Linda Sher

A bioartificial liver to treat severe acute liver failure.

ObjectiveTo test the safety and efficacy of a bioartificial liver support system in patients with severe acute liver failure. Summary Background DataSummary Background Data authors developed a bioartificial liver using porcine hepatocytes. The system was tested in vitro and shown to have differentiated liver functions (cytochrome P450 activity, synthesis of liver-specific proteins, bilirubin synthesis, and conjugation). When tested in vivo in experimental animals with liver failure, it gave substantial metabolic and hemodynamic support. MethodsSeven patients with severe acute liver failure received a double lumen catheter in the saphenous vein; blood was removed, plasma was separated and perfused through a cartridge containing 4 to 6 X 109 porcine hepatocytes, and plasma and blood cells were reconstituted and reinfused. Each treatment lasted 6 to 7 hours. ResultsResults patients tolerated the procedure(s) well, with neurologic improvement, decreased intracranial pressure (23.0 ± 2.3 to 7.8 ± 1.7 mm Hg; p < 0.005) associated with an increase in cerebral perfusion pressure, decreased plasma ammonia (163.3 ± 21.3 to 112.2 ± 9.8 μMoles/L; p < 0.01), and increased encephalopathy index (0.60 ± 0.17 to 1.24 ± 0.22; p < 0.03). All patients survived, had a liver transplant, and were discharged from the hospital. ConclusionsConclusions bioartificial liver is safe and serves as an effective “bridge” to liver transplant in some patients.

Risk Factors for Graft Survival After Liver Transplantation from Donation After Cardiac Death Donors: An Analysis of OPTN/UNOS Data

Due to increasing use of allografts from donation after cardiac death (DCD) donors, we evaluated DCD liver transplants and impact of recipient and donor factors on graft survival. Liver transplants from DCD donors reported to UNOS were analyzed against donation after brain death (DBD) donor liver transplants performed between 1996 and 2003. We defined a recipient cumulative relative risk (RCRR) using significant risk factors identified from a Cox regression analysis: age; medical condition at transplantation; regraft status; dialysis received and serum creatinine. Graft survival from DCD donors (71% at 1 year and 60% at 3 years) were significantly inferior to DBD donors (80% at 1 year and 72% at 3 years, p < 0.001). Low‐risk recipients (RCRR ≤ 1.5) with low‐risk DCD livers (DWIT < 30 min and CIT < 10 h, n = 226) achieved graft survival rates (81% and 67% at 1 and 3 years, respectively) not significantly different from recipients with DBD allografts (80% and 72% at 1 and 3 years, respectively, log‐rank p = 0.23). Liver allografts from DCD donors may be used to increase the cadaveric donor pool, with favorable graft survival rates achieved when low‐risk grafts are transplanted in a low‐risk setting. Whether transplantation of these organs in low‐risk recipients provides a survival benefit compared to the waiting list is unknown.

The use of a pig liver xenograft for temporary support of a patient with fulminant hepatic failure

A 26-year-old female patient with fulminant hepatic failure and a history of autoimmune hepatitis was heterotopically transplanted with a pig hepatic xenograft to provide temporary metabolic support prior to transplantation with a human donor organ. Circulating natural antipig antibodies were removed prior to transplantation by plasmapheresis and ex vivo en bloc perfusion of the donor pig kidneys. The liver xenograft functioned after transplantation as measured by active bile production, stabilization of prothrombin levels, and reduction in the circulating levels of lactic acid and the enzymes AST and ALT. Despite the removal of greater than 90% of the recipients natural xenoantibodies prior to transplantation, the levels of antibody rapidly returned and were associated with antibody and complement-mediated rejection of the donor graft. Immunohistochemical evidence of graft rejection could be detected by the deposition of antibody, complement components including properdin, and endothelial swelling as early as 3 hr posttransplantation. These lesions progressed in severity and were accompanied by evidence of thrombosis and ischemic necrosis of the liver xenograft by 34 hrs posttransplantation. The main portal vein, hepatic artery, and vena cava were patent. The placement of the liver graft did not result in any improvement in the neurological status of the patient and she died 34 hr after xenografting due to irreversible brain damage. The information derived from this case has renewed interest in the clinical use of bioartificial devices and whole organ perfusion using xenogeneic tissue for temporary bridging of patients prior to allografting.

