The MBOAT7 rs641738 variant is associated with an improved outcome in primary sclerosing cholangitis.

BACKGROUND AND AIMS: Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease that causes liver cirrhosis, leading to liver failure. Additionally, PSC is a risk factor for cholangiocarcinoma. Its mechanism is unknown, and liver transplantation remains the sole curative option. The membrane bound O-acyltransferase domain containing 7 (MBOAT7) rs641738 and rs626283 variant alleles have been associated with both an accelerated progression of the disease and a higher risk for developing a more severe phenotype in many chronic hepatic diseases. Thus, we analysed their effect on long-term outcomes and laboratory parameters in PSC patients. METHODS: We determined MBOAT7 genotypes and estimated the actuarial survival rate free of liver transplantation, using the Kaplan-Meier estimator. The differences between the estimates were analysed using the log-rank test. Patient blood was drawn and analysed for different serum parameters including cholestatic markers. Additionally, MBOAT7 RNA expression in human hepatic cell lines MZCHA1 (a biliary adenocarcinoma cell line), HepG2 (a hepatocellular carcinoma cell line), LX-2 (hepatic stellate cell line) and H-69 (cholangiocyte cell line) was analysed. RESULTS: Transplant-free survival was significantly prolonged in carriers of two rs641738 variant alleles, which was referred to as the TT genotype (mean 19.6 years; 95% confidence interval [CI]: 16.3-22.9 years) compared to the CC (mean 15.4 years, 95% CI 12.8-18.0 years) and heterozygous genotypes (mean 13.2 years, 95% CI 11.4-15.0 years) (P=0.017). This effect was restricted to male patients. We confirmed the high expression of MBOAT7 in hepatic stellate cells and found that MBOAT7 is less expressed in biliary epithelial cell lines, compared to parenchymal hepatic cells. CONCLUSIONS: Unlike other chronic liver diseases, carrying two MBOAT7 variant alleles does not seem to affect PSC patients negatively, but seems to have a positive effect on transplant-free survival. This study could help improve individual prognosis in PSC patients and give some new perspective on the involvement of the immune system in PSC.

Multidrug-Resistant Bacteria and Disease Progression in Patients with End-Stage Liver Disease and after Liver Transplantation.

BACKGROUND: Multidrug-resistant (MDR) pathogens represent an emerging challenge in end-stage liver disease and in liver transplant recipients. METHODS: We evaluated the impact of MDR bacteria upon clinical outcomes in patients with end-stage liver disease (n = 777) at the time of enrollment on the liver transplant (LTx) waiting list, after first LTx (n = 645), and after second LTx (n = 128). RESULTS: Colonization/infection with MDR bacteria was present in 72/777 patients on the waiting list, in 98/645 patients at first LTx, and in 46/128 patients at second LTx. While on the LTx waiting list, the time until first hydropic decompensation (p = 0.021), hepatic encephalopathy (p < 0.001) and hepatorenal syndrome (p < 0.001) was reduced in the presence of MDR bacteria, which remained an independent risk factor of poor survival in multivariate analysis (p < 0.001). Following first and second liver transplant, MDR bacteria were associated with an increased risk of infection-related deaths (first LTx: p < 0.001; second LTx: p = 0.037) and reduced actuarial survival (first LTx: p < 0.001; second LTx: p = 0.046). CONCLUSIONS: We showed that MDR pathogens are associated with poor outcomes before, after first and after recurrent LTx.

Prevalence of human herpesviruses in biliary fluid and their association with biliary complications after liver transplantation.

