Acute liver failure

Hepatocyte transplantation in acute liver failure

The majority of patients with acute liver failure (ALF) die waiting for orthotopic liver transplantation (OLT). No other treatment modality is shown to improve survival. This study was conducted to assess the safety and feasibility of hepatocyte transplantation (HT) and subsequent engraftment and function of donor cells. Functional and structural integrity of cryopreserved and thawed human hepatocytes were assessed by their morphological characteristics, induction of P-4501A1 transcription, and survival in vivo by xenotransplantation into rats. Five patients with severe ALF underwent intrasplenic (4 patients) and/or intrahepatic (2 patients) HT through angiography under cyclosporine immunosuppression. All patients had grade III to IV encephalopathy and factor V levels less than 0.5 U/mL, were ventilator and dialysis dependent, and were not OLT candidates. Three of the 5 patients who survived 48 hours after HT had substantial improvement in encephalopathy scores, arterial ammonia levels, and prothrombin times. Clinical improvement was paralleled by an increase in aminopyrine and caffeine clearances. All 3 patients lived substantially longer than expected based on clinical experience after HT (12, 28, and 52 days) but eventually died. Postmortem examination showed the presence of transplanted hepatocytes in liver and spleen by light microscopy and fluorescent in situ hybridization (FISH). Cryopreserved and thawed human hepatocytes can be transplanted into recipients with ALF with some acceptable but definite complications. Engraftment of donor hepatocytes was proven by histological examination and FISH by both transjugular biopsy and at autopsy. Improvement in brain edema, encephalopathy grade, and clearance of antipyrine and caffeine suggested function, albeit with a 24- to 72-hour delay posttransplantation.

Liver transplantation. American Association for the Study of Liver Diseases

Liver transplantation has revolutionized the care of patients with end-stage liver disease. Liver transplantation is indicated for acute or chronic liver failure from any cause. Because there are no randomized controlled trials of liver transplantation versus no therapy, the efficacy of this surgery is best assessed by carefully comparing postoperative survival with the known natural history of the disease in question. The best examples of this are in primary biliary cirrhosis and primary sclerosing cholangitis, for which well-validated disease-specific models of natural history are available. There are currently relatively few absolute contraindications to liver transplantation. These include severe cardiopulmonary disease, uncontrolled systemic infection, extrahepatic malignancy, severe psychiatric or neurological disorders, and absence of a viable splanchnic venous inflow system. One of the most frequently encountered contraindications to transplantation is ongoing destructive behavior caused by drug and alcohol addiction. The timing of the surgery can have a profound impact on the mortality and morbidity of patients undergoing liver transplantation. Because of the long waiting lists for donor organs, the need to project far in advance when transplantation might be required has proven to be one of the greatest challenges to those treating patients with end-stage liver disease. Three important questions must be addressed in a patient being considered for liver transplantation: (1) when should the patient be referred for possible transplantation? (2) when should the patient be listed for transplantation? and (3) when is the patient too sick to have a reasonable chance of surviving the perioperative period?

Living-related liver transplantation for patients with fulminant and subfulminant hepatic failure

The prognosis for patients with fulminant (FHF) or subfulminant hepatic failure (SFHF) has improved since the introduction of liver transplantation. However, the death rate of patients awaiting liver transplantation is high, possibly because of the difficulty in obtaining grafts in a timely manner, given the relative shortage of cadaveric donors. Between June 1990 and June 1999, 106 patients underwent living-related liver transplantation (LRLT) at Shinshu University Hospital. Among them, 8 patients had FHF and 6 had SFHF; these 14 patients are the subjects of this report. The graft volumes (GV) ranged from 231 mL to 625 mL, corresponding to 35% to 105% of the recipients' standard liver volume (SLV). The postoperative courses of all donors were uneventful. Following liver transplantation, all grafts functioned favorably, with normalization of serum total bilirubin within 3 to 5 days and normalization of coagulation profiles within 4 to 7 days. Thirteen of the 14 recipients are still alive. The actuarial 6-month, 1-year, and 5-year survival rates were 100%, 90%, and 90%, respectively. In the present study, when the ratio of the GV to the recipient's SLV was more than 35%, the graft was able to support the patient's metabolic demand after liver transplantation for FHF or SFHF. Because of the urgent nature of liver transplantation in this clinical condition, concerns over informed consent may be even greater than for elective LRLT. Nevertheless, the high success rate and low donor risk may justify this option for pediatric patients, as well as for a limited population of adult patients suffering from FHF or SFHF.

Auxiliary partial orthotopic liver transplantation for acute liver failure in two children

Acute liver failure in children and adults is associated with a high mortality rate. At present the treatment of choice is orthotopic whole-liver transplantation. However, allogeneic liver transplantation necessitates lifelong immunosuppressive therapy, which is associated with substantial risks to the patient. Temporary auxiliary partial orthotopic liver transplantation has been developed recently as an alternative, enabling the native liver to regenerate while avoiding the risks of long-term immunosuppressive treatment. Here we describe two cases of partial orthotopic liver transplantation in children. Auxiliary partial orthotopic liver transplantation was performed in two boys (5 and 6 years old) suffering from acute liver failure of unknown origin. The native left lateral liver lobes (segment II and II) were removed and replaced by left lateral liver grafts from young blood-group-compatible adults. In the first child the native liver, which was 80% necrotic at time of transplantation, showed regeneration within two weeks and the partially necrotic graft could be surgically removed on day 15 after auxiliary transplantation. Four years after transplantation, the child is in excellent condition with normal liver function and does not require any treatment. In the second case the native liver (90% necrotic at time of transplantation) regenerated within 6 weeks of transplantation, at which time the transplanted liver was removed. The patient developed aplastic anemia and died 2 months after transplantation from candida sepsis. The conclusion was that auxiliary partial liver transplantation in childhood provides a valuable option to maintain liver function in acute liver failure until functional recovery of the native liver. The main advantage over whole-liver transplantation is the chance to avoid lifelong immunosuppression. However, there is a higher surgical risk. Therefore, auxiliary transplantation should be considered carefully in every case of acute liver failure in children.

