Extrahepatic peribiliary glands express alpha-amylase isozymes, trypsin and pancreatic lipase: an immunohistochemical analysis

A postnatal network of co-hepato/pancreatic stem/progenitors in the biliary trees of pigs and humans

A network of co-hepato/pancreatic stem/progenitors exists in pigs and humans in Brunner's Glands in the submucosa of the duodenum, in peribiliary glands (PBGs) of intrahepatic and extrahepatic biliary trees, and in pancreatic duct glands (PDGs) of intrapancreatic biliary trees, collectively supporting hepatic and pancreatic regeneration postnatally. The network is found in humans postnatally throughout life and, so far, has been demonstrated in pigs postnatally at least through to young adulthood. These stem/progenitors in vivo in pigs are in highest numbers in Brunner's Glands and in PDGs nearest the duodenum, and in humans are in Brunner's Glands and in PBGs in the hepato/pancreatic common duct, a duct missing postnatally in pigs. Elsewhere in PDGs in pigs and in all PDGs in humans are only committed unipotent or bipotent progenitors. Stem/progenitors have genetic signatures in liver/pancreas-related RNA-seq data based on correlation, hierarchical clustering, differential gene expression and principal component analyses (PCA). Gene expression includes representative traits of pluripotency genes (SOX2, OCT4), endodermal transcription factors (e.g. SOX9, SOX17, PDX1), other stem cell traits (e.g. NCAM, CD44, sodium iodide symporter or NIS), and proliferation biomarkers (Ki67). Hepato/pancreatic multipotentiality was demonstrated by the stem/progenitors' responses under distinct ex vivo conditions or in vivo when patch grafted as organoids onto the liver versus the pancreas. Therefore, pigs are logical hosts for translational/preclinical studies for cell therapies with these stem/progenitors for hepatic and pancreatic dysfunctions.

A Biliary Mucinous Cystic Neoplasm with Intrahepatic and Lymph Node Metastases

A 51-year-old woman who presented with a large cystic liver tumor with mural nodules in the lateral segment developed Trousseau's syndrome. A mural nodule directly invaded her liver parenchyma. Metastatic nodules were detected in the right lobe and portal/paraaortic lymph nodes. The pathological findings showed mucin-producing adenocarcinoma cells to have invaded the fibrous stroma forming a micropapillary cluster. She developed obstructive jaundice due to tumor progression and subsequently died of hepatic failure. Invasive biliary mucinous cystic neoplasm (MCN) is a rare form of a malignant tumor with a relatively favorable prognosis. This is a very rare case biliary MCN with invasive carcinoma that showed intrahepatic and lymph node metastases.

Combined liver-kidney perfusion enhances protective effects of normothermic perfusion on liver grafts from donation after cardiac death

It has been shown that combined liver-kidney normothermic machine perfusion (NMP) is able to better maintain the circuit's biochemical milieu. Nevertheless, whether the combined perfusion is superior to liver perfusion alone in protecting livers from donation after circulatory death (DCD) is unclear. We aimed to test the hypothesis and explored the mechanisms. Livers from 15 DCD pig donors were subjected to either static cold storage (group A), liver-alone NMP (group B), or combined liver-kidney NMP (group C). Livers were preserved for 6 hours and reperfused ex vivo for 2 hours to simulate transplantation or were transplanted in situ. During perfusion, group C showed an improved acid-base and biochemical environment in the circuit over group B. After reperfusion, the architecture of the liver grafts was best preserved in group C, followed by group B, then group A, as shown by the histology and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining of both hepatocytes and biliary epithelium. Ki-67 staining showed substantial hepatocyte proliferation and biliary epithelial regeneration after perfusion in group B and group C. Group C produced more bile in the reperfusion phase than those in group A and group B, with more physiological bile composition and less severe biliary epithelium injury. Von Willebrand factor-positive endothelial cells and E-selectin expression decreased in both group B and group C. Combined liver-kidney NMP not only produced more adenosine triphosphate, protected the nitric oxide signaling pathway, but also diminished oxidative stress (high mobility group box-1 protein and 8-hydroxy-2-deoxy guanosine levels) and inflammatory cytokine (IL6 and IL8) release when compared with liver-alone NMP and CS. In addition, the 7-day survival rate of liver transplant recipients was higher in group C than that in groups A and B. In conclusion, combined liver-kidney NMP can better protect DCD livers from warm ischemia and reperfusion injury probably by maintaining the stability of the internal environment and by abolishing oxidative stress injury. Liver Transplantation 24 67-79 2018 AASLD.

Human ductal plate and its derivatives express antigens of cholangiocellular, hepatocellular, hepatic stellate/progenitor cell, stem cell, and neuroendocrine lineages, and proliferative antigens

Molecular mechanisms of human ductal plate (DP) development and differentiation (DD) are unclear. The author immunohistochemically investigated expressions of cholangiocellular antigens (CEA, CA19-9, EMA, MUC1, MUC2, MUC5AC, MUC6, mucins, CK7, and CK19), hepatocellular antigens (HepPar1, AFP, CK8, and CK18), hepatic stellate/progenitor cell (HSC) antigens or stem cell (SC) antigens (C-erbB2, CD56, chromogranin, synaptophysin, bcl2, NSE, NCAM, KIT, and PDGFRA), and proliferating antigen (Ki67) in 32 human fetal livers (HFL). The DD of human intrahepatic bile duct (IBD) could be categorized into four stages: DP, remodeling DP, remodeled DP, and immature IBD. All the molecules examined were expressed in the DP and DP derivatives. These results suggest that human DP or DP derivatives have capacities to differentiate into cholangiocellular, hepatocellular, HSC, SC, and neuroendocrine lineages. The data also suggest that NCAM, KIT/SC factor-signaling, NSE, HGF/MET signaling, PDGFa/PDGFRA signaling, chromogranin, synaptophysin, and CD56 play important roles in DD of DP and biliary cells of HFL. DP, DP derivatives, and IBD in HFL have proliferative capacity.

