The Natural History of Severe Acute Liver Injury.

OBJECTIVES: Acute liver failure (ALF) is classically defined by coagulopathy and hepatic encephalopathy (HE); however, acute liver injury (ALI), i.e., severe acute hepatocyte necrosis without HE, has not been carefully defined nor studied. Our aim is to describe the clinical course of specifically defined ALI, including the risk and clinical predictors of poor outcomes, namely progression to ALF, the need for liver transplantation (LT) and death. METHODS: 386 subjects prospectively enrolled in the Acute Liver Failure Study Group registry between 1 September 2008 through 25 October 2013, met criteria for ALI: International Normalized Ratio (INR)≥2.0 and alanine aminotransferase (ALT)≥10 × elevated (irrespective of bilirubin level) for acetaminophen (N-acetyl-p-aminophenol, APAP) ALI, or INR≥2.0, ALT≥10x elevated, and bilirubin≥3.0 mg/dl for non-APAP ALI, both groups without any discernible HE. Subjects who progressed to poor outcomes (ALF, death, LT) were compared, by univariate analysis, with those who recovered. A model to predict poor outcome was developed using the random forest (RF) procedure. RESULTS: Progression to a poor outcome occurred in 90/386 (23%), primarily in non-APAP (71/179, 40%) vs. only 14/194 (7.2%) in APAP patients comprising 52% of all cases (13 cases did not have an etiology assigned; 5 of whom had a poor outcome). Of 82 variables entered into the RF procedure: etiology, bilirubin, INR, APAP level and duration of jaundice were the most predictive of progression to ALF, LT, or death. CONCLUSIONS: A majority of ALI cases are due to APAP, 93% of whom will improve rapidly and fully recover, while non-APAP patients have a far greater risk of poor outcome and should be targeted for early referral to a liver transplant center.

Rituximab-associated hepatitis B virus (HBV) reactivation in lymphoproliferative diseases: meta-analysis and examination of FDA safety reports.

BACKGROUND: Rituximab has been associated with hepatitis B virus reactivation (HBV-R). However, the characteristics and scope of this association remain largely undefined. METHODS: We completed a comprehensive literature search of all published rituximab-associated HBV-R cases and from the Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) MedWatch database. Literature and FDA cases were compared for completeness, and a meta-analysis was completed. RESULTS: One hundred and eighty-three unique cases of rituximab-associated HBV-R were identified from the literature (n = 27 case reports, n = 156 case series). The time from last rituximab to reactivation was 3 months (range 0-12), although 29% occurred >6 months after last rituximab. Within FDA data (n = 118 cases), there was a strong signal for rituximab-associated HBV-R [proportional reporting ratio = 28.5, 95% confidence interval (CI) 23.9-34.1; Empiric Bayes Geometric Mean = 26.4, 95% CI 21.4-31.1]. However, the completeness of data in FDA reports was significantly inferior compared with literature cases (P < 0.0001). Among HBV core antibody (HBcAb(+)) series, the pooled effect of rituximab-based therapy showed a significantly increased risk of HBV-R compared with nonrituximab-treated patients (odds ratio 5.73, 95% CI 2.01-16.33; Z = 3.33, P = 0.0009) without heterogeneity (χ(2) = 2.12, P = 0.5473). CONCLUSIONS: The FDA AERS provided strong HBV-R safety signals; however, literature-based cases provided a significantly more complete description. Furthermore, meta-analysis of HBcAb(+) series identified a more than fivefold increased rate of rituximab-associated HBV-R.

An analysis of acute changes in interleukin-6 levels after treatment of hepatitis C with consensus interferon.

