Tumor Necrosis Factor Directs Allograft-Related Innate Responses and Its Neutralization Improves Hepatocyte Engraftment in Rats.

The innate immune system plays a critical role in allograft rejection. Alloresponses involve numerous cytokines, chemokines, and receptors that cause tissue injury during rejection. To dissect these inflammatory mechanisms, we developed cell transplantation models in dipeptidylpeptidase-deficient F344 rats using mycophenolate mofetil and tacrolimus for partial lymphocyte-directed immunosuppression. Syngeneic hepatocytes engrafted in liver, whereas allogeneic hepatocytes were rejected but engrafted after immunosuppression. These transplants induced mRNAs for >40 to 50 cytokines, chemokines, and receptors. In allografts, innate cell type-related regulatory networks extended to granulocytes, monocytes, and macrophages. Activation of Tnfa and its receptors or major chemokine receptor-ligand subsets persisted in the long term. An examination of the contribution of Tnfa in allograft response revealed that it was prospectively antagonized by etanercept or thalidomide, which resolved cytokine, chemokine, and receptor cascades. In bioinformatics analysis of upstream regulator networks, the Cxcl8 pathway exhibited dominance despite immunosuppression. Significantly, Tnfa antagonism silenced the Cxcl8 pathway and decreased neutrophil and Kupffer cell recruitment, resulting in multifold greater engraftment of allogeneic hepatocytes and substantially increased liver repopulation in retrorsine/partial hepatectomy model. We conclude that Tnfa is a major driver for persistent innate immune responses after allogeneic cells. Neutralizing Tnfa should help in avoiding rejection and associated tissue injury in the allograft setting.

An Overview of Liver Transplant Pathology: Data from a Tertiary Referral Centre in Western India.

INTRODUCTION AND AIM: 1. Study of liver explants - Etiologic types of end-stage chronic liver disease (ESCLD) and acute liver failure (ALF) in adults and children. 2. Assessment of donor steatosis and incidental granulomas. 3. Post-transplant liver biopsies. MATERIAL AND METHODS: Specimens of 180 explant hepatectomies, 173 donor wedge and 30 core liver biopsies, and 58 post transplant liver biopsies received in our department from April 2013 to March 2017. RESULTS: 1. Most common causes of ESCLD in adults were: alcohol related (30.32%), hepatitis virus related (18.71%) and non-alcoholic steatohepatitis related (18.06%); and in children ≤ 12 years were: biliary atresia (27.27%), autoimmune disease (18.18%) and Wilson's disease (18.18%). Most common causes of ALF in adults and children were anti-tubercular therapy induced and idiopathic respectively. 2. Prevalence rate of moderate steatosis (between 30-60%) was 4.28%. Incidental granulomas were seen in 5 cases. 3. Most common diagnoses of post-transplant biopsies in adults included acute cellular rejection (ACR) (36.17%), recurrence of viral disease (8.51%) and moderate non-specific portal triaditis (8.51%). Among children ≤ 12 years, most common diagnoses included unremarkable liver parenchyma, ACR and ischemia/reperfusion injury. CONCLUSION: 1. Alcohol- and hepatitis- virus related ESCLD, and biliary atresia are leading indications for liver transplantation in adults and children respectively. 2. Prevalence of 4.28% of moderate steatosis, is much lower than that documented in western literature. Only 5 cases of incidental granulomas is unexpectedly low in a country endemic for tuberculosis. 3. Most common diagnoses of post-transplant liver biopsies in adults has been acute rejection, which is similar to the findings from much larger published series.

Thalidomide promotes transplanted cell engraftment in the rat liver by modulating inflammation and endothelial integrity.

