Is nestin a diagnostic marker for combined hepatocellular-cholangiocarcinoma?

BACKGROUND AND AIMS: The type IV intermediate filament, nestin, may be a candidate diagnostic marker for combined hepatocellular-cholangiocarcinoma (cHCC-CCA). Therefore, the significance of nestin as a diagnostic marker for cHCC-CCA categorized by the World Health Organization (WHO) 2019 classification and its relationship with clinicopathological features were examined in the present study. METHODS AND RESULTS: Nestin expression was immunohistochemically assessed in the liver sections from 75 patients with cHCC-CCA, 22 with small duct-type intrahepatic cholangiocarcinoma (iCCA), 20 with large duct-type iCCA and 35 with hepatocellular carcinoma (HCC). Nestin expression and its relationship with clinicopathological features and genetic alterations were investigated in cHCC-CCA. Nestin expression was detected in significantly more patients with cHCC-CCA (66.7%) than in those with large duct-type iCCA (5%) (P < 0.01), HCC (2.9%) (P < 0.01) and small duct-type iCCA (40.9%) (P < 0.05). Nestin expression was partly associated with neural cell adhesion molecule (NCAM) and vimentin expression. Nestin expression was also observed in significantly more patients with small duct-type iCCA than in those with large duct-type iCCA and HCC (P < 0.01). Nestin-positive cHCC-CCA was characterized by a smaller tumour size, the more frequent presence of cholangiolocellular carcinoma (CLC) components, a higher rate of p53 overexpression and a higher rate of multiple genetic alterations (P < 0.05). Furthermore, p53 overexpression was associated with a higher histological grade and multiple genetic alterations (P < 0.05) in nestin-positive cHCC-CCA. CONCLUSION: Nestin may be a useful diagnostic marker for a specific subgroup of cHCC-CCA and small duct-type iCCA associated with CLC components, p53 mutations and multiple genetic alterations, which are related to stemness and multipotent differentiation.

Functional Immune Anatomy of the Liver-As an Allograft.

The liver is an immunoregulatory organ in which a tolerogenic microenvironment mitigates the relative "strength" of local immune responses. Paradoxically, necro-inflammatory diseases create the need for most liver transplants. Treatment of hepatitis B virus, hepatitis C virus, and acute T cell-mediated rejection have redirected focus on long-term allograft structural integrity. Understanding of insults should enable decades of morbidity-free survival after liver replacement because of these tolerogenic properties. Studies of long-term survivors show low-grade chronic inflammatory, fibrotic, and microvascular lesions, likely related to some combination of environment insults (i.e. abnormal physiology), donor-specific antibodies, and T cell-mediated immunity. The resultant conundrum is familiar in transplantation: adequate immunosuppression produces chronic toxicities, while lightened immunosuppression leads to sensitization, immunological injury, and structural deterioration. The "balance" is more favorable for liver than other solid organ allografts. This occurs because of unique hepatic immune physiology and provides unintended benefits for allografts by modulating various afferent and efferent limbs of allogenic immune responses. This review is intended to provide a better understanding of liver immune microanatomy and physiology and thereby (a) the potential structural consequences of low-level, including allo-antibody-mediated injury; and (b) how liver allografts modulate immune reactions. Special attention is given to the microvasculature and hepatic mononuclear phagocytic system.

Interleukin-32 production associated with biliary innate immunity and proinflammatory cytokines contributes to the pathogenesis of cholangitis in biliary atresia.

Biliary atresia (BA) is thought to be associated with infections by viruses such as Reoviridae and is characterized histologically by fibrosclerosing cholangitis with proinflammatory cytokine-mediated inflammation. Interleukin (IL)-32 affects the continuous inflammation by increasing the production of proinflammatory cytokines. In this study, the role of IL-32 in the cholangitis of BA was examined. Immunohistochemistry for IL-32 and caspase 1 was performed using 21 samples of extrahepatic bile ducts resected from BA patients. Moreover, using cultured human biliary epithelial cells (BECs), the expression of IL-32 and its induction on stimulation with a Toll-like receptor [(TLR)-3 ligand (poly(I:C)] and proinflammatory cytokines was examined. BECs composing extrahepatic bile ducts showing cholangitis expressed IL-32 in BA, but not in controls. Caspase 1 was expressed constantly on BECs of both BA and control subjects. Furthermore, poly(I:C) and proinflammatory cytokines [(IL-1ß, interferon (IFN)-γ and tumour necrosis factor (TNF)-α] induced IL-32 expression strongly in cultured BECs, accompanying the constant expression of TLR-3 and caspase 1. Our results imply that the expression of IL-32 in BECs was found in the damaged bile ducts of BA and induced by biliary innate immunity via TLR-3 and proinflammatory cytokines. These findings suggest that IL-32 is involved initially in the pathogenic mechanisms of cholangitis in BA and also plays an important role in the amplification and continuance of periductal inflammatory reactions. It is therefore tempting to speculate that inhibitors of IL-32 could be useful for attenuating cholangitis in BA.