A randomized, multicenter study comparing steroid-free immunosuppression and standard immunosuppression for liver transplant recipients with chronic hepatitis C

This randomized, prospective, multicenter trial compared the safety and efficacy of steroid‐free immunosuppression (IS) to the safety and efficacy of 2 standard IS regimens in patients undergoing transplantation for hepatitis C virus (HCV) infection. The outcome measures were acute cellular rejection (ACR), severe HCV recurrence, and survival. The patients were randomized (1:1:2) to tacrolimus (TAC) and corticosteroids (arm 1; n = 77), mycophenolate mofetil (MMF), TAC, and corticosteroids (arm 2; n = 72), or MMF, TAC, and daclizumab induction with no corticosteroids (arm 3; n = 146). In all, 295 HCV RNA–positive subjects were enrolled. At 2 years, there were no differences in ACR, HCV recurrence (biochemical evidence), patient survival, or graft survival rates. The side effects of IS did not differ, although there was a trend toward less diabetes in the steroid‐free group. Liver biopsy samples revealed no significant differences in the proportions of patients in arms 1, 2, and 3 with advanced HCV recurrence (ie, an inflammation grade ≥ 3 and/or a fibrosis stage ≥ 2) in years 1 (48.2%, 50.4%, and 43.0%, respectively) and 2 (69.5%, 75.9%, and 68.1%, respectively). Although we have found that steroid‐free IS is safe and effective for liver transplant recipients with chronic HCV, steroid sparing has no clear advantage in comparison with traditional IS. Liver Transpl, 2011.

Expanding the Donor Kidney Pool: Utility of Renal Allografts Procured in a Setting of Uncontrolled Cardiac Death

The chronic shortage of deceased kidney donors has led to increased utilization of donation after cardiac death (DCD) kidneys, the majority of which are procured in a controlled setting. The objective of this study is to evaluate transplantation outcomes from uncontrolled DCD (uDCD) donors and evaluate their utility as a source of donor kidneys.

Efficacy of tacrolimus as rescue therapy for chronic rejection in orthotopic liver transplantation: A report of the U.S. multicenter liver study group

BACKGROUND A study was performed by 17 different U.S. liver transplantation centers to determine the safety and efficacy of conversion from cyclosporine to tacrolimus for chronic allograft rejection. METHODS Ninety-one patients were converted to tacrolimus a mean of 319 days after liver transplantation. The indication for conversion was ongoing chronic rejection confirmed by biochemical and histologic criteria. Patients were followed for a mean of 251 days until the end of the study. RESULTS Sixty-four patients (70.3%) were alive with their initial hepatic allograft at the conclusion of the study period and were defined as the responder group. Twenty-seven patients (29.7%) failed to respond to treatment, and 20 of them required a second liver graft. The actuarial graft survival for the total patient group was 69.9% and 48.5% at 1 and 2 years, respectively. The actuarial patient survival at 1 and 2 years was 84.4% and 81.2%, respectively. Two significant positive prognostic factors were identified. Patients with a total bilirubin of < or = 10 mg/dl at the time of conversion had a significantly better graft and patient survival than patients converted with a total bilirubin > 10 mg/dl (P=0.00002 and P=0.00125, respectively). The time between liver transplantation and conversion also affected graft and patient survival. Patients converted to tacrolimus < or = 90 days after transplantation had a 1-year actuarial graft and patient survival of 51.9% and 65.9%, respectively, compared with 73.2% and 87.7% for those converted > 90 days after transplantation. The mean total bilirubin level for the responder group was 7.1 mg/dl at the time of conversion and decreased significantly to a mean of 3.4 mg/dl at the end of the study (P=0.0018). Thirteen patients (14.3%) died during the study. Sepsis was the major contributing cause of death in most of these patients. CONCLUSIONS Our results suggest that conversion to tacrolimus for chronic rejection after orthotopic liver transplantation represents an effective therapeutic option. Conversion to tacrolimus before development of elevated total bilirubin levels showed a significant impact on long-term outcome.

Reciprocal regulation by TLR4 and TGF-β in tumor-initiating stem-like cells

Tumor-initiating stem-like cells (TICs) are resistant to chemotherapy and associated with hepatocellular carcinoma (HCC) caused by HCV and/or alcohol-related chronic liver injury. Using HCV Tg mouse models and patients with HCC, we isolated CD133(+) TICs and identified the pluripotency marker NANOG as a direct target of TLR4, which drives the tumor-initiating activity of TICs. These TLR4/NANOG-dependent TICs were defective in the TGF-β tumor suppressor pathway. Functional oncogene screening of a TIC cDNA library identified Yap1 and Igf2bp3 as NANOG-dependent genes that inactivate TGF-β signaling. Mechanistically, we determined that YAP1 mediates cytoplasmic retention of phosphorylated SMAD3 and suppresses SMAD3 phosphorylation/activation by the IGF2BP3/AKT/mTOR pathway. Silencing of both YAP1 and IGF2BP3 restored TGF-β signaling, inhibited pluripotency genes and tumorigenesis, and abrogated chemoresistance of TICs. Mice with defective TGF-β signaling (Spnb2(+/-) mice) exhibited enhanced liver TLR4 expression and developed HCC in a TLR4-dependent manner. Taken together, these results suggest that the activated TLR4/NANOG oncogenic pathway is linked to suppression of cytostatic TGF-β signaling and could potentially serve as a therapeutic target for HCV-related HCC.

Live donor liver transplantation without blood products: strategies developed for Jehovah's Witnesses offer broad application.