Cystic micropapillary neoplasm of peribiliary glands with concomitant perihilar cholangiocarcinoma

We report a case of a 75-year-old man with cystic micropapillary neoplasm of peribiliary glands detected preoperatively by radiologic examination. Enhanced computed tomography showed a low-density mass 2.2 cm in diameter in the right hepatic hilum and a cystic lesion around the common hepatic duct. Under a diagnosis of perihilar cholangiocarcinoma, right hepatectomy with caudate lobectomy and bile duct resection were performed. Pathological examination revealed perihilar cholangiocarcinoma mainly involving the right hepatic duct. The cystic lesion was multilocular and covered by columnar lining epithelia exhibiting increased proliferative activity and p53 nuclear expression; it also contained foci of micropapillary and glandular proliferation. Therefore, the lesion was diagnosed as a cystic micropapillary neoplasm of peribiliary glands and resembled flat branch-type intraductal papillary mucinous neoplasm of the pancreas. Histological examination showed the lesion was discontinuous with the perihilar cholangiocarcinoma. Immunohistochemistry showed the cystic neoplasm was strongly positive for MUC6 and that the cholangiocarcinoma was strongly positive for MUC5AC and S100P. These results suggest these two lesions have different origins. This case warrants further study on whether this type of neoplasm is associated with concomitant cholangiocarcinoma as observed in pancreatic intraductal papillary mucinous neoplasm with concomitant pancreatic duct adenocarcinoma.

"Biliary Diseases with Pancreatic Counterparts": Cross-sectional Imaging Findings

On the basis of the similarities in the histopathologic findings and the clinical-biologic behaviors of select biliary and pancreatic conditions, a new disease concept, "biliary diseases with pancreatic counterparts," has been proposed. Both nonneoplastic and neoplastic pathologic conditions of the biliary tract have their counterparts in the pancreas. Immunoglobulin G4 (IgG4)-related sclerosing cholangitis is the biliary manifestation of IgG4-related sclerosing disease, and type 1 autoimmune pancreatitis is its pancreatic counterpart. People with chronic alcoholism can develop peribiliary cysts and fibrosis as well as pancreatic fibrosis and chronic pancreatitis simultaneously. Pancreatic ductal adenocarcinoma, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm are considered pancreatic counterparts for the biliary neoplasms of extrahepatic cholangiocarcinoma, intraductal papillary neoplasm of the biliary tract, and hepatic mucinous cystic neoplasm, respectively. The anatomic proximity of the biliary tract and the pancreas, the nearly simultaneous development of both organs from the endoderm of the foregut, and the presence of pancreatic exocrine acini within the peribiliary glands surrounding the extrahepatic bile ducts are suggested as causative factors for these similarities. Interestingly, these diseases show "nearly" identical findings at cross-sectional imaging, an observation that further supports this new disease concept. New information obtained with regard to biliary diseases can be used for evaluation of pancreatic abnormalities, and vice versa. In addition, combined genetic and molecular studies may be performed to develop novel therapeutic targets. For both biliary and pancreatic diseases, imaging plays a pivotal role in initial diagnosis, evaluation of treatment response, efficacy testing of novel drugs, and long-term surveillance.

Development of extrahepatic bile duct excluding gall bladder in human fetuses: histological, histochemical, and immunohistochemical analysis

BACKGROUND

The fetal development of extrahepatic bile ducts (EBD) is unkown.

MATERIALS AND METHODS

Development of EBD was examined by immunohistochemistry in 16 fetuses of 7-40 gestational week (GW). Gall bladder (GB) was not investigated.

RESULTS

At seven GW, a hepato-pancreatic bud (HPB) was seen near the hepatic hilus. At eight GW, embryonic EBD, GB and pacreas developed from HPB. Portal veins (PV) and hepatic arteries (HAs) were present in EBD at eight GW. Liver parenchyma was already present in seven GW. At eight GW, EBD at porta hepatis (PH) was already established; PH EBD was derived from ductal plate (DP). The distal and middle EBD gradually develeped and took shape of EBD at nine GW. In PH, cystic and hepatic ducts developed from DP at eight GW. EBD developed further, accompanying many nerve fibers (NF) at PH and distal and middle EBD. Apparent PV and HA were seen around 12 GW. Around 20 GW, HA and capillaries proliferated, giving rise to peribiliary capillary plexus (PCP) in all parts of EBD. EBD grew gradually further, and around 30 GW extrahepatic peribiliary glands (EPG) emerged from EBD but not from cystic duct. Around 36 GW, exocrine pancreatic acinar cells emerged from remodeled DP at PH. At term (40 GW), EBD was established but was as yet immature. Numerous NF were present around EBD. Histochemically, EBD epithelium had no mucins at 7-12 GW but contained neutral and acidic mucins at 23-40 GW. EPG had abundant neutral and acidic mucins. Immunohistochemically, alpha-fetoprotein (AFP) was consistently positive in the epithelial and mesenychyma. The NF and muscles of HPB present at seven GW were positive for neural cell adhesion molecule (NCAM), neuron-specific enolase (NSE), platelet-derived growth factor receptor-α (PDGFRA), and KIT, but they disappeared in nine GW. Expressions of cytokeratin (CK) seven and CK19 in EBD and EPG were slight or none, while expression of CK8 was moderate, and that of CK18 was strong. NF were positive for NCAM, NSE, synaptophysin, and chromogranin, and PDGFRA. MUC1 and MUC6 apomucins were noted in EBD and EPG. EPG contained numerous endocrine cells positive for chromogranin, synaptophysin, NCAM and NSE. A few endocrine cells positive for these antigens were seen in EBD. Numeous KIT-positive stem cells (SC) were seen in PH, EBD, PV, HA, PCP, and EPG. NCAM-positive and bcl-2-positive SC were also located in these structures. Epithelial cells of EBD and EPG showed expressions of MET, PDGFRA, CA19-9, MUC1, MUC2, MUC6, KIT, bcl-2, and ErbB2. No expressions of HepPar1, carcinoembryonic antigen (CEA), and epithelial membrane antigen (EMA) were noted.