Acute liver failure associated with prolonged use of bromfenac leading to liver transplantation. The Acute Liver Failure Study Group

Bromfenac, a nonnarcotic analgesic nonsteroidal anti-inflammatory drug, was associated with reversible, minor elevations in serum aminotransferase levels during clinical trials. The aim of this study is to describe the clinical, laboratory, and histological features of 4 patients with severe bromfenac hepatotoxicity identified at 3 tertiary care centers participating in the US Acute Liver Failure Study Group. Bromfenac was administered for chronic musculoskeletal disorders to 4 women in therapeutic doses of 25 to 100 mg/d for a minimum of 90 days. All patients reported a prodrome of malaise and fatigue and presented with severe, symptomatic hepatocellular injury with associated hypoprothrombinemia. None of the subjects had underlying liver or kidney disease, and there was no evidence of a hypersensitivity reaction. Other identifiable causes of acute liver failure were uniformly excluded. Despite supportive measures, all the subjects developed progressive liver failure over 5 to 37 days, leading to emergency liver transplantation in 3 patients and death in 1 patient while awaiting transplantation. Extensive confluent parenchymal necrosis that appeared to begin in the central zones and was accompanied by a predominantly lymphocytic infiltrate was noted in all the livers examined. Nodular regeneration was seen in the 2 patients with a more protracted clinical course. Administration of therapeutic doses of bromfenac for greater than 90 days was associated with the development of acute liver failure leading to liver transplantation or death in 4 adult women. The poor outcomes observed in this series, coupled with the inability to identify individuals at risk for severe, idiosyncratic bromfenac hepatotoxicity, preclude further use of bromfenac in the medical community.

Biphasic effect of colchicine on acute liver injury induced by carbon tetrachloride or by dimethylnitrosamine in mice

BACKGROUND/AIMS

The effects of colchicine on acute liver injury induced by carbon tetrachloride or by dimethylnitrosamine in mice were examined.

METHODS

Nonlethal acute liver injury was induced in male BALB/c mice by a single intraperitoneal injection of 0.8 ml/kg carbon tetrachloride or 15 mg/kg dimethylnitrosamine. 0.6 mg/kg colchicine was administered 18 h or 2 h intraperitoneally before hepatotoxin treatment.

RESULTS

Reversible centrilobular to mid-zone necrosis and apoptosis occupying half the liver lobular area was evoked by carbon tetrachloride, and dimethylnitrosamine, respectively. Administration of colchicine 18 h before hepatotoxins markedly suppressed liver injury, whereas colchicine administration 2 h before the hepatotoxins accelerated it. The hepatoprotective effect evoked by colchicine was due to reduction in liver cytochrome P450 content and P450 2E1 activity. In contrast, the hepatodestructive effect seen in the carbon tetrachloride model was related to the extent of lipid peroxidation promoting plasma membrane destruction, while the hepatodestructive effect in the dimethylnitrosamine model was due to suppression of Bcl-X(L) expression, leading to acceleration of apoptosis.

CONCLUSIONS

A biphasic effect of colchicine on carbon tetrachloride- and dimethylnitrosamine-induced acute liver injury was seen. The time interval between colchicine administration and the hepatotoxin treatment is crucial to the subsequent development of liver lesions.

The Significance of Hepatitis G Virus in Serum of Patients With Sporadic Fulminant and Subfulminant Hepatitis of Unknown Etiology

Excluding acute hepatic failure caused by drugs, the etiology of fulminant hepatitis (FH) remains unknown in many patients. There are conflicting data about a possible pathogenic role for the hepatitis G virus (HGV) in patients with cryptogenic fulminant hepatitis (non–A-E FH). We investigated the presence of circulating HGV in 36 patients with well-documented non–A-E fulminant and 5 patients with subfulminant hepatitis from 3 geographic locations in the United States. Serum HGV RNA was determined by reverse transcriptase-polymerase chain reaction using primers from the NS5 region of the HGV genome. HGV RNA was also measured before and after liver transplantation in 5 patients and at different time points in 7 patients. Serum samples were recoded and reanalyzed for HGV RNA using different primer sets to assess the validity of the HGV RNA assay. HGV was present in serum of 14 of the 36 patients (38.8%) with non–A-E fulminant hepatitis. Twenty percent of patients from the Northeast, 11% of the patients from the Southeast, and 50% from the Mid-Atlantic regions of the United States had circulating HGV RNA. The use of therapeutic blood products was significantly associated with the presence of serum HGV RNA (P < .02). Retesting for HGV RNA with different primers was positive in all but 1 case. HGV RNA is not causally related to non–A-E fulminant hepatitis. The finding of HGV RNA in serum from these patients is likely related to the administration of blood product transfusion after the onset of fulminant hepatitis.

The Significance of Hepatitis G Virus in Serum of Patients With Sporadic Fulminant and Subfulminant Hepatitis of Unknown Etiology

Excluding acute hepatic failure caused by drugs, the etiology of fulminant hepatitis (FH) remains unknown in many patients. There are conflicting data about a possible pathogenic role for the hepatitis G virus (HGV) in patients with cryptogenic fulminant hepatitis (non–A-E FH). We investigated the presence of circulating HGV in 36 patients with well-documented non–A-E fulminant and 5 patients with subfulminant hepatitis from 3 geographic locations in the United States. Serum HGV RNA was determined by reverse transcriptase-polymerase chain reaction using primers from the NS5 region of the HGV genome. HGV RNA was also measured before and after liver transplantation in 5 patients and at different time points in 7 patients. Serum samples were recoded and reanalyzed for HGV RNA using different primer sets to assess the validity of the HGV RNA assay. HGV was present in serum of 14 of the 36 patients (38.8%) with non–A-E fulminant hepatitis. Twenty percent of patients from the Northeast, 11% of the patients from the Southeast, and 50% from the Mid-Atlantic regions of the United States had circulating HGV RNA. The use of therapeutic blood products was significantly associated with the presence of serum HGV RNA (P &lt; .02). Retesting for HGV RNA with different primers was positive in all but 1 case. HGV RNA is not causally related to non–A-E fulminant hepatitis. The finding of HGV RNA in serum from these patients is likely related to the administration of blood product transfusion after the onset of fulminant hepatitis.

Azoxymethane-induced fulminant hepatic failure in C57BL/6J mice: characterization of a new animal model

Without transplantation, approximately 50-90% of all patients with fulminant hepatic failure (FHF) die. This poor outcome is due in part to the absence of an appropriate animal model, which would allow for a greater understanding of the pathophysiology of this syndrome. Given the reports of liver injury in humans and livestock fed cycad palm nuts on the island of Guam, we hypothesized that the active ingredient azoxymethane (AOM) could cause FHF. We therefore evaluated AOM in C57BL/6J mice. Histologically, we observed microvesicular steatosis 2 h, sinusoidal dilatation 4 h, and centrilobular necrosis 20 h after AOM administration, and transmission electron microscopy showed that this agent causes mitochondrial injury. FHF was associated with all four stages of encephalopathy, as well as by a prodromal period of decreased eating and drinking lasting approximately 15 h before the development of stage I encephalopathy (i.e., loss of scatter reflex). Late encephalopathy was associated with increased arterial ammonia, decreased serum glucose, and evidence of brain edema (astrocyte swelling). We show that AOM-induced FHF is highly reproducible, without evidence of lot-to-lot variability, and is dose dependent. These findings therefore suggest that AOM is an excellent agent for the study of FHF, as well as indicate that Guamanian FHF may be due to AOM found in unwashed cycad palm nuts.