Objective:Developing strategies for transfusion-free live donor liver transplantation in Jehovahs Witness patients. Summary Background Data:Liver transplantation is the standard of care for patients with end-stage liver disease. A disproportionate increase in transplant candidates and an allocation policy restructuring, favoring patients with advanced disease, have led to longer waiting time and increased medical acuity for transplant recipients. Consequently, Jehovahs Witness patients, who refuse blood product transfusion, are usually excluded from liver transplantation. We combined blood augmentation and conservation practices with live donor liver transplantation (LDLT) to accomplish successful LDLT in Jehovahs Witness patients without blood products. Our algorithm provides broad possibilities for blood conservation for all surgical patients. Methods:From September 1998 until June 2001, 38 LDLTs were performed at Keck USC School of Medicine: 8 in Jehovahs Witness patients (transfusion-free group) and 30 in non-Jehovahs Witness patients (transfusion-eligible group). All transfusion-free patients underwent preoperative blood augmentation with erythropoietin, intraoperative cell salvage, and acute normovolemic hemodilution. These techniques were used in only 7%, 80%, and 10%, respectively, in transfusion-eligible patients. Perioperative clinical data and outcomes were retrospectively reviewed. Data from both groups were statistically analyzed. Results:Preoperative liver disease severity was similar in both groups; however, transfusion-free patients had significantly higher hematocrit levels following erythropoietin augmentation. Operative time, blood loss, and postoperative hematocrits were similar in both groups. No blood products were used in transfusion-free patients while 80% of transfusion-eligible patients received a median of 4.5+/− 3.5 units of packed red cell. ICU and total hospital stay were similar in both groups. The survival rate was 100% in transfusion-free patients and 90% in transfusion-eligible patients. Conclusions:Timely LDLT can be done successfully without blood product transfusion in selected patients. Preoperative preparation, intraoperative cell salvage, and acute normovolemic hemodilution are essential. These techniques may be widely applied to all patients for several surgical procedures. Chronic blood product shortages, as well as the known and unknown risk of blood products, should serve as the driving force for development of transfusion-free technology.

NANOG Metabolically Reprograms Tumor-Initiating Stem-like Cells through Tumorigenic Changes in Oxidative Phosphorylation and Fatty Acid Metabolism

Stem cell markers, including NANOG, have been implicated in various cancers; however, the functional contribution of NANOG to cancer pathogenesis has remained unclear. Here, we show that NANOG is induced by Toll-like receptor 4 (TLR4) signaling via phosphorylation of E2F1 and that downregulation of Nanog slows down hepatocellular carcinoma (HCC) progression induced by alcohol western diet and hepatitis C virus protein in mice. NANOG ChIP-seq analyses reveal that NANOG regulates the expression of genes involved in mitochondrial metabolic pathways required to maintain tumor-initiating stem-like cells (TICs). NANOG represses mitochondrial oxidative phosphorylation (OXPHOS) genes, as well as ROS generation, and activates fatty acid oxidation (FAO) to support TIC self-renewal and drug resistance. Restoration of OXPHOS activity and inhibition of FAO renders TICs susceptible to a standard care chemotherapy drug for HCC, sorafenib. This study provides insights into the mechanisms of NANOG-mediated generation of TICs, tumorigenesis, and chemoresistance through reprogramming of mitochondrial metabolism.

Course of enterovesical fistulas in Crohn's disease

Enterovesical fistulas occurred in 38 of 683 patients (5.6 percent) with Crohns disease admitted to The Mount Sinai Hospital between 1960 and 1977. There were 22 ileovesical fistulas, 8 colovesical fistulas, and 8 fistulas of combined ileal and colonic origin. These cases fell into three different pathophysiologic categories: 16 patients presented with sepsis after a mean duration of 7 years of Crohns disease, 19 presented without sepsis after a mean of 10 years of disease, and 3 elderly cancer patients presented with an average 25 years disease duration. Sepsis was usually due to deep pelvic or lower quadrant abscess with spontaneous rupture into the bladder. Nonseptic fistulization was a later, more gradual process, reflecting slow penetration into the bladder from a site of chronic cicatrizing bowel disease. Cancer was a very late complication, arising in each patient from an excluded loop. Although medical treatment was successful in delaying surgery in 6 patients and obviated surgery altogether in 2 patients, 36 of 38 patients (95 percent) eventually required operation. Postoperative mortality in this series was limited to two patients (5 percent) with preoperative intraabdominal abscess and sepsis. Five other deaths, unrelated to urinary complications, were caused by intestinal cancer in three patients and by intestinal complications of recurrent Crohns disease in two patients. The urologic course of patients with enterovesical fistula was completely benign. All operated patients were cured of their enterovesical fistulas, and no urologic sequelae developed. Subsequent reoperations that were required in 45 percent of these patients were all for recurrent bowel disease and not for fistula or other urologic problems.