patients with PBC, PDC-E2 mRNA was found in periportal hepatocytes in 16 of 17 cases (94%). In contrast, interlobular bile ducts and septal bile ducts had detectable levels of PDC-E2 mRNA in only 1 of 17 (6%) and 3 of 8 (38%) cases, respectively. Interestingly, proliferating bile ductules contained detectable levels of mRNA in 12 of 15 cases (80%). In control liver, periportal hepatocytes were positive in 15 of 17 cases (88%). Interlobular bile ducts, septal bile ducts, and proliferating bile ductules expressed mRNA signals in 4 of 17 (24%), 2 of 10 (20%), and 14 of 16 (88%), respectively. When formalin-fixed, paraffin-embedded sections were examined by immunohistochemical staining with anti-PDC-E2 monoclonal antibody (mAb) C355.1, the interlobular bile ducts showed typical aberrant apical staining in all 10 PBC cases, but 0 of 9 liver controls. Periportal hepatocytes, proliferating bile ductules and infiltrating mononuclear cells stained with C355.1 but in a characteristic mitochondrial staining pattern. The presence of a PDC-E2-like molecule recognized by C355.1 is not reflected by the expression levels of PDC-E2 mRNA in the BEC of patients with PBC.(Hepatology 1997 Jan;25(1):27-32)

Accumulation of multiple T-cell clonotypes in the liver of primary biliary cirrhosis

The histological hallmark of primary biliary cirrhosis (PBC) is the destruction of the interlobular and septal bile ducts accompanied by a dense accumulation of lymphocytes; this constellation of features is termed chronic nonsuppurative destructive cholangitis. To analyze the T cells responsible for bile duct destruction, the T-cell receptor (TCR) Vβ repertoire was studied in liver biopsy specimens, and also in peripheral blood lymphocytes (PBL) obtained from seven patients with PBC in the early stage (Scheuer's stage I or II). The complementary DNA (cDNA) of each TCR Vβ1-20 chain was amplified by reverse-transcription polymerase chain reaction (RT-PCR), and the PCR products were examined by single-strand conformation polymorphism (SSCP) analysis. On the RT-PCR/SSCP analysis, a leukemic cell line, HPB-ALL, showed bands in TCR Vβ 5.2 and Vβ 6, indicating clonal expansion with distinct TCR. In the PBL from healthy subjects, the PCR products were amplified from many TCR Vβ and were shown as smears on SSCP, suggesting that PBL consist of diverse T-cell clones. In PBC, many TCR Vβ products were amplified by RT-PCR in both liver tissues and PBL, and no biased expression of a particular Vβ was observed. SSCP analysis revealed multiple bands in most Vβ chains, suggesting the presence of selected but multiple T-cell clones. Both the number and types of Vβ showing clonal expansion were heterogeneous in the PBC patients. A comparative RT-PCR SSCP analysis of each TCR Vβ between tissue lymphocytes and PBL revealed the presence of some identical T-cell clones in both the PBC liver and the PBL. These results suggest that T cells infiltrating the liver in PBC consist of multiple clonotypes and that T-cell clones accumulated in the liver are also present in PBL.(Hepatology 1997 Jan;25(1):33-7)

Accumulation of Multiple T–Cell Clonotypes in the Liver of Primary Biliary Cirrhosis

The histological hallmark of primary biliary cirrhosis (PBC) is the destruction of the interlobular and septal bile ducts accompanied by a dense accumulation of lymphocytes; this constellation of features is termed chronic nonsuppurative destructive cholangitis. To analyze the T cells responsible for bile duct destruction, the T–cell receptor (TCR) Vβ repertoire was studied in liver biopsy specimens, and also in peripheral blood lymphocytes (PBL) obtained from seven patients with PBC in the early stage (Scheuer's stage I or II). The complementary DNA (cDNA) of each TCR Vβ1–20 chain was amplified by reverse–transcription polymerase chain reaction (RT–PCR), and the PCR products were examined by single–strand conformation polymorphism (SSCP) analysis. On the RT–PCR/SSCP analysis, a leukemic cell line, HPB–ALL, showed bands in TCR Vβ 5.2 and Vβ 6, indicating clonal expansion with distinct TCR. In the PBL from healthy subjects, the PCR products were amplified from many TCR Vβ and were shown as smears on SSCP, suggesting that PBL consist of diverse T–cell clones. In PBC, many TCR Vβ products were amplified by RT–PCR in both liver tissues and PBL, and no biased expression of a particular Vβ was observed. SSCP analysis revealed multiple bands in most Vβ chains, suggesting the presence of selected but multiple T–cell clones. Both the number and types of Vβ showing clonal expansion were heterogeneous in the PBC patients. A comparative RT–PCR SSCP analysis of each TCR Vβ between tissue lymphocytes and PBL revealed the presence of some identical T–cell clones in both the PBC liver and the PBL. These results suggest that T cells infiltrating the liver in PBC consist of multiple clonotypes and that T–cell clones accumulated in the liver are also present in PBL.