Feasibility and Efficacy of Adjuvant Chemotherapy With Gemcitabine After Liver Transplantation for Perihilar Cholangiocarcinoma - A Multi-Center, Randomized, Controlled Trial (pro-duct001).

Background: Liver transplantation (LT) is considered a therapeutic option for unresectable perihilar cholangiocarcinoma (PHC) within defined criteria. It remains uncertain whether patients can safely receive adjuvant chemotherapy after LT. Methods: We performed a prospective, multi-center, randomized, non-blinded two-arm trial (pro-duct001). Patients after LT for unresectable PHC within defined criteria were randomized to adjuvant gemcitabine (LT-Gem group) and LT alone (LT alone group). The primary objective was to investigate if adjuvant chemotherapy is feasible in ≥ 85% of patients after LT. The primary endpoint was the percentage of patients completing the 24 weeks course of adjuvant chemotherapy. Secondary endpoints included overall survival (OS) and disease-free (DFS), and complication rates. Results: Twelve patients underwent LT for PHC, of which six (50%) were eligible for randomization (LT-Gem: three patients, LT alone: three patients). Two out of three patients discontinued adjuvant chemotherapy after LT due to intolerance. The study was prematurely terminated due to slow enrollment. One patient with PHC had underlying primary sclerosing cholangitis (PSC). Tumor-free margins could be achieved in all patients. In both the LT-Gem and the LT alone group, the cumulative 1-, 3-, and 5-year OS and DFS rates were 100%, 100%, 67%, and 100%, 67% and 67%, respectively. Conclusions: This prospective, multi-center study was prematurely terminated due to slow enrollment and a statement on the defined endpoints cannot be made. Nevertheless, long-term survival data are consistent with available retrospective data and confirm defined criteria for LT. Since more evidence of LT per se in unresectable PHC is urgently needed, a prospective, non-randomized follow-up study (pro-duct002) has since been launched.

[The use of immuno-oncologic therapy in hepatocellular carcinoma in the context of liver transplantation. An interdisciplinary benefit/risk assessment]. / Der Einsatz der immunonkologischen Therapie beim hepatozellulären Karzinom im Kontext der Lebertransplantation Eine interdisziplinäre Risiko-Nutzen-Abwägung.

BACKGROUND: Multiple systemic therapy options have been recently approved for the treatment of hepatocellular carcinoma (HCC). In particular, immuno-oncology combination therapies can now achieve impressive response rates and significantly prolonged survival with good tolerability. These immuno-oncology (IO)-based combinations are currently not only evaluated for the therapy of advanced HCC, but increasingly also in earlier stages in terms of peri-interventional therapy concepts and also for down-sizing to local therapies. In the context of liver transplantation (LTx), a particularly critical benefit/risk assessment must be made before the use of immunotherapeutics in the context of multimodal concepts, since the risk of a potentially lethal rejection can be significantly increased by immunotherapy. METHODS: This review is based on a selective literature search performed between December 2020 and April 2021 in the PubMed and Cochrane Library databases. Guidelines, expert opinions, and recommendations from professional societies were given special consideration. RESULTS: Nearly one in five LTx in Germany are performed due to HCCs. In this context, LTx is a curative therapy option not only for the underlying liver disease but also for the malignant tumor. Individual case reports indicate that IO therapy prior to LTx may increase the risk of rejection or liver failure after subsequent liver transplantation. Since 2015, immunotherapeutics have also been widely used for tumor therapy in patients after LTx. In small case series, rejection rates of 36%, associated with rejection-related mortality of 20% of treated patients, have been described. A similar incidence of rejection has also been described following the use of immunotherapeutics in patients after other organ transplantations. CONCLUSION: In the context of organ transplantation, IO therapy carries the risk of graft rejection, which can lead to graft loss and also patient death. However, from today's point of view, IO-based therapy can be considered in the context of organ transplantation with a careful benefit/risk assessment.

[Severe secondary sclerosing cholangitis as manifestation of a very rare underlying disease]. / Schwere sekundär sklerosierende Cholangitis als Manifestation einer sehr seltenen Grunderkrankung.

