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Background and Aims: Patients with a choledochal malformation, formerly described as cysts, are at increased risk of developing a cholangiocarcinoma and resection is recommended. Given the low incidence of choledochal malformation (CM) in Western countries, the incidence in these countries is unclear. Our aim was to assess the incidence of malignancy in CM patients and to assess postoperative outcome. Methods: In a nationwide, retrospective study, all adult patients who underwent surgery for CM between 1990 and 2016 were included. Patients were identified through the Dutch Pathology Registry and local patient records and were analysed to determine the incidence of malignancy, as well as postoperative mortality and morbidity. Results: A total of 123 patients with a CM were included in the study (Todani Type I, n = 71; Type II, n = 10; Type III, n = 3; Type IV, n = 27; unknown, n = 12). Median age was 40 years (range 18‐70) and 81% were female. The majority of patients (99/123) underwent extrahepatic bile duct resection, with additional liver parenchyma resections in eight patients, only exploration in two, and a local cyst resection in eight patients. Postoperative 30‐day mortality was 2% (2/123) and limited to patients who underwent liver resection. Severe morbidity occurred in 24%. In 14 of the 123 patients (11%), a malignancy was found in the resected specimen. One patient developed a periampullary malignancy 7 years later. Conclusions: In a large Western series of CM patients, 11% were found to have a malignancy. This justifies resection in these patients, despite the risk of morbidity (24%) and mortality (2%). [ABSTRACT FROM AUTHOR]

Background & Aims In addition to their function in thrombosis and haemostasis, platelets play an important role in the stimulation of liver regeneration. It has been suggested that platelets deliver mitogenic cargo to the regenerating liver, and accumulation of platelets in the regenerating liver has been demonstrated. We studied kinetics of platelet influx in the regenerating liver and investigated the signal that initiates platelet influx. Methods We visualized platelets in the liver remnant after partial hepatectomy in mice using intravital microscopy and assessed liver regeneration by examination of liver/body weight ratio and the number of proliferating hepatocytes examined by immunohistochemistry. Results We demonstrated rapid but transient platelet influx into the liver remnant after a partial liver resection. Liver regeneration in thrombocytopenic mice was substantially impaired as evidenced by a reduced liver-to-body weight ratio and decreased numbers of proliferating hepatocytes at day 3 compared to mice with normal platelet counts. In contrast, liver regeneration was only mildly impaired when thrombocytopaenia was induced 2 hours after partial liver resection. Platelet influx into the liver remnant was virtually absent in the presence of an antibody to von Willebrand factor ( VWF) suggesting that VWF release from liver sinusoidal endothelial cells mediates platelet influx. Additionally, liver regeneration in mice deficient in VWF was markedly impaired. Conclusions A rapid but transient VWF-dependent platelet influx into the liver remnant drives platelet-mediated liver regeneration. [ABSTRACT FROM AUTHOR]

Background & Aims Cirrhosis frequently affects multiple components of hemostasis. Reversal of the coagulopathy of these patients is frequently required in case of bleeding episodes, or as prophylaxis before invasive procedures. Although 1-deamino-8-D-arginine vasopressin ( DDAVP) is widely used as a pro-hemostatic agent in patients with cirrhosis, it is unclear whether DDAVP truly enhances hemostasis in these patients. Here we investigated the hemostatic effects of a single bolus of DDAVP in patients with cirrhosis. Methods Ten patients with cirrhosis (child B or C) and ten patients with mild haemophilia A received an intravenous single bolus of 0.3 microgram/kg DDAVP. Plasma was collected prior to and at 1, 3, 6, and 24 h after DDAVP administration. Levels of Von Willebrand factor ( VWF), VWF propeptide, factor VIII ( FVIII), and ADAMTS13 were measured in all plasma samples, whereas VWF multimers and functional VWF-dependent platelet adhesion were determined in the samples pre- and 1 h after DDAVP administration. Results Following DDAVP administration, VWF, FVIII, and VWF propeptide levels increased in patients with haemophilia, while patients with cirrhosis only showed an increase in VWF propeptide and FVIII levels. High molecular weight VWF multimers and VWF-dependent platelet adhesion increased in patients with haemophilia one hour after DDAVP administration, but did not change in the patients with cirrhosis. Levels of ADAMTS13 were unaffected in both patient groups after DDAVP. Conclusion The lack of relevant effects of DDAVP on laboratory indices of primary hemostasis in patients with cirrhosis is in line with previous clinical study results in these patients. [ABSTRACT FROM AUTHOR]

