A Gradient of Intestinal Inflammation in Primary Sclerosing Cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a progressive liver disease associated with inflammatory bowel disease (IBD). The percentage of PSC patients diagnosed with concomitant IBD varies considerably between studies. This raises the question whether all PSC patients would show intestinal inflammation if screened thoroughly, even in the absence of symptoms. METHODS: To address this question, we collected intestinal biopsies of healthy controls (n = 34), PSC (n = 25), PSC-IBD (n = 41), and IBD (n = 51) patients in a cross-sectional study and carried out cytokine expression profiling, 16S sequencing, in-depth histology, and endoscopy scoring. RESULTS: We found that the vast majority of PSC patients even without clinically manifest IBD showed infiltration of immune cells and increased expression of IL17A and IFNG in intestinal biopsies. However, expression of IL10 and FOXP3 were likewise increased, which may explain why these PSC patients have intestinal inflammation only on a molecular level. This subclinical inflammation in PSC patients was focused in the distal colon, whereas PSC-IBD patients showed inflammation either at the distal colon or on the right side of the colon and the terminal ileum. Furthermore, we observed that PSC patients without IBD showed signs of dysbiosis and exhibited a distinct microbial profile compared with healthy controls. CONCLUSIONS: We found a gradient of intestinal inflammation in the vast majority of PSC patients even in the absence of IBD. Thus, further studies evaluating the effect of anti-inflammatory therapies in PSC patients and their impact on the emergence of clinically manifest IBD and colorectal cancer development are needed.

[Endoscopic Resection for GEP-NET]. / Spannungsfeld endoskopische Resektionsverfahren bei GEP-NET // Endoscopic resection for GEP-NET.

Neuroendocrine tumours (NET) are rare tumours of the gastrointestinal tract. Many of these are diagnosed incidentally during routine upper and lower GI endoscopy. Complete surgical resection is the treatment of choice for localised tumours. For small tumours with no associated risk factors for metastases, endoscopic resection can be performed with curative intent. This endoscopic approach is standard of care for gastric, duodenal and rectal NET. In contrast, NET of the jejunum and ileum should not be treated endoscopically, as they exhibit a high rate of metastases independent of tumour size. The feasibility of an endoscopic resection is defined by the technical possibility of achieving an R0 resection, the complication rate of the procedure and the suspected rate of lymph node metastases. In general, endoscopic resection is recommended for tumours less than 1 cm in size, since they can be successfully endoscopically resected without major complications and carry a low risk of metastases. All tumours above 2 cm should be surgically resected, as endoscopic R0 resection is unlikely and risk of lymph node metastases is high. Tumours of between 1 cm and 2 cm could be approached by both surgical or endoscopic resection. A novel approach for these "in between" tumours is a combined endoscopic-laparoscopic rendezvous to achieve limited organ-sparing resection with maximal safety. This approach is particularly useful for duodenal NET as the risk of perforation is high for endoscopic resection.

Hybrid APC in Combination With Resection for the Endoscopic Treatment of Neoplastic Barrett's Esophagus: A Prospective, Multicenter Study.

INTRODUCTION: The current therapy of neoplastic Barrett's esophagus (BE) consists of endoscopic resection plus ablation, with radiofrequency ablation as the best studied technique. This prospective trial assesses a potential alternative, namely hybrid argon plasma ablation. METHODS: Consecutive patients with neoplastic BE undergoing ablation after curative endoscopic resection (89.6%) or primarily were included into this prospective trial in 9 European centers. Up to 5 ablation sessions were allowed for complete eradication of BE (initial complete eradication of intestinal metaplasia [CE-IM]), by definition including BE-associated neoplasia, documented by 1 negative endoscopy with biopsies. The main outcome was the rate of initial CE-IM in intention-to-treat (ITT) and per-protocol (PP) samples at 2 years. The secondary end points were the rate of recurrence-free cases (sustained CE-IM) documented by negative follow-up endoscopies with biopsies and immediate/delayed adverse events. RESULTS: One hundred fifty-four patients (133 men and 21 women, mean age 64 years) received a mean of 1.2 resection and 2.7 ablation sessions (range 1-5). Initial CE-IM was achieved in 87.2% of 148 cases in the PP analysis (ITT 88.4%); initial BE-associated neoplasia was 98.0%. On 2-year follow-up of the 129 successfully treated cases, 70.8% (PP) or 65.9% (ITT) showed sustained CE-IM; recurrences were mostly endoscopy-negative biopsy-proven BE epithelium and neoplasia in 3 cases. Adverse events were seen in 6.1%. DISCUSSION: Eradication and recurrence rates of Barrett's intestinal metaplasia and neoplasia by means of hybrid argon plasma coagulation at 2 years seem to be within expected ranges. Final evidence in comparison to radiofrequency ablation can only be provided by a randomized comparative trial.