Induction of elastin expression in vascular endothelial cells relates to hepatoportal sclerosis in idiopathic portal hypertension: possible link to serum anti-endothelial cell antibodies.

Hepatoportal sclerosis accompanied by dense elastic fibre deposition is generally regarded as the primary lesion in the development of idiopathic portal hypertension (IPH). This study was performed to clarify the mechanism of elastic fibre deposition in the peripheral portal tracts of IPH liver in relation to serum anti-endothelial cell antibodies (AECA). In-vitro experiments were performed using human dermal microvascular endothelial cells (HMVEC) and patients' sera. The presence of serum AECA was assayed by a cell-based enzyme-linked immunosorbent assay (ELISA) using HMVEC. Immunohistochemical analysis of elastin was performed using liver tissue sections of IPH patients. IPH sera contained one or more AECA that could bind to the vascular endothelial cells of the peripheral portal tracts of the liver. When the value of AECA greater than the mean ± 2 standard deviations of healthy controls was regarded as positive, the positive detection rate of either immunoglobulin (Ig)G, IgA or IgM AECA in IPH sera was 30% (10 of 33 cases). IPH sera induced the expression of elastin in HMVEC, which appeared to be associated with the presence of AECA. Apoptosis was also induced in HMVEC by the stimulation with IPH sera. In vivo, elastin expression was observed in the endothelial cells of the peripheral portal tracts of IPH livers in a proportion of cases. The disease pathogenesis of IPH seems to be heterogeneous, and this study elucidated a possible contribution of the induction of elastin expression in the portal vessels to hepatoportal sclerosis of IPH, which might be linked to serum AECA as a causative factor.

The role of natural killer (NK) and NK T cells in the loss of tolerance in murine primary biliary cirrhosis.

One of the major obstacles in dissecting the mechanism of pathology in human primary biliary cirrhosis (PBC) has been the absence of animal models. Our laboratory has focused on a model in which mice, following immunization with a xenobiotic chemical mimic of the immunodominant autoepitope of the E2 component of pyruvate dehydrogenase complex (PDC-E2), develop autoimmune cholangitis. In particular, following immunization with 2-octynoic acid (a synthetic chemical mimic of lipoic acid-lysine located within the inner domain of PDC-E2) coupled to bovine serum albumin (BSA), several strains of mice develop typical anti-mitochondrial autoantibodies and portal inflammation. The role of innate immune effector cells, such as natural killer (NK) cells and that NK T cells, was studied in this model based on the hypothesis that early events during immunization play an important role in the breakdown of tolerance. We report herein that, following in-vivo depletion of NK and NK T cells, there is a marked suppression of anti-mitochondrial autoantibodies and cytokine production from autoreactive T cells. However, there was no change in the clinical pathology of portal inflammation compared to controls. These data support the hypothesis that there are probably multiple steps in the natural history of PBC, including a role of NK and NK T cells in initiating the breakdown of tolerance. However, the data suggest that adaptive autoimmune effector mechanisms are required for the progression of clinical disease.

Risk factors for recurrence of primary sclerosing cholangitis after living donor liver transplantation in Japanese registry.

The outcomes of primary sclerosing cholangitis (PSC) after living donor liver transplantation (LDLT) in a large series have not been reported. We aimed to determine long-term patient and graft survival, risk factors for PSC recurrence, and the significance of recurrence after LDLT in a Japanese registry. Questionnaires concerning patient characteristics, treatments, and clinical courses were used. Data of 114 patients undergoing primary LDLT for PSC from July 1996 to December 2008 in 29 institutions were evaluated. For strict diagnoses of recurrence, patients with hepatic artery thrombosis (n = 8), ABO-blood-type-incompatible transplantation (n = 8), and established ductopenic rejection (n = 2) were excluded and 96 patients were analyzed for risk factors. Recurrence was diagnosed in 26 patients (27%) at 8 to 79 months after transplantation. Patient, graft, and recurrence-free survivals were 78, 74 and 57% at 5 years after LDLT, respectively. The graft loss rate was 69 versus 23% in patients with versus without recurrence, respectively. Multivariate analysis revealed that high MELD scores, first-degree-relative donors, postoperative CMV infection, and early biliary anastomotic complications were significant risk factors for recurrence. PSC recurrence was a significant risk factor of graft loss but not patient death. PSC recurrence was frequent and had significant impacts on outcomes after LDLT.