CONCLUSIONS

Although the findings have limitatios because this study of humans are descriptive one, the present data suggest that the processes of the development and differentiation of EBD system may be associated with EBD SC, CK prolifes, SFC/KIT signaling, HGF/MET signaling, PDGRa/PDGFRA signaling, fibroblast growth factor/ErbB2 signaling, neuroendocrine lineage, NF differentiation, pancreatic aninar cell differentiation, PCP differentiation, MUC apomucins differentiation, and expressions of AFP and CA19-9. HepPar1, EMA and CEA were not involved in them.

Huge clusters of embryonic stem cells in human embryos: a morphologic study

BACKGROUND

Nothing is known about huge clusters (HC) of embryonic stem cells (ESC) in human fetal organs (HFO).

AIM

To know the status of HC-ESC in HFO.

METHODS

Morphology and immunohistochemistry (IHC) in 32 HFO of 7-40 gestational weeks (GW).

RESULTS

HC-ESC were seen in many HFO including central nervous system, spinal cords, spine, soft tissue, bone, skin, thyroid, lung, liver, pancreas, gall bladder, extrahepatic bile duct, adrenal, kidney, bladder, foregut, midgut, hindgut, female and male genital organs, and neurons. HC-ESC's were composed of two populations depending on constituting cells. One were large cells with ample acidophilic cytoplasms with vesicular nuclei and nucleoli. The other were small cells with scant cytoplasm with hyperchromatic nuclei without nucleoli, resembling lymphocytes. The HC-ESC were frequently showed neuronal differentiation. HC-ESC were positive for NCAM, synaptophysin, NSE, chromogranin, PDGFRA, AFP, ErbB2, bcl-2, KIT, MET. They were negative for CD45, CD3, CD20, EMA, CEA, CA19-9, cytokeratin (CK) 7, CK8, CK18, CK19, MUC1, MUC2, MUC5AC, and MUC6. The mean Ki-67 labeling index (LI) was 13% ± 7%. HC-ESC showed a little glycogen but lacked mucins. These HC-ESC were seen in 7-25 GW, and they were rarely seen in 26-40 GW.

CONCLUSIONS

The morphology, IHC, and ontogeny of HC-ESC were described.

Human fetal ductal plate revisited. I. ductal plate expresses NCAM, KIT, MET, PDGFRA, and neuroendocrine antigens (NSE, chromogranin, synaptophysin, and CD56)

BACKGROUND

The molecular mechanisms of ductal plate (DP) development and differentiation (DD) in human fetal livers (HFLs) are unclear.

MATERIALS AND METHODS

The author immunohistochemically investigated expressions of NCAM, KIT, KIT, PDGFRA, and neuroendocrine antigens in 32 HFLs.

RESULTS

The processes of human intrahepatic bile duct (IBD) DD could be categorized into four stages: DP, remodeling DP, remodeled DP, and mature IBD. NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. The biliary elements were positive for cytokeratin (CK)7, 8, 18, and 19. The hepatoblasts were positive for CK8 and CD18, but negative for CK7 and CK19; however, periportal hepatoblasts showed biliary-type CKs (CK7 and CK19). NCAM was always expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. KIT was occasionally (12/32 cases) expressed in DP and remodeling DP, but not in remodeled DP and mature IBD. NCAM expression was also seen in some hepatoblasts and hematopoietic cells and neurons. KIT was also expressed in some hepatoblasts, hematopoietic cells, and mast cells. MET and PDGFRA were strongly expressed in DP, remodeling DP, remodeled DP, and mature IBD. MET and PDGFRA were also strongly expressed in hepatoblasts and hematopoietic cells. MET and PDGFRA were not expressed in portal mesenchyme, portal veins, sinusoids, and hepatic veins. DP showed immunoreactive chromogranin, synaptophysin, neuron-specific enolase (NSE), and CD56. Expressions of chromogranin and CD56 were infrequently seen in remodeling DP. No expressions of these four neuroendocrine antigens were seen in remodeled DP and mature IBD. The nerve fibers were consistently positive for chromogranin, synaptophysin, NSE, and CD56 in the portal mesenchyme in the stages of remodeling DP, remodeled DP, and mature IBDs.

CONCLUSIONS

The data suggest that NCAM, KIT/stem cell factor-signaling, NSE, hepatocyte growth factor/MET signaling, PDGFα/PDGFRA signaling, chromogranin, synaptophysin, and CD56 play important roles in DD of biliary cells of HFL. They also suggest that the DP cells having neuroendocrine molecules give rise to hepatic stem/progenitor cells.