BACKGROUND: Beta-herpesviruses are common opportunistic pathogens that cause morbidity after liver transplantation (LT). METHODS: Objective of the study was to evaluate the prevalence and correlation of herpesviruses in bile, blood and liver tissue and to investigate their association with biliary complications and retransplantation (re-LT) free survival after LT. The study design is a single-center case-control study. We performed quantative polymerase chain reaction (qPCR) for herpesvirus 1-8 DNA in bile, blood and liver tissue of 73 patients after first LT and analyzed their clinical courses retrospectively. RESULTS: The median follow-up was 48 months (range 2-102), during which a total of 16 patients underwent re-LT and 11 patients died. Of the patients, 46.5% received valganciclovir prophylaxis at the time of bile sample acquisition. Cytomegalovirus (CMV) (18.3%), human herpesvirus 6 (HHV-6) (34.2%), human herpesvirus 7 (HHV-7) (20.5%) and Epstein-Barr virus (EBV) (16.4%) were highly prevalent in bile after LT, while herpes simpex virus 1 and 2 (HSV-1, HSV-2), varicella-zoster virus (VZV) and human herpesvirus 8 (HHV-8) were not or rarely detected in bile. Valganciclovir prophylaxis did not reduce the prevalence of HHV-6 and HHV-7 in bile, but it did reduce the presence of CMV and EBV. The presence of HHV-6 in bile was associated with non-anastomotic biliary strictures (NAS) and acute cellular rejection (ACR). CONCLUSIONS: CMV, EBV, HHV-6 and HHV-7 are more prevalent in biliary fluid than in liver biopsy or blood serum after LT. HHV-6 and HHV-7 might be associated with biliary complications after LT. Biliary fluids might be an attractive target for routine herpesvirus detection.

Successful combination of direct antiviral agents in liver-transplanted patients with recurrent hepatitis C virus.

AIM: To analyze the safety and efficiency of direct-acting antiviral (DAA) regimens in liver-transplanted patients with hepatitis C virus (HCV) reinfection. METHODS: Between January 2014 and December 2016, 39 patients with HCV reinfection after liver transplantation were treated at our tertiary referral center with sofosbuvir (SOF)-based regimens, including various combinations with interferon (IFN), daclatasvir (DAC), simeprivir (SIM) and/or ledipasvir (LDV). Thirteen patients were treated with SOF + IFN ± RBV. Ten patients were treated with SOF + DAC ± RBV. Fiveteen patients were treated with fixed-dose combination of SOF + LDV ± RBV. One patient was treated with SOF + SIM + RBV. Three patients with relapse were retreated with SOF + LDV + RBV. The treatment duration was 12-24 wk in all cases. The decision about the HCV treatment was made by specialists at our transplant center, according to current available or recommended medications. RESULTS: The majority of patients were IFN-experienced (29/39, 74.4%) and had a history of hepatocellular carcinoma (26/39, 66.7%) before liver transplantation. Sustained virological response at 12 wk (SVR12) was achieved in 10/13 (76.9%) of patients treated with SOF + IFN ± RBV. All patients with relapse were treated with fixed-dose combination of SOF + LDV + RBV. Patients treated with SOF + DAC + RBV or SOF + LDV + RBV achieved 100% SVR12. SVR rates after combination treatment with inhibitors of the HCV nonstructural protein (NS)5A and NS5B for 24 wk were significantly higher, as compared to all other therapy regimens (P = 0.007). Liver function was stable or even improved in the majority of patients during treatment. All antiviral therapies were safe and well-tolerated, without need of discontinuation of treatment or dose adjustment of immunosuppression. No serious adverse events or any harm to the liver graft became overt. No patient experienced acute cellular rejection during the study period. CONCLUSION: Our cohort of liver-transplanted patients achieved high rates of SVR12 after a 24-wk course of treatment, especially with combination of NS5A and NS5B inhibitors.

Methanobactin reverses acute liver failure in a rat model of Wilson disease.

In Wilson disease (WD), functional loss of ATPase copper-transporting ß (ATP7B) impairs biliary copper excretion, leading to excessive copper accumulation in the liver and fulminant hepatitis. Current US Food and Drug Administration- and European Medicines Agency-approved pharmacological treatments usually fail to restore copper homeostasis in patients with WD who have progressed to acute liver failure, leaving liver transplantation as the only viable treatment option. Here, we investigated the therapeutic utility of methanobactin (MB), a peptide produced by Methylosinus trichosporium OB3b, which has an exceptionally high affinity for copper. We demonstrated that ATP7B-deficient rats recapitulate WD-associated phenotypes, including hepatic copper accumulation, liver damage, and mitochondrial impairment. Short-term treatment of these rats with MB efficiently reversed mitochondrial impairment and liver damage in the acute stages of liver copper accumulation compared with that seen in untreated ATP7B-deficient rats. This beneficial effect was associated with depletion of copper from hepatocyte mitochondria. Moreover, MB treatment prevented hepatocyte death, subsequent liver failure, and death in the rodent model. These results suggest that MB has potential as a therapeutic agent for the treatment of acute WD.