BACKGROUND & AIMS: For liver-directed cell therapy, efficient engraftment of transplanted cells is critical. This study delineated whether anti-inflammatory and endothelial disrupting properties of thalidomide could promote transplanted cell engraftment and proliferation in liver. METHODS: We used dipeptidyl peptidase IV-deficient rats for cell transplantation studies, including gene expression analysis, morphological tissue analysis, serological assays, cell culture assays, and assays of transplanted cell engraftment and proliferation. RESULTS: Thalidomide-pretreatment increased engraftment and proliferation of transplanted hepatocytes due to decreased inflammation. Moreover, thalidomide exacerbated cell transplantation-induced endothelial injury. This combined anti-inflammatory and endothelial injury effect of thalidomide was superior to the anti-inflammatory effect alone of repertaxin or etanercept, which block cytokines/chemokines/receptor-dependent inflammation. In thalidomide-pretreated animals, liver repopulation accelerated, including when cells were primed with bosentan to block endothelin-1 receptors. CONCLUSIONS: Thalidomide improved transplanted cell engraftment and liver repopulation. Therefore, this class of drugs will advance applications of liver cell therapy in people. LAY SUMMARY: This work aimed to develop effective drug treatments for improving engraftment of transplanted cells because that constitutes a critical step in rebuilding liver with healthy cells. Studies in animal models of cell transplantation led to identification of an old drug, thalidomide, which blocked inflammation and altered the liver microenvironment to yield superior engraftment and proliferation of transplanted cells. This will be appropriate for liver cell therapy in people.

Ischemic preconditioning affects long-term cell fate through DNA damage-related molecular signaling and altered proliferation.

Despite the potential of ischemic preconditioning for organ protection, long-term effects in terms of molecular processes and cell fates are ill defined. We determined consequences of hepatic ischemic preconditioning in rats, including cell transplantation assays. Ischemic preconditioning induced persistent alterations; for example, after 5 days liver histology was normal, but γ-glutamyl transpeptidase expression was observed, with altered antioxidant enzyme content, lipid peroxidation, and oxidative DNA adducts. Nonetheless, ischemic preconditioning partially protected from toxic liver injury. Similarly, primary hepatocytes from donor livers preconditioned with ischemia exhibited undesirably altered antioxidant enzyme content and lipid peroxidation, but better withstood insults. However, donor hepatocytes from livers preconditioned with ischemia did not engraft better than hepatocytes from control livers. Moreover, proliferation of hepatocytes from donor livers preconditioned with ischemia decreased under liver repopulation conditions. Hepatocytes from donor livers preconditioned with ischemia showed oxidative DNA damage with expression of genes involved in MAPK signaling that impose G1/S and G2/M checkpoint restrictions, including p38 MAPK-regulated or ERK-1/2-regulated cell-cycle genes such as FOS, MAPK8, MYC, various cyclins, CDKN2A, CDKN2B, TP53, and RB1. Thus, although ischemic preconditioning allowed hepatocytes to better withstand secondary insults, accompanying DNA damage and molecular events simultaneously impaired their proliferation capacity over the long term. Mitigation of ischemic preconditioning-induced DNA damage and deleterious molecular perturbations holds promise for advancing clinical applications.

Etanercept blocks inflammatory responses orchestrated by TNF-α to promote transplanted cell engraftment and proliferation in rat liver.

UNLABELLED: Engraftment of transplanted cells is critical for liver-directed cell therapy, but most transplanted cells are rapidly cleared from liver sinusoids by proinflammatory cytokines/chemokines/receptors after activation of neutrophils or Kupffer cells (KCs). To define whether tumor necrosis factor alpha (TNF-α) served roles in cell-transplantation-induced hepatic inflammation, we used the TNF-α antagonist, etanercept (ETN), for studies in syngeneic rat hepatocyte transplantation systems. After cell transplantation, multiple cytokines/chemokines/receptors were overexpressed, whereas ETN before cell transplantation essentially normalized these responses. Moreover, ETN down-regulated cell-transplantation-induced intrahepatic release of secretory cytokines, such as high-mobility group box 1. These effects of ETN decreased cell-transplantation-induced activation of neutrophils, but not of KCs. Transplanted cell engraftment improved by several-fold in ETN-treated animals. These gains in cell engraftment were repeatedly realized after pretreatment of animals with ETN before multiple cell transplantation sessions. Transplanted cell numbers did not change over time, indicating absence of cell proliferation after ETN alone. By contrast, in animals preconditioned with retrorsine and partial hepatectomy, cell transplantation after ETN pretreatment significantly accelerated liver repopulation, compared to control rats. CONCLUSION: TNF-α plays a major role in orchestrating cell-transplantation-induced inflammation through regulation of multiple cytokines/chemokines/receptor expression. Because TNF-α antagonism by ETN decreased transplanted cell clearance, improved cell engraftment, and accelerated liver repopulation, this pharmacological approach to control hepatic inflammation will help optimize clinical strategies for liver cell therapy.