Prediction of hepatic encephalopathy in paracetamol overdose: a prospective and validated study

BACKGROUND

Paracetamol overdose may cause hepatic encephalopathy (HE). This condition demands specialized care and, in some instances, liver transplantation evaluation. No model is available for predicting HE. We aimed to set up and validate a model for predicting the occurrence of HE in paracetamol overdose.

METHODS

Prospectively, 161 patients with single-dose paracetamol overdose and no HE (defined as hepatic coma grade II or more) on admission were studied during a 26-month period. Patients admitted during the first 13-month period constituted a learning set to construct a model to predict the occurrence of HE. Patients admitted in the second 13-month period constituted the validation set. Serial biochemical variables (measured twice daily), the time line after the overdose, and demographic data were used for univariate testing, and significant factors were assessed in various multiple logistic regression analyses.

RESULTS

Thirty-two patients (20%), 15 in the first period and 17 in the second, developed HE grade II. The best model (the highest chi-square) for HE included: log10 (hours from overdose to antidote treatment), log10 (plasma coagulation factors on admission), and platelet count hours from overdose (chi-square = 41.2, P < 0.00001). In the validation set 88% (confidence interval (CI), 64%-99%) of the patients who developed HE were correctly predicted by the constructed model, whereas 90% (CI, 79%-96%) of the patients in the non-HE group were correctly predicted.

CONCLUSIONS

The constructed model for predicting HE in paracetamol overdose proved sensitive and accurate in the validation set and should be valuable for transferring high-risk patients to a liver intensive care unit/transplantation facility.

The hydroxyl radical scavengers dimethylsulfoxide and dimethylthiourea protect rats against thioacetamide-induced fulminant hepatic failure

BACKGROUND/AIMS

Reactive oxygen species, proinflammatory cytokines, glutathione depletion and nitric oxide have all been implicated in the pathogenesis of fulminant hepatic failure. The aim of the present study was to examine the respective roles of these factors in the pathogenesis of thioacetamide-induced fulminant hepatic failure in rats.

METHODS

Fulminant hepatic failure was induced by 3 consecutive intraperitoneal injections of thioacetamide (400 mg/kg) at 24-h intervals. Rats were pretreated with one of the following agents: the free radical scavengers dimethylsulfoxide (4 g/kg every 6 h) or dimethylthiourea (200 mg/kg every 12 h), the glutathione donor, N-acetylcysteine (130 or 200 mg/kg every 6 h), or the anti-tumor necrosis factor-alpha agents pentoxifylline (100 and 200 mg/kg) and soluble tumor necrosis factor receptor (100 or 1000 microg/rat). The nitric oxide synthase inhibitor N-mono-methyl arginine ester (L-NAME, 0.1 mg/ml) was administered in the drinking water, starting 7 days prior to thioacetamide administration.

RESULTS

Serum levels of liver enzymes, blood ammonia and prothrombin time and the stage of hepatic encephalopathy were significantly improved in rats treated with dimethylsulfoxide or dimethylthiourea compared to the other treatment groups (p<0.001). Liver histology and the survival rate in these rats were not adversely affected by thioacetamide administration (p<0.001), while in all the other treatment groups those parameters were similar to control rats with fulminant hepatic failure. Furthermore, dimethylsulfoxide ameliorated liver damage and improved survival even when its administration was initiated 8 and 16 h after the first thioacetamide injection. The hepatic concentration of methanesulfinic acid, which is produced after direct interaction of dimethylsulfoxide with hydroxyl radicals, was increased five-fold in rats treated with thioacetamide+dimethylsulfoxide (p<0.001), suggesting a role for hydroxyl radical scavenging in the protection from fulminant hepatic failure in this model. In the group of thioacetamide-treated rats that were pretreated with L-NAME, liver enzymes, blood ammonia levels and the mortality rate were higher than in the control group, treated with thioacetamide only.

CONCLUSIONS

In thioacetamide-induced fulminant hepatic failure, the hydroxyl radical scavengers dimethylsulfoxide and dimethylthiourea prevent liver injury. Neither N-acetylcysteine nor antagonists of tumor necrosis factor-alpha are protective in this rat model. Inhibition of nitric oxide formation aggravates liver damage and reduces the survival of rats with thioacetamide-induced liver damage.

Xenogeneic, extracorporeal liver perfusion in primates improves the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio)

In fulminant hepatic failure (FHF), the development of hepatic encephalopathy is associated with grossly abnormal concentrations of plasma amino acids (PAA). Normalization of the ratio of branched-chain amino acids to aromatic amino acids (Fischer's ratio) correlates with clinical improvement. This study evaluated changes in PAA metabolism during 4 h of isolated, normothermic extracorporeal liver perfusion using a newly designed system containing human blood and a rhesus monkey liver. Bile and urea production were within the physiological range. Release of the transaminases AST, ALT and LDH were minimal. The ratio of branched (valine, leucine, isoleucine) to aromatic (tyrosine, phenylalanine) amino acids increased significantly. These results indicate that a xenogeneic extracorporeal liver perfusion system is capable of significantly increasing Fischer's ratio and may play a role in treating and bridging patients in FHF in the future.

Auxiliary versus orthotopic liver transplantation for acute liver failure. EURALT Study Group. European Auxiliary Liver Transplant Registry

BACKGROUND/AIMS/METHODS

We report 1-year results after auxiliary liver transplantation for acute liver failure in a cohort of 47 patients transplanted in 12 European centers as compared with those of 384 consecutive patients undergoing orthotopic liver transplantation for acute liver failure in the Eurotransplant area.

RESULTS

One-year patient survival resp. retransplant-free patient survival did not differ between orthotopic (61%, 232/384 resp. 52%, 200/384) and auxiliary liver transplantation (62%, 29/47 resp. 53%, 25/47). One-year patient survival resp. retransplant-free patient survival after auxiliary partial orthotopic liver transplantation was 71% (25/35) resp. 60% (21/35), not significantly different from orthotopic liver transplantation (61%, 232/384 resp. 52%, 200/384), while both transplantation techniques had better 1-year patient survival resp. retransplant-free patient survival than after heterotopic auxiliary liver transplantation (33%, 4/12) (p < 0.05). Primary nonfunction was more frequent after heterotopic auxiliary liver transplantation (3/12, 25%) than after orthotopic liver transplantation (21/384, 5.5%), while the incidence did not differ between orthotopic liver transplantation and auxiliary partial orthotopic liver transplantation (3/35, 8.5%). Portal vein thrombosis was more frequent after both heterotopic auxiliary liver transplantation (5/12, 42%) and auxiliary partial orthotopic liver transplantation (5/35, 14%) than after orthotopic liver transplantation (2/384, 0.5%) (p < 0.001). Of the patients, 65% (17/26) surviving auxiliary liver transplantation for 1 year without retransplantation by orthotopic liver transplantation were free of immunosuppression within 1 year, compared with none of the patients transplanted by orthotopic liver transplantation (p < 0.01).

