Hepatitis G virus infection in fulminant hepatic failure

Association of fulminant non-A non-B hepatitis with homozygosity for HLA A1-B8-DR3

BACKGROUND

For the majority of cases of acute liver failure in western Europe and North America an etiology cannot be defined. The condition is most often called fulminant non-A, non-B (NANB) hepatitis. Features such as female preponderance and presence of serum autoantibodies suggest a possible autoimmune basis. The aim of the present paper was to examine a possible human leukocyte antigen (HLA) association with fulminant NANB hepatitis.

METHODS

HLA A, B, and DR data of 55 adult Caucasian fulminant NANB patients were compared with those of 1449 local Caucasian controls.

RESULTS

In Caucasian patients, homozygosity (but not heterozygosity) for the alleles A1, B8, and DR3 were associated with fulminant NANB hepatitis (Pcorrected = 0.02, <0.00001 and 0.002, respectively). Greatest relative risk (RR) was associated with homozygosity for the A1-B8-DR3 haplotype (P < 0.00001; RR: 12.8; 95% confidence interval [CI]: 5.7-22.3). HLA DR8 was also associated with development of the syndrome (RR: 4.2; 95%CI: 1.6-9.2).

CONCLUSIONS

Homozygosity for the HLA haplotype A1-B8-DR3 confers susceptibility to the development of fulminant NANB hepatitis. This observation may imply a role for the immune response genes (which are flanked by HLA B and DR) in the pathogenesis of this syndrome.

Etiology and outcome of fulminant hepatic failure managed at an Australian liver transplant unit

BACKGROUND AND AIMS

The primary aims were to identify the incidence, etiology and outcome of all adult cases of fulminant hepatic failure (FHF) presenting to the Victorian Liver Transplant Unit over the 14 year period since the Unit was established in 1988.

METHODS

The database of the Unit was used to identify all adult patients (>16 years) who were referred to the Austin and Repatriation Medical Center in Melbourne with FHF between 1988 and 2001. The Austin and Repatriation Medical Center is the sole provider of adult liver transplantation services for the states of Victoria and Tasmania.

RESULTS

80 patients (64 female, 14 male) with FHF were referred, at a rate of approximately one case per million population per year. The mean age was 37.6 +/- 13.7 years. Most cases were due to either paracetamol poisoning n = 29 (36%) or non-A non-B (idiopathic) hepatitis n = 27 (34%). Thirty-five patients were listed for transplantation, of which 26 underwent the procedure (77% of transplantation patients currently alive). Nine patients were listed for transplantation but did not undergo the procedure, eight died before a donor became available and one recovered. Of the 30 patients who survived without transplantation, 20 cases were due to paracetamol poisoning.

CONCLUSIONS

Liver transplantation has had a major impact on survival of patients with FHF, most significantly in patients with FHF due to causes other than paracetamol poisoning, in whom survival without transplantation is uncommon. Survival in those who undergo transplantation for FHF is excellent, but a significant percentage of patients listed for transplantation die before a donor organ becomes available.

[Is GB virus C alias "hepatitis" G virus involved in human pathology?]

GB virus-C alias "hepatitis" virus G was discovered in 1995 as a putative causative virus of non A-E hepatitis. It is a very common virus found in 1 to 5% of eligible blood donors in developed countries. Numerous studies over seven years led to the exclusion of its role as a significant etiological agent of hepatitis. Its in vivo replication site is still unknown. Its direct involvement in the induction of significant hepatic or extra-hepatic diseases could not be demonstrated. However, coinfections with other viruses may contribute to changes in the evolution of both liver disease (negatively) and HIV/AIDS (favourably). Today, no country has decided to screen GBV-C in blood donors. However, more studies are necessary before the absence of influence of GBV-C infection on human health in the context of other viral infections could be confirmed definitely. This article is a review of the literature on a possible involvement of GBV-C in pathologies whether associated or not to other infections.

Prevalence and significance of hepatitis GB virus-c/hepatitis G virus viremia in a large cohort of patients with chronic hepatitis B infection, with chronic hepatitis C infection, and on renal replacement therapy in Hong Kong

A total of 455 patients were recruited to study the prevalence of hepatitis GB virus-C/hepatitis G virus viremia in Hong Kong. There was no significant increase in the prevalence of hepatitis GB virus-C viremia in asymptomatic hepatitis B virus- and hepatitis C virus-infected patients compared to that of controls (1.56% and 7.14%, respectively, vs 3.85%, both P = NS). Renal patients as a whole had a significantly higher prevalence of hepatitis GB virus-C viremia compared to that of controls (13.95% vs 3.85%, P = 0.0271). The duration of the replacement therapy, especially for patients with peritoneal dialysis was associated with a higher chance of hepatitis GB virus-C viremia. Among renal patients, renal transplanted patients had the highest prevalence of hepatitis GB virus-C viraemia (19.1%) probably because of a higher susceptibility as a result of immunosuppression. However, hepatitis GB virus-C viraemia did not cause liver biochemistry derangement in renal transplanted patients.