Microbiological Assessment of Bile and Corresponding Antibiotic Treatment: A Strobe-Compliant Observational Study of 1401 Endoscopic Retrograde Cholangiographies.

The aim of this study was to determine the antibiotic susceptibility profiles of bacteria in bile samples and to analyze the clinical relevance of the findings as only limited information about risk factors for elevated frequence of bacterial and fungal strains in routinely collected bile samples has been described so far.A prospective cohort study at a tertiary care center was conducted. Seven hundred forty-four patients underwent 1401 endoscopic retrograde cholangiographies (ERCs) as indicated by liver transplantation (427/1401), primary sclerosing cholangitis (222/1401), choledocholithiasis only (153/1401), obstruction due to malignancy (366/1401), or other conditions (233/1401). Bile samples for microbiological analysis were obtained in all patients.The 71.6% (823/1150) samples had a positive microbiological finding, and 57% (840/1491) of the bacterial isolates were gram-positive. The main species were Enterococcus spp (33%; 494/1491) and Escherichia coli (12%; 179/1491). Of the samples, 53.8% had enteric bacteria and 24.7% had Candida spp; both were associated with clinical and laboratory signs of cholangitis (C-reactive proteins 35.0 ±â€Š50.1 vs 44.8 ±â€Š57.6; 34.5 ±â€Š51.2 vs 52.9 ±â€Š59.7; P < 0.001), age, previous endoscopic intervention, and immunosuppression. Multi-resistant (MR) strains were found in 11.3% of all samples and were associated with clinical and laboratory signs of cholangitis, previous intervention, and immunocompromised status. In subgroup analysis, strain-specific antibiotic therapy based on bile sampling was achieved in 56.3% (89/158) of the patients. In cases with a positive bile culture and available blood culture, blood cultures were positive in 29% of cases (36/124), and 94% (34/36) of blood cultures had microbial species identical to the bile cultures.Bactobilia and fungobilia can usually be detected by routine microbiological sampling, allowing optimized, strain-specific antibiotic treatment. Previous endoscopic intervention, clinical and laboratory signs of cholangitis, and age are independent risk factors. MR bacteria and fungi are an evolving problem in cholangitis, especially in immunocompromised patients.

Outcomes and risk factors for cancer patients undergoing endoscopic intervention of malignant biliary obstruction.

BACKGROUND: Malignant bile duct obstruction is a common problem among cancer patients with hepatic or lymphatic metastases. Endoscopic retrograde cholangiography (ERC) with the placement of a stent is the method of choice to improve biliary flow. Only little data exist concerning the outcome of patients with malignant biliary obstruction in relationship to microbial isolates from bile. METHODS: Bile samples were taken during the ERC procedure in tumor patients with biliary obstruction. Clinical data including laboratory values, tumor-specific treatment and outcome data were prospectively collected. RESULTS: 206 ERC interventions in 163 patients were recorded. In 43 % of the patients, systemic treatment was (re-) initiated after successful biliary drainage. A variety of bacteria and fungi was detected in the bile samples. One-year survival was significantly worse in patients from whom multiresistant pathogens were isolated than in patients, in whom other species were detected. Increased levels of inflammatory markers were associated with a poor one-year survival. The negative impact of these two factors was confirmed in multivariate analysis. In patients with pancreatic cancer, univariate analysis showed a negative impact on one-year survival in case of detection of Candida species in the bile. Multivariate analysis confirmed the negative prognostic impact of Candida in the bile in pancreatic cancer patients. CONCLUSION: Outcome in tumor patients with malignant bile obstruction is associated with the type of microbial biliary colonization. The proof of multiresistant pathogens or Candida, as well as the level of inflammation markers, have an impact on the prognosis of the underlying tumor disease.

Association of serum zinc levels with liver function and survival in patients awaiting liver transplantation.