CONCLUSIONS

Auxiliary liver transplantation, especially auxiliary partial orthotopic liver transplantation, offers an advantage over orthotopic liver transplantation in acute liver failure in terms of a chance of a life free of immunosuppression, apparently without jeopardizing chances of survival. Reduction of the incidence of primary nonfunction and vascular complications should be a focus of research in auxiliary liver transplantation. These findings need to be confirmed in a prospective study.

Fulminant Hepatic Failure

The initial approach to a patient with fulminant hepatic failure includes assessment of the grade of encephalopathy and the cause of hepatic failure. Aggressive supportive therapy with early referral to a transplantation center is recommended for patients with advancing encephalopathy. A critical component of the transplant decision process is the ongoing clinical assessment of reversibility of neurologic status; liver transplantation continues to be the only successful intervention in patients with advanced encephalopathy. Emerging therapies such as auxiliary transplantation and extracorporeal liver assist devices are being perfected or rigorously evaluated.

Intracranial pressure during liver transplantation for fulminant hepatic failure

During orthotopic liver transplantation (OLT) for fulminant hepatic failure (FHF), some patients develop cerebral injury secondary to intracranial hypertension. We monitored intracranial pressure (ICP) and cerebral perfusion pressure (CPP) before and during OLT in 12 FHF patients undergoing transplantation. All four patients who had normal ICP preoperatively maintained normal ICP/CPP throughout OLT. During OLT, four of the eight patients with pretransplant intracranial hypertension had six episodes of ICP increase. These episodes of intracranial hypertension occurred during failing liver dissection (n=3) and graft reperfusion (n=3). At the end of the anhepatic phase, the ICP was lower than the preoperative ICP in all patients, and was below 15 mmHg in all but one patient. These data suggest that in FHF patients who develop intracranial hypertension before OLT, dissection of the native liver and graft reperfusion are associated with a risk of brain injury resulting from intracranial hypertension and cerebral hypoperfusion.

Etiology and outcome for 295 patients with acute liver failure in the United States

Little information is available on acute liver failure (ALF) in the United States. We gathered demographic data retrospectively for a 2-year period from July 1994 to June 1996 on all cases of ALF from 13 hospitals (12 liver transplant centers). Data on the patients included age, hepatic coma grade on admission, presumed cause, transplantation, and outcome. Among 295 patients, 74 (25%) survived spontaneously, 121 (41%) underwent transplantation, and 99 (34%) died without undergoing transplantation. Ninety-two of 121 patients (76%) survived 1 year after transplantation. Acetaminophen overdose was the most frequent cause (60 patients; 20%), followed by cryptogenic/non A non B non C (NANBNC; 15%), idiosyncratic drug reactions (12%), hepatitis B (10%), and hepatitis A (7%). Spontaneous survival rates were highest for patients with acetaminophen overdose (57%) and hepatitis A (40%) and lowest for those with Wilson's disease (no survivors of 18 patients). The transplantation rate was highest for Wilson's disease (17 of 18 patients; 94%) and lowest for autoimmune hepatitis (29%) and acetaminophen overdose (12%). Age did not differ between survivors and nonsurvivors, perhaps reflecting a selection bias for patients transferred to liver transplant centers. Coma grade on admission was not a significant determinant of outcome, but showed a trend toward affecting both survival and transplantation rate. These findings on retrospectively studied patients from the United States differ from those previously gathered in the United Kingdom and France, highlighting the need for further study of trends in each country.

The effects of serum from patients with acute liver failure on the growth and metabolism of Hep G2 cells

In many bioartificial liver systems currently being designed and evaluated for use in fulminant hepatic failure, direct contact is required between the patient's blood and the liver cells in the device. The efficacy of such devices will be influenced by the interaction of fulminant hepatic failure (FHF) patient serum with the cells. We have found that FHF serum inhibits the growth rate and the synthesis of DNA, RNA, and protein; disturbs glutathione homeostasis; and induces morphological changes in cultured human Hep G2 cells. These interactions should influence the design of bioartificial liver devices based on proliferating cell lines and indicate the requirement to pretreat FHF patient plasma to reduce the toxin load.

Acute parvovirus B19 infection associated with fulminant hepatitis of favourable prognosis in young children

BACKGROUND

The cause of fulminant hepatitis (FH) in children is unexplained in up to 50% of cases. We report parvovirus B19 as an agent associated with FH in children and compare clinical characteristics of these patients with those of age-matched patients with FH of other origin.

METHODS

45 patients presented with FH. No cause was apparent in 21 patients. Parvovirus B19 genome was retrospectively sought by PCR in serum collected at admission in 41 patients.

FINDINGS

Parvovirus B19 genome was detected in serum from four of 21 patients with unexplained FH (four of 11 younger than 5 years). No B19 DNA was detected in serum from patients with other types of FH or from 82 patients with biliary atresia. Parvovirus B19 IgM was detected in one of the four patients. Patients with parvovirus B19 infection had significantly lower bilirubin concentrations than age-matched patients with FH due to hepatitis A (nine) or other causes (nine) (poisoning with amanita excluded). All patients with parvovirus B19 survived without orthotopic liver transplantation, with restoration of normal liver function within 17 days.

INTERPRETATION

In patients younger than 5 years with FH of unexplained origin, evidence of acute parvovirus B19 was associated with a distinct clinical pattern. In particular, low bilirubin concentrations and rapid recovery of liver function without transplantation were distinctive features.

Marked increases of aminotransferase levels after cresol ingestion

A 26-year-old woman developed marked increases in levels of aminotransferases about 24 hours after ingestion of 70 mL of 50% cresol. Responding to supportive measures, the patient recovered without any significant complications. Cresol and/or its metabolite may have caused transient hepato-cellular injury in this patient. In cresol poisoning, hepato-cellular injury can manifest even after a 24-hour asymptomatic period.

Management of acute liver failure

Acute liver failure represents one of the most challenging conditions in gastroenterology. In most cases, there is no effective therapy making supportive intensive care the most important management tool. These patients frequently develop multi-organ failure, placing them at risk of systemic infections, cerebral edema, hemodynamic instability, coagulopathy and various renal and metabolic complications. Successful management of the patient with acute liver failure requires an understanding of the pathophysiology and management of these complications. An overview of acute liver failure and its most common complications is presented.