Langerhans cell histiocytosis (LCH) is a very rare cause of secondary sclerosing cholangitis. We report the case of a 42-year-old male patient with sclerosing cholangitis and histological evidence of LCH from a bile duct biopsy. Due to rapid disease progression and exhaustion of conservative therapeutic approaches the patient received a liver transplantation. Nearly 2 years after transplantation the patient has a good graft function and no signs of recurrence of the underlying LCH.

Evolution of liver stiffness and post-treatment surveillance by liver elastography for HCV patients in the DAA era.

OBJECTIVE: Baseline liver stiffness (LS) is prognostically relevant in patients with chronic hepatitis C virus (HCV) infection but may change after successful HCV eradication. Data on post-treatment LS for a further risk stratification remain scarce. Here, we study the kinetics of LS and laboratory parameters in patients undergoing HCV treatment and analyze the association of post-treatment LS with outcome parameters. METHODS: In a cohort of 1011 chronic HCV patients undergoing DAA treatment, we identified 404 patients with sequential LS and laboratory assessments with or without viral eradication. Additionally, outcome parameters were correlated with post-treatment LS after successful HCV therapy. RESULTS: LS significantly decreased from a median of 8.8 to 6.1 kPa in 346 patients after HCV eradication, but significantly increased from a median of 10.5 to 11.9 kPa in 58 patients without viral clearance. In 78 patients with two sequential post-treatment measurements, LS decreased from 12.6 to 8.7 kPa after a median 344 d, with a further decrease to 7.0 kPa after a median of 986 d after end of treatment (EoT). In 400 patients with a post-treatment LS assessment after viral eradication, only 9 liver-related events occurred over a median follow-up (FU) of 23 months. All events were observed in patients with a post-treatment LS >20 kPa. CONCLUSIONS: After successful HCV eradication, LS improves sequentially, suggesting an initial phase of necroinflammation regression followed by a second phase of true fibrosis regression. Overall, liver-related events were rarely observed and seem to be limited to patients with a post-treatment LS >20 kPa, so that these patients require a closer clinical monitoring.

Presence of donor specific HLA class 2 antibodies (DSA class 2) is associated with development of graft fibrosis more than 10 years after liver transplantation-a retrospective single center study.

Here the impact of donor specific human leukocyte antigen (HLA) class 2 antibodies (DSA cl 2) on long term outcome after liver transplantation (LT) was investigated. Altogether 156 (44 pediatric and 112 adult) LT recipients were included in the study. Graft fibrosis was assessed by liver elastography and biopsy. DSA cl 2 were determined by Luminex technology. 46% of LT recipients were positive for DSA cl 2 after a median follow-up of 15 years. In the multivariate analysis DSA cl 2 were significantly associated with immunosuppressive monotherapy (OR 5.42; 95% CI: 1.02-28.90; p = .048). Compared to DSA cl 2 negative patients, positive recipients had significantly more graft fibrosis based on the liver stiffness (mean 9.4 ± 9.0 kPa vs. 6.5 ± 6.3 kPa; p < .002) and fibrosis stages determined by liver elastography (p = .016) and the performed liver biopsies (p = .002). Also, a significantly higher incidence of chronic rejections (11% vs. 2%; p = .045) and graft losses (6% vs. 0%; p = .043) were found. In the multivariate regression analysis DSA cl 2 were significantly associated with graft fibrosis (OR 4.57; 95% CI 1.59-13.10; p = .005). So, these data suggest that development of DSA cl 2 occurs more often with immunosuppressive monotherapy and may ultimately result in chronic rejection and graft fibrosis.

Current Challenges in the Post-Transplant Care of Liver Transplant Recipients in Germany.

Improving long-term patient and graft survival after liver transplantation (LT) remains a major challenge. Compared to the early phase after LT, long-term morbidity and mortality of the recipients not only depends on complications immediately related to the graft function, infections, or rejection, but also on medical factors such as de novo malignancies, metabolic disorders (e.g., new-onset diabetes, osteoporosis), psychiatric conditions (e.g., anxiety, depression), renal failure, and cardiovascular diseases. While a comprehensive post-transplant care at the LT center and the connected regional networks may improve outcome, there is currently no generally accepted standard to the post-transplant management of LT recipients in Germany. We therefore described the structure and standards of post-LT care by conducting a survey at 12 German LT centers including transplant hepatologists and surgeons. Aftercare structures and form of cost reimbursement considerably varied between LT centers across Germany. Further discussions and studies are required to define optimal structure and content of post-LT care systems, aiming at improving the long-term outcomes of LT recipients.