Endothelin-1 receptor A blocker darusentan decreases hepatic changes and improves liver repopulation after cell transplantation in rats.

UNLABELLED: Cell transplantation-induced hepatic ischemia and recruitment of vasoconstrictors (e.g., endothelin-1; Edn1) leads to clearance of transplanted cells and poses problems for liver repopulation. Therefore, we determined whether darusentan (DAR), which potently blocks Edn1 receptor type A, could benefit cell engraftment. We transplanted primary F344 rat hepatocytes with or without DAR in dipeptidyl peptidase IV-deficient rats. Analysis of microcirculatory events included hepatic ischemia, endothelial injury, including with gene expression arrays, and activations of Kupffer cells (KCs), neutrophils, or hepatic stellate cells (HSCs). The retrorsine-partial hepatectomy model was used for liver repopulation studies. Whether DAR was directly cytoprotective was examined in cultured rat hepatocytes or CFSC-8B rat HSCs. We found that DAR induced hepatic sinusoidal vasodilation, caused more transplanted cells to be deposited in liver parenchyma, and decreased hepatic ischemia and endothelial injury. This lessened perturbations in expression of endothelial biology genes, including regulators of vessel tone, inflammation, cell adhesion, or cell damage, versus drug-untreated controls. Moreover, in DAR-treated animals, cell transplantation-induced activation of KCs, albeit not of neutrophils, decreased, and fewer HSCs expressed desmin. In DAR-treated rats, improvements in cell engraftment led to greater extent of liver repopulation, compared to drug-untreated controls. In cell-culture assays, DAR did not stimulate release of cytoprotective factors, such as vascular endothelial growth factor, from HSCs. Moreover, DAR did not protect hepatocytes from tumor necrosis factor alpha- or oxidative stress-induced toxicity. Endothelin receptor A blockade in vitro did not improve engraftment of subsequently transplanted hepatocytes. CONCLUSION: Systemic administration of DAR decreases hepatic ischemia-related events and thus indirectly improves cell engraftment and liver repopulation. This vascular mechanism may permit the development of combinatorial drug-based regimens to help optimize cell therapy.

Directly acting drugs prostacyclin or nitroglycerine and endothelin receptor blocker bosentan improve cell engraftment in rodent liver.

UNLABELLED: To optimize strategies for liver-directed cell therapy, prevention of initial transplanted cell losses is particularly important for subsequent liver repopulation. After cell transplantation in hepatic sinusoids, perturbations in hepatic microcirculation along with changes in various liver cell types are among the earliest changes. Therefore, for advancing further concepts in cell engraftment we studied vascular and related events in the liver after transplanting syngeneic hepatocytes into dipeptidyl peptidase IV-deficient rats. We treated rats with vascular drugs to define whether deleterious cell transplantation-induced events could be controlled followed by improvements in transplanted cell engraftment and proliferation. We found cell transplantation altered liver gene expression related to vessel tone, inflammation, cell adhesion, thrombosis, or tissue damage/remodeling. This was due to hepatic ischemia, endothelial injury, and activation of neutrophils, Kupffer cells, and hepatic stellate cells. Treatment of rats before cell transplantation with the angiotensin converting enzyme blocker, lisinopril, or angiotensin II receptor blocker, losartan, did not improve cell engraftment. By contrast, direct-acting nitroglycerine or prostacyclin improved cell engraftment and also kinetics of liver repopulation. These drugs lowered hepatic ischemia and inflammation, whereas pretreatment of rats with the dual endothelin-1 receptor blocker, bosentan, improved cell engraftment independently of hepatic ischemia or inflammation, without improving liver repopulation. However, incubation of hepatocytes with bosentan protected cells from cytokine toxicity in vitro and produced superior cell engraftment and proliferation in vivo. CONCLUSION: Cell transplantation-induced changes in hepatic microcirculation contributed to transplanted cell clearances from liver. Vascular drugs, such as nitroglycerine, prostacyclin, and bosentan, offer opportunities for improving cell therapy results through superior cell engraftment and liver repopulation. Ongoing clinical use of these drugs will permit rapid translation of the findings in people.