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-1 beta 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-1 beta, 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-1 beta, IL-23p19 and chemokines. Several IL-17-positive cells had infiltrated damaged bile ducts and the expression of IL-6 and IL-1 beta 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.

Molecular mimicry in primary biliary cirrhosis. Evidence for biliary epithelial expression of a molecule cross-reactive with pyruvate dehydrogenase complex-E2.

Sera from patients with primary biliary cirrhosis (PBC) react with enzymes of the 2-oxo dehydrogenase pathways, particularly PDC-E2. These enzymes are present in all nucleated cells, yet autoimmune damage is confined to biliary epithelial cells. Using a panel of eight mouse monoclonal antibodies and a human combinatorial antibody specific for PDC-E2, we examined by indirect immunofluorescence and confocal microscopy sections of liver from patients with PBC, progressive sclerosing cholangitis, and hepatocarcinoma. The monoclonal antibodies gave typical mitochondrial immunofluorescence on biliary epithelium and on hepatocytes from patients with either PBC, progressive sclerosing cholangitis, or hepatocarcinoma. However, one of eight mouse monoclonal antibodies (C355.1) and the human combinatorial antibody reacted with great intensity and specificity with the luminal region of biliary epithelial cells from patients with PBC. Simultaneous examination of these sections with an antiisotype reagent for human IgA revealed high IgA staining in the luminal region of biliary epithelial cells in patients with PBC. IgG and IgA antibodies to PDC-E2 were detected in the bile of patients with PBC but not normal controls. We believe that this data may be interpreted as indicating that a molecule cross-reactive with PDC-E2 is expressed at high levels in the luminal region of biliary epithelial cells in PBC.

Interferon gamma accelerates NF-kappaB activation of biliary epithelial cells induced by Toll-like receptor and ligand interaction.

BACKGROUND: The Toll-like receptor (TLR) family recognises pathogen associated molecular patterns (PAMPs) and plays a pivotal role in the innate immune response. Biliary epithelial cells (BECs) lining the intrahepatic bile ducts are potentially exposed to bacterial components in bile, and murine BECs possess TLRs that recognise PAMPs, resulting in nuclear factor kappaB (NF-kappaB) activation. AIMS: To examine the presence of TLRs in human BECs and the influence of cytokines and PAMPs on TLR expression and NF-kappaB activation. METHODS: The expression of TLR2-5, MD-2, MyD88, and IRAK1 was examined in human liver tissue and cultured BECs by immunohistochemistry or reverse transcription polymerase chain reaction. The influence of PAMPs (peptidoglycan and lipopolysaccharide) in cultured cells preincubated with interferon gamma (IFNgamma) was evaluated by NF-kappaB activation. RESULTS: TLR2-5, MyD88, and IRAK-1 proteins were detectable in BECs of the intrahepatic biliary tree in human liver tissue. TLR2-5, MD-2, MyD88, and IRAK-1 mRNA was demonstrated in human cultured BECs. The expression of these TLRs was upregulated by IFNgamma, and TLR2 was upregulated by tumour necrosis factor alpha. Interleukins 4 and 6 failed to induce TLR upregulation. Interestingly, preincubation with IFNgamma synergistically increased the upregulation of NF-kappaB induced by PAMPs in cultured BECs. CONCLUSION: These results suggest that the TLR family is present in human biliary cells and participates in the innate immunity of the intrahepatic biliary tree. Disordered regulation of TLRs after intracellular signalling by cytokines and PAMPs may be involved in immune mediated biliary diseases.

Proposal for standardized criteria for the diagnosis of benign, borderline, and malignant hepatocellular lesions arising in chronic advanced liver disease.

Although current literature contains many cases of putative premalignant hepatocellular proliferations and small hepatocellular carcinomas, no consistent nomenclature and diagnostic criteria have been put forward to describe them. These nodules, which are being detected by radiographic techniques in cirrhotic livers and removed during transplantation procedures, represent a new and challenging histologic spectrum of liver pathology. In this study, a multinational panel of five liver pathologists reviewed 23 such nodules and were able to reach a consensus on the diagnostic criteria and to devise a standard nomenclature to describe the histologic lesions. We recommend that benign nodules showing little histologic difference from cirrhotic nodules be classified as regenerative or macroregenerative, and nodules with atypical features not diagnostic of carcinoma be classified as borderline. Such standardization should facilitate further study of the pathologic features and clinical behavior of these lesions.