Sanguineous normothermic machine perfusion improves hemodynamics and biliary epithelial regeneration in donation after cardiac death porcine livers

The effects of normothermic machine perfusion (NMP) on the postreperfusion hemodynamics and extrahepatic biliary duct histology of donation after cardiac death (DCD) livers after transplantation have not been addressed thoroughly and represent the objective of this study. Ten livers (5 per group) with 60 minutes of warm ischemia were preserved via cold storage (CS) or sanguineous NMP for 10 hours, and then they were reperfused for 24 hours with whole blood in an isolated perfusion system to simulate transplantation. In our experiment, the arterial and portal vein flows were stable in the NMP group during the entire reperfusion simulation, whereas they decreased dramatically in the CS group after 16 hours of reperfusion (P < 0.05); these findings were consistent with severe parenchymal injury. Similarly, significant differences existed between the CS and NMP groups with respect to the release of hepatocellular enzymes, the volume of bile produced, and the levels of enzymes released into bile (P < 0.05). According to histology, CS livers presented with diffuse hepatocyte congestion, necrosis, intraparenchymal hemorrhaging, denudated biliary epithelium, and submucosal bile duct necrosis, whereas NMP livers showed very mild injury to the liver parenchyma and biliary architecture. Most importantly, Ki-67 staining in extrahepatic bile ducts showed biliary epithelial regeneration. In conclusion, our findings advance the knowledge of the postreperfusion events that characterize DCD livers and suggest NMP as a beneficial preservation modality that is able to improve biliary regeneration after a major ischemic event and may prevent the development of ischemic cholangiopathy in the setting of clinical transplantation.

Alcohol-related injury to peribiliary glands is a cause of peribiliary cysts: based on analysis of clinical and autopsy cases

BACKGROUND AND GOAL

Peribiliary cysts, which are known to be associated with various hepatobiliary diseases including alcoholic liver disease, have been reported to originate in the peribiliary glands along the biliary tree. The causal relationship between the peribiliary cysts and alcohol-related hepatic and pancreatic disease were examined in this study.

METHODS AND RESULTS

Peribiliary cysts were surveyed in the radiologic reports of out-patients and in-patients at our hospital (between 2007 and 2011), and a total of 31 patients with peribiliary cysts were found; 9 patients were associated with alcoholic liver disease and 2 patients with alcoholic pancreatitis. Among 202 consecutive autopsy cases with a history of heavy drinking (chronic alcoholics) at our Department (between 1990 and 2011), peribiliary cysts were found in 29 cases (14%), and the frequency of these cysts was correlated with the degree of alcohol-related hepatic fibrosis. Interestingly, peribiliary cysts were frequently associated with adenitis of the peribiliary glands (72%), and peribiliary adenitis and cyst formation correlated well with the degree of pancreatic fibrosis.

CONCLUSIONS

These results suggest that peribiliary cysts are more likely to occur in chronic alcoholics. The frequent association of peribiliary cysts with the degree of alcohol-related hepatic fibrosis suggests the involvement of the hepatic fibrogenetic process in peribiliary cyst formation. The frequent association of peribiliary adenitis and cyst formation with the degree of pancreatic fibrosis in chronic alcoholics suggests the involvement of alcoholic injuries in the pancreas, resulting in progressive fibrosis, and peribiliary glands, resulting in adenitis and cyst formation.

Identification of intramural epithelial networks linked to peribiliary glands that express progenitor cell markers and proliferate after injury in mice

Peribiliary glands (PBGs) are clusters of epithelial cells residing in the submucosal compartment of extrahepatic bile ducts (EHBDs). Though their function is largely undefined, they may represent a stem cell niche. Here, we hypothesized that PBGs are populated by mature and undifferentiated cells capable of proliferation in pathological states. To address this hypothesis, we developed a novel whole-mount immunostaining assay that preserves the anatomical integrity of EHBDs coupled with confocal microscopy and found that PBGs populate the entire length of the extrahepatic biliary tract, except the gallbladder. Notably, in addition to the typical position of PBGs adjacent to the duct mucosa, PBGs elongate and form intricate intramural epithelial networks that communicate between different segments of the bile duct mucosa. Network formation begins where the cystic duct combines with hepatic ducts to form the common bile duct (CBD) and continues along the CBD. Cells of PBGs and the peribiliary network stain positively for α-tubulin, mucins, and chromogranin A, as well as for endoderm transcription factors SRY (sex determining region Y)-box 17 and pancreatic and duodenal homeobox 1, and proliferate robustly subsequent to duct injury induced by virus infection and bile duct ligation.

CONCLUSION

PBGs form elaborate epithelial networks within the walls of EHBDs, contain cells of mature and immature phenotypes, and proliferate in response to bile duct injury. The anatomical organization of the epithelial network in tubules and the link with PBGs support an expanded cellular reservoir with the potential to restore the integrity and function of the bile duct mucosa in diseased states.

Participation of peribiliary glands in biliary tract pathophysiologies

AIM: To investigate the roles of peribiliary glands around the bile ducts in the pathophysiology of the biliary tract.

METHODS: The expression of fetal pancreatic markers, pancreatic duodenal homeobox factor 1 (PDX1) and hairy and enhancer of split 1 (HES1) and endodermal stem/progenitor (S/P) cell markers [CD44s, chemokine receptor type 4 (CXCR4), SOX9 and epithelial cell adhesion molecule (EpCAM)] were examined immunohistochemically in 32 normal adult livers (autopsy livers) and 22 hepatolithiatic livers (surgically resected livers). The latter was characterized by the proliferation of the peribiliary glands. Immunohistochemistry was performed using formalin-fixed, paraffin-embedded tissue sections after deparaffinization. Although PDX1 and HES1 were expressed in both the nucleus and cytoplasm of epithelial cells, only nuclear staining was evaluated. SOX9 was expressed in the nucleus, while CD44s, CXCR4 and EpCAM were expressed in the cell membranes. The frequency and extent of the expression of these molecules in the lining epithelia and peribiliary glands were evaluated semi-quantitatively based on the percentage of positive cells: 0, 1+ (focal), 2+ (moderate) and 3+ (extensive).