Cytokine production has been implicated in the antiviral response to interferon-alpha (IFN-alpha) in hepatitis C and in the development of IFN-alpha-related side effects. We characterized acute changes in serum cytokine levels following administration of a single dose of consensus IFN (IFN-con1) and during continuous treatment of chronic hepatitis C patients. Serum samples were collected at baseline, at multiple times early after IFN administration, and weekly thereafter. Viral RNA titers were assessed by RT-PCR, and viral kinetics were followed. ELISA assays were used to measure IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-16. Serum cytokine levels were low at baseline. IL-6 was detected in patients with hepatitis C but not in healthy control subjects by either ELISA or RT-PCR, indicating that low levels of circulating IL-6 were associated with hepatitis C infection. None of the cytokines measured increased significantly after IFN administration except for IL-6. IL-6 levels rose rapidly, peaked at 6-15 h in a dose-dependent manner, and returned to baseline by 48 h in both patients receiving a single dose of IFN and those receiving continuous treatment. This was confirmed by RT-PCR. Pretreatment IL-6 levels were directly correlated with area under the curve (AUC) for IL-6 during the 24 h after IFN dosing (r = 0.611, p = 0.007). Viral titers decreased within 24-48 h after a single dose of IFN-con1. Changes in hepatitis C RNA titers were not significantly associated with pretreatment IL-6 levels or with changes in IL-6 levels. In conclusion, (1) baseline serum cytokine levels, except for IL-6, were low or within the normal range in patients with hepatitis C, (2) IL-6 levels were detected in some patients with hepatitis C before treatment but not in healthy controls, (3) IL-6 levels increased acutely after a single dose of IFN-alpha, and IL-6 induction was related to baseline IL-6 level, and (4) changes in IL-6 levels did not correlate with the early virologic response to IFN.

D-xylose malabsorption: characteristic finding in patients with the AIDS wasting syndrome and chronic diarrhea.

The AIDS wasting syndrome (AWS) is characterized by > 10% loss of baseline body weight during 6 months and may occur in patients with or without associated chronic diarrhea. To determine whether the presence of small-intestinal malabsorption is associated with the development of AWS in human immunodeficiency virus (HIV)-infected patients with chronic diarrhea, we retrospectively reviewed the results of D-xylose testing performed in the clinical evaluation of 21 consecutive HIV-infected patients with chronic diarrhea. A thorough search for small-intestinal pathogens was performed including upper endoscopy, duodenal biopsy, and aspirate for culture and ova and parasite examination. These studies were negative in all patients except two who were excluded from the study. In the 19 patients with no identifiable pathogens, the 1-h serum D-xylose concentration was significantly lower in patients with AWS than in those without, 8.3 +/- 0.8 versus 23.7 +/- 3.4 mg/dl, respectively, p < 0.001. Urine D-xylose excretion during 5 h was also significantly lower in the group with AWS, although creatinine clearance was similar in the two groups. Patients with AWS were more often refractory to standard antidiarrheal therapy with loperamide or diphenoxylate and carried a poor prognosis (90% mortality at 1 year versus 22% mortality in the group without AWS). These data indicate that small intestinal malabsorption is a major component in the severe wasting seen in some HIV-infected patients with chronic diarrhea. Patients with markedly abnormal D-xylose tests may require more potent antidiarrheal therapy and are expected to have a high mortality as a possible consequence of intestinal dysfunction.

Spontaneous bacterial peritonitis: an update on evaluation, management, and prevention.

Spontaneous bacterial peritonitis (SBP) is a serious complication in patients with cirrhotic ascites. Greater understanding of the pathogenesis and risk factors for the development of SBP recently has improved our ability to prevent and treat the infection. The decreased threshold for performing diagnostic paracentesis in cirrhotic patients coupled with the use of non-nephrotoxic antibiotics have resulted in decreasing mortality rates for patients with SBP. Despite these advances, recurrence is common and often fatal. Thus, the prevention of SBP by diuresis and oral antibiotic prophylaxis has recently been studied. This review summarizes the recent developments in SBP, with an emphasis on patient management and prevention of SBP.

Protein C deficiency in splanchnic venous thrombosis.

Deficiencies of protein C activity and antigen were observed in eight consecutive patients with splanchnic venous thrombosis. There was a significant reduction in the ratio of protein C to factor X. Six of the eight patients had a decrease in antithrombin III, but free protein S antigen was within normal limits in all but two subjects. It is proposed that a thrombogenic stimulus such as stasis, altered hormonal milieu, or failure of hepatic clearance of activated coagulants results in consumption of protein C and antithrombin III, predisposing to splanchnic venous occlusion. This further impairs hepatic function, prevents restitution of protein C and antithrombin levels, and promotes continuing venous thrombosis. Thus, a vicious cycle of thrombosis and hepatic damage is perpetuated.

Daily interferon therapy for hepatitis C virus infection in liver transplant recipients.