An unusual case of epithelial-myoepithelial carcinoma of the liver.

The authors present an unusual case of an epithelial-myoepithelial carcinoma of the liver in a 67-year-old man who was admitted for resection of a gastric adenocarcinoma. At operation, a 3 x 3 cm mass in the right liver lobe was also removed. This mass consisted of duct-like structures with dual differentiation. The inner layer was composed of an epithelial lining, and the outer layer consisted of clear cells, all unrelated to the moderately well-differentiated gastric adenocarcinoma. The clear cells were positive for S-100 and alpha-smooth muscle actin, suggesting myoepithelial origin. The mass was considered to be low-grade epithelial-myoepithelial carcinoma. However, the patient had a history of an oral nodule present since childhood, resected 10 years previously. These slides were reviewed and revealed a mixture of clear cells and basal cells with squamous differentiation. In addition, there were duct-like structures with the two-layer pattern found in the liver tumor. This tumor had numerous mitotic figures and showed perineural invasion, suggesting a high grade of malignancy. These findings led to an interpretation of the oral tumor as also being epithelial-myoepithelial carcinoma, which had remained as "benign" for more than 50 years and subsequently underwent malignant transformation. During this long period, liver metastases may have occurred and remained low-grade. Alternatively, the liver and oral tumors may have arisen separately in the foregut during embryologic development, remaining low-grade until malignant transformation occurred.

Ciliated hepatic foregut cyst. A mucus histochemical, immunohistochemical, and ultrastructural study in three cases in comparison with normal bronchi and intrahepatic bile ducts.

We describe herein the morphologies of three cases of ciliated hepatic cysts and compare them with those of normal bronchi and intrahepatic bile ducts. Grossly, the hepatic cysts were located in the subcapsular region. They were solitary, unilocular, and rather small (less than 4 cm in diameter). Histologically, the cyst wall consisted of four layers: pseudostratified ciliated columnar epithelia with mucous cells, subepithelial connective tissue, smooth-muscle bundles, and an outermost fibrous capsule. The epithelial cytoplasm contained neutral, carboxylated, and sulfated mucus. We noted moderate immunoreactivity to keratin, epithelial membrane antigen, carcinoembryonic antigen, DU-PAN-2 and secretory component; weak immunoreactivity to cytokeratin CAM 5.2, cytokeratin AE1 + 3, and carbohydrate antigen 19-9; and faint or negative immunoreactivity to IgA and IgM. Cilia were immunoreactive to actin and tubulin; smooth muscles were immunoreactive to actin and desmin. Ultrastructural observations revealed definite cilia arranged in a 9 + 2 pattern as well as mucous cells. These morphologic features of the hepatic cysts were similar to those of normal bronchi but different from those of normal bile ducts. Our findings suggest that ciliated hepatic cysts arise from the embryonic foregut and differentiated toward bronchial structures in the liver.

Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants.

Hepatic angiomyolipoma (AML) is frequently misdiagnosed. HMB-45 is a promising immunomarker for this tumor that leads to recognition of some AMLs with unusual morphology. The purpose of this collaborative study is to better define the morphologic variations of AML. Thirty AMLs were examined, including four biopsy specimens and two fine-needle aspirates. The diagnosis was confirmed by the presence of HMB-45-positive myoid cells. Almost half the cases were originally misdiagnosed as carcinomas or sarcomas. There was marked female predominance (25:5), and the mean age was 48.7 years (range 29-68). Three patients (10%) had evidence of tuberous sclerosis and all had renal AML. According to the line of differentiation and predominance of tissue components, the tumors was subcategorized into mixed, lipomatous (> or = 70% fat), myomatous (< or = 10% fat), and angiomatous type. The mixed type was the most common (11 resected cases), comprising sheets of epithelioid muscle cells admixed with islands of adipocytes, abnormal vessels, and frequently, hematopoietic cells. Six tumors (including three from biopsy specimens) were heavily fatty and showed predominantly adipocytes with epithelioid and short spindle myoid cells webbed between fat cells. Of 10 myomatous AMLs, five tumors showed a pure sinusoidal trabecular pattern and comprised mainly epithelioid cells. Typically, mature adipocytes were absent or scanty, but fat was seen as fine droplets within cytoplasm or as occasional large globules in sinusoids. Pelioid and inflammatory pseudotumor-like patterns were identified focally. Regarding cellular features of the myoid cells, most of the epithelioid cells were either eosinophilic or clear with spiderweb cell morphology. Three AMLs showed an almost purely oncocytic appearance with scanty fat. Large pleomorphic epithelioid cells existed as small foci. Spindle cells arranged in long fascicles were uncommon. D-PAS-positive globules were common around pelioid areas. Brown pigments with staining characteristics of hemosiderin and/or melanin were noted. In conclusion, we propose HMB-45-positive myoid cells as the defining criterion of hepatic AML, which is a tumor capable of dual myomatous and lipomatous differentiation and melanogenesis. Because of its protean morphologic appearance, recognition of the various variant patterns and cell types is important for a correct diagnosis, assisted by immunohistochemical confirmation with HMB-45. Trabecular and oncocytic cell tumors appear to stand out as distinctive subtypes.