Nonselective inhibition of prostaglandin-endoperoxide synthases by naproxen ameliorates acute or chronic liver injury in animals.

The rising prevalence of hepatic injury due to toxins, metabolites, viruses, etc., necessitates development of further mechanisms for protecting the liver and for treating acute or chronic liver diseases. To examine whether inhibition of inflammation is directed by cyclo-oxygenase pathways, we performed animal studies with naproxen, which inhibits prostaglandin-endoperoxide synthases 1 and 2 and is in extensive clinical use. We administered carbon tetrachloride to induce acute liver injury and ligated the common bile duct to induce chronic liver injury in adult rats. These experimental manipulations produced abnormalities in liver tests, tissue necrosis, compensatory hepatocyte or biliary proliferation, and onset of fibrosis, particularly after bile duct ligation. After carbon tetrachloride-induced acute injury, naproxen decreased liver test abnormalities, tissue necrosis and compensatory hepatocellular proliferation. After bile duct ligation-induced chronic injury, naproxen decreased liver test abnormalities, tissue injury and compensatory biliary hyperplasia. Moreover, after bile duct ligation, naproxen-treated rats showed more periductular oval liver cells, which have been classified as hepatic progenitor cells. In naproxen-treated rats, we found greater expression in hepatic stellate cells and mononuclear cells of cytoprotective factors, such as vascular endothelial growth factor. The ability of naproxen to induce expression of vascular endothelial growth factor was verified in cell culture studies with CFSC-8B clone of rat hepatic stellate cells. Whereas assays for carbon tetrachloride toxicity using cultured primary hepatocytes established that naproxen was not directly cytoprotective, we found conditioned medium containing vascular endothelial growth factor from naproxen-treated CFSC-8B cells protected hepatocytes from carbon tetrachloride toxicity. Therefore, naproxen was capable of ameliorating toxic liver injury, which involved naproxen-induced release of physiological cytoprotective factors in nonparenchymal liver cells. Such drug-induced release of endogenous cytoprotectants will advance therapeutic development for hepatic injury.

Hepaticoduodenostomy for Recurrent Biliary Anastomotic Stricture after Liver Transplant.

Biliary strictures afterlivertransplant are amenable to endoscopic dilatation or percutaneous dilatation and stenting in most cases. In rare cases, for recurrence or tight stricture, surgery is required, and hepaticojejunostomy is the favored procedure. We report a case of posttransplant stricture in a duct-to-duct anastomosis that could not be accessed due to prior gastric bypass. Despite multiple percutaneous transhepatic cholangiography dilatations, the stricture recurred, and the patient was taken up for bilioenteric bypass. During surgery, dense adhesions in the infracolic compartment with chronically twisted jejunal loops, due to prior mini gastric bypass, were encountered, which prevented the creation of a jejunal Roux limb. Hepaticoduodenostomy was performed with no recurrence of stricture at 12 months. Hepaticoduodenostomy is a viable option for surgical management of recurrent biliary strictures, especially in a setting of prior bariatric/diversion procedures.

Analysis of donor morbidity in 177 donor hepatectomies for living donor liver transplant: Experience from a high-volume centre in western India.