RESULTS: In normal livers, PDX1 was infrequently expressed in the lining epithelia, but was frequently expressed in the peribiliary glands. In contrast, HES1 was frequently expressed in the lining epithelia, but its expression in the peribiliary glands was focal, suggesting that the peribiliary glands retain the potential of differentiation toward the pancreas and the lining epithelia exhibit properties to inhibit such differentiation. This unique combination was also seen in hepatolithiatic livers. The expression of endodermal S/P cell markers varied in the peribiliary glands in normal livers: SOX9 and EpCAM were frequently expressed, CD44s infrequently, and CXCR4 almost not at all. The expression of these markers, particularly CD44s and CXCR4, increased in the peribiliary glands and lining epithelia in hepatolithiatic livers. This increased expression of endodermal S/P cell markers may be related to the increased production of intestinal and gastric mucin and also to the biliary neoplasia associated with the gastric and intestinal phenotypes reported in hepatolithiasis.

CONCLUSION: The unique expression pattern of PDX1 and HES1 and increased expression of endodermal S/P cell markers in the peribiliary glands may be involved in biliary pathophysiologies.

The biliary tree--a reservoir of multipotent stem cells

The biliary tree is composed of intrahepatic and extrahepatic bile ducts, lined by mature epithelial cells called cholangiocytes, and contains peribiliary glands deep within the duct walls. Branch points, such as the cystic duct, perihilar and periampullar regions, contain high numbers of these glands. Peribiliary glands contain multipotent stem cells, which self-replicate and can differentiate into hepatocytes, cholangiocytes or pancreatic islets, depending on the microenvironment. Similar cells-presumably committed progenitor cells-are found in the gallbladder (which lacks peribiliary glands). The stem and progenitor cell characteristics indicate a common embryological origin for the liver, biliary tree and pancreas, which has implications for regenerative medicine as well as the pathophysiology and oncogenesis of midgut organs. This Perspectives article describes a hypothetical model of cell lineages starting in the duodenum and extending to the liver and pancreas, and thought to contribute to ongoing organogenesis throughout life.

Intraductal oncocytic papillary neoplasm of the bile duct: the first case of peribiliary gland origin

We report herein the first case of intraductal oncocytic papillary neoplasm of the bile duct arising from a peribiliary gland of the left hepatic duct. The patient was a 63-year-old Japanese man. Radiological and cholangioscopic examinations revealed intraductal tumor of the left hepatic duct. After pathological diagnosis of adenocarcinoma by cholangioscopic biopsy, a surgical hepatobiliary resection was performed. Pathological examination revealed papillary tumor in the left hepatic duct. Histologically, the tumor was identified as papillary neoplasm comprising oncocytic cells and delicate fibrovascular cores. Interestingly, this tumor originated from the cystic space in the bile duct wall. This cystic space was histologically identified as a cystically dilated peribiliary gland. Carcinoma in situ was observed in this cystic peribiliary gland at the bottom of the tumor, but not on any areas of biliary epithelium. This case suggests that intraductal papillary neoplasm can arise from both biliary epithelium and peribiliary glands.

Enhanced detection of cholangiocarcinoma with serum trypsinogen-2 in patients with severe bile duct strictures

BACKGROUND/AIMS

Primary sclerosing cholangitis (PSC) is associated with a high risk of cholangiocarcinoma. Our aim was to evaluate the diagnostic value of trypsinogen-1, trypsinogen-2, tumour-associated trypsin inhibitor, human chorionic gonadotropin beta and trypsin-2-alpha(1)-antitrypsin for cholangiocarcinoma and to compare them with CA19-9 and CEA.

METHODS

The study consisted of 84 patients with either PSC or cholangiocarcinoma or both referred for liver transplantation or other liver surgery. The serum concentrations were determined by time-resolved immunofluorometric assays.

RESULTS

Forty-six patients were transplanted due to PSC; in 3 of the explanted livers cholangiocarcinoma was found incidentally. All transplanted patients had severe biliary strictures together with cirrhosis or pre-cirrhosis. Twenty-nine of 38 patients with cholangiocarcinoma were candidates for intervention. In all, 8 patients had both PSC and cholangiocarcinoma. Receiver-operating characteristics curve analysis showed that serum trypsinogen-2 had the highest accuracy in differentiating between cholangiocarcinoma and PSC. The area under the curve (AUC) value was 0.804 for trypsinogen-2 and 0.613 for CA19-9. Serum trypsinogen-2 also showed the highest accuracy for differentiation between PSC and PSC with simultaneous cholangiocarcinoma with an AUC value of 0.759.

CONCLUSIONS

Our results suggest that serum trypsinogen-2 is a most useful marker for diagnosing patients with cholangiocarcinoma, and it is superior to serum CA19-9 and CEA.

Cystic duct and Heister's "valves"

The anatomy and physiology of the cystic duct have been relatively neglected by anatomists and the function of the spiral mucosal folds or "valves" of Heister, first described in 1732, remains obscure. The gross and microscopic anatomy of the cystic duct is reviewed together with results from laboratory investigations into the function of the cystic duct and its spirally arranged folds. The duct and spiral folds contain muscle fibers responsive to pharmacologic, hormonal, and neural stimuli. There is, however, no convincing evidence of a discrete muscular sphincter within the duct. Although the cystic duct is unlikely to play a major role in gallbladder filling and emptying, it appears to function as more than a passive conduit. Coordinated, graded muscular activity in the cystic duct in response to hormonal and neural stimuli may facilitate gallbladder emptying. The principal function of the internal spiral folds that are found in man and other animals may be to preserve patency of this narrow, tortuous tube rather than to regulate bile flow.