Immunohistochemical and immunoelectron microscopic analyses of alpha-amylase isozymes in human intrahepatic biliary epithelium and hepatocytes.

The expression and localization of the pancreatic and salivary isozymes of alpha-amylase in the intrahepatic biliary epithelium and hepatocytes were examined by the immunohistochemical method with polyclonal and monoclonal antibodies in 45 normal autopsied human livers. Immunoelectron microscopic studies with the protein A-gold method were performed with the monoclonal antibodies (MAb) on seven of the livers. The intrahepatic biliary system was divided into large ducts, septal ducts, interlobular ducts, bile ductules, and peribiliary glands. Immunohistochemically, pancreatic isozyme was observed in the supranuclear cytoplasm of the epithelium of large ducts, septal ducts, and peribiliary glands in almost all livers. Interlobular ducts expressed pancreatic isozyme in only four (9%) livers. Bile ductules and hepatocytes were negative for pancreatic isozyme in all cases. Expression of salivary isozyme was observed in the supranuclear cytoplasm of the epithelium of large ducts, septal ducts, interlobular ducts, bile ductules, and peribiliary glands in almost all livers, although the expression in interlobular ducts and bile ductules was weak. Hepatocytes were weakly positive for salivary isozyme. Immunoelectron microscopy revealed that both pancreatic and salivary isozymes were located in the supranuclear cytoplasm of the epithelium of large ducts, septal ducts, and peribiliary glands, and that hepatocytes had no pancreatic isozyme but contained salivary isozyme. These data suggest that pancreatic and salivary isozymes of alpha-amylase are produced by the intrahepatic biliary epithelium and secreted into intrahepatic biliary lumens, and that they may play an important role in the physiology of the intrahepatic biliary tree and hepatic bile. It is also suggested that hepatocytes produce a small amount of salivary alpha-amylase that may be secreted into the biliary tree.

Proliferative activity of carcinoma of the papilla of vater - an immunohistochemical study demonstrating proliferating cell nuclear antigen (pcna).

The expression of proliferative cell nuclear antigen (PCNA) in carcinomas of the papilla of Vater were studied. The PCNA LI of the specimens ranged from 13.0 to 72.8% (mean +/- standard deviation=43.1 +/- 16.4%). The tumors with lymph node involvement had a higher PCNA LI than those without lymph node involvement. The PCNA LI of tumors extending to duodenum or pancreas was significantly higher than that of tumors restricted to the muscle of the sphincter of Oddi. These results indicate that PCNA LI is one of the important factors indicating spread of tumor, i.e., lymph node involvement and depth of invasion.

Inhibitory effect of a serine protease inhibitor, FOY-305 on the invasion and metastasis of human pancreatic cancers.

We examined the inhibitory effect of a serine protease inhibitor, FOY-305, on the invasion and metastasis of human pancreatic cancers. The in vitro matrigel invasion assay showed that the invasiveness of Capan-1 human pancreatic cancer cells was inhibited by FOY-305 treatment in a dose-dependent manner at concentrations greater than 100 nM. Intrasplenic injection of Capan-1 cells in nude mice resulted in frequent metastases to liver, however, its incidence was significantly decreased by FOY-305 treatment. These findings suggest that a serine protease inhibitor, FOY-305 can inhibit tumor invasion and metastasis by blocking the serine protease-mediated activation cascade.