Quantitative analysis of submucosal excision depth in endoscopic resection for early Barrett's cancer.

BACKGROUND : Following endoscopic resection of early-stage Barrett's esophageal adenocarcinoma (BEA), further oncologic management then fundamentally relies upon the accurate assessment of histopathologic risk criteria, which requires there to be sufficient amounts of submucosal tissue in the resection specimens. METHODS : In 1685 digitized tissue sections from endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) performed for 76 early BEA cases from three experienced centers, the submucosal thickness was determined, using software developed in-house. Neoplastic lesions were manually annotated. RESULTS : No submucosa was seen in about a third of the entire resection area (mean 33.8 % [SD 17.2 %]), as well as underneath cancers (33.3 % [28.3 %]), with similar results for both resection methods and with respect to submucosal thickness. ESD results showed a greater variability between centers than EMR. In T1b cancers, a higher rate of submucosal defects tended to correlate with R1 resections. CONCLUSION : The absence of submucosa underneath about one third of the tissue of endoscopically resected BEAs should be improved. Results were more center-dependent for ESD than for EMR. Submucosal defects can potentially serve as a parameter for standardized reports.

Possible tumour cell reimplantation during curative endoscopic therapy of superficial Barrett's carcinoma.

BACKGROUND AND AIMS: Endoscopic resection has been established as curative therapy for superficial cancer arising from Barrett's oesophagus (BE); recurrences are very rare. Based on a case series with unusual and massive early recurrences, we analyse the issue of tumour cell reimplantation. METHODS: This hypothesis was developed on the basis of two out of seven patients treated by circumferential (n=6) or nearly circumferential (n=1) en bloc and R0 endoscopic resection of T1 neoplastic BE. Subsequently, a prospective histocytological analysis of endoscope channels and accessories was performed in 2 phases (cytohistological analysis; test for cell viability) in 22 different oesophageal carcinoma patients undergoing endoscopy. Finally, cultures from two oesophageal adenocarcinoma cell lines were incubated with different triamcinolone concentrations (0.625-10 mg/mL); cell growth was determined on a Multiwell plate reader. RESULTS: Cancer regrowth in the two suspicious cases (male, 78/71 years) occurred 7 and 1 months, respectively, after curative tumour resection. Subsequent surgery showed advanced tumours (T2) with lymph node metastases; one patient died. On cytohistological examinations of channels and accessories, suspicious/neoplastic cells were found in 4/10 superficial and in all 5 advanced cancers. Further analyses in seven further advanced adenocarcinoma cases showed viable cells in two channel washing specimens. Finally, cell culture experiments demonstrated enhanced tumour cell growth by triamcinolone after 24 hours compared with controls. CONCLUSIONS: Tumour cell reimplanation from contaminated endoscopes and accessories is a possible cause of local recurrence after curative endoscopic therapy for superficial Barrett carcinoma; also, corticosteroid injection could have promoted tumour regrowth in these cases.

Laparoscopic lymph node sampling: a new concept for patients with high-risk early esophagogastric junction cancer resected endoscopically.

