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Background & Aims Damage to hepatic sinusoidal endothelial cells (SECs) initiates sinusoidal obstruction syndrome (SOS), which is most commonly a consequence of myeloablative chemoirradiation or ingestion of pyrrolizidine alkaloids such as monocrotaline (Mct). This study examines whether SECs are of bone marrow origin, whether bone marrow repair can be a determinant of severity of liver injury, and whether treatment with progenitor cells is beneficial. Methods Mct-treated female rats received infusion of male whole bone marrow or CD133 + cells at the peak of sinusoidal injury. The Y chromosome was identified in isolated SECs by fluorescent in situ hybridization. Bone marrow suppression was induced by irradiation of both lower extremities with shielding of the abdomen. Results SECs in uninjured liver have both hematopoietic (CD45, CD33) and endothelial (CD31) markers. After Mct-induced SOS, infusion of bone marrow–derived CD133 + progenitor cells replaces more than one quarter of SECs. All CD133 + cells recovered from the SEC fraction after injury are CD45 + . CD133 + /CD45 + progenitors also repaired central vein endothelium. Mct suppresses CD133 + /CD45 + progenitors in bone marrow by 50% and in the circulation by 97%. Irradiation-induced bone marrow suppression elicited SOS from a subtoxic dose of Mct, whereas infusion of bone marrow during the necrotic phase of SOS nearly eradicates histologic features of SOS. Conclusions SECs have both hematopoietic and endothelial markers. Bone marrow–derived CD133 + /CD45 + progenitors replace SECs and central vein endothelial cells after injury. Toxicity to bone marrow progenitors impairs repair and contributes to the pathogenesis of SOS, whereas timely infusion of bone marrow has therapeutic benefit.

Occult infection with hepatitis C virus (HCV) is defined as the presence of the HCV genome in either liver tissue or peripheral blood monocytes, despite constant negative results from tests for HCV RNA in serum. We investigated whether patients who maintained a sustained virologic response 12 weeks after therapy (SVR12) with direct-acting antiviral (DAA) agents for recurrent HCV infection after liver transplantation had occult HCV infections. We performed a prospective study of 134 patients with recurrent HCV infection after liver transplantation who were treated with DAAs, with or without ribavirin, from 2014 through 2016 (129 patients achieved an SVR12). In >10% of the patients who achieved SVR12 (n = 14), serum levels of aminotransferases did not normalize during or after DAA therapy, or they normalized transiently but then increased sharply after DAA therapy. Of these 14 patients, 9 were assessed for occult HCV infection by reverse transcription quantitative polymerase chain reaction. This analysis revealed that 55% of these patients (n = 5) had an occult infection, with the detection of negative strand viral genome, indicating viral replication. These findings indicate the presence of occult HCV infection in some patients with abnormal levels of serum aminotransferases, despite SVR12 to DAAs for HCV infection after liver transplantation.

Background & Aims Capillarization, characterized by loss of differentiation of liver sinusoidal endothelial cells (LSECs), precedes the onset of hepatic fibrosis. We investigated whether restoration of LSEC differentiation would normalize crosstalk with activated hepatic stellate cells (HSC) and thereby promote quiescence of HSC and regression of fibrosis. Methods Rat LSECs were cultured with inhibitors and/or agonists and examined by scanning electron microscopy for fenestrae in sieve plates. Cirrhosis was induced in rats using thioacetamide, followed by administration of BAY 60-2770, an activator of soluble guanylate cyclase (sGC). Fibrosis was assessed by Sirius red staining; expression of α-smooth muscle actin was measured by immunoblot analysis. Results Maintenance of LSEC differentiation requires vascular endothelial growth factor-A stimulation of nitric oxide–dependent signaling (via sGC and cyclic guanosine monophosphate) and nitric oxide–independent signaling. In rats with thioacetamide-induced cirrhosis, BAY 60-2770 accelerated the complete reversal of capillarization (restored differentiation of LSECs) without directly affecting activation of HSCs or fibrosis. Restoration of differentiation to LSECs led to quiescence of HSCs and regression of fibrosis in the absence of further exposure to BAY 60-2770. Activation of sGC with BAY 60-2770 prevented progression of cirrhosis, despite continued administration of thioacetamide. Conclusions The state of LSEC differentiation plays a pivotal role in HSC activation and the fibrotic process.