Hepatitis G virus infection in acute fulminant hepatitis: prevalence of HGV infection and sequence analysis of a specific viral strain

Hepatitis G virus (HGV) is a recently discovered RNA virus, which belongs to the Flaviviridae family. Although HGV infection is usually not associated with elevated serum transaminases, some recent studies have reported that HGV infection is found in a significant number of patients with fulminant hepatitis and may play a role in its etiopathogenesis. In this study the prevalence of HGV infection was determined in 500 healthy blood donors and in 24 patients admitted to hospital because of acute liver failure caused by fulminant hepatitis. The presence of HGV RNA was tested in sera, obtained at admission and before any transfusion was given, by a sensitive seminested reverse transcriptase-polymerase chain reaction (RT-PCR) assay specific for detection of the non-structural (NS)5 region. Nine of the 500 blood donors (1.8%) and two of the 24 patients (8.3%) were found to be HGV RNA positive. One patient was co-infected with HCV and was known to be an intravenous (i.v.) drug user. After intensive supporting treatment, this patient recovered completely. The second patient had no serological markers of known viral hepatitis infection, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and herpes simplex virus (HSV). This patient was successfully transplanted. From both patients, from HGV RNA-positive healthy blood donors and from other patients coinfected with HCV, a part of the HGV NS3 region (nucleotides 4191-4345, EMBL entry U45966) was cloned and sequenced. Sequence comparison revealed that the NS3 region of HGV in patients with fulminant hepatitis contained three nucleotide substitutions as part of the six substitutions described in previous work. These nucleotide substitutions were not found in the tested blood donors or in patients with HCV co-infection. Our findings therefore support the concept of the association of fulminant hepatitis with infection of a specific HGV strain.

Therapy of viral hepatitis

Worldwide viral hepatitis is the most common cause of jaundice, chronic liver disease cirrhosis and hepatocellular carcinoma. While important advances have been made in prevention of viral hepatitis, therapy of this disease remains unsatisfactory. There are no specific therapies of proven benefit for acute hepatitis, although use of alpha-interferon during the acute phase of hepatitis C may result in a decrease in the rate of chronicity. For chronic viral hepatitis, alpha-interferon has been widely used, but is expensive, poorly tolerated and limited in effectiveness. New antiviral agents and use of combinations of antivirals are now being evaluated and promise to provide a therapy that is effective in the majority of patients. The currently recommended therapy of chronic hepatitis B is a 4- to 6-month course of alpha-interferon in doses of 5-10 million units three times a week; a regimen that results in sustained clearance of hepatitis B virus (HBV) DNA and hepatitis B e antigen (HBeAg) from serum in approximately one-third and a loss of hepatitis B surface antigen (HBsAg) in one-tenth of patients. Long-term follow-up of patients who respond to interferon treatment with clearance of HBeAg indicate that the majority ultimately clear HBsAg as well and have continued remission in the liver disease, although low levels of HBV DNA can commonly be detected in liver tissue. Better therapies of hepatitis B are needed. Recently, several oral 'second-generation' nucleoside analogues have been developed that have potent activity against HBV. The best studied is lamivudine (3-thiacytidine) which results in marked inhibition of HBV DNA levels and improvement in serum aminotransferases and hepatic histology in the majority of patients. When stopped, however, most patients relapse and the shortcomings of long-term therapy have been the development of viral resistance in up to one-quarter of patients within a year and a higher percentage with more prolonged therapy. Future approaches of therapy of promise for hepatitis B are combinations of lamivudine with interferon and other antiviral nucleoside analogues. The currently recommended therapy of chronic hepatitis C is a 12- to 18-month course of alpha interferon in doses of 3 million units three times a week: a regimen that results in sustained clearance of hepatitis C virus (HCV) RNA in approximately 20% of patients. Sustained responses have been associated with marked improvements in hepatic histology and long-term studies indicate that the majority of patients remain free of virus in serum and liver, suggesting a 'cure' of infection. Responses to interferon correlate to some degree with clinical and virological features, including young age, absence of hepatic fibrosis, low levels of HCV RNA in serum and HCV genotypes 2 and 3. (ABSTRACT TRUNCATED)

Internal bioartificial liver with xenogeneic hepatocytes prevents death from acute liver failure: an experimental study

OBJECTIVE

To demonstrate that a bioartificial liver, using allogeneic or xenogeneic hepatocytes protected from rejection by a semipermeable membrane, could prevent death from acute liver failure.

SUMMARY BACKGROUND DATA

An implantable bioartificial liver using isolated hepatocytes could be an alternative to orthotopic liver transplantation to treat patients with acute liver failure. It could serve either as a bridge until liver transplantation or as the main treatment until recovery of the native liver. However, allogeneic or xenogeneic hepatocytes that could be used in clinical applications are spontaneously rejected.

METHODS

Acute liver failure was induced in rats by 95% liver resection. Twenty-five million hepatocytes harvested in rats (allogeneic) or guinea pigs (xenogeneic) were encapsulated in a semipermeable membrane to protect them from rejection. The hollow fibers containing hepatocytes were transplanted into the peritoneum of recipient rats. Survival rates were compared between rats transplanted or not with hepatocytes.

RESULTS

In groups not transplanted with viable hepatocytes, 73% to 93% of rats died after 95% liver resection. The mortality rate was reduced to 39% in rats transplanted with allogeneic hepatocytes and 36% in rats transplanted with xenogeneic hepatocytes. The bioartificial liver could be removed 1 month after transplantation, when regeneration of the native liver was complete. Allogeneic and xenogeneic hepatocytes remained viable.

CONCLUSIONS

The implantable bioartificial liver was able to prevent death in this model of acute liver failure. This could be an important step toward clinical application of the method.

Review article: the management of acute liver failure

Acute liver failure (ALF) is a relatively uncommon but dramatic clinical syndrome with high mortality rates, in which a previously normal liver fails within days or weeks. Paracetamol overdose remains the major cause of ALF in the UK, while viral hepatitis is the commonest cause world-wide. Cerebral oedema is the leading cause of death in patients with ALF. Despite advances in intensive care and the development of new treatment modalities, ALF remains a condition of high mortality best managed in specialist centres. Orthotopic liver transplantation is the only new treatment modality that has made a significant impact in improving outcome. Bioartificial liver support systems and hepatocyte transplantation are new promising treatment options that may change the management of ALF in the future.