BACKGROUND AND AIMS: Endoscopic resection is considered a curative treatment for early upper GI cancers under certain histologic (low-risk) criteria. In tumors not completely fulfilling these criteria but resected R0 endoscopically, esophagectomy is still advised because of an increased risk of lymph node (LN) metastases (LNM). However, the benefit-risk ratio, especially in elderly patients at higher risk for radical surgery, can be debated. We now present the outcome of our case series of laparoscopic LN sampling (LLS) in patients with T1 esophagogastric junction tumors, which had been completely resected by endoscopy but did not fulfill the low-risk criteria (G1/2, m, L0, V0). METHODS: Retrospective review was done of all patients with T1 cancer undergoing LLS with at least 1 high-risk parameter after endoscopic resection during an 8-year period. Repeated endoscopy with biopsy and abdominothoracic CT had been performed before. The patients were divided into 2 periods: before (n = 8) and after (n = 12) the introduction of an extended LLS protocol (additional resection of the left gastric artery). In cases of positive LN, patients underwent conventional oncologic surgery; if negative, follow-up was performed. The main outcome was the number of harvested LNs by means of LLS and the percentage of positive LNs found. RESULTS: Twenty patients with cardia (n = 1) and distal esophageal/Barrett's cancer (n = 19) were included. The LN rate with use of the extended LLS technique increased by 12% (period 1: median 12 [range, 5-19; 95% CI, 3.4-15.4] vs period 2: median 17.5 [range, 12-40; 95% CI, 12.8-22.2]; P = .013). There were 2 adverse events: 1 inadvertent chest tube removal and 1 postoperative pneumonia. In 15% of cases, patients had positive LNs. and in 2 cases there was local recurrence at the endoscopic resection site, all necessitating surgery. CONCLUSIONS: An extended technique of laparoscopic LN sampling appears to provide adequate LN numbers and is a safe approach with short hospital stay only. Only long-term follow-up of larger patient numbers will allow conclusions about miss rate as well as oncologic adequacy of this concept.

Alterations of the bile microbiome in primary sclerosing cholangitis.

BACKGROUND: Patients with primary sclerosing cholangitis (PSC) display an altered colonic microbiome compared with healthy controls. However, little is known on the bile duct microbiome and its interplay with bile acid metabolism in PSC. METHODS: Patients with PSC (n=43) and controls without sclerosing cholangitis (n=22) requiring endoscopic retrograde cholangiography were included prospectively. Leading indications in controls were sporadic choledocholithiasis and papillary adenoma. A total of 260 biospecimens were collected from the oral cavity, duodenal fluid and mucosa and ductal bile. Microbiomes of the upper alimentary tract and ductal bile were profiled by sequencing the 16S-rRNA-encoding gene (V1-V2). Bile fluid bile acid composition was measured by high-performance liquid chromatography mass spectrometry and validated in an external cohort (n=20). RESULTS: The bile fluid harboured a diverse microbiome that was distinct from the oral cavity, the duodenal fluid and duodenal mucosa communities. The upper alimentary tract microbiome differed between PSC patients and controls. However, the strongest differences between PSC patients and controls were observed in the ductal bile fluid, including reduced biodiversity (Shannon entropy, p=0.0127) and increase of pathogen Enterococcus faecalis (FDR=4.18×10-5) in PSC. Enterococcus abundance in ductal bile was strongly correlated with concentration of the noxious secondary bile acid taurolithocholic acid (r=0.60, p=0.0021). CONCLUSION: PSC is characterised by an altered microbiome of the upper alimentary tract and bile ducts. Biliary dysbiosis is linked with increased concentrations of the proinflammatory and potentially cancerogenic agent taurolithocholic acid.

Usefulness of biochemical remission and transient elastography in monitoring disease course in autoimmune hepatitis.

BACKGROUND & AIMS: Liver fibrosis regression but also progression may occur in patients with autoimmune hepatitis (AIH) under treatment. There is a need for non-invasive surrogate markers for fibrosis development in AIH to better guide immunosuppressive treatment. The aims of the study were to assess the impact of complete biochemical remission defined as normalisation of aminotransferases and IgG on histological activity and fibrosis development, and the value of repeat transient elastography (TE) measurement for monitoring disease progression in AIH. METHODS: A total of 131 liver biopsies from 60 patients with AIH and more than 900 TE from 125 patients with AIH, 130 with primary biliary cholangitis (PBC) and 100 with primary sclerosing cholangitis (PSC), were evaluated. Time intervals between TE were at least 12 months. Patients with AIH were treated for at least six months at first TE. RESULTS: In contrast to PBC and PSC, a decrease of liver stiffness (LS) was observed in the whole group of patients with AIH (-6.2%/year; 95% CI -12.6% to -0.2%; p = 0.04). The largest decrease of LS was observed in patients with severe fibrosis at baseline (F4: -11.7%/year; 95% CI -19% to -3.5%; p = 0.006). Complete biochemical remission was strongly linked to regression of LS ("remission": -7.5%/year vs. "no remission": +1.7%/year, p <0.001). Similarly, complete biochemical remission predicted low histological disease activity and was the only independent predictor for histological fibrosis regression (relative risk3.66; 95% CI1.54-10.2; p = 0.001). Patients with F3/F4-fibrosis, who remained in biochemical remission showed a considerable decrease of fibrosis stage (3.7 ±â€¯0.5 to 1.8 ±â€¯1.7; p = 0.007) on histological follow-up. CONCLUSIONS: This study demonstrates that complete biochemical remission is a reliable predictor of a good prognosis in AIH and leads to fibrosis regression that can be monitored by TE. LAY SUMMARY: Autoimmune hepatitis is an inflammatory disease of the liver, which often progresses to cirrhosis if left untreated or in the case of insufficient treatment response. Current guidelines have defined biochemical remission (normalisation of biochemical markers for liver inflammation) as a major goal in the treatment of AIH. However, data on the prognostic relevance of this definition are scarce. Herein, we demonstrate that the current definition of biochemical remission is a reliable surrogate for low disease activity on histological assessment and for a beneficial long-term disease course. In addition, we establish transient elastography, a non-invasive ultrasound-based method of measuring scarring of liver tissue, as a reliable tool to monitor disease course in AIH.