BACKGROUND: Living donor liver transplant (LDLT) is based on the principle of double equipoise. Organ shortage in Asian countries has led to development of high-volume LDLT programs with good outcomes. Safety of live liver donor is the Achilles heel of LDLT program and every effort should be made to achieve low morbidity and near zero mortality rates. METHODS: We retrospectively analyzed our prospectively maintained donor morbidity data (outcomes) of 177 donors in a new transplant program setup in western India by an experienced surgeon. The primary end point was to analyze the morbidity rates and the factors associated with it. RESULTS: None of the donors in our cohort of 177 donors developed grade IV or V complication (Clavien-Dindo classification). One-fourth (1/4th) of the donors developed complications ranging from grade I to grade III(b). The rate of complications according to modified Clavien-Dindo classification is as follows: (1) grade I in 5.6% (n = 10), (2) grade II in 14.6% (n = 26), (3) grade III(a) in 3.9% (n = 7), (4) grade III(b) in 2.2% (n = 4). Three donors (1.6%) developed post-hepatectomy intra-abdominal bleeding and required re-exploration (grade IIIb). All of them recovered well post-surgery and are doing well in follow-up. The mean follow-up of the entire cohort was 2871 ± 521 days (range 1926-3736 days). CONCLUSION: Donor safety (outcome) is determined by meticulous donor surgery and good-quality remnant.

Impact and Consequences of Recipient Gastroduodenal Artery Ligation Before Hepatic Artery Anastomosis During Orthotopic Liver Transplantation.

OBJECTIVES: The recipient's gastroduodenal artery is often ligated before the hepatic artery anastomosis during orthotopic liver transplant, to gain either mobility or length of recipient's hepatic artery, potentially protecting the anastomosis by preventing "steal syndrome." In this study, our aim was to evaluate the consequences of gastroduodenal artery ligation and its effect on prevention of hepatic artery thrombosis. MATERIALS AND METHODS: We retrospectively analyzed deceased-donor orthotopic liver transplant procedures (n = 210) performed at a single center between January 2016 and July 2021 to compare outcomes between recipients with (group 1) and recipients without (group 2) gastroduodenal artery ligation. Group 1 included 78 patients (37%), in which the recipient's common hepatic artery was used for arterial anastomosis; group 2 included 132 patients (63%), in which the right hepatic artery orthe proper hepatic artery was used for arterial anastomosis. Occurrences of hepatic artery thrombosis, postoperative hyperamylasemia, nausea and vomiting, and delayed feeding were compared between the groups. RESULTS: There was no incidence of hepatic artery thrombosis reported in either group. In group 1, 31 patients (39.7%) were reported to have postoperative hyperamylasemia, ranging from 200 to 4700 U/L accompanied by delayed feeding, whereas, in group 2, only 16 of 132 patients (12%) had postoperative hyperamylasemia, ranging from 200 to 1400 U/L (P < .01). CONCLUSIONS: Ligation of recipient's gastroduodenal artery is not associated with decreased risk of hepatic artery thrombosis compared with nonligation. However, the procedure does have consequences in the form of possible postoperative hyperamylasemia, leading to delayed feeding probably due to decreased oral tolerance.

The "W" Technique: A Safe and Reproducible Technique for Hepatic Artery Reconstruction in Living Donor Liver Transplantation.

BACKGROUND Reconstruction of the hepatic arterial inflow can be technically demanding in living donor liver transplantation, and thrombosis can result in graft loss and mortality. We describe the safe and reproducible "W" technique to reconstruct the hepatic artery and outcomes before and after adoption of the technique in a consecutive series of liver transplants at 2 high-volume living donor liver transplant centers. MATERIAL AND METHODS Prospectively collected data were analyzed to compare the outcomes before and after introduction of a standardized "W" technique for reconstruction of the hepatic artery in 2 high-volume living donor liver transplant programs. RESULTS In a consecutive series of 675 liver transplants, of which 27 were deceased donor transplants and 648 were living donor transplants, 443 transplants were performed with a standard interrupted reconstruction of the hepatic artery under loupes. These transplants were performed by a single surgeon, with an incidence of hepatic artery thrombosis of 2%. After introduction of the "W" technique, despite the arterial reconstruction being done by several surgeons in the early part of their learning curve, the incidence of hepatic artery thrombosis decreased to 0.86% in the next 232 transplants. CONCLUSIONS The "W" technique is a simple, easy to learn and teach technique for reconstruction of the hepatic artery without the use of the operating microscope in living donor liver transplantation.