Hypothyroidism minimizes liver damage and improves survival in rats with thioacetamide induced fulminant hepatic failure

Recent data from animal studies suggest that induced hypothyroidism prevents the hyperdynamic circulation in portal vein ligated rats, liver cirrhosis in rats chronically treated with thioacetamide (TAA), and immune-mediated acute liver injury induced in mice by concanavalin A. Therefore, the aim of this present study is to determine whether hypothyroidism would likewise prevent fulminant hepatic failure (FHF) in rats. FHF was induced by 3 consecutive ip injections of TAA (400 mg/kg) at 24-hour intervals. Hypothyroidism was induced in rats by either methimazole (MMI) or propylthiouracil (PTU) and surgical thyroidectomy and was confirmed by elevated serum thyroid stimulating hormone levels. Serum levels of liver enzymes, blood ammonia, and prothrombin time were significantly lower in all 3 groups of hypothyroid rats. The stage of hepatic encephalopathy (HE) and the survival rates were significantly improved in the hypothyroid rats (P < .01); the histologic examination of their livers showed less necrosis and inflammation (P < .01). In the hypothyroid rats, the serum levels of malondialdehyde 48 hours after thioacetamide (TAA) administration were lower than in control rats (P < .01). Exogenous supplementation of hypothyroid rats with L-thyroxine started 48 hours before TAA administration abrogated the protective effects of hypothyroidism. The serum levels of tumor necrosis factor alfa (TNF-alpha), interleukin (IL) 2 and IL-6 after 24 hours were slightly lower in the hypothyroid rats, but the administration of soluble receptor of TNF (10-1,000 microg/rat) did not prevent the induction of fulminant liver failure by TAA. Oxygen extraction, studied in isolated perfused liver preparation, was significantly lower in livers of hypothyroid rats (P < .01). These results suggest that induced hypothyroidism decreases the development of liver injury in a rat model of FHF. The mechanism may involve diminished oxidative cell injury caused by decreased oxygen utilization and hypometabolism associated with hypothyroidism.

Ribavirin Inhibits Viral-Induced Macrophage Production of TNF, IL-1, the Procoagulant fgl2 Prothrombinase and Preserves Th1 Cytokine Production But Inhibits Th2 Cytokine Response

Ribavirin, a synthetic guanosine analogue, possesses a broad spectrum of activity against DNA and RNA viruses. It has been previously shown to attenuate the course of fulminant hepatitis in mice produced by murine hepatitis virus strain 3. We therefore studied the effects of ribavirin on murine hepatitis virus strain 3 replication, macrophage production of proinflammatory mediators including TNF, IL-1, and the procoagulant activity (PCA), fgl2 prothrombinase; and Th1/Th2 cytokine production. Although ribavirin had inhibitory effects on viral replication (&lt;1 log), even at high concentrations complete eradication of the virus was not seen. In contrast, at physiologic concentrations (up to 500 μg/ml), ribavirin markedly reduced viral-induced parameters of macrophage activation. With ribavirin treatment, the concentrations of PCA, TNF-α and IL-1β all decreased to basal concentrations: PCA from 941 ± 80 to 34 ± 11 mU/106 cells; TNF-α from 10.73 ± 2.15 to 2.74 ± 0.93 ng/ml; and IL-1β from 155.91 ± 22.62 to 5.74 ± 0.70 pg/ml. The inhibitory effects of ribavirin were at the level of gene transcription as evidenced by Northern analysis. Both in vitro and in vivo, ribavirin inhibited the production of IL-4 by Th2 cells, whereas it did not diminish the production of IFN-γ in Th1 cells. In contrast, ribavirin had no inhibitory effect on TNF-α and IL-1β production in LPS-stimulated macrophages. These results suggest that the beneficial effects of ribavirin are mediated by inhibition of induction of macrophage proinflammatory cytokines and Th2 cytokines while preserving Th1 cytokines.

Earlier identification of patients at risk from acetaminophen-induced acute liver failure

OBJECTIVE

To determine whether the Acute Physiology and Chronic Health Evaluation (APACHE) II system for the measurement of severity of illness is able to provide an accurate risk of hospital death in patients with acetaminophen-induced acute liver failure or identify those patients needing transfer for possible hepatic transplantation.

DESIGN

Data for admission (first 24 hrs) APACHE II scores and King's criteria for urgent transplantation were collected prospectively to compare the APACHE II system and the King's criteria for the prediction of death or need for transplantation.

SETTING

A nine-bed specialist liver failure unit (LFU).

PATIENTS

One hundred two consecutive patients admitted to the LFU with acetaminophen self-poisoning and a prolonged prothrombin time were studied.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An APACHE II score of > 15 points was associated with a high mortality (13/20 patients, five of whom survived following hepatic transplantation). There was no relation between APACHE II risk and outcome (mean APACHE II risk of death 0.8%, actual hospital mortality 16%). An APACHE II score of > 15 had a similar power of prediction of death as the King's criteria (sensitivity 82% and 65%, respectively; specificity 98% and 99%, respectively), when considering those patients who were transplanted as "deaths." An APACHE II score of > 15 was able to identify four more patients than the King's criteria on the first day of admission to the LFU.

CONCLUSIONS

The crude admission APACHE II score correlated well with mortality in patients with acetaminophen-induced acute liver failure. However, the calculated APACHE II risk of death, using the original drug overdose coefficient, was poorly calibrated. Since specialist liver scores are unfamiliar in the general intensive care setting, the use of an APACHE II score might earlier identify more patients at risk of needing a liver transplant, and hence, expedite appropriate transfer to a specialist liver unit.

[Intraperitoneal transplantation of isolated hepatocytes of the pig: the implantable bioartificial liver]

The general aim is to prepare a bioartificial liver to treat acute hepatic failure using allo- and xenogeneic hepatocytes, immunoprotected by macroencapsulation and transplanted into the peritoneal cavity. The goal of this study was to prepare a large amount of isolated porcine hepatocytes, to encapsulate them within biocompatible membranes for transplant in allo- and xenogeneic combinations and to examine the viability and functionality of the cells 6 weeks later. Hepatocyte isolation was performed in 12 kg pigs (n = 15) by dissociation of the liver with collagenase D (1 g) without oxygenation. Encapsulation of the hepatocyte suspension (10(7)/mL) was performed in hydrogel membranes AN69; hollow fibers (2 m x 0.8 mm) and flaskes (1.8 cm), and transplanted to Yucatan pigs (n = 4) and Lewis rats (n = 12). Six weeks later, they were removed to study the cell viability by histological examination, and the production of albumin by immunonephelometry. The rate of isolated hepatocytes was 38 +/- 5 x 10(9)/mL by liver of pig and the mean viability was 93 +/- 2%. Six weeks after transplantation, hepatocytes were viable, organized in lobules, and showed conserved albumin production. The same results were observed for allogenic and xenogeneic combinations. In conclusion, this method of liver dissociation allowed for preparation of a large amount of isolated hepatocytes from a single pig liver, theoretically sufficient to treat a patient with acute liver failure. Hydrogel membranes were well tolerated and allowed immunoprotection without immunosuppression. Transplanted hepatocytes remained functional. This work is an important step in progress toward clinical application.