Aberrant expression of pyloric gland-type mucin in mucin-producing bile duct carcinomas: A clear difference between the core peptide and the carbohydrate moiety

The authors have recently defined the clinopathological entity of a mucin-producing bile duct tumor (MPBT), and divided MPBT into two distinct subtypes: 'columnar-type' and 'cuboidal-type' MPBT. Mucin core protein 6 (MUC6), which is present in normal pyloric glands, had higher expression levels in cuboidal-type tumors than in columnar-type tumors. In the pyloric glands, a carbohydrate antigen detected by monoclonal antibody HIK1083 (CA/HIK1083) is also expressed. In order to evaluate the coexpression pattern of MUC6 and CA/HIK1083 in MPBT, expression profiles were evaluated in 38 surgically excised mucin-producing bile duct carcinomas (MPBC; cuboidal-type, n = 15; columnar-type, n = 23), using immunohistochemistry. The staining rate was graded as follows: -, <5% of neoplastic cells stained; +, 5% to <20%; + +, 20% to <50%; + + +, > or =50%. In cuboidal-type MPBC, MUC6 was positive in all cases (+ + +, 13/15; + +, 1/15; +, 1/15), whereas CA/HIK1083 was negative in all cases (-, 15/15; P < 0.0001). In columnar-type MPBC, MUC6 was positive in 65% of cases (+ + +, 6/23; + +, 8/23; +, 1/23; -, 8/23), and CA/HIK1083 was positive in 52% (+ +, 3/23; +, 9/23; -, 11/23; not significant). Our results clearly demonstrate that cuboidal-type MPBC have an aberrant pyloric glandular phenotype, that is, MUC6+/CA/HIK1083-. This unique profile may be related to different outcomes of patients with MPBC.

The Ratio of Trypsin-2-α1-Antitrypsin to Trypsinogen-1 Discriminates Biliary and Alcohol-induced Acute Pancreatitis

Background: Rapid determination of the etiology of acute pancreatitis (AP) enables institution of appropriate treatment. We evaluated the ability of trypsinogen-1, trypsinogen-2, trypsin-1-α1-antitrypsin (AAT), and trypsin-2-AAT in serum to identify the etiology of AP.

Methods: The study consisted of 67 consecutive patients with AP admitted to Helsinki University Central Hospital. Forty-two had alcohol-induced AP, 16 had biliary AP, and 9 had unexplained etiology. Serum samples were drawn within 12 h after admission. Trypsinogen-1, trypsinogen-2, trypsin-1-AAT, and trypsin-2-AAT were determined by time-resolved immunofluorometric assays. Logistic regression was used to estimate the ability of the serum analytes to discriminate between alcohol-induced and biliary AP. The validity of the tests was evaluated by ROC curve analysis.

Results: Patients with alcohol-induced AP had higher median values of trypsin-1-AAT (P = 0.065), trypsinogen-2 (P = 0.034), and trypsin-2-AAT (P &lt;0.001) than those with biliary AP, who had higher values of amylase (P = 0.002), lipase (P = 0.012), and alanine aminotransferase (P = 0.036). The ratios of trypsin-2-AAT to trypsinogen-1, lipase, or amylase efficiently discriminated between biliary and alcohol-induced AP (areas under ROC curves, 0.92–0.96).

Conclusions: Trypsinogen-2 and trypsin-2-AAT are markedly increased in AP of all etiologies, whereas trypsinogen-1 is increased preferentially in biliary AP. The trypsin-2-AAT/trypsinogen-1 ratio is a promising new marker for discrimination between biliary and alcohol-induced AP.

Expression of pancreatic alpha-amylase protein and messenger RNA in hilar primitive bile ducts and hepatocytes during human fetal liver organogenesis: an immunohistochemical and in situ hybridization study

AIMS/BACKGROUND

This study was conducted to evaluate the expression of pancreatic digestive enzymes in hilar bile ducts and hepatocytes during human fetal liver organogenesis.

METHODS

We investigated the expression of pancreatic alpha-amylase protein and messenger RNA (mRNA) in hilar primitive bile ducts and hepatocytes by immunohistochemistry and in situ hybridization techniques, using 11 human fetal livers of various gestational ages. The specificity of the immunohistochemistry and in situ hybridization procedures was confirmed by Western blot analysis and in situ hybridization using sense probes, respectively.

RESULTS

Immunoreactivity of pancreatic alpha-amylase protein and expression of pancreatic alpha-amylase mRNA were present not only in the primitive ductal cells of the hilar region including the ductal plate, remodelling bile ducts and remodeled bile ducts but also in primitive hepatocytes of the hilar region, though the immunoreactivity and mRNA signals in the primitive hepatocytes disappeared in the third trimester. There was perfect correlation between immunohistochemistry and in situ hybridization.

CONCLUSIONS

These results suggest that primitive biliary cells and hepatocytes of the hilar region in the human fetus do express pancreatic alpha-amylase protein and mRNA, and that the primitive biliary epithelial cells and hepatocytes in the hilar region share a common cell lineage with exocrine pancreatic cells.

Advances in the laboratory diagnostics of acute pancreatitis

Acute pancreatitis is a rather common abdominal disorder. In most patients the disease is mild, but about 20% of cases develop a severe necrotizing form of the disease with complications. In an emergency setting, the diagnosis of acute pancreatitis remains problematic and several patients with severe disease are diagnosed only at autopsy. Measurements of amylase or lipase are the principal laboratory methods for diagnosing acute pancreatitis. However, their sensitivity and specificity are generally considered unsatisfactory. Recent advances in the knowledge of the pathogenesis of acute pancreatitis and advances in laboratory technology have revealed new diagnostic possibilities. Especially assays based on trypsin pathophysiology have brought new alternatives for diagnostics and severity grading of the disease. Additionally, development of phospholipase A2 determinations and discovery of a new pancreatic protein, pancreatitis-associated protein, are very interesting. This article summarizes the value of new methods in the laboratory diagnostics of acute pancreatitis.

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.