Hepatic stellate cells promote hepatocyte engraftment in rat liver after prostaglandin-endoperoxide synthase inhibition.

BACKGROUND & AIMS: Hepatic inflammation occurs immediately after cells are transplanted to the liver, but the mechanisms that underlie this process are not fully defined. We examined cyclooxygenase pathways that mediate hepatic inflammation through synthesis of prostaglandins, prostacyclins, thromboxanes, and other prostanoids following transplantation of hepatocytes. METHODS: We transplanted F344 rat hepatocytes into syngeneic dipeptidyl peptidase IV-deficient F344 rats. Changes in cyclooxygenase pathways were analyzed, and specific pathways were blocked pharmacologically; the effects on cell engraftment and native liver cells were determined. RESULTS: Transplantation of hepatocytes induced hepatic expression of prostaglandin-endoperoxide synthases 1 and 2, which catalyze production of prostaglandin H2, as well as the downstream factor thromboxane synthase, which produces thromboxane A2 (a regulator of vascular and platelet responses in inflammation). Transplanted hepatocytes were in proximity with liver cells that expressed prostaglandin-endoperoxide synthases. The number of engrafted hepatocytes increased in rats given naproxen or celecoxib before transplantation but not in rats given furegrelate (an inhibitor of thromboxane synthase) or clopodigrel (an antiplatelet drug). Naproxen and celecoxib did not prevent hepatic ischemia or activation of neutrophils, Kupffer cells, or inflammatory cytokines, but they did induce hepatic stellate cells to express cytoprotective genes, vascular endothelial growth factor and hepatocyte growth factor, and matrix-type metalloproteinases and tissue inhibitor of metalloproteinase-1, which regulate hepatic remodeling. CONCLUSIONS: Activation of cyclooxygenase pathways interferes with engraftment of transplanted hepatocytes in the liver. Pharmacologic blockade of prostaglandin-endoperoxide synthases stimulated hepatic stellate cells and improved cell engraftment.

Hepatocyte transplantation-induced liver inflammation is driven by cytokines-chemokines associated with neutrophils and Kupffer cells.

BACKGROUND & AIMS: Hepatocyte transplantation-induced liver inflammation impairs cell engraftment. We defined whether proinflammatory cytokines and chemokines played roles in regulation of hepatocyte engraftment in the liver. METHODS: We performed studies over up to 3 weeks in rat hepatocyte transplantation systems. Expression of 84 cytokine-chemokine genes was studied by quantitative real-time polymerase chain reactions. Expression of selected up-regulated genes was verified by immunohistochemistry. Hepatic recruitment of neutrophils was demonstrated by myeloperoxidase activity assays, and Kupffer cell activation was established by carbon phagocytosis assays. The role of neutrophils and Kupffer cells in regulating expression of cytokine-chemokine genes as well as cell engraftment was determined by cell depletion studies. RESULTS: Within 6 hours after syngeneic cell transplantation, expression of 25 cytokine-chemokine genes increased by 2- to 123-fold, P < .05. These genes were largely associated with activated neutrophils and macrophages, including chemokine ligands, CXCL1, CXCL2, CCL3, CCL4; chemokine receptors, CXCR1 or CXCR2, CCR1, CCR2; and regulatory cytokines tumor necrosis factor alpha and interleukin-6. Inflammatory cells in the liver immunostained for CCR1, CCR2, CXCR1, and CXCR2, which indicated that up-regulated messenger RNA was appropriately translated. When neutrophils and Kupffer cells were depleted with neutrophil antiserum and gadolinium chloride, respectively, before transplanting cells, cell transplantation-induced cytokine-chemokine responses were attenuated. Virtually all abnormalities subsided in animals treated with neutrophil antiserum plus gadolinium chloride. Moreover, depletion of neutrophils or Kupffer cells improved engraftment of transplanted cells. CONCLUSIONS: Cell transplantation-induced liver inflammation involves proinflammatory cytokine-chemokine systems capable of modulation by neutrophils and Kupffer cells. This offers new directions for optimizing cell therapy strategies.