Risk of cholangiocarcinoma in patients with primary sclerosing cholangitis: diagnosis and surveillance.

PURPOSE OF REVIEW: Primary sclerosing cholangitis (PSC) is associated with an increased risk of hepatobiliary and extrahepatic malignancy. Particularly the risk of cholangiocarcinoma (CCA) is greatly increased. To provide potentially curative treatments for affected patients an early diagnosis of CCA is crucial. We here review the current advances with respect to CCA diagnosis and surveillance and discuss a rational approach on how to perform surveillance of CCA in PSC patients. RECENT FINDINGS: Given the shortcomings of the current modalities for the surveillance and diagnosis of CCA in PSC, recent studies have focused on novel biomarkers for CCA. These include serum biomarkers (e.g., circulating angiopoeitin-2, cytokeratin-19 fragments, and antiglycoprotein 2 IgA autoantibodies, microRNA) as well as proteomics obtained from urine and/or bile. Novel approaches that may enhance the diagnostic value of brush cytology in future include the optimization of fluorescence in situ hybridization probes and the assessment of genetic aberrations. In addition, studies on advanced techniques (e.g., single-operator cholangioscopy and probe-based confocal laser endomicroscopy) have shown promising results with respect to CCA detection. SUMMARY: Despite recent advances in the diagnosis of CCA in PSC, the detection of early-stage CCA remains difficult. A better understanding of CCA pathogenesis and large prospective studies on novel biomarkers and techniques are required to timely diagnose CCA in the future.

Validation of Transient Elastography and Comparison with Spleen Length Measurement for Staging of Fibrosis and Clinical Prognosis in Primary Sclerosing Cholangitis.

BACKGROUND: Patients with primary sclerosing cholangitis (PSC) develop progressive liver fibrosis and end-stage liver disease. Non-invasive and widely available parameters are urgently needed to assess disease stage and the risk of clinical progression. Transient elastography (TE) has been reported to predict fibrosis stage and disease progression. However, these results have not been confirmed in an independent cohort and comparison of TE measurement to other non-invasive means is missing. METHODS: In a retrospective study we collected data from consecutive PSC patients receiving TE measurements from 2006 to 2014 (n = 139). Data from 62 patients who also underwent a liver biopsy were used to assess the performance of TE and spleen length (SL) measurement for the staging of liver fibrosis. Follow-up data from this cohort (n = 130, Hamburg) and another independent cohort (n = 80, Paris) was used to compare TE and SL as predictors of clinical outcome applying Harrel's C calculations. RESULTS: TE measurement had a very good performance for the diagnosis and exclusion of higher fibrosis stages (≥F3: AUROC 0.95) and an excellent performance for the diagnosis and exclusion of cirrhosis (F4 vs. < F4: AUROC 0.98). Single-point TE measurement had very similar predictive power for patient outcome as previously published. In a combined cohort of PSC patients (n = 210), SL measurements had a similar performance as TE for the prediction of patient outcome (5 x cross-validated Harrel's C 0.76 and 0.72 for SL and TE, respectively). CONCLUSIONS: Baseline TE measurement has an excellent performance to diagnose higher fibrosis stages in PSC. Baseline measurements of SL and TE have similar usefulness as predictive markers for disease progression in patients with PSC.