BACKGROUND: Hepatitis C virus infection persists after liver transplantation and causes recurrent liver injury in the majority of patients. Standard dose interferon therapy has been largely unsuccessful for hepatitis C in transplant recipients. METHODS: Twelve patients, at least 7 months posttransplant, with detectable hepatitis C virus RNA in serum and features of hepatitis C on liver biopsy were randomized to interferon-alpha2a, 3 mU daily for 12 months (n=8) or no treatment (n=4). The tolerability of daily interferon dosing in liver transplant recipients was evaluated and effects on hepatitis C virus RNA level, quasispecies evolution, and liver histology were studied. RESULTS: Treated patients had an improvement in histological activity index at the end of therapy relative to controls (median reduction of 2 versus median increase of 1.5) (P=0.04). Four treated patients had a virological response (all bDNA negative, one qualitative polymerase chain reaction negative) compared with none of the untreated patients. Only two of six treated patients tested had evidence of quasispecies diversification on therapy. Seven of eight patients in the treatment group required dose reduction for fatigue and/or depression. They tolerated 1.5 mU of interferon-alpha2a daily. Two treated patients developed graft dysfunction, one of who had histological evidence of rejection and subsequent graft loss. CONCLUSIONS: Low daily doses of interferon were tolerated by liver transplant recipients and provided histological benefit without associated quasispecies diversification in most cases. These findings provide a rationale to study low dose daily or pegylated interferon maintenance therapy for the management of hepatitis C posttransplant.

Metallopanstimulin is overexpressed in a patient with colonic carcinoma.

BACKGROUND: Human metallopanstimulin (MPS-1) is a 9.4-kDa multifunctional ribosomal S27 nuclear "zinc finger" protein which is expressed in a wide variety of actively proliferating cells and tumor tissues. In this paper, we present a case of overexpression of MPS-1 in colon cancer tissues of a seventeen year old male. METHODS: Biopsies at the anastomosis and adjacent normal colonic mucosa were obtained by colonoscopy twelve months after right hemicolectomy for an ascending colon well differentiated adenocarcinoma. Immunohistochemical localization of MPS-1 protein was performed by using specific anti-MPS-1 antibodies directed against the N-terminal region of this protein. RESULTS: Immunohistochemistry demostrated an overexpression of MPS-1 in colonic mucosa crypts in the samples obtained at the anastomosis. In contrast, no expression of MPS-1 was observed in the adjacent normal mucosa. Histopathology performed with hematoxilin and eosin staining revealed focal crypt distortion and proliferation, but no carcinoma. CONCLUSIONS: In this case, the overexpression of MPS-1 was a more definitive evidence of malignant transformation than histology, as demonstrated by the clinical course of the disease. The results support the hypothesis that increased levels of tissue MPS-1 may correlate with a more aggressive behavior of colon malignancy.

Swallowing disorders and nutritional support.

Evaluation of nutritional needs in patients with swallowing disorders should include a global assessment. This includes a nutritional assessment, a determination of the metabolic state, and a separation of the causes of nutrient deficits due to the patient's underlying disease(s) from diminished nutrient intake related to the dysphagia. Techniques for intense nutritional support are surveyed, and the complications of each are discussed.

Management of hepatocellular carcinoma: staging and treatment.

Hepatocellular carcinoma (HCC) is a common malignancy worldwide. Viral hepatitis B and C and cirrhosis are the most important risk factors. The two most established methods of screening are ultrasound and alpha-fetoprotein serum levels followed serially. The intervals of testing and cost efficacy have not yet been established. When HCC is discovered staging is important in order to guide treatment. Assessment for portal vein patency by ultrasonography and dynamic CT are noninvasive and sensitive. Magnetic resonance imaging and lipiodol CT are also helpful. The treatment depends on the patient's clinical condition related to liver function and other comorbid conditions and the number, size, and location of the lesions. The roles of tumor resection, liver transplantation, percutaneous alcohol injection, transarterial chemoembolization, and systemic chemotherapy are dependent on staging. Careful selection of patients and combined treatment modalities may be the keys to improve survival.

Brain edema in rabbits with galactosamine-induced fulminant hepatitis. Regional differences and effects on intracranial pressure.