Background & Aims The tumor suppressor PTEN inhibits AKT2 signaling; both are aberrantly expressed in liver tumors. We investigated how PTEN and AKT2 regulate liver carcinogenesis. Loss of PTEN leads to spontaneous development of liver tumors from progenitor cells. We investigated how the loss of PTEN activates liver progenitor cells and induces tumorigenesis. Methods We studied mice with liver-specific disruptions in Pten and the combination of Pten and Akt2 to investigate mechanisms of liver carcinogenesis. Results PTEN loss leads to hepatic injury and establishes selective pressure for tumor-initiating cells (TICs), which proliferate to form mixed-lineage tumors. The Pten- null mice had increasing levels of hepatic injury before proliferation of hepatic progenitors. Attenuation of hepatic injury by deletion of Akt2 reduced progenitor cell proliferation and delayed tumor development. In Pten / Akt2 -null mice given 3,5- diethoxycarbonyl -1,4 dihydrocollidine (DDC), we found that the primary effect of AKT2 loss was attenuation of hepatic injury and not inhibition of progenitor-cell proliferation in response to injury. Conclusions Liver carcinogenesis in Pten- null mice requires not only the transformation of TICs but selection pressure from hepatic injury and cell death, which activates TICs. Further research is required to elucidate the mechanism for hepatic injury and its relationship with TIC activation.

We sought to develop a rodent model of spontaneous bacterial peritonitis and report here the preliminary results of carbon tetrachloride-induced cirrhosis in which ascites and bacterial peritonitis predictably develop. Of 41 rats that survived the initial carbon tetrachloride toxicity, 38 (92.7%) developed cirrhosis with ascites. Of these 38, 21 (55.3%) developed 24 episodes of ascitic fluid infection without iatrogenic colonization. No surgically treatable source of infection was identified at autopsy in any rat; therefore, the infections were presumed to be "spontaneous." Eight (50%) of the 16 rats with culture-positive ascitic fluid at postmortem examination also had spontaneous pleural fluid infection with the same organism. Escherichia coli and Proteus sp. were the organisms most commonly isolated. This rodent model of cirrhosis with ascites appears to be the first high-yield animal model of spontaneous bacterial peritonitis. Ascitic fluid infection in these rats resembles ascitic fluid infection in humans. This model will allow further investigation of the mechanisms of pathogenesis of ascitic fluid infection and provide insight into the prevention and treatment of spontaneous bacterial peritonitis and pleural fluid infection in patients with cirrhosis.

Background & Aims: Colchicine improved survival and reversed cirrhosis in several small clinical trials. We compared the efficacy and safety of long-term colchicine, as compared with placebo, in patients with advanced alcoholic cirrhosis. Methods: Five hundred forty-nine patients with advanced (Pugh B or C) alcoholic cirrhosis were randomized to receive either colchicine 0.6 mg twice per day (n = 274) or placebo (n = 275). Treatment lasted from 2 to 6 years. The primary outcome was all-cause mortality. Secondary outcomes were liver-related morbidity and mortality. Liver biopsy was requested prior to entry and after 24 months of treatment. Results: Attendance at scheduled clinic visits and adherence with study medication were similar in colchicine and placebo groups. Alcohol intake was less than 1 drink per day in 69% of patients. In an intention-to-treat analysis, all-cause mortality was similar in colchicine (49%) and placebo (45%) patients (P = .371). Mortality attributed to liver disease was 32% in colchicine and 28% in placebo patients (P = .337). Fewer patients receiving colchicine developed hepatorenal syndrome. In 54 patients with repeat liver biopsies after 24 or more months of treatment, cirrhosis improved to septal fibrosis in 7 patients (3 colchicine, 4 placebo) and to portal fibrosis in 1 patient (colchicine). Conclusions: In patients with advanced alcoholic cirrhosis, colchicine does not reduce overall or liver-specific mortality. Liver histology improves to septal fibrosis in a minority of patients after 24 months of treatment, with similar rates of improvement in patients receiving placebo and colchicine. Colchicine is not recommended for patients with advanced alcoholic cirrhosis.