Ectonucleoside triphosphate diphosphohydrolase 1 and 5'-nucleotidase ecto gene polymorphisms and acute cellular rejection after liver transplantation.

The single nucleotide polymorphisms (SNPs) rs11188513, rs7071836, rs10748643, rs9450279, rs4458647, and rs6922 map in the genes of ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) and 5'-nucleotidase ecto. We investigated whether these SNPs and haplotypes of these SNPs are associated with an acute cellular rejection after liver transplantation. A total of 69 recipients with an acute cellular rejection and 138 recipients without an acute cellular rejection were analyzed. Analyzed individually, no SNP demonstrates an association, but the haplotype rs11188513T-rs7071836G-rs10748643A of the ENTPD1 gene appeared more frequently in recipients without rejection and conversely, the haplotype rs11188513T-rs7071836G-rs10748643G of the ENTPD1 gene was more often represented in recipients with rejection. These two haplotypes seem to be important for the susceptibility of an acute cellular rejection after liver transplantation.

Metamizole: An underrated agent causing severe idiosyncratic drug-induced liver injury.

AIMS: Drug-induced liver injury (DILI) is a heterogenous entity leading to liver damage. We have analysed the frequency, biochemical and histological patterns and clinical courses of DILI cases due to metamizole at our tertiary care centre in Hamburg, Germany. METHODS: Consecutive patients with DILI who presented to our clinic were analysed retrospectively. Causes of acute hepatitis other than DILI were excluded. RESULTS: In total, 154 DILI cases were admitted to our centre from 2008 to 2017. After phenprocoumon, metamizole was the second most frequent putative agent causing DILI (23 of all 154 DILI cases, 14,9%). The biochemical pattern on admission of metamizole-induced DILI cases was hepatocellular with median levels of alanine transaminase (779 U/L, 64-3532 U/L) by far exceeding median alkaline phosphatase levels (131 U/L, 42-578 U/L). In 17 of the 23 cases (74%) liver biopsy was performed. Moderate to severe inflammatory histological activity and severe centrilobular necrosis (>30%) was present in 76.5 and 35.3%, respectively. Metamizole was involved in 2 DILI cases progressing to acute liver failure, then receiving liver transplantation and still alive at time of assessment. Our data were supported by re-exposure in 4 patients. Furthermore, a database search for metamizole-induced liver injury in the European Medicines Agency's database identified about 300 reports on suspected metamizole-induced DILI in Europe. CONCLUSION: Elevation of liver enzymes or acute liver failure are not mentioned in the German drug label of metamizole as potential side effects. Our study reveals that in Germany and Europe, metamizole is a frequent and underrated agent causing DILI.

Impact of TBX21, GATA3, and FOXP3 gene polymorphisms on acute cellular rejection after liver transplantation.

The single nucleotide polymorphisms (SNPs) rs4794067, rs2275806, rs2232365, and rs3761548 map in the genes of TBX21, GATA3, and FOXP3 involved in mediating acute cellular rejection. We investigated whether these SNPs are associated with acute cellular liver transplant rejection. The SNPs were analyzed in recipients with early acute cellular rejection (n = 97), recipients with late acute cellular rejection (n = 49), and recipients without rejection (n = 149). There was no association between acute cellular rejection and SNPs rs4794067, rs2275806, and rs2232365. In contrast, the allele -3279A of FOXP3 SNP rs3761548 exhibited a higher frequency in recipients with late acute cellular rejection as compared with recipients without rejection. This result indicates that the allele -3279A of the SNP rs3761548 may predispose to the development of late acute cellular rejection.

Polymorphisms of the human platelet antigen-1, -2, -3, -5, and -15 systems and acute cellular liver transplant rejection.