Brain edema and intracranial hypertension are major complications of fulminant hepatic failure. We investigated the development of brain edema and monitored intracranial pressure in rabbits with toxic hepatitis induced by galactosamine. Using a gravimetric technique to assay small tissue samples, we found that brain water was increased in cortical grey matter, but not in subcortical, mesencephalic, and pontine white matter, or in the cerebellum. The proportion of water in cerebral grey matter in control animals was 80.96% +/- 0.49% with significant elevations to 81.96% +/- 0.47% and 82.95% +/- 1.49% in mild and severe encephalopathy, respectively. This corresponds to mean increases in tissue volume of 5.5% and 11.7%. The hippocampal grey matter also accumulated water in severe encephalopathy with a 30% increase in mean tissue volume. The regional increase in brain water was confirmed by the wet-dry weight method. Neither hypotension, hypoxia, nor severe hypoglycemia were present to account for the edema. Intracranial pressure was monitored continuously in unanesthetized rabbits via an intraventricular cannula as encephalopathy developed. The pressure was normal in the mild stage, but was intermittently elevated in animals with severe encephalopathy. The normal range of intracranial pressure was 2-9 mmHg and the range of peak values in galactosamine-treated rabbits was 18-55 mmHg. The regional differences in brain water accumulation suggest that cellular swelling and abnormalities in the movement of water across the blood-brain barrier may account for the brain edema in this model.

Hemodynamic and renal effects of atrial natriuretic factor in portal hypertensive rats. Potentiation by Phe-Ile-Orn-vasopressin.

The effects of atrial natriuretic factor (ANF) on splanchnic hemodynamics and renal function in portal hypertensive models are described incompletely. Furthermore, ANF-induced vasodilatation and hypotension may limit the assessment of its own renal physiological effects. We infused ANF (human ANF 102-126) to anesthetized portal vein-ligated rats, a model with prehepatic portal hypertension. Arterial pressure was reduced by 17%, but portal pressure was unaffected. Diuresis and natriuresis were explained in part by an increase in glomerular filtration rate; in addition, renal vascular resistance was significantly decreased. The natriuretic response to ANF was slightly, but significantly, decreased in portal hypertensive rats as compared to controls (fractional excretion of sodium, 1.8 +/- 0.4 vs. 2.9 +/- 0.3; P less than .05). The addition of Phe-Ile-Orn-vasopressin, a V1 receptor agonist, normalized arterial pressure but induced a significant decrease in portal pressure (15 +/- 0.9 mm Hg base line vs. 12.8 +/- 0.7 combination group; P less than .01). Furthermore, the combination of both drugs markedly potentiated the natriuretic effects (0.4 +/- 0.1 microEq/min of control vs. 10.0 +/- 2.3 ANF vs. 32.2 +/- 3.3 combination group; P less than .001). The natriuretic potentiation resulted from increments in glomerular filtration rate and renal blood flow. Normalization of arterial pressure may enhance the renal physiological effects of ANF, in this portal hypertensive model.

Autoimmune hepatitis: a histological variant associated with prominent centrilobular necrosis.

A patient presented with pruritus and recent elevation of aminotransferases. The case fulfilled most of the criteria for the diagnosis of autoimmune hepatitis and achieved clinical and complete biochemical response to steroid therapy. However, the liver biopsy specimen revealed an unusual histological pattern consisting of severe centrilobular necrosis demarcated by a thin rim of hepatitic reaction. In contrast, the portal tracts appeared almost normal. This histological appearance has not been associated with autoimmune hepatitis. This presentation and the histology may represent an early pattern of autoimmune injury to the liver.

Effect of body temperature on brain edema and encephalopathy in the rat after hepatic devascularization.

Brain edema is a fatal complication of fulminant hepatic failure and its pathogenesis remains unclear. To determine its presence in a model of ischemic hepatic failure, rats were subjected to a portacaval anastomosis followed by hepatic artery ligation. Brain water was measured using the sensitive gravimetric method. Preliminary studies revealed marked hypothermia in devascularized animals kept at room temperature (26.9 degrees +/- 2.8 degrees C). An additional group of devascularized rats was kept in an incubator. As expected for hypothermia, such animals had a lower arterial pressure and heart rate; the duration of encephalopathy was markedly prolonged. Water content of the cortical gray matter was only increased in normothermic devascularized rats: 80.14% +/- 0.31%, normal; 80.06% +/- 0.22%, portacaval shunt only; 80.42% +/- 0.26%, devascularized at room temperature; 81.29% +/- 0.38%, devascularized at controlled temperature (p less than 0.001). Such differences could not be detected using the dry-weight technique in whole cerebral hemispheres. Astrocyte changes in the cortical gray matter were noted in both edematous and nonedematous devascularized groups, coupled with the presence of vesicles containing horseradish peroxidase in the endothelial capillary cell. This suggests that in this model, brain edema may be due to both a cytotoxic mechanism and changes in the permeability of the blood-brain barrier. Future studies with this widely used model will require strict control of temperature to allow interpretation of experimental results. A therapeutic role for hypothermia in the management of brain edema deserves further attention.