Normal and abnormal development of the human intrahepatic biliary system: a review

Morphology and immunohistochemical features of the developmental process of the human intrahepatic biliary system (IBS) are reviewed. Human IBS arises from the ductal plate, a double-layered cylindrical structure located at the interface between portal mesenchyme and primitive hepatocytes. The ductal plate first appears from primitive hepatocytes (hepatoblasts) around 8 gestational weeks (GW), and its formation proceeds from the hepatic hilum to the periphery. The ductal plate gradually undergoes remodeling from 12 GW; some parts of the ductal plate disappear and other parts migrate into the portal mesenchyme. Around 20 GW, the migrated duct cells transform into immature bile ducts and peribiliary glands. Some immature peribiliary glands transform into pancreatic acinar cells around postnatal 3 months. The immature biliary elements express cytokeratins no. 7, 8, 18 and 19. Several growth factors (TGF-alpha, HGF) and their receptors (EGFR, MET, ERBB2) were expressed in the primitive IBS cells. Some extracellular matrix proteins including type IV collagen, laminin and tenascin are expressed in the mesenchyme around the primitive IBS. During IBS remodeling, apoptosis and cell proliferation occur with appropriate expression of apoptosis-related proteins (bcl-2, Fas, c-myc, Lewis(y)). Some pancreatic digestive enzymes (alpha-amylase, trypsinogen, lipase), cathepsin B, and matrix metalloproteinases (MMP-1, 2, 3, 9) and their inhibitors (TIMP-1, 2) are expressed in the remodeling IBS cells. Glycoconjugate residues of glycoproteins gradually appear during IBS development. The appropriate expression of these immunophenotypes may play an important role in the normal development of IBS.

Serum samples from pancreatectomized patients contain trypsinogen immunoreactivity

The concentrations of trypsinogen-1 and -2 in serum samples from patients who have undergone pancreatectomy were measured by highly sensitive and specific time-resolved immunofluorometric assays. The isoenzyme pattern was determined by ion-exchange chromatography and determination of immunoreactivity in the fractions. All samples contained trypsinogen-2, the mean level being one fifth of that in healthy controls. Trypsinogen-1 was detected in one of nine samples. In addition to the main trypsinogen isoenzymes, we observed in normal serum two trypsinogen isoenzymes previously found in mucinous ovarian cyst fluid. Our results suggest that trypsinogen is not exclusively expressed by the pancreas and certain tumors but that it also may be produced by normal extrapancreatic tissues. This should be considered when an assay of trypsinogen in serum is used for clinical purposes.

Serum trypsinogen-2 and trypsin-2-alpha(1)-antitrypsin complex in malignant and benign digestive-tract diseases. Preferential elevation in patients with cholangiocarcinomas

Serum concentrations of trypsinogen-2 and trypsin-2-alpha(1)-antitrypsin (trypsin-2-AAT) were determined in 145 patients with malignant and 61 with benign digestive-tract diseases. The validity of these tests for detection of cancer was compared with that of CA 19-9 and CEA. Elevated levels of trypsinogen-2 (>90 micrograms/l) and trypsin-2-AAT (>25 micrograms/l) were found in 46% and 42%, respectively, of patients with malignant disease and the levels of trypsinogen-2 were significantly higher than in those with benign disease (p<0.005). High trypsinogen-2 and trypsin-2-AAT concentrations were found most often in patients with biliary and pancreatic cancer, but also in benign obstructive biliary disease. Our results suggest that trypsinogen-2 and trypsin-2-AAT are new potential markers for cholangiocarcinomas.

Utility of pancreatic digestive enzyme immunohistochemistry in the differential diagnosis of hepatocellular carcinoma, cholangiocarcinoma and metastatic adenocarcinoma of the liver

To test the diagnostic utility of pancreatic digestive enzyme immunohistochemistry in liver cancers, the expression of three pancreatic digestive enzymes (trypsinogen, chymotrypsinogen and pancreatic lipase) was investigated in cholangiocarcinoma (CC) (n = 42), hepatocellular carcinoma (HCC) (n = 35), combined HCC-CC (n = 11) and metastatic adenocarcinoma (MA) of the liver (n = 34; 4 gastric cancer, 5 pancreatic cancer and 25 colon cancer). In CC, 15 (36%) expressed one or more of these enzymes, while the remaining 27 (64%) did not express any enzymes. In MA, 13 (38%) expressed one or more of these enzymes, while the remaining 21 (62%) did not express any enzymes. Expression of trypsinogen, chymotrypsinogen and lipase was noted in 15 CC (36%), 11 CC (25%) and 15 CC (36%), respectively, and in 9 MA (26%), 6 MA (18%) and 13 MA (38%), respectively. There was no significant difference in the positive ratio of each enzyme between CC and MA. In positive cases, the enzymes were expressed with a cytoplasmic granular pattern. In MA, there was no significant difference in the positive ratio of the enzymes among the primary sites. In contrast to CC and MA, these enzymes were not expressed in any cases of HCC and combined HCC-CC. These data suggest that pancreatic digestive enzyme immunohistochemistry may be useful for differential diagnosis between HCC and CC or MA as well as between combined HCC-CC and CC or MA, but it is not useful for differential diagnosis between CC and MA. A positive reaction for these enzymes is indicative of CC or MA and is against the diagnosis of HCC or combined HCC-CC, and a negative reaction is noncontributory to the differential diagnosis.