PURPOSE: Zinc is an important trace element with catalytic and defensive functions. We assessed the impact of zinc deficiency in patients with end-stage liver disease awaiting liver transplantation. METHODS: Serum zinc levels were measured at the time of evaluation for liver transplantation (n = 368). Patients were dichotomized in two groups based on low and normal zinc serum levels. RESULTS: Serum zinc levels are tightly associated with liver function as patients with low zinc levels (n = 226) had a higher Model for End-Stage Liver Disease (MELD) score (15.0 [5.0-40.0]) than patients with normal zinc (n = 142) levels (9.0 [6.0-34.0]; p < 0.00). Multivariate analysis demonstrated that serum zinc levels function as an independent predictor of hepatic decompensation (hydropic decompensation: odds ratio [OR] 0.82; 95% confidence interval [CI] 0.70-0.96; p = 0.015; hepatic encephalopathy: OR 0.80; 95% CI 0.71-0.90; p = 0.000; spontaneous bacterial peritonitis: OR 0.85; 95% CI 0.72-1.00; p = 0.047; hepatorenal syndrome: OR 0.83; 95% CI 0.72-0.95; p = 0.011). Actuarial survival free of liver transplantation was reduced for low-zinc patients (26.7 ± 4.0 months; 95% CI 18.8-34.6) compared to patients with normal zinc levels (30.9 ± 3.0 months; 95% CI 24.9-36.9; p = 0.008). Reduction of zinc levels for patients on the transplantation list resulted in a 28.3-fold increased risk of death/liver transplantation (95% CI 3.2-244.8, p < 0.001). CONCLUSIONS: Serum zinc levels are associated with reduced survival in end-stage liver disease patients. Whether or not zinc supplementation might be beneficial for patients on a liver transplantation list requires further study.

Risk factors and outcome in patients with primary sclerosing cholangitis with persistent biliary candidiasis.

BACKGROUND: Candidiasis is commonly observed in patients with primary sclerosing cholangitis (PSC), but the clinical risk factors associated with its presence have not been fully investigated. In this study, we aimed to analyse the incidence, risk factors, and transplantation-free survival in primary sclerosing cholangitis (PSC) patients with persistent biliary candidiasis. METHODS: We retrospectively analysed patients diagnosed with PSC who were admitted to our department during 2002 to 2012. One-hundred fifty patients whose bile cultures were tested for fungal species were selected, and their clinical and laboratory parameters were investigated. The results of endoscopic retrograde cholangiography (ERC) and bile cultures were analysed using chart reviews. The cases of biliary candidiasis were sub-classified as transient or persistent. RESULTS: Thirty out of 150 (20.0%) patients had biliary candidiasis. Although all patients demonstrated comparable baseline characteristics, those with biliary candidiasis showed significantly reduced transplantation-free survival (p < 0.0001) along with a markedly elevated frequency of cholangiocarcinoma (CCA) (p = 0.04). The patients were further sub-classified according to the transient (15/30) or persistent (15/30) nature of their biliary candidiasis. A subgroup analysis showed reduced survival with a greater necessity for orthotopic liver transplantation (OLT) only in patients with persistence of Candida (p = 0.007). The survival in the patients with transient biliary candidiasis was comparable to that in candidiasis-free patients. In a multivariate regression analysis that included Mayo risk score (MRS), sex, age, dominant stenosis, inflammatory bowel disease, autoimmune hepatitis overlap syndrome, and number of times ERC was performed, biliary candidiasis was an independent risk factor for reduced survival (p = 0.008). Risk factors associated with acquisition of biliary candidiasis were age at PSC diagnosis and number of ERCs. CONCLUSIONS: The persistence of biliary candidiasis is associated with markedly reduced transplantation-free survival in PSC patients. By contrast, actuarial survival in patients with transient biliary candidiasis approaches that for patients without any evidence of biliary candidiasis. Further studies on the treatment of persistent biliary candidiasis in patients with PSC are warranted.

PNPLA3 in end-stage liver disease: alcohol consumption, hepatocellular carcinoma development, and transplantation-free survival.