The human platelet antigen (HPA)-1, -2, -3, -5, and -15 systems are characterized as polymorphic alloantigens expressed on platelets and endothelial cells. In this retrospective study, we investigated, whether HPA-1, -2, -3, -5, and -15 incompatibilities are associated with acute cellular liver transplant rejection. A total of 96 Caucasian liver transplant recipients and corresponding donors were analyzed, 43 with biopsy proven acute cellular rejection (BPAR) and 53 without acute cellular rejection (No-BPAR). Polymorphisms of mentioned HPA systems were determined by polymerase chain reaction-sequence specific primers (PCR-SSP). Our data demonstrate that acute cellular rejection episodes were associated with HPA-3 incompatibility (58% HPA-3 incompatibility in BPAR group vs. 32% HPA-3 incompatibility in No-BPAR group, p=0.013). Furthermore, the frequency of HPA-3bb genotype was significantly higher in BPAR recipients as compared to No-BPAR recipients (30% vs 6%, p=0.002). On the other hand, there was no association between acute cellular rejection and the other tested HPA systems. We conclude that in the Caucasian population the HPA-3 system confers susceptibility to acute cellular rejection after liver transplantation.

Factors associated with long-term survival after liver transplantation: A retrospective cohort study.

AIM: To identify predictive factors associated with long-term patient and graft survival (> 15 years) in liver transplant recipients. METHODS: Medical charts of all de novo adult liver transplant recipients (n = 140) who were transplanted in Hamburg between 1997 and 1999 were retrospectively reviewed. In total, 155 transplantations were identified in this time period (15 re-transplantations). Twenty-six orthotopic liver transplant (OLT) recipients were early lost to follow-up due to moving to other places within 1 year after transplantation. All remaining 114 patients were included in the analysis. The following recipient factors were analysed: Age, sex, underlying liver disease, pre-OLT body mass index (BMI), and levels of alanine aminotransferase (ALT), bilirubin, creatinine and gamma-glutamyltransferase (gamma-GT), as well as warm and cold ischemia times. Furthermore, the following donor factors were assessed: Age, BMI, cold ischemia time and warm ischemia time. All surviving patients were followed until December 2014. We divided patients into groups according to their underlying diagnosis: (1) hepatocellular carcinoma (n = 5, 4%); (2) alcohol toxic liver disease (n = 25, 22.0%); (3) primary sclerosing cholangitis (n = 6, 5%); (4) autoimmune liver diseases (n = 7, 6%); (5) hepatitis C virus cirrhosis (n = 15, 13%); (6) hepatitis B virus cirrhosis (n = 21, 19%); and (7) other (n = 35, 31%). The group "other" included rare diagnoses, such as acute liver failure, unknown liver failure, stenosis and thrombosis of the arteria hepatica, polycystic liver disease, Morbus Osler and Caroli disease. RESULTS: The majority of patients were male (n = 70, 61%). Age and BMI at the time point of transplantation ranged from 16 years to 69 years (median: 53 years) and from 15 kg/m2 to 33 kg/m2 (median: 24), respectively. Sixty-six OLT recipients (58%) experienced a follow-up of 15 years after transplantation. Recipient's age (P = 0.009) and BMI (P = 0.029) were identified as risk factors for death by χ2-test. Kaplan-Meier analysis confirmed BMI or age above the median as predictors of decreased long-term survival (P = 0.008 and P = 0.020). Hepatitis B as underlying disease showed a trend for improved long-term survival (P = 0.049, χ2-test, P = 0.055; Kaplan-Meier analysis, Log rank). Pre-transplant bilirubin, creatinine, ALT and gamma-GT levels were not associated with survival in these patients of the pre-era of the model of end stage liver disease. CONCLUSION: The recipients' age and BMI were predictors of long-term survival after OLT, as well as hepatitis B as underlying disease. In contrast, donors' age and BMI were not associated with decreased survival. These findings indicate that recipient factors especially have a high impact on long-term outcome after liver transplantation.

High Clinical Manifestation Rate in an Imported Outbreak of Hepatitis E Genotype 1 Infection in a German Group of Travellers Returning from India