Electron microscopic evaluation of brain edema in rabbits with galactosamine-induced fulminant hepatic failure: ultrastructure and integrity of the blood-brain barrier.

Brain edema is a major complication of fulminant hepatic failure and is responsible for death in a large percentage of patients. We previously demonstrated the progressive accumulation of water in grey matter areas of the brain in the rabbit with galactosamine-induced fulminant hepatic failure. We now report the electron microscopic morphology of the brain in the same model of acute hepatic failure following the intravenous injection of horseradish peroxidase, an intravascular tracer which forms an electron-dense reaction product. Rabbits with both mild and severe encephalopathy had normal blood pressures and blood gases at the time of study. Fixation of brain tissue was obtained by whole-body perfusion. Marked swelling of the cytoplasm, perineuronal and perivascular processes of astrocytes were noted in cortical gray, but not white, matter areas; the other cellular components of the brain had normal morphology. Capillary endothelial cells were normal, and there was no evidence of horseradish peroxidase in endothelial cell vesicles, basement membranes or the brain parenchyma, suggesting that the blood-brain barrier was impermeable to large molecules. Histologic evidence of brain edema is seen in this model, with swelling of astrocytes as the primary manifestation of the accumulation of water. Damage to astrocytes or inhibition of their function may contribute to the pathogenesis of hepatic encephalopathy in this model.

Randomized, double-blind study of intravenous human albumin in hypoalbuminemic patients receiving total parenteral nutrition.

OBJECTIVE: To determine whether replacement of human albumin will improve a patient's prognosis. DESIGN: A randomized, double-blind, controlled study in which 25 g of human albumin vs. placebo was administered intravenously daily. SETTING: A university-affiliated hospital. PATIENTS: Thirty-six patients with hypoalbuminemia (serum albumin of <2.5 g/dL), receiving total parenteral nutrition. None of the patients had known cancer, cirrhosis, or nephrotic syndrome. INTERVENTIONS: Each patient received at least 6 days of therapy (6 to 24 days of albumin; 7 to 32 days of placebo). Four subjects were excluded from the study since they received therapy for <6 days. One patient was excluded from the study after nephrotic syndrome was identified. Albumin metabolic rates for those patients receiving albumin were estimated using the formula: Metabolism of albumin = 25 g/day + (albumin 1 - albumin 2)(Vd)/days, where albumin 1 and 2 are the serum albumin concentrations (g/L) at the beginning and end of the serum sampling intervals, respectively; Vd is the volume of distribution (L); and days relates to the number of days of the sampling interval. MEASUREMENTS AND MAIN RESULTS: Sixteen patients received albumin; 15 patients received placebo. One patient receiving placebo and two patients receiving albumin died within 30 days. One patient who received placebo and three patients who received albumin developed sepsis or bacteremia; four patients who received placebo and seven patients who received albumin developed pneumonia during the study (NS). The serum albumin increased in all patients receiving intravenous albumin, but one patient received intravenous albumin for only 6 days. The mean serum albumin concentration increased by 1.42 g/dL in the albumin patients, and increased by 0.29 in the placebo patients (p < .0001 by unpaired t-test). Mean initial albumin metabolism was 17.4 g/day (0.3 g/kg/day). At the end of therapy, albumin metabolism was 20.5 g/day (0.36 g/kg/day) (paired t-test, p = .4, NS). CONCLUSIONS: a) The administration of intravenous albumin to hypoalbuminemic patients receiving total parenteral nutrition does not improve morbidity or mortality. b) Albumin metabolic rates, initially related to the catabolic state, are high; later, these rates are high related to filling of the albumin space and gluconeogenesis. c) On the basis of the high albumin catabolic rates at the end of the infusion, doses of albumin of <25 g/day might be sufficient to replace albumin stores.