Primary biliary cirrhosis an epithelitis: evidence of abnormal salivary gland immunohistochemistry.

Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unknown etiology. Nearly 93% of patients with PBC exhibit evidence of focal sialoadenitis. In an earlier study, we reported evidence of aberrant expression of PDC-E2, or a mimeotope, in the salivary glands of patients with PBC that had Sjogren's syndrome. At the time of the previous study, data was not yet available regarding patients with PBC without sicca complaints. Therefore, to investigate the extent of salivary gland involvement in PBC, we collected lip biopsy sections from 9 PBC patients diagnosed as PBC by liver biopsy, without clinical or histologic features of Sjogren's syndrome and 9 PBC patients with established Sjogren's syndrome. Using immunohistochemical staining with both a murine monoclonal antibody. C355.1, and a human combinatorial antibody, SP4, we examined the ducts of these salivary glands for the presence of the characteristic aberrant staining pattern found in patients with PBC. We report that 6/9 PBC patients fulfilling established Sjogren's syndrome criteria and 6/9 PBC patients lacking features of Sjogren's syndrome showed intense staining of the ductal epithelial cells of the salivary gland. These data suggest that the PBC-specific antigen recognized by C355.1 and SP4 in bile duct epithelial cells is expressed aberrantly in the salivary gland in 66% of patients with PBC, independent of Sjogren's syndrome. This finding suggests a common disease process in these two tissues. Further, expression of this molecule may be an early marker of salivary gland involvement in patients with PBC.

Necroinflammatory changes in hepatic lobules in primary biliary cirrhosis with less well-defined cholestatic changes.

Primary biliary cirrhosis (PBC) is characterized by nonsuppurative inflammation and destruction of interlobular bile ducts. In this study we examined the necroinflammatory changes in hepatic lobules in PBC in the absence of cholestatic changes secondary to bile duct destruction, viral hepatitis types B and C, and progression of histologic stages. Kupffer cell hyperplasia, mononuclear sinusoidal infiltrates, and focal hepatocellular necroses were found frequently in the hepatic lobules. Some cases also showed perivenular zonal necrosis and central to central bridging necrosis. Focal necroses and swollen Kupffer cells were associated with lymphocytes with plump eosinophilic cytoplasm, resembling epithelioid cells. Well-developed and less-defined epithelioid cell granuloma also was occasionally found. The size, number, and distribution of these intralobular necroinflammatory changes varied from case to case and also from lobule to lobule in the same case. beta-2-Microglobulin was expressed on hepatocytes in areas of intralobular necrosis, in association with activated T cells. Laboratory data reflecting necroinflammatory changes in the hepatocytes tended to be elevated in the patients with zonal necroses. It is suggested in this study that necroinflammatory changes in the hepatic lobules are constant and inherent features in PBC and easily recognizable at an earlier histologic stage, and that hepatocytes, in addition to bile duct epithelium, may be targets of the immunologically mediated destruction that characterizes PBC.

Expression of ABH blood group antigens, receptors of Ulex europaeus agglutinin I, and factor VIII-related antigen on sinusoidal endothelial cells in adenomatous hyperplasia in human cirrhotic livers.

Adenomatous hyperplasia, a hyperplastic parenchymal nodule in the cirrhotic liver, has been presumed to be a preneoplastic lesion in human hepatocarcinogenesis. In this study, phenotypes of the sinusoidal endothelium were examined in adenomatous hyperplasia, hepatocellular carcinoma, cirrhosis, chronic active hepatitis, and normal livers. Adenomatous hyperplasia (n = 74) was histologically classified into two types: ordinary (n = 35) and atypical (n = 39). While the former lacked hepatocellular atypia, the latter consisted of atypical hepatocytes equivocal as to benignity and malignancy, in some of which overt malignant foci were found. The expression of A, B, and H blood group antigens, receptors of Ulex europaeus agglutinin I, and factor VIII-related antigen on the sinusoidal endothelium was minimal or nil in normal livers. It was mild and focal in chronic active hepatitis, cirrhosis, and ordinary adenomatous hyperplasia, while expression was moderate in atypical adenomatous hyperplasia with or without malignant foci, and severe in malignant foci in atypical adenomatous hyperplasia and in hepatocellular carcinoma. These data suggest that phenotypes of the sinusoidal endothelium of atypical adenomatous hyperplasia are closely related to the development of hepatocellular carcinoma, and phenotypic changes of the sinusoidal endothelium occur stepwise corresponding to various stages of hepatocarcinogenesis in cirrhotic livers.