BACKGROUND AND AIMS: The rs738409 variant (I148M) of the patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene is associated with several liver malfunctions. Its impact on end-stage liver disease has not been addressed yet. METHODS: The I148M polymorphism was genotyped in a well-characterized cohort of 421 Caucasian patients and retrospectively analyzed from the time of enrollment at Eurotransplant. RESULTS: The G allele of the I148M variant was significantly overrepresented in patients with alcoholic liver disease (ALD, P < 0.001) and associated with hepatocellular carcinoma (HCC) development (odds ratio [OR] = 2.399; 95% confidence interval [CI]: 1.292-4.455; P = 0.008) while not affecting the other liver disease entities. Time until hydropic decompensation (P = 0.04) and hepatic encephalopathy (P = 0.043) was significantly impaired for ALD patients carrying either one or two mutated G alleles. Actuarial survival free of liver transplantation was further reduced for ALD carriers of the I148M variant (CC = 30.7 months ± 7.9, 95% CI: 15.1-46.2 vs CG/GG: 17.1 months ± 3.3, 95% CI: 3.3-10.6; P = 0.012) compared with wild-type patients. Cox multivariate analysis identified the PNPLA3 I148M genotype as an independent predictor actuarial survival free of liver transplantation (OR = 1.77; 95% CI: 1.27-2.47; P = 0.001). CONCLUSIONS: In end-stage liver disease patients, we identified ALD to be predominantly affected by the PNPLA3 I148M variant resulting in an increased risk of HCC and reduced transplantation free survival. Genetic testing of the I148M genotype in ALD patients awaiting liver transplantation might be beneficial for these patients.

Current strategies for immunosuppression following liver transplantation.

BACKGROUND: New strategies for immunosuppression (IS) after liver transplantation (LTx) are in part responsible for the increased patient and graft survival seen over time. With a few basic exceptions-notably the continued use of steroids and calcineurin inhibitors (CNIs)-IS drugs and regimens being used today are different from those used 30 years ago. While graft loss due to acute or chronic rejection has become rare, the side effect burden of IS drugs exerts a significant toll on patients. CONCEPTS/TRENDS: CNIs continue to form the backbone of IS regimens, although their use is hampered by nephrotoxicity and other adverse effects. Consequently, a variety of CNI reduction or withdrawal strategies have formed the basis of clinical trials or entered into clinical practice. These trials have included the use of everolimus, an mTOR inhibitor, and anti-interleukin-2 receptor antibodies. Basiliximab, as well as other lymphocyte nondepleting and depleting agents, have shown benefit in induction regimens. SUMMARY: Along with steroid reduction or elimination, current strategies for IS after LTx continue to explore novel combinations of agents, with an aim toward striking a balance between diminution of rejection and the need for avoiding adverse effects of the IS drugs. Long-term maintenance strategies are also discussed in this review, as is development of tolerance and antibody-mediated rejection.

Biliary phosphatidylcholine and lysophosphatidylcholine profiles in sclerosing cholangitis.

AIM: To analyze phospholipid profiles in intrahepatic bile from patients with primary sclerosing cholangitis (PSC) and secondary sclerosing cholangitis (SSC). METHODS: Intrahepatic bile specimens collected via endoscopic retrograde cholangiography from 41 patients were analyzed. Fourteen of these patients were diagnosed with PSC, 10 with SSC, 11 with choledocholithiasis or no identifiable biliary disease, and 6 with cholangiocellular carcinoma (CCC). Bile acid, cholesterol, protein, and bilirubin contents as well as pancreas lipase activity in bile were determined by biochemical methods. Phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) species were quantified using nano-electrospray ionization tandem mass spectrometry. RESULTS: Bile from all the examined patient groups showed a remarkably similar PC and LPC species composition, with only minor statistical differences. Total biliary PC concentrations were highest in controls (8030 ± 1843 µmol/L) and lowest in patients with CCC (1969 ± 981 µmol/L) (P = 0.005, controls vs SSC and CCC, respectively, P < 0.05). LPC contents in bile were overall low (4.2% ± 1.8%). Biliary LPC/PC ratios and ratios of biliary PC to bilirubin, PC to cholesterol, PC to protein, and PC to bile acids showed no intergroup differences. CONCLUSION: PC and LPC profiles being similar in patients with or without sclerosing cholangitis, these phospholipids are likely not of major pathogenetic importance in this disease group.

FUT2 and FUT3 genotype determines CA19-9 cut-off values for detection of cholangiocarcinoma in patients with primary sclerosing cholangitis.