No Evidence That Azathioprine Increases Risk of Cholangiocarcinoma in Patients With Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: Patients with primary sclerosing cholangitis (PSC) are at increased risk for developing cholangiocarcinoma (CCA). Patients with PSC also can have inflammatory bowel diseases (IBDs) or features of autoimmune hepatitis (AIH), and therefore are treated with azathioprine. Azathioprine has been associated with an increased risk for malignancy, therefore we investigated whether azathioprine use affects the risk of CCA in persons with PSC. METHODS: We performed a retrospective study of well-defined patients with PSC using data collected from 3 large-volume, tertiary care centers in Germany and Norway. We analyzed data from 638 patients (70% men; 5900 patient-years of follow-up evaluation); 91 patients had received azathioprine therapy (considered to be effective at 90 days after first intake). Risk analysis was performed using the Cox proportional hazard model when risks competing with study end points were present. RESULTS: Of patients who received azathioprine treatment, 3.3% developed CCA, compared with 6.8% of patients without azathioprine treatment. However, azathioprine did not significantly affect the risk for CCA (hazard ratio, 0.96; 95% confidence interval, 0.29-3.13; P = .94). The only factor associated with an increased risk of CCA was age 35 years or older at PSC diagnosis (hazard ratio, 3.87; 95% confidence interval, 1.96-7.67; P < .01). Patient sex, concomitant IBD, or AIH did not affect the risk of CCA. Overall, the cumulative 10-year incidence of CCA was 4.6% and the cumulative 15-year incidence was 7.7%. CONCLUSIONS: A retrospective analysis of patients with PSC treated at tertiary centers in Europe found no evidence that azathioprine significantly affects the risk of CCA. Azathioprine therefore should not be withheld from patients with PSC and concomitant IBD and/or AIH.

Transient elastography in autoimmune hepatitis: Timing determines the impact of inflammation and fibrosis.

BACKGROUND & AIMS: There is an unmet need for the non-invasive monitoring of fibrosis progression in patients with autoimmune hepatitis (AIH). The aim of this study was to assess the diagnostic performance of transient elastography in patients with AIH and to investigate the impact of disease activity on its diagnostic accuracy. METHODS: Optimal cut-offs were defined in a prospective pilot study (n=34) and the diagnostic performance of transient elastography validated in an independent second cohort (n=60). To explore the impact of disease activity on liver stiffness, patients were stratified according to biochemical response and the time interval between start of immunosuppression and transient elastography. RESULTS: Liver stiffness strongly correlated with histological fibrosis stage (pilot study: ρ=0.611, p<0.001; validation cohort: ρ=0.777, p<0.0001). ROC curves defined an area under the receiver operating curve of 0.95 for diagnosing cirrhosis at the optimal cut-off of 16kPa. The performance of transient elastography was impaired when patients were analysed in whom transient elastography was performed within 3months from start of treatment. In this setting, liver stiffness correlated with histological grading (ρ=0.558, p=0.001), but not with staging. In contrast, using the cut-off of 16kPa, the accuracy for diagnosing cirrhosis was excellent in patients treated for 6months or longer (area under the receiver operating curve 1.0). CONCLUSIONS: Liver inflammation has a major impact on liver stiffness in the first months of AIH treatment. However, transient elastography has an excellent diagnostic accuracy for separating severe from non-severe fibrosis after 6months of immunosuppressive treatment. LAY SUMMARY: Transient elastography is a special ultrasound scan, which assesses liver stiffness as a surrogate marker for liver fibrosis/scarring. Transient elastography has been shown to be a reliable non-invasive method to assess liver fibrosis in various chronic liver diseases, it takes less than 5min and has a high patient acceptance. The current study validated for the first time this technique in a large cohort of patients with autoimmune hepatitis (AIH) and demonstrates that it is a reliable tool to detect liver fibrosis in treated AIH. For the monitoring of potential disease progression under treatment, the validation of liver stiffness as non-invasive marker of liver fibrosis will greatly improve patient care in autoimmune hepatitis.

Opposing role of tumor necrosis factor receptor 1 signaling in T cell-mediated hepatitis and bacterial infection in mice.