The mechanical origins of the obstruction in sinusoidal obstruction syndrome are initiated by dehiscence of sinusoidal endothelial cells from the space of Disse. The biochemical changes that permit the dehiscence of the sinusoidal endothelial cells were investigated.In vitro and in vivo studies examined changes induced by monocrotaline, a pyrrolizidine alkaloid that induces sinusoidal obstruction syndrome in both humans and experimental animals.In the monocrotaline-induced rat model of sinusoidal obstruction syndrome, there was an early increase of matrix metalloproteinase-9 and a later, lower-magnitude increase of matrix metalloproteinase-2 in the liver. In vitro studies of sinusoidal endothelial cells, hepatocytes, stellate cells, and Kupffer cells showed that sinusoidal endothelial cells are the major source of both basal and monocrotaline-induced matrix metalloproteinase-9/matrix metalloproteinase-2 activity. Monocrotaline caused depolymerization of F-actin in sinusoidal endothelial cells, and blocking of F-actin depolymerization prevented the increase in matrix metalloproteinase activity. Administration of matrix metalloproteinase inhibitors prevented the signs and histological changes associated with sinusoidal obstruction syndrome.Monocrotaline causes depolymerization of F-actin in sinusoidal endothelial cells, which leads to increased expression of metalloproteinase-9 and matrix metalloproteinase-2 by sinusoidal endothelial cells. Inhibition of matrix metalloproteinase-9 and matrix metalloproteinase-2 prevents the development of sinusoidal obstruction syndrome, establishing that matrix metalloproteinase inhibitors may be a therapeutically viable strategy for prevention.

Pseudomembranous colitis (PMC) is a frequently severe, sometimes fatal iatrogenic disease that is antibiotic-associated in almost all cases. The most common clinical features of PMC include abdominal pain, watery diarrhea, fever, leukocytosis, hypoalbuminemia, and hypovolemia. Ascites, not considered a well-known feature of PMC, is fairly common, based on a review of the English language literature but has not been characterized fully. This case report describes 5 patients with PMC who presented with low serum-ascites albumin gradient (SAAG) and neutrocytic ascites, without evidence of infectious, malignant, or inflammatory peritoneal disease, which has not been reported previously. In 1 patient, massive low SAAG ascites was the presenting manifestation of PMC, a feature also not reported previously. Three of the 5 (60%) patients had acquired immunodeficiency syndrome. The characteristics of the fluid specimens in these 5 patients and the possible pathogenetic mechanisms are proposed. The findings suggest that PMC should be included in the differential diagnosis of low SAAG ascites, especially in patients with acquired immunodeficiency syndrome.

Background: In an ultrasound pilot study of acute alcoholic hepatitis (AAH), parallel tubular structures within the liver subsegments were observed. Pulse-Doppler flowmetry revealed that these structures were formed by a dilated hepatic arterial branch and an adjacent portal venous branch. This finding was termed the "pseudoparallel channel sign" (PPCS). The aims of this study were to assess the significance of this sign and show the characteristic ultrasound findings of AAH. Methods: PPCS was specifically searched for on ultrasonography by two physician operators in consecutive patients (77 AAH, 119 other alcoholic liver disease, 49 nonalcoholic liver disease, and 15 healthy patients). Results: PPCS was observed in 90% of patients with AAH and in 23% of patients with other alcoholic liver disease. This sign was not detected in nonalcoholic liver disease or healthy patients. Biopsy specimens were available in 100 patients, 51 of whom were patients with alcoholism. In those 51 patients, PPCS gave a sensitivity of 82%, a specificity of 87%, and an accuracy of 84% in diagnosing AAH. Patients with criteria of AAH had more segments involved with PPCS than patients without. Conclusions: PPCS may be an important diagnostic finding in AAH.

Differentiated, but not capillarized, SEC promote reversion of stellate cells (HSC) to quiescence. Capillarization precedes fibrosis In Vivo. Thus restoring SEC differentiation may promote resolution of fibrosis. This study examines whether NO maintains SEC phenotype In Vitro through the soluble guanylate cyclase (sGC)/cGMP/protein kinase G (PKG) pathway and whether In Vivo activation of sGC accelerates reversal of capillarization and cirrhosis. Methods Rat SEC were cultured for 2 days with inhibitors or agonists and examined by scanning EM for fenestrae in sieve plates, defining features of SEC differentiation. Controls: SEC cultured alone (complete defenestration) or with 40 ng/ml VEGF (fully fenestrated). Thioacetamide-induced (200mg/kg i.p. biw for 3 weeks) cirrhosis was followed by 0.3 mg/ kg p.o. BAY 60-2770 (kind gift from Bayer Schering Pharma), an NO-independent activator of sGC. Sirius red staining for fibrosis was assessed blindly (semi-quantitative score 0-6). In Vitro studies 1.SEC cultured with VEGF plus L-NAME (nitric oxide synthase inhibitor), with VEGF/ODQ (sGC inhibitor) or with VEGF/Rp-8-pCPT-PET-cGMPS (PKG inhibitor) defenestrated completely. Thus the NO/cGMP pathway is necessary to maintain fenestrated SEC. 2.SEC grown with DETA-NONOate (6μM) produced similar levels of NO and cGMP to SEC cultured with VEGF, but SEC defenestrated. SEC grown with YC-1 (sGC activator) or 8-pCPT-cGMP (cGMP analog) defenestrated. Thus the NO/cGMP pathway alone is insufficient to maintain SEC phenotype. 3.SEC grown with VEGF, L-NAME and DETA-NONOate, with VEGF, L-NAME and YC-1, or with VEGF, ODQ and 8-pCPT-cGMP remained fully fenestrated. Thus maintenance of SEC phenotype requires both VEGF and the NO/cGMP pathway. 4.BAY60-2770 alone was not sufficient to reverse HSC activation, but reversal required co-cultured SEC and was NO-independent. In Vivo studies with BAY 60-2770 1-week treatment normalized cGMP level in SEC [0.82± 0.02 fmol/μg protein in normal vs 0.83± 0.05 fmol/μg protein in treated vs 0.47±0.06 fmol/μg protein in solvent controls (p= 0.011)] and completely reversed capillarization [normal porosity 6.80 ± 0.31%; 6.24±0.37% in treated vs 3.14 ± 0.22% in solvent controls (p