BACKGROUND & AIMS: Allelic variants of fucosyltransferases 2 and 3 (FUT2/3) influence serum levels of CA19-9, a screening parameter commonly used for detection of biliary malignancy in PSC. We aimed at improving diagnostic accuracy of CA19-9 by determining the impact of FUT2/3 genotypes. METHODS: CA19-9 levels were measured in 433 PSC patients, 41 of whom had biliary malignancy. Genotypes for FUT3 and FUT2 were used to assign patients to one of three groups: A, no FUT3 activity regardless of FUT2 activity; B, both FUT2 and FUT3 activity and C, no FUT2 activity without loss of FUT3 activity. Group-specific cut-off values were determined by Youden's index. RESULTS: The median CA19-9 values of cancer-free patients were significantly different (p<0.001) in Groups A (2.0U/ml), B (17.0U/ml), and C (37.0U/ml). Biliary malignancy patients in Groups B and C had significantly higher CA19-9 values than cancer-free patients (p<0.001). The optimal cut-off, as determined by ROC analysis, for all patients was 88.5U/ml. Optimal cut-off values in Groups A, B, and C were 4.0U/ml, 74.5U/ml, and 106.8U/ml, respectively. Use of these values improved sensitivity of CA19-9 in Groups B and C. Further, use of group-dependent cut-off values with 90% sensitivity resulted in a 42.9% reduction of false positive results. CONCLUSIONS: Use of FUT2/3 genotype-dependent cut-off values for CA19-9 improved sensitivity and reduced the number of false positive results.

Occult cytomegalovirus cholangitis as a potential cause of cholestatic complications after orthotopic liver transplantation? A study of cytomegalovirus DNA in bile.

Cholestatic complications, important causes of morbidity and mortality after orthotopic liver transplantation (OLT), often have an unclear etiology. Human cytomegalovirus (CMV) infections occur in immunosuppressed patients and can be detected in blood samples. However, CMV analyses of body fluids and biopsies are more sensitive. Here we evaluated whether a CMV analysis of bile could reveal occult CMV cholangitis. We evaluated OLT patients undergoing endoscopic retrograde cholangiography (ERC) for suspected biliary complications after OLT at a tertiary care center. Biliary CMV DNA levels were measured with real-time polymerase chain reaction. A nonanastomotic biliary lesion (NABL) group consisted of patients with nonanastomotic strictures (NASs) at the time of ERC (n = 59) and patients with normal ERC findings but microscopic biliary lesions in biopsy samples (n = 12). The anastomotic stricture (AS) group comprised patients with ASs only (n = 53). In all, 124 OLT patients underwent 240 ERC procedures. Biliary CMV DNA was detected in 14 of the 124 patients and was more frequently found in the NABL group (12/71 for the NABL group versus 2/53 for the AS group, P = 0.02). Concurrent sampling of CMV DNA in blood yielded negative results. Biliary CMV was more frequently detected in patients with a positive recipient status (13/73 or 17.8% versus 1/44 or 2.3%, P < 0.05). There was no significant difference in the incidence of biliary CMV between patients with a high-risk CMV status and patients with a low-risk CMV status. The median interval between OLT and biliary CMV detection was 8.4 months (range = 0.4-212.8 months). In conclusion, biliary CMV was detected in a substantial number of patients after OLT and was significantly associated with NASs or microscopic biliary lesions. A potential occult CMV infection could, therefore, be considered as a contributory etiological factor in the development of biliary complications.

Extended analysis of a genome-wide association study in primary sclerosing cholangitis detects multiple novel risk loci.

BACKGROUND & AIMS: A limited number of genetic risk factors have been reported in primary sclerosing cholangitis (PSC). To discover further genetic susceptibility factors for PSC, we followed up on a second tier of single nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS). METHODS: We analyzed 45 SNPs in 1221 PSC cases and 3508 controls. The association results from the replication analysis and the original GWAS (715 PSC cases and 2962 controls) were combined in a meta-analysis comprising 1936 PSC cases and 6470 controls. We performed an analysis of bile microbial community composition in 39 PSC patients by 16S rRNA sequencing. RESULTS: Seventeen SNPs representing 12 distinct genetic loci achieved nominal significance (p(replication) <0.05) in the replication. The most robust novel association was detected at chromosome 1p36 (rs3748816; p(combined)=2.1 × 10(-8)) where the MMEL1 and TNFRSF14 genes represent potential disease genes. Eight additional novel loci showed suggestive evidence of association (p(repl) <0.05). FUT2 at chromosome 19q13 (rs602662; p(comb)=1.9 × 10(-6), rs281377; p(comb)=2.1 × 10(-6) and rs601338; p(comb)=2.7 × 10(-6)) is notable due to its implication in altered susceptibility to infectious agents. We found that FUT2 secretor status and genotype defined by rs601338 significantly influence biliary microbial community composition in PSC patients. CONCLUSIONS: We identify multiple new PSC risk loci by extended analysis of a PSC GWAS. FUT2 genotype needs to be taken into account when assessing the influence of microbiota on biliary pathology in PSC.