UNLABELLED: Death receptor (DR) ligands such as tumor necrosis factor (TNF) have been identified as fundamental mediators of liver damage both in mouse models and in humans. While the essential site of function of DR signaling is conceivably the hepatocyte, a systematic analysis is missing. Using mice with conditional gene ablation, we analyzed the tissue-specific function of DR signaling in T cell-dependent (concanavalin A) and independent (lipopolysaccharide/galactosamine) hepatitis and in models of bacterial infection (Listeria monocytogenes, lipopolysaccharide). We report that lipopolysaccharide/galactosamine-induced liver injury depends on hepatocyte-intrinsic TNF receptor 1 (p55, TNFR1). In contrast, we show that T cell-induced hepatitis was independent of TNFR1 signaling in hepatocytes, T cells, or endothelial cells. Moreover, T cell-induced hepatitis was independent of hepatocyte-intrinsic Fas-associated protein with death domain, TNF-related apoptosis-inducing ligand receptor, or Fas signaling. Instead, concanavalin A-induced hepatitis was completely prevented in mice with myeloid-derived cell (MDC)-specific deletion of TNFR1. Significantly, however, mice lacking TNFR1 in MDCs succumbed to listeria infection, although they displayed similar sensitivity toward endotoxin-induced septic shock when compared to control mice. These results suggest that TNFR1 signaling in MDCs is a critical mediator of both the detrimental and the protective functions of TNF in T cell-induced hepatitis and bacterial infection, respectively. CONCLUSION: The critical site of action of DRs is completely dependent on the nature of hepatitis; the data specify MDCs as the essential cell type of TNFR1 function in T cell-mediated hepatitis and in the response to listeria, thereby identifying the opposing role of MDC TNFR1 in autoimmunity and bacterial infection. (Hepatology 2016;64:508-521).

NEMO Prevents Steatohepatitis and Hepatocellular Carcinoma by Inhibiting RIPK1 Kinase Activity-Mediated Hepatocyte Apoptosis.

IκB kinase/nuclear [corrected] factor κB (IKK/NF-κB) signaling exhibits important yet opposing functions in hepatocarcinogenesis. Mice lacking NEMO in liver parenchymal cells (LPC) spontaneously develop steatohepatitis and hepatocellular carcinoma (HCC) suggesting that NF-κB prevents liver disease and cancer. Here, we show that complete NF-κB inhibition by combined LPC-specific ablation of RelA, c-Rel, and RelB did not phenocopy NEMO deficiency, but constitutively active IKK2-mediated NF-κB activation prevented hepatocellular damage and HCC in NEMO(LPC-KO) mice. Knock-in expression of kinase inactive receptor-interacting protein kinase 1 (RIPK1) prevented hepatocyte apoptosis and HCC, while RIPK1 ablation induced TNFR1-associated death domain protein (TRADD)-dependent hepatocyte apoptosis and liver tumors in NEMO(LPC-KO) mice, revealing distinct kinase-dependent and scaffolding functions of RIPK1. Collectively, these results show that NEMO prevents hepatocarcinogenesis by inhibiting RIPK1 kinase activity-driven hepatocyte apoptosis through NF-κB-dependent and -independent functions.

How Should Cancer Surveillance in Primary Sclerosing Cholangitis Be Performed?

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease affecting the intra- and extrahepatic bile duct system that can ultimately cause liver cirrhosis. Apart from the risk of progression to end-stage liver disease the prognosis of PSC is primarily determined by the risk to develop hepatobiliary or extrahepatic malignancies. A reasonable surveillance strategy for PSC patients must allow the detection of early cancer that will permit a potentially curative therapy. METHODS: Current guidelines on malignancy within the context of PSC as well as the primary literature were reviewed for this article. RESULTS: Here, we focus on a concise review of the three tumors most commonly associated with PSC: cholangiocellular carcinoma (CCA), gallbladder cancer, and colorectal carcinoma. For cancer surveillance in this patient group, endoscopy, cholangiography, cross-sectional imaging, and the use of serum tumor markers are principally available. Furthermore, for the diagnosis of CCA novel approaches were recently suggested to improve sensitivity and specificity to detect this malignancy. CONCLUSION: We review different aspects of cancer surveillance in patients with PSC. Since prospective data on the surveillance of malignant tumors is unavailable, we discuss a rational approach on how to perform cancer surveillance in patients with PSC.