Abstract: Background. There are only few reports about travel-associated, imported tropical hepatitis E virus (HEV) genotype 1 infections within Western travellers. We describe the clinical course of a single outbreak of hepatitis E in a German travellers group returning from India and compare the results of two commercial HEV-seroassays. Material and methods. After identifying hepatitis E in an index patient returning from a journey to India all 24 members of this journey were tested for anti-HEV-IgG and IgM using two commercial seroassays (Wantai and Mikrogen), for HEV-RNA by PCR and HEV-Ag by an antigen-assay (Wantai). Results. 5/24 (21%) individuals were viraemic with viral loads between 580-4,800,000 IU/mL. Bilirubin and ALT levels in these patients ranged from 1.3-14.9 mg/dL (mean 7.3 mg/dL, SD 5.6 mg/dL) and 151-4,820 U/L (mean 1,832U/L, SD 1842U/L), respectively and showed significant correlations with viral loads (r = 0.863, p < 0.001; r = 0.890, p < 0.001). No risk factor for food-borne HEV-transmission was identified. All viraemic patients (5/5) tested positive for anti-HEV-IgG and IgM in the Wantai-assay but only 4/5 in the Mikrogen-assay. Wantai-HEV-antigen-assay was negative in all patients. Six months later all previously viraemic patients tested positive for anti-HEV-IgG and negative for IgM in both assays. However, two non-viremic individuals who initially tested Wantai-IgM-positive stayed positive indicating false positive results. Conclusions. Despite the exact number of exposed individuals could not be determined HEV genotype 1 infections have a high manifestation rate of more than 20%.The Wantai-antigen-test failed, the Wantai-IgMrapid-test and the Mikrogen-IgM-recomblot showed a better performance but still they cannot replace real-time PCR for diagnosing ongoing HEV-infections.

Selection and use of immunosuppressive therapies after liver transplantation: current German practice.

In recent years, immunosuppression (IS) after liver transplantation (LT) has become increasingly diversified as the choice of agents has expanded and clinicians seek to optimize the balance of immunosuppressive potency with the risk of adverse events in individual patients. Calcineurin inhibitors (CNIs) are the primary agents used for patients undergoing liver transplantation. Other therapeutic agents like interleukin-2 receptor antagonists are not universally administered, but can be considered for the delay or reduction in CNI exposure. An early addition of mycophenolate mofetil (MMF) or the mTOR inhibitor everolimus also allows for the reduction in the CNI dose. To reduce the risk of malignancy, in particular of skin tumors, as well as to prevent the deterioration of renal function, everolimus-based therapy may be advantageous. Apart from patients with autoimmune hepatitis, steroids are withdrawn within 3-6 months after transplantation. Overall, immunosuppression can only be standardized in a limited proportion of patients due to specific clinical requirements and risk factors. Future studies should attempt to refine accurate individualization of the immunosuppressive regimen in specific difficult-to-treat patient subpopulations.

Early Initiation of Everolimus After Liver Transplantation: A Single-Center Experience.

BACKGROUND: Evidence relating to early everolimus use after liver transplantation remains limited. MATERIAL AND METHODS: Ninety-one adult patients undergoing liver transplantation at our center during 2007-2012 in whom everolimus therapy was initiated <3 months post-transplant were analyzed retrospectively. Everolimus was started on days 1-5 in 50 patients (group 1) and after day 5 in 41 patients (group 2). Most patients continued to receive low-dose cyclosporine (59.3%, target 50-80 ng/ml) or low-dose tacrolimus (25.3%; target 3-5 ng/ml). Mean follow-up was 4.6 years. RESULTS: One-, three- and five-year patient survival rates were 80.5%, 74.2%, and 70.5%, respectively, and did not differ between groups 1 and 2. Six patients (6.6%) developed biopsy-proven acute rejection after a median of 47 days (range 27-356 days). Everolimus was discontinued due to adverse events in 21 patients (23.1%). Incisional hernia repair occurred in 14.0% and 9.4% of patients in group 1 and 2, respectively. Renal function remained stable during follow-up, despite poor baseline function. CONCLUSIONS: Everolimus with very low-dose calcineurin inhibitor given immediately after liver transplantation appears safe and effective, achieving a low rejection rate with well-preserved renal function.

Role of the Fyn -93A>G polymorphism (rs706895) in acute rejection after liver transplantation.