Transjugular intrahepatic portosystemic shunt in nonliver transplant candidates: is it indicated?

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is an effective treatment of severe portal hypertension complications. Liver transplantation (LT) candidacy has not been a prerequisite to TIPS placement in some medical centers. OBJECTIVES: To investigate the outcome and survival of non-LT candidates after TIPS. METHODS: From November 1991 to February 1994, all patients referred for TIPS placement were evaluated for LT candidacy. Exclusions for LT included: age (> 70 yr), other significant medical conditions, or noncompliance. Indications for TIPS included refractory variceal bleeding during an acute bleed, recurrent bleeding after more than or equal to four sessions of sclerotherapy, or refractory ascites. RESULTS: Sixty patients received TIPS. Nineteen were considered non-LT candidates. Over a 2-yr follow-up, 14 of these non-LT candidates did not survive. Their median age was 63.5 compared with 56.5 yr for LT candidate nonsurvivors (p < 0.05). Among the 14 non-LT candidate nonsurvivors, 10 were Childs C class, and eight had emergent TIPS placement. The 2-year mortality rate was 84% for non-LT candidates versus 24% for LT candidates. Median survival time for non-LT candidates was 2.6 months compared with 20 months in the LT candidates (p < 0.001). Only one death was due to a TIPS-related complication. CONCLUSIONS: TIPS is unquestionably an advancement in the management of patients with portal hypertension complications. Non-LT candidates, compared with LT candidates, tended to be older and of a Child-Pugh C class, and they had survival rates often less than 90 days post-TIPS. Given these high mortality rates, we need to address whether TIPS is indicated in these non-LT candidates.

Hemodynamic evaluation of isosorbide dinitrate in alcoholic cirrhosis. Pharmacokinetic-hemodynamic interactions.

Isosorbide dinitrate, a long-acting organic nitrate, has been shown to decrease portal pressure in the experimental animal and humans. We conducted a double-blind randomized hemodynamic evaluation of the effects of placebo and 10 mg and 20 mg isosorbide dinitrate in stable individuals with alcoholic cirrhosis. Baseline values for all three groups were similar. Isosorbide dinitrate resulted in a peak reduction of the hepatic venous gradient of 24.7% +/- 3.0%, with significantly decreased values 4 h after the administration of the 20-mg dose. A reduction of arterial pressure and cardiac index (peak decrease of 25.7% +/- 1.5%) was well tolerated by 13 of 15 patients. Changes in mean arterial pressure were not predictive of modifications in the hepatic vein wedge pressure. There was no relation between the area under the plasma isosorbide dinitrate concentration curve and hemodynamic changes. Levels of isosorbide-5-mononitrate, a vasoactive metabolite, were detectable for an 8-h period. Isosorbide dinitrate significantly reduced portal pressure in stable cirrhotics, in association with systemic hemodynamic changes. Thus, titration of isosorbide dinitrate is required to maximize hemodynamic benefits in individual patients. As the decrease in portal pressure is more predictable than the effect of previously tested pharmacologic agents, isosorbide dinitrate should be evaluated for its efficacy in the management of portal hypertension.

Differential expression of metallopanstimulin/S27 ribosomal protein in hepatic regeneration and neoplasia.

We have previously shown that human metallopanstimulin-1 (MPS-1) is a ubiquitous 9.4-kd multifunctional ribosomal S27/nuclear "zinc finger" protein that is expressed at high levels in a wide variety of actively proliferating cells and tumor tissues. In this study, we examined the expression of MPS-1 in chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Tissue samples were obtained at the time of tumor resection, needle biopsy, or liver transplantation. MPS- 1 was studied by immunohistochemistry by use of specific antibodies to the N-terminus of MPS-1 in a biotin/streptavidin-amplified system. In chronic hepatitis, hepatocytes had very weak MPS-1 immunostaining. In contrast, hepatocytes in regenerating cirrhotic nodules stained strongly for MPS-1. In well-differentiated hepatocellular carcinoma, MPS-1 presence was intense at the periphery of the malignant nodule. In poorly differentiated hepatocellular carcinoma, MPS-1 presence was notably intense in malignant hepatocytes invading the septal tissues, in close contact with neovascular structures. These results suggest that MPS-1 may be involved in both progression toward malignancy in regenerating cirrhotic nodules and in subsequent steps of hepatocarcinogenesis.