Fulminant hepatitis and the new G/GBV-C flavivirus

A new virus within the family Flaviviridae. 'hepatitis' G/GBV-C, has been incriminated by several authors as a causative factor of idiopathic or cryptogenic fulminant hepatitis, a syndrome of presumed viral aetiology. Review of worldwide data from 22 studies on 364 cases indicates that G/GBV-C infection is present in approximately 20% of idiopathic cases but a similar or even higher prevalence is detected in fulminant hepatitis of viral B, D or C aetiology, reflecting a high rate of parenteral viral exposure rather than a specific aetiology of fulminant hepatic failure. An aetiopathogenic role of G/GBV-C in fulminant hepatitis seems to be further refuted by the analysis of other data in the literature. The presence of G/GBV-C infection in fulminant hepatic failure is largely a result of secondary infection or coinfection. The aetiopathogenetic mystery of cryptogenic or idiopathic fulminant hepatitis remains unsolved.

Treatment of severe liver failure with a bioartificial liver

Orthotopic liver transplantation (OLT) is the definitive therapy for severe liver failure. However, many patients die before an organ becomes available, mostly from cerebral edema. To provide temporary liver support, we developed a bioartificial liver (BAL) based on porcine hepatocytes and a charcoal column. Fifty-four consecutive BAL treatments were carried out in three groups of patients: Group I (n = 15) patients presented with FHF were listed for emergent OLT, Group II (n = 3) patients with primary non-function (PNF) of their liver grafts required urgent re-transplantation and Group III (n = 10) patients with acute exacerbation of chronic liver disease were not candidates for OLT. Patients were managed in a critical care unit receiving maximal standard support. Each BAL treatment was conducted for 6 hours. In Group I, all patients showed significant neurologic improvement, intracranial pressure (ICP) decreased and cerebral perfusion pressure (CPP) increased; other significant improvements, included lowered plasma ammonia and liver enzymes and increased glucose. One patient recovered spontaneously without OLT, all other patients were "bridged" to OLT, and recovered. Group II: PNF patients showed similar benefits. Group III: Chronic liver patients demonstrated transient beneficial effects after BAL treatment(s), however, most (n = 8) eventually succumbed to sepsis and multiple organ failure as they were not candidates for OLT; two patients, recovered, later were successfully transplanted and survived. Our clinical experience demonstrates that the BAL can serve as a bridge to OLT in patients with acute liver failure.

Acute hepatitis E by a new isolate acquired in the United States

OBJECTIVE

To report the first case of acute hepatitis E by a novel isolate acquired in the United States and confirmed by nucleotide sequencing.

MATERIAL AND METHODS

We describe the clinical manifestations and the results of associated laboratory studies in a man who was found to have acute hepatitis E infection.

RESULTS

A 62-year-old man was hospitalized because of fever, abdominal pain, and jaundice. After an initial evaluation did not provide a cause, his serum was found to be positive for IgG anti-hepatitis E virus (HEV) by three antibody assays. Serum was also positive for HEV RNA by reverse transcriptase polymerase chain reaction (PCR). Sequencing results from the PCR products demonstrated substantial differences at the nucleotide level between this strain and the known Mexican and Burmese strains.

CONCLUSION

On the basis of this initial report, HEV should be considered an etiologic agent in patients with acute non-ABC hepatitis in the United States.

Extracorporeal liver support: cell-based therapy for the failing liver

It is perhaps self-evident to state that a liver support device is possible as long as the artificial organ provides liver function. This basic concept has received woefully little attention, mainly because "liver function" escapes precise definition. We have seen a variety of liver-assist devices that have little to do with liver function over the past 30 years. Recent work has focused on the liver as a biochemical reactor, rather than an excretory organ, and the paradigm has shifted away from blood purification and toward metabolic support. This new generation of devices includes viable liver cells, which provide the necessary biochemical function without needing to identify the numerous metabolic pathways necessary to support the patient with a failing liver. This approach is the most effective and least invasive method available with current technology, and it has yielded exciting data. Questions about the mass of cells required to provide adequate support, the timing and length of treatment, and the source of cellular material continue to be debated. Here we address theoretical and practical problems in developing an extracorporeal liver-assist device (ELAD) and suggest the future role of extracorporeal liver support in the management of liver failure.

Acetaminophen toxicity in an urban county hospital

BACKGROUND

The prevalence and characteristics of acetaminophen-associated liver injury in hospitalized patients are not well defined.

METHODS

We identified patients hospitalized for excessive acetaminophen ingestion at an urban county hospital over a 40-month period (1992 to 1995) and reviewed their medical records to determine the incidence and clinical features of the ingestions and their outcomes.

RESULTS

Of the 71 patients studied, 50 were classified as having taken acetaminophen during suicide attempts and 21 as having accidentally poisoned themselves while attempting to relieve pain. The suicidal patients had ingested almost twice as much acetaminophen as those in the accidental-overdose group (median, 20 vs. 12 g; P=0.009). Among the patients for whom data were available, 63 percent of those in the accidental-overdose group and 25 percent of those in the suicidal group had chronic alcohol abuse (P=0.009). The patients in the accidental-overdose group more often had severe liver necrosis (aminotransferase levels, >3500 IU per liter; 52 percent vs. 14 percent; P=0.002), and were more likely to have hepatic coma (33 percent vs. 6 percent, P=0.006). There were four deaths (19 percent) in the accidental-overdose group and one (2 percent) in the suicidal group (P=0.04). Five patients -- three in the accidental-overdose group and two in the suicidal group -- had ingested 4 g of acetaminophen or less. Acetaminophen ingestion accounted for 12 percent of all patients hospitalized with overdoses (71 of 589) and 40 percent of patients with acute liver failure (10 of 25) during the study period.

CONCLUSIONS

In an urban county hospital, patients hospitalized with acetaminophen toxicity related to accidental misuse had higher rates of morbidity and mortality than those who attempted suicide, even though the latter had taken more acetaminophen. A higher frequency of chronic alcohol abuse among the patients with accidental overdoses may be one explanation.