Bile salt-induced pro-oxidant liver damage promotes transplanted cell proliferation for correcting Wilson disease in the Long-Evans Cinnamon rat model.

Insights into disease-specific mechanisms for liver repopulation are needed for cell therapy. To understand the efficacy of pro-oxidant hepatic perturbations in Wilson disease, we studied Long-Evans Cinnamon (LEC) rats with copper toxicosis under several conditions. Hepatocytes from healthy Long-Evans Agouti (LEA) rats were transplanted intrasplenically into the liver. A cure was defined as lowering of copper to below 250 microg/g liver, presence of ATPase, Cu++ transporting, beta polypeptide (atp7b) messenger RNA (mRNA) in the liver and improvement in liver histology. Treatment of animals with the hydrophobic bile salt, cholic acid, or liver radiation before cell transplantation produced cure rates of 14% and 33%, respectively; whereas liver radiation plus partial hepatectomy followed by cell transplantation proved more effective, with cure in 55%, P < 0.01; and liver radiation plus cholic acid followed by cell transplantation was most effective, with cure in 75%, P < 0.001. As a group, cell therapy cures in rats preconditioned with liver radiation plus cholic acid resulted in less hepatic copper, indicating greater extent of liver repopulation. We observed increased hepatic catalase and superoxide dismutase activities in LEC rats, suggesting chronic oxidative stress. After liver radiation or cholic acid, hepatic lipid peroxidation levels increased, indicating further oxidative injury, although we did not observe overt additional cytotoxicity. This contrasted with healthy animals in which liver radiation and cholic acid produced hepatic steatosis and loss of injured hepatocytes. We concluded that pro-oxidant perturbations were uniquely effective for cell therapy in Wilson disease because of the nature of preexisting hepatic damage.

Thromboelastographic evaluation of coagulation in patients with extrahepatic portal vein thrombosis and non-cirrhotic portal fibrosis: a pilot study.

BACKGROUND AND AIMS: Non-cirrhotic portal hypertension due to extrahepatic portal vein thrombosis (EHO) and non-cirrhotic portal fibrosis (NCPF) is a major cause of upper gastrointestinal hemorrhage in India. Hypercoagulability has been proposed to explain the thrombosis in the portal vein in EHO and intrahepatic portal vein radicals in NCPF. However, some authors have reported hypocoagulability in these patients. Thromboelastography (TEG), which gives a dynamic assessment of coagulation, has potential for evaluating coagulation in these patients but has not been used so far. It was the aim of this study to evaluate the coagulation status in patients of EHO and NCPF using TEG. METHODS: Thirty patients with EHO and 19 patients with NCPF were studied. TEG was done in all patients. R (reaction time), K (constant), alpha (angle), MA (maximal amplitude), A 60 (width of tracing after 60 min) were recorded and TEG index calculated and compared to controls. RESULTS: Seven patients (23.3%) in the EHO group and eight (42.1%) in the NCPF group had severe thrombocytopenia (platlets, < 50 000 cells/dL). TEG showed significantly shorter R, higher MA and larger A in both EHO and NCPF compared to controls (P < 0.01). Thrombocytopenia normalized A but R continued to be significantly shorter in EHO and NCPF. Overt hypercoagulability (TEG index, > +2.5) was seen in two patients with EHO and one patient with NCPF. CONCLUSION: A latent hypercoagulable state exists in patients with EHO and NCPF which is partially masked by the thrombocytopenia secondary to splenomegaly and hypersplenism.