Background Primary sclerosing cholangitis ( PSC) is a chronic inflammatory disease of the bile ducts, frequently necessitating orthotopic liver transplantation ( OLT), often accompanied by inflammatory bowel disease ( IBD). Matrix metalloproteinases ( MMPs) are associated with fibrotic diseases caused by the involvement in tissue remodelling. Aim To evaluate the contribution of MMP-2 and -9 promoter polymorphisms to disease severity in PSC, as assessed by death or need for OLT. Methods Matrix metalloproteinase-2 (−1306 C/T) and -9 (−1562 C/T) gene promoter polymorphisms were analyzed in 132 PSC patients. Follow-up was from onset PSC until death, OLT or end of follow-up. Results Twenty-year cumulative incidence ( CI) of death or OLT for PSC patients with MMP-2 CT genotype was 86.5% compared to 52.8% for CC genotype ( P = 0.030) and reached 100% at 11.3 years for TT genotype. In patients with IBD, CIs were similar: 20-years CI of death or OLT for MMP-2 CT genotype was 86.0% compared to 49.0% for CC genotype and 100% at 11.3 years for TT genotype. Patients without IBD showed a similar trend in 20 years CI for MMP-2 CT (77.8%) compared to CC (57.8%) and CI for TT genotype reached 100% at 9.3 years. Multivariate analysis showed, along with age at diagnosis, a stepwise increase in hazard ratio for MMP-2 T-allele polymorphism for death or OLT. MMP-9 genotype was not associated with disease severity in PSC. Conclusion Matrix metalloproteinase-2 C to T-1306 gene promoter polymorphism in PSC is an independent risk factor for disease severity as reflected by the need for OLT or disease progression leading to mortality. [ABSTRACT FROM AUTHOR]

Traditionally, perioperative bleeding complications were a major concern during orthotopic liver transplantation, but a tremendous decline in transfusion requirements has been reported over the last decade. In recent years, there has been an increasing awareness towards perioperative thrombotic complications, including liver vessel thrombosis, and systemic venous and arterial thromboembolic events. Whereas a number of these thrombotic complications were previously categorized as surgical complications, increasing clinical and laboratory evidence suggest a role for the haemostatic system in thrombotic complications occurring during and after transplantation. High levels of the platelet adhesive protein von Willebrand factor with low levels of its regulator ADAMTS13, an increased potential to generate thrombin, and temporary hypofibrinolysis are all indicative of increased haemostatic potential after transplantation. Clinical evidence for a role of the haemostatic system in post-operative thromboses includes a higher thrombotic risk in patients with various acquired thrombotic risk factors. Although data on efficacy of anticoagulant therapy after liver transplantation are scarce, one study has shown a significant decrease in the risk for late hepatic artery thrombosis by antithrombotic therapy with aspirin. These findings suggest that antihaemostatic therapy in prevention or treatment of thromboembolic complications after liver transplantation may be relevant. Studies on efficacy and safety of these interventions are required as many of the thrombotic complications have a pronounced negative impact on graft and patient survival. [ABSTRACT FROM AUTHOR]

Background & Aim Experimental studies in animals have suggested that liver regeneration is impaired in steatotic livers. However, few studies have focused on the impact of steatosis in patients undergoing partial hepatectomy ( PH). This study aims to determine the role of steatosis on liver regeneration in humans following PH. Methods Eighty-eight patients undergoing PH were included in this study. All patients underwent CT-scanning of the liver preoperatively and 7 days after surgery. Additional CT-scans were performed 6 months post-operatively. Preoperative and post-operative volumes of the total liver ( TLV), future liver remnant ( FLR) and liver remnant ( LR) were measured on CT-scans. Regeneration indices ( RI) were calculated at 7 days and 6 months using the formula: (Volume LR−Volume FLR)/Volume FLR × 100%. Based on histological examination of the resected part of the liver, patients were classified into three groups: (1) no steatosis, (2) mild steatosis (1-29%) and (3) moderate-to-severe steatosis (≥30%). Results The early RI (at day 7) was 40%, 24% and 20% for patients in group 1, 2 and 3 respectively. Late RI (at 6 months) was 81% for group 1, 44% for group 2 and 22% for group 3 ( P = 0.019). At 7 days, the LR represented 79%, 80% and 79% of the TLV for groups 1-3. At 6 months, this was 93%, 92% and 79% respectively. Conclusion Although early RI after PH did not differ in patients with or without steatosis, the late RI in patients with moderate-to-severe steatosis was lower, suggesting that late liver regeneration is impaired in these patients. [ABSTRACT FROM AUTHOR]

Background & Aims Although regeneration of intrahepatic bile ducts has been extensively studied and intrahepatic progenitor cells have been identified, few studies have focussed on the extrahepatic bile duct ( EHBD). We hypothesized that local progenitor cells are present within the EHBD of humans. Human EHBD specimens ( n = 17) were included in this study. Methods Specimens of normal EHBD tissue were obtained from healthy donor livers ( n = 6), mildly injured EHBD from patients with cholangitis ( n = 6) and severely injured EHBD from patients with ischaemic type biliary lesions ( n = 5). Double immunostaining for K19 and the proliferation marker Ki-67 was performed to identify and localize proliferating cells. In addition, immunofluorescent doublestaining using antibodies against K19 and c-Kit was performed to identify and localize cholangiocytes co-expressing putative progenitor cell markers. Results In normal EHBD, few Ki-67+ cells were detected, whereas large numbers of Ki-67+ were found in the diseased EHBD. In EHBD affected by cholangitis, Ki-67+ cells were mainly located in the basal layer of the lumen. EHBD specimens from patients with ischaemic type biliary lesions displayed histological signs of epithelial cell loss and large numbers of Ki-67+ cells were observed in the peribiliary glands. C-Kit expression was localized throughout the EHBD wall and immunofluorescent doublestaining identified a few K19+/c-Kit+ cells in the luminal epithelium of the EHBD as well as in the peribiliary glands. Conclusions These findings support the hypothesis that progenitor cells exist in the EHBD and that the peribiliary glands can be considered a local progenitor cell niche in the human EHBD. [ABSTRACT FROM AUTHOR]