Colchicine treatment was used in this randomized placebo-controlled trial in patients with severe acute alcoholic hepatitis [serum bilirubin greater than or equal to 5 mg/dL (85.5 mumol/L) mean, 17.5 +/- 7.5 mg/dL (299.25 +/- 128.25 mumol/L)]. Hospitalization mortality and morbidity and the effect on biochemical test results were the end points of the treatment. Patients in the two groups were evenly matched by demographics and laboratory test results. Mean time to study entry was less than 7 days from admission. The duration of the trial was 30 days. Thirty-six patients (24 men, 12 women) received colchicine (1 mg orally every morning) and 36 (25 men, 11 women) received an identical placebo. Seven (19%) colchicine-treated and six (17%) control patients died during the index hospitalization after a mean of 17.4 +/- 10.8 and 17.8 +/- 5.3 days, respectively (NS). During a 4-month follow-up period from entry into the trial, there were two additional deaths in each group. No differences between placebo- and colchicine-treated patients were observed in any of the laboratory parameters (serum bilirubin, aspartate transaminase, alanine transaminase, prothrombin activity, albumin, white blood cell count, hemoglobin, and creatinine) that were followed up over the 30-day treatment period. The frequency of complications did not differ statistically between the two groups. This study showed no effect of colchicine treatment on mortality and morbidity of severe alcoholic hepatitis. Colchicine cannot be recommended for the treatment of patients with alcoholic hepatitis.

Sixty-seven patients entered a double-blind, controlled trial to evaluate the efficacy of propylthiouracil treatment in severe alcoholic hepatitis. Twenty-three percent (7 of 31) given propylthiouracil and 19% (7 of 36) given placebo died during the 6-wk study. Propylthiouracil treatment did not reduce the frequency and incidence of complications in alcoholic hepatitis, but induced hypothyroidism in 4 patients. Treatment produced no beneficial effect on any of the hepatic biochemical tests. We were unable to show any beneficial effect of propylthiouracil treatment on morbidity and mortality in patients with severe acute alcoholic hepatitis.

Survival rates were compared in 82 patients who underwent therapeutic portacaval shunt. All patients were followed for at least 5 years after shunt or until death. Survival rates were calculated by Life Table methods. Based on a combination of currently accepted histological and clinical criteria, there were 45 patients with Laennec's cirrhosis, 29 patients with postnecrotic cirrhosis, 11 of whom had histological evidence of chronic active hepatitis, and 8 patients with primary biliary cirrhosis. Survival rates were similar in all three groups, alcoholic cirrhosis, postnecrotic cirrhosis, and primary biliary cirrhosis. Hepatic reserve, as defined by Child's classification, provided the best criteria for predicting survival. The type of shunt, end-to-side, side-to-side, or splenorenal, did not influence survival. Histological evidence of chronic active hepatitis adversely affected survival in patients with postnecrotic cirrhosis. However, histological evidence of ongoing alcoholic hepatitis in patients with Laennec's cirrhosis did not influence survival adversely. The data indicate that once a patient with cirrhosis has bled from esophageal varices, the etiology of the cirrhosis is not a major factor in determining survival after a therapeutic portacaval shunt.

The overall prevalence of delta-antibody among 80 patients with chronic infection of hepatitis B virus in the Los Angeles area was found to be 24%. Twenty-three patients had a histologic diagnosis of persistent hepatitis and 57 had chronic active hepatitis with or without cirrhosis. Only 1 patient among those with persistent viral hepatitis had delta-antibody, whereas 18 with chronic active hepatitis had delta-antibody in their sera (p less than 0.05).