Selection of prognostic factors of acute hepatitis type non-A, non-B for patient listing for liver transplantation

The aim of this study was to select prognostic factors from information available on admission in order to list patients for liver transplantation before the onset of hepatic encephalopathy in patients with fatal hepatitis type non-A, non-B. Information regarding patient profile and biochemical data obtained on admission was analyzed by multiple stepwise logistic regression, and independent prognostic factors related to death were selected. Four parameters were selected as independent prognostic factors. Patient age (over 50 years), serum total bilirubin level (over 10 mg/dl), peripheral leukocyte count, and prothrombin time were independently related to death. Positive predictive value, negative predictive value, and predictive accuracy were 0.86, 0.79, and 0.84, respectively. Our model is able to predict a patient's fatal outcome much earlier than other currently used models. It will be helpful for early referral to a transplant center.

Selection of patients for liver transplantation in 1997 and beyond

Liver transplantation is now accepted as the standard surgical-medical treatment for end-stage liver disease, as well as replacement therapy for certain inborn errors of metabolism. While improvements in surgical methods and new immunosuppressive agents have improved survival, there remains a chronic shortage of available donor organs. This article offers guidelines for the physician, discussing indications for liver transplantation, controversial selection issues, contraindications, and finally, the future of liver transplantation.

Xenobiotic-induced hepatotoxicity: mechanisms of liver injury and methods of monitoring hepatic function

Xenobiotic-induced liver injury is a clinically important etiology of hepatic disease that, if not recognized, can lead to hepatic failure. In this article we discuss the mechanisms of xenobiotic-induced liver injury, various factors that can alter the risk and severity of injury, the clinical and laboratory manifestations of injury, and the methods used to detect the presence of injury and (or) functioning liver mass.

Treatment of surgically induced acute liver failure by transplantation of conditionally immortalized hepatocytes

The shortage of human livers available for hepatocyte isolation limits its clinical application. The availability of cloned, conditionally immortalized hepatocytes that could be grown in culture but would lose their transformed phenotype and provide metabolic support upon transplantation would greatly facilitate the treatment of acute liver failure. Toward this goal, we transduced isolated Lewis rat hepatocytes using a replication-defective recombinant retrovirus capable of transferring a gene encoding a thermolabile mutant simian virus 40 T antigen (SV40ts). The cloned, immortalized hepatocytes proliferate at 33 degrees C. At the nonpermissive temperatures (37-39 degrees C), they stop growing and exhibit characteristics of differentiated hepatocytes. These cells did not produce tumors when transplanted in mice with severe combined immunodeficiency disease or in syngeneic rats. To induce acute liver failure, Lewis rats were subjected to 90% hepatectomy (Hpx) and given 5% oral dextrose. All rats that did not undergo hepatocyte transplantation died within 96 hr. Fifty percent of rats that received intrasplenic injection of 10 x 10(6) primary Lewis rat hepatocytes (G2, n=6) or 10 x 10(6) SV40ts-conditionally immortalized (SV40ts-ci) hepatocytes (G3, n=8) 1 day before 90% hepatectomy survived, whereas 80% of rats that received an intraperitoneal injection of 200 x 10(6) primary Lewis rat hepatocytes (G4, n=10) or 200 x 10(6) SV40ts-ci hepatocytes (G5, n=10) on the day of hepatectomy survived. Survival after intraperitoneal injection of a cellular homogenate of 200 x 10(6) primary Lewis rat (G7, n=9) or SV40ts-ci hepatocytes (G8, n=10) on the day of Hpx was 33% and 40%, respectively, whereas survival after intraperitoneal injection of 200 x 10(6) Lewis rat bone marrow cells (G6, n=7) was 29%. Thus, transplanted, conditionally immortalized hepatocytes can be as effective as primary hepatocytes in supporting life during acute liver insufficiency. This work represents the first step in developing an hepatocyte cell line that would partially alleviate the organ-donor shortage and could be of potential clinical value.

Viral hepatitis in older adults

The objective of this paper is to review the epidemiology, manifestations, therapy, and prevention of viral hepatitis in older people and to discuss issues of prevention and management. In developed countries a significant portion of the adult population is not immune to Hepatitis A virus (HAV). Morbidity and mortality from HAV infection increases with age. A safe and effective hepatitis A vaccine is available and health authorities should consider immunization early in life and for healthy adults as well as for potential high risk groups such as nursing home residents. Acute hepatitis due to Hepatitis B virus (HBV) is rare in older people and is usually a mild disease. Most older patients with chronic HBV infection who suffer from advanced liver disease have no evidence of ongoing viral replication. Therefore, they are not candidates for interferon therapy. Those with evidence of ongoing viral replication and compensated liver disease should be offered interferon or be included in clinical trials with new antiviral drugs such as lamivudine. Since the response rate to hepatitis B vaccination decreases with age, developing vaccines with greater immunogenicity is crucial. Hepatitis C virus (HCV) is the most frequent cause of acute viral hepatitis in older people. Acute hepatitis C is usually a mild disease in this age group. Because many older patients with chronic HCV infection have compensated liver disease, they could benefit from antiviral therapy. In light of the low response rate to interferon in older patients with chronic hepatitis C and the side effects of the drug, interferon therapy should be reserved for those with the best chance of response. "Combination" antiviral therapy should be on trial for older patients with chronic HCV infection who do not respond to interferon. The recently discovered RNA virus, Hepatitis G (HGV), has been associated with liver disease in older people. It's role in the pathogenesis of liver injury remains to be elucidated.

Clinical experience with a bioartificial liver in the treatment of severe liver failure. A phase I clinical trial

OBJECTIVE

The purpose of this study was to develop a bioartificial liver (BAL) to treat patients with severe liver failure until they can be either transplanted or recover spontaneously.

SUMMARY BACKGROUND DATA

Severe acute liver failure is associated with high mortality. Liver transplantation has emerged as an effective therapy for patients who did not respond to standard management. However, because of the donor organ shortage and urgent need for transplantation, many patients die before they can be transplanted and others do not survive after transplantation, primarily because of intracranial hypertension.

METHODS

Three groups of patients with severe acute liver failure were treated with the BAL. In group 1 (n = 18) were patients with fulminant hepatic failure (FHF), in group 2 (n = 3) were patients with primary nonfunction (PNF) of a transplanted liver, and in group 3 (n = 10) were patients with acute exacerbation of chronic liver disease. Patients in groups 1 and 2 were candidates for transplantation at the time they entered the study, whereas patients in group 3 were not.

RESULTS

In group 1, 16 patients were "bridged" successfully to transplantation, 1 patient was bridged to recovery without a transplant, and 1 patient died because of concomitant severe pancreatitis. In group 2, all patients were bridged successfully to retransplantation. In group 3, two patients were supported to recovery and successful transplants at later dates; the other eight patients, although supported temporarily with the BAL, later died because they were not candidates for transplantation.

CONCLUSIONS

The authors' clinical experience with the BAL has yielded encouraging results. A randomized, controlled, prospective trial (phase II-III) is being initiated to determine the efficacy of the system.