Background: The role of the immune system in the pathogenesis of nonanastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT) is unclear. A loss-of-function mutation in the CC chemokine receptor 5 (CCR5-Δ32) leads to changes in the immune system, including impaired chemotaxis of regulatory T cells. Aim: To investigate the impact of the CCR5-Δ32 mutation on the development of NAS. Methods: In 384 OLTs, we assessed the CCR5 genotype in donors and recipients and correlated this with the occurrence of NAS. Results: The CCR5-Δ32 allele was found in 65 (16.9%) recipients. The cumulative incidence of NAS at 5 years was 6.5% in wild-type (Wt) recipients vs 17.2% for carriers of the CCR5-Δ32 allele ( P<0.01). In recipients with CCR5-Δ32, 50% of all NAS occurred >2 years after OLT, compared with 10% in the Wt group. In multivariate regression analysis, the adjusted risk of developing NAS was four-fold higher in recipients with CCR5-Δ32 ( P<0.01). The highest risk of NAS was seen in patients transplanted for primary sclerosing cholangitis (PSC), who also carried CCR5-Δ32 (relative risk 5.4, 95% confidence interval 2.2-12.9; P<0.01). Donor CCR5 genotype had no impact on the occurrence of NAS. Conclusions: Patients with the CCR5-Δ32 mutation have a four-fold higher risk of developing NAS, compared with Wt recipients. This risk is even higher in patients with CCR5-Δ32 transplanted for PSC. Late development of NAS is significantly more present in patients with CCR5-Δ32. These data suggest that the immune system plays a critical role in the development of NAS after OLT. [ABSTRACT FROM AUTHOR]

Background: Nonanastomotic biliary strictures (NAS) are a serious complication after orthotopic liver transplantation (OLT). Matrix metalloproteinases (MMPs) are involved in connective tissue remodelling in chronic liver disease and complications after OLT. Aim: To evaluate the relationship between MMP-2 and MMP-9 gene polymorphisms and NAS. Methods: MMP-2 (−1306 C/T) and MMP-9 (−1562 C/T) gene promoter polymorphisms were analysed in 314 recipient-donor combinations. Serum levels of these MMPs were determined in subgroups of patients as well. NAS were identified with various radiological imaging studies performed within 4 years after OLT and defined as any stricture, dilation or irregularity of the intra- or extrahepatic bile ducts of the liver graft followed by an intervention, after exclusion of hepatic artery thrombosis and anastomotic strictures. Results: The average incidence of NAS was 15%. The major clinical risk factor for the development of NAS was PSC in the recipient. The presence of the MMP-2 CT genotype in donor and/or recipient was associated with a significantly higher incidence of NAS, up to 29% when both donor and recipient had the MMP-2 CT genotype ( P=0.003). In the multivariate analyses, pre-OLT PSC (hazard ratio 2.1, P=0.02) and MMP-2 CT genotype (hazard ratio 3.5, P=0.003) were found to be independent risk factors for the development of NAS after OLT. No obvious association was found between NAS and the MMP-9 genotype and serum levels of the MMPs. Conclusion: MMP-2 CT genotype of donor and recipient is an independent risk factor, in addition to PSC, for the development of NAS after OLT. [ABSTRACT FROM AUTHOR]

Background: The model of end-stage liver disease (MELD) score is nowadays widely used to prioritize patients for liver transplantation. Aims: To assess the contribution of the individual components of the MELD score in interlaboratory variability. Methods: We sent 15 samples from patients listed for liver transplantation to seven different European laboratories who were asked to measure all three variables. In addition, 10 samples from patients on oral anticoagulant treatment were sent to the same labs for the international normalised ratio (INR) measurement. Results and Conclusions: In all 15 samples, a substantial and clinically relevant variation in the calculated MELD score was observed between laboratories. The mean difference in the MELD score between the highest- and the lowest-scoring laboratory was 4.8. The variation in creatinine measurements resulted in differences of up to three MELD points in a single patient when comparing the highest and the lowest scoring lab. The variation in bilirubin measurements only accounted for a difference of one point between the highest- and the lowest-scoring laboratory, but the variation in INRs resulted in differences of 2 to 12 MELD points. MELD scores or INR values were not substantially different in laboratories that used the Owren instead of the more widely used Quick methodology for INR measurements. The variability in the INR in patients on oral anticoagulants was substantially less as compared with the variability in patients with liver disease. In conclusion, we observed a large interlaboratory variation in the MELD score. This variation in the MELD score is primarily caused by the INR. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article on the status of platelet activation in patients with liver disease in the 2011 issue.

A letter to the editor is presented in response to the article "Low-molecular-weight heparin in patients with advanced cirrhosis," by L. P. Bechmann and colleagues in a 2011 issue.