S100A9 is a biliary protein marker of disease activity in primary sclerosing cholangitis.

BACKGROUND AND AIMS: Bile analysis has the potential to serve as a surrogate marker for inflammatory and neoplastic disorders of the biliary epithelium and may provide insight into biliary pathophysiology and possible diagnostic markers. We aimed to identify biliary protein markers of patients with primary sclerosing cholangitis (PSC) by a proteomic approach. METHODS: Bile duct-derived bile samples were collected from PSC patients (n = 45) or patients with choledocholithiasis (n = 24, the control group). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to analyse the proteins, 2-D-gel patterns were compared by densitometry, and brush cytology specimens were analysed by RT-PCR. RESULTS: A reference bile-duct bile proteome was established in the control group without signs of inflammation or maligancy comprising a total of 379 non-redundant biliary proteins; 21% were of unknown function and 24% had been previously described in serum. In PSC patients, the biliary S100A9 expression was elevated 95-fold (p<0.005), serum protein expression was decreased, and pancreatic enzyme expression was unchanged compared to controls. The S100A9 expression was 2-fold higher in PSC patients with high disease activity than in those with low activity (p<0.05). The brush cytology specimens from the PSC patients with high disease activity showed marked inflammatory activity and leukocyte infiltration compared to the patients with low activity, which correlated with S100A9 mRNA expression (p<0.05). CONCLUSIONS: The bile-duct bile proteome is complex and its analysis might enhance the understanding of cholestatic liver disease. Biliary S100A9 levels may be a useful marker for PSC activity, and its implication in inflammation and carcinogenesis warrants further investigation.

Genome-wide association analysis in primary sclerosing cholangitis identifies two non-HLA susceptibility loci.

Primary sclerosing cholangitis (PSC) is a chronic bile duct disease affecting 2.4-7.5% of individuals with inflammatory bowel disease. We performed a genome-wide association analysis of 2,466,182 SNPs in 715 individuals with PSC and 2,962 controls, followed by replication in 1,025 PSC cases and 2,174 controls. We detected non-HLA associations at rs3197999 in MST1 and rs6720394 near BCL2L11 (combined P = 1.1 × 10⁻¹6 and P = 4.1 × 10⁻8, respectively).

Genetic analysis of BIRC4/XIAP as a putative modifier gene of Wilson disease.

Wilson disease (WD) is an autosomal-recessive copper overload disorder caused by mutations in the copper-transporting adenosine triphosphatase (ATPase) ATP7B. It presents with a highly variable clinical phenotype ranging from asymptomatic to fulminant hepatic failure or progressive neurological involvement. No clear genotype-phenotype correlation has been established. Thus, variants in modifier genes could have an impact on WD manifestation and severity. Recently, the antiapoptotic protein baculoviral IAP repeat-containing protein 4 BIRC4/XIAP has been suggested as a regulator of copper-induced cell death. With the aim of investigating a putative role of BIRC4/XIAP as modifier gene in individuals with copper overload, we analyzed a WD patient cohort (n = 98) for sequence variants at the BIRC4/XIAP locus. When compared with clinical data, the previously described coding single nucleotide polymorphisms (SNPs) at the BRIC4/XIAP locus (rs28382721, rs28382722, rs28382723, rs5956583, rs28382740, rs12838858, rs28382741) did not correlate with age of onset or clinical presentation in our collective. However, three previously unreported variants in the BIRC4/XIAP gene were identified (c.1-26 T > G; c.1408A > T; p.T470S; c.1019A > G; p.N340S). The two patients with variants leading to amino acid exchanges in the BIRC4/XIAP protein showed a remarkably early disease onset at the age of 5 years. Furthermore, one of these patients was only heterozygous for disease-causing mutations in the ATP7B gene. In summary, these data emphasize the need to further elucidate a role of BIRC4/XIAP variants as putative pathogenetic factors in copper overload disorders.