Expression of pancreatic trypsinogen/trypsin and cathepsin B in human cholangiocarcinomas and hepatocellular carcinomas

We evaluated in situ expression of pancreatic trypsinogen (PT) and cathepsin B (CB) in 10 normal livers, 37 cholangiocarcinomas (CCs), and 36 hepatocellular carcinomas (HCCs). In normal livers, PT was expressed in intrahepatic large bile ducts, septal bile ducts, and peribiliary glands, and CB was present in hepatocytes and all epithelial cells of the intrahepatic biliary system. In CCs, PT was present in 26 (70%), of which 24 expressed PT both in CC cells and the CC stroma, and the remaining two showed PT only in CC cells. The ratio of PT-positive cases was high in well-differentiated CCs, moderate in moderately differentiated CCs, and low in poorly differentiated CCs. PT in the CC stroma was present in continuity with PT-positive CC cells, suggesting that PT was secreted from CC cells. The CC stroma positive for PT frequently showed destructive features. CB was present in 32 CCs (86%) and located in both CC cells and the CC stroma. All PT-positive CCs simultaneously expressed CB, suggesting a close association of PT and CB. In HCCs, in contrast, PT was not present in any cases. CB was present in 33 HCCs (92%) and located in both HCC cells and the HCC stroma. In positive specimens, PT immunoreactivity was finely granular in the cytoplasm, whereas CB immunoreactivity was diffuse in the entire cytoplasm. These data suggest that after malignant transformation CCs and HCCs continue to express PT and CB, and CB, respectively. It seems possible that PT secreted from CC cells is converted into trypsin by CB, and that trypsin and CB play a role in CC invasion by degrading extracellular matrix proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of pancreatic enzymes (alpha-amylase, trypsinogen, and lipase) during human liver development and maturation

BACKGROUND/AIMS

Although pancreatic enzymes have been found in hilar intrahepatic bile ducts in adult humans, their expression during human liver development is unclear. The aim of this study was to clarify the temporal expression of pancreatic enzymes at various stages of human liver development.

METHODS

We immunohistochemically investigated pancreatic alpha-amylase, trypsinogen, and lipase expression in fetal, neonatal, juvenile, and adult human livers.

RESULTS

In hilar duct development, alpha-amylase but not trypsinogen or lipase was expressed in the ductal plate. These three enzymes were expressed in biliary cells migrating into the mesenchyma, in immature ducts in fetal livers, and in maturing and mature ducts in postnatal livers. Their expression was weak and diffusely cytoplasmic in fetal livers, whereas in postnatal livers their expression was strong, granular, and located in the supranuclear cytoplasm. Expression was not found in developing peripheral ducts. These enzymes were expressed in immature hepatocytes (9-25 weeks' gestation) but disappeared thereafter. Enzyme expression was mild in fetal pancreata and strong in adult pancreata.

CONCLUSIONS

Pancreatic enzymes may be present in primitive hilar bile ducts and hepatocytes in fetal livers; hilar ducts, hepatocytes, and pancreas may have similar fetal enzymatic profiles. Intrahepatic hilar bile ducts, hepatocytes, and exocrine pancreas may have a common cell lineage.

Immunocytochemical localization of elastase 1 in human pancreas

By light and electron microscopic immunocytochemistry the distribution is described of human pancreatic elastase 1 (E1) during ontogenesis, in adults, in cases of acute and chronic pancreatitis, acute pancreatic ischaemia as well as pancreatic tumours. E1-positive cells were first detected in ductal sprouts in the 14th gestational week. Complete acini expressing E1 could be found from the 17th to the 20th week of gestation onwards. Scattered distinct E1-positive epithelia could be found in the ducts of fetal and adult pancreas. By immunoelectron microscopy, E1 was localized in rough endoplasmic reticulum, condensing vacuoles, zymogen granules of acinar epithelia and in acinar lumina. E1 appeared to be distributed homogeneously in zymogen granules. As specific markers of acinar cells, both monoclonal antibodies under study identified heterotopic pancreatic acini in peribiliar glands of the liver and also helped to visualize different damage patterns in pancreatitis. The acinar epithelia surrounding acute lipolytic necroses initially reacted more intensely with the E1-antibodies than undamaged pancreatic tissue. In acute ischaemia, acinar cells which are dissociated from intercalated ducts lost their immunocytochemical reactivity for E1. Pancreatic parenchyma involved in advanced acute pancreatitis as well as in chronic inflammation was detected only weakly by both E1-antibodies. However, atrophic lobules in post-inflammatory scars were stained more intensely by the E1-antibodies than normal parenchyma. Pancreatic tumours (adenomas, adenocarcinomas, solid-cystic tumours and islet cell tumours) were not labelled by these antibodies.

Pancreatic enzymes in the epithelium of intrahepatic large bile ducts and in hepatic bile in patients with extrahepatic bile duct obstruction

AIM

To determine whether pancreatic enzymes are present in hepatic bile and in intrahepatic bile duct epithelium.

METHODS

The activity and proteins of pancreatic enzymes (pancreatic alpha-amylase, lipase, trypsin/trypsinogen) in hepatic bile were investigated using biochemical and western blot analyses in 25 patients with extrahepatic bile duct obstruction. Immunolocalization of enzyme proteins was evaluated by immunohistochemistry in 20 necropsy livers with extrahepatic bile duct obstruction.

RESULTS

Western blot analysis showed proteins of pancreatic alpha-amylase, lipase, and trypsin in 19 of 25 (76%), 10 of 25 (40%), and 14 of 25 (56%) patients, respectively. Pancreatic alpha-amylase and lipase activities was present in every bile specimen. Radioimmunoassay showed that trypsin was present in every bile sample. Immunohistochemically, the immunoreactivity of the three enzymes was present in epithelia and in the lumina of intrahepatic large bile ducts, septal bile ducts, and peribiliary glands in all cases.

CONCLUSIONS

These results strongly suggest that biliary epithelia of larger intrahepatic ducts produce pancreatic alpha-amylase, lipase, and trypsin, and that these enzymes are secreted into the lumina of intrahepatic bile ducts.