Primary sclerosing cholangitis and cholangiocarcinoma: pathogenesis and modes of diagnostics.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease caused by progressive inflammation of the intra- and extrahepatic bile duct system. PSC patients have an increased risk to develop hepatobiliary as well as extrahepatic malignancies. The goal of a surveillance strategy for hepatobiliary malignancy in these patients is the detection of early cancer which will allow a potentially curative therapy. Here, we focus on a conceptual review of the pathogenesis of cholangiocellular carcinoma and gallbladder cancer and we will discuss a rational approach for the surveillance of these malignancies in PSC patients.

c-FLIP maintains tissue homeostasis by preventing apoptosis and programmed necrosis.

As a catalytically inactive homolog of caspase-8, a proapoptotic initiator caspase, c-FLIP blocks apoptosis by binding to and inhibiting caspase-8. The transcription factor nuclear factor κB (NF-κB) plays a pivotal role in maintaining the homeostasis of the intestine and the liver by preventing death receptor-induced apoptosis, and c-FLIP plays a role in the NF-κB-dependent protection of cells from death receptor signaling. Because c-Flip-deficient mice die in utero, we generated conditional c-Flip-deficient mice to investigate the contribution of c-FLIP to homeostasis of the intestine and the liver at developmental and postnatal stages. Intestinal epithelial cell (IEC)- or hepatocyte-specific deletion of c-Flip resulted in perinatal lethality as a result of the enhanced apoptosis and programmed necrosis of the IECs and the hepatocytes. Deficiency in the gene encoding tumor necrosis factor-α (TNF-α) receptor 1 (Tnfr1) partially rescued perinatal lethality and the development of colitis in IEC-specific c-Flip-deficient mice but did not rescue perinatal lethality in hepatocyte-specific c-Flip-deficient mice. Moreover, adult mice with interferon (IFN)-inducible deficiency in c-Flip died from hepatitis soon after depletion of c-FLIP. Pretreatment of IFN-inducible c-Flip-deficient mice with a mixture of neutralizing antibodies against TNF-α, Fas ligand (FasL), and TNF-related apoptosis-inducing ligand (TRAIL) prevented hepatitis. Together, these results suggest that c-FLIP controls the homeostasis of IECs and hepatocytes by preventing cell death induced by TNF-α, FasL, and TRAIL.

Hepatocyte IKK2 protects Mdr2-/- mice from chronic liver failure.

UNLABELLED: Mice lacking the Abc4 protein encoded by the multidrug resistance-2 gene (Mdr2(-/-)) develop chronic periductular inflammation and cholestatic liver disease resulting in the development of hepatocellular carcinoma (HCC). Inhibition of NF-κB by expression of an IκBα super-repressor (IκBαSR) transgene in hepatocytes was shown to prevent HCC development in Mdr2(-/-) mice, suggesting that NF-κB acts as a tumour promoter in this model of inflammation-associated carcinogenesis. On the other hand, inhibition of NF-κB by hepatocyte specific ablation of IKK2 resulted in increased liver tumour development induced by the chemical carcinogen DEN. To address the role of IKK2-mediated NF-κB activation in hepatocytes in the pathogenesis of liver disease and HCC in Mdr2(-/-) mice, we generated Mdr2-deficient animals lacking IKK2 specifically in hepatocytes using the Cre-loxP system. Mdr2(-/-) mice lacking IKK2 in hepatocytes developed spontaneously a severe liver disease characterized by cholestasis, major hyperbilirubinemia and severe to end-stage fibrosis, which caused muscle wasting, loss of body weight, lethargy and early spontaneous death. Cell culture experiments showed that primary hepatocytes lacking IKK2 were more sensitive to bile acid induced death, suggesting that hepatocyte-specific IKK2 deficiency sensitized hepatocytes to the toxicity of bile acids under conditions of cholestasis resulting in greatly exacerbated liver damage. Mdr2(-/-)IKK2(Hep-KO) mice remarkably recapitulate chronic liver failure in humans and might be of special importance for the study of the mechanisms contributing to the pathogenesis of end-stage chronic liver disease or its implications on other organs. CONCLUSION: IKK2-mediated signaling in hepatocytes protects the liver from damage under conditions of chronic inflammatory cholestasis and prevents the development of severe fibrosis and liver failure.