The tyrosine kinase Fyn phosphorylates tyrosine residues on key targets involved in early T-cell signal transduction. T-cell signal transduction is one essential step for acute transplant rejection. The aim of this study was to evaluate the association of Fyn -93A>G single nucleotide polymorphism (SNP) (rs706895) with the susceptibility to acute rejection episodes in liver transplantation. In total, 72 liver transplant recipients with one biopsy proven acute rejection (S-BPAR), 56 with multiple BPAR (M-BPAR), 105 without BPAR (No-BPAR), and 145 healthy controls were enrolled in this case-control study. The SNP was genotyped by polymerase chain reaction-allele specific restriction enzyme analysis (PCR-ASRA) and was analyzed for a recessive and a dominant model. The Fyn -93G allele exhibits in healthy controls a statistically significant lower frequency than in liver recipients (18% vs. 24%; p=0.046) or in liver recipients with BPAR (18% vs. 27%; p=0.017). However, the genotype and allele frequencies of the Fyn -93A>G SNP demonstrate no significant differences between recipients with acute rejection episodes (S-BPAR and M-BPAR) and No-BPAR recipients. Thus our results provide no evidence that the Fyn -93A>G SNP contributes to the susceptibility to acute liver transplant rejection in a Caucasian population.

Lack of association between CD40 polymorphisms and acute rejection in German liver transplant recipients.

CD40 and its ligand, CD154, are major costimulatory molecules whose interactions are important in alloreactive transplant rejection. The aim of this study was to examine the association of CD40 polymorphisms with the susceptibility to acute rejection episodes in liver transplantation. In total, 112 liver transplant recipients with biopsy proven acute rejections (BPAR), 97 without BPAR (WBPAR), and 112 healthy control individuals were enrolled in the study. Two single nucleotide polymorphisms (SNPs) of CD40 gene (rs1883832 and rs4810485) were genotyped by polymerase chain reaction-allele specific restriction enzyme analysis (PCR-ASRA). Both SNPs has been tested for a recessive and a dominant model. No significant differences were found in the genotype and allele frequencies of the SNPs rs1883832 and rs4810485 between BPAR liver recipients and WBPAR recipients. Our results do not suggest an important role of tested CD40 SNPs in the susceptibility to acute liver transplant rejection in a Caucasian population.

Transcapsular arterial neovascularization of liver transplants increases the risk of intraoperative bleeding during retransplantation.

Arterial neovascularization of liver grafts can be a source of significant blood loss during retransplantation. This study evaluated the effect of transcapsular arterial neovascularization on intraoperative blood loss during retransplantation and long-term follow-up. Eleven consecutive patients with transcapsular arterial neovascularization (seven male, four female; nine children, two adults; mean age 12.3 ± 16.3 years) and the same number of matched control patients were analysed. Blood loss was calculated based on transfusion requirements. The volume of transfused units of red blood cells per kilogram bodyweight until hepatectomy and during the entire procedure was significantly higher in patients with neovascularization than in control patients (0.32 ± 0.21 vs. 0.14 ± 0.11, and 0.94 ± 0.83 vs. 0.36 ± 0.38 respectively; P-values 0.027). Neovascularization was associated with extensive intra-abdominal adhesions and a longer operating time until hepatectomy (175.6 ± 52.1 min vs. 124.3 ± 34.9 min, P-value 0.015). Postoperative revisions were performed more frequently in patients with neovessels. Graft survival did not differ between groups. Assessment for transcapsular arterial neovascularization should be included in preoperative Doppler ultrasound protocols to identify patients at risk of a complicated intra- and postoperative course in case of retransplantation.

High toxicity of sorafenib for recurrent hepatocellular carcinoma after liver transplantation.

Treatment options of recurrent hepatocellular carcinoma (HCC) after liver transplantation are limited and data on systemic compounds for advanced tumor stages in transplant recipients are sparse. We retrospectively analyzed the toxicity, tolerability, and efficacy of sorafenib in combination with mTOR inhibitors (mTORi), or calcineurin inhibitors (CNI) in transplant recipients with recurrent HCC. In total, 20 of 92 patients transplanted for HCC within a 10-year time period, experienced tumor recurrence. In case of ineligibility for other treatment options, patients received sorafenib (n = 13). In addition, CNI were stopped and switched to mTORi in nine patients, whereas CNI were continued in four patients. Grade 3-4 adverse events were observed in 92% of all patients necessitating sorafenib discontinuation in 77%. The most common severe adverse events were acute hepatitis, diarrhea, hand-foot - skin reaction and bone marrow suppression. In patients receiving sorafenib/mTORi one patient achieved partial response, and four achieved stable disease. In this cohort of liver transplant recipients side effects prevented full dosing of sorafenib and necessitated discontinuation of sorafenib in the majority of patients, yet antitumor efficacy seemed promising in combination with mTORi.

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.