Acute liver failure: established and putative hepatitis viruses and therapeutic implications

Any virus that can cause an acute hepatitis will, on occasion, give rise to acute liver failure. Such infections can be separated into those due to the primary hepatitis viral infections A to E and those where hepatitis occurs as part of a systemic viral infection, as with infection with, for instance, Epstein-Barr virus, cytomegalovirus, Varicella zoster virus, adenovirus and Herpes simplex virus. In general, the frequency with which the different hepatitis viruses are responsible for acute liver failure is related to their underlying prevalence in particular countries. An apparent exception is the striking geographical variation in the reported prevalence of acute liver failure due to hepatitis C virus infection, with a much higher proportion of cases generally attributed to this agent in Japan and Taiwan than in Western countries. Recent work has focused on the possible importance of mutant hepatitis B viral strains, co- and super-infection with known hepatitis viruses and certain newly described agents that may account for otherwise unexplained cases of acute liver failure. Despite an improved understanding of the pathogenesis of complicating cerebral oedema and advances in general supportive care, it is likely that the most severely affected patients with acute liver failure due to viral causes will survive only with liver transplantation, at least until approaches for promoting adequate liver regeneration are successfully developed and implemented.

Acute hepatic failure: a Western perspective

Acute hepatic failure (AHF) is an uncommon, devastating syndrome, which results in death or the need for liver transplantation in more than 50% of cases. While AHF has numerous causes, most cases are due to viral hepatitis and drug toxicity or idiosyncratic reactions. A significant group with indeterminate causation remains, despite careful investigation. In many of these cases a viral aetiology is suspected, although yet not proven. Major differences exist in the aetiology of AHF between the West and Eastern countries. A wider range of aetiologies exists in the West. Common causes include acetaminophen toxicity and idiosyncratic drug reactions, while viral hepatitis is less frequent. Hepatitis E infection is rarely seen in Western countries in contrast to its high prevalence in the East. The mainstay of AHF management is supportive care in an intensive care unit. Liver transplantation is now the standard of care in many Western liver units for individuals who have a less than 20% probability of survival. Lack of availability of donor livers at short notice remains a significant problem. Methods of liver support used while waiting for a donor liver or for the native liver to regenerate include bioartificial livers, extracorporeal liver-assist devices, extracorporeal whole organ perfusion (human and transgenic pig) and hepatocyte transplantation. The effectiveness of these methods remains unproven and awaits controlled clinical trials. Both transplantation and liver-support methods require specialized units and expensive and complicated equipment. Further research is necessary to identify modalities of therapy that would be effective as well as widely accessible.

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.

Infection with a novel human DNA virus (TTV) has no pathogenic significance in patients with liver diseases

BACKGROUND/AIMS

A recently identified DNA virus, termed TT virus (TTV), has been associated with post-transfusional hepatitis, and a high prevalence of TTV infection in patients with acute or chronic liver disease of unknown etiology has been reported from Japan, but few data are available about TTV infection in other countries.

METHODS

Using hemi-nested-PCR amplification to detect TTV-DNA sequences in serum, we investigated TTV infection in blood donors and in patients with liver diseases of varied etiology.

RESULTS

The prevalence of TTV infection was 13.7% in blood donors (23/168), 18.6% in chronic hepatitis C (19/102), 28.6% in chronic hepatitis B (16/56), 29.9% in hepatocellular carcinoma (20/67), 9.1% in cryptogenic chronic liver disease (2/22) and 39.6% in fulminant hepatitis (19/48). The prevalence of TTV infection in patients with virus-induced or idiopathic fulminant hepatitis was similar. Comparison of TTV-infected and non-infected patients did not reveal significant differences concerning demographic, epidemiological or histopathological features. In patients with hepatitis C, response to interferon therapy was not related to TTV infection. Phylogenetic analysis of TTV isolates showed that at least three different types of TTV are present in Spain.

CONCLUSIONS

Our data suggest that TTV infection is frequent among blood donors and patients with acute liver disease. However, pathogenic effects associated with TTV infection were not observed.

The spectrum of hepatobiliary disease in primary hypogammaglobulinaemia

OBJECTIVE

To study the prevalence of hepatobiliary disease in a clinically and immunologically well-characterized group of 88 adult Norwegian patients with primary hypogammaglobulinaemia.

SUBJECTS

Eighty-eight patients with primary hypogammaglobulinaemia were followed and signs and symptoms of liver disease were recorded. The patients were examined clinically and radiologically on a regular basis with liver biopsies performed when indicated. All patients were tested for hepatitis C virus (HCV) RNA, hepatitis G virus (HGV) RNA and hepatitis B virus (HBsAg).

RESULTS

Twenty-one patients were HCV RNA-positive, all having signs of chronic liver disease. Only four patients were HGV RNA-positive, of whom two were also HCV RNA-positive. Amongst the 67 HCV RNA-negative patients, 26 had signs of chronic liver disease, including two who were HGV RNA-positive. HCV RNA-negative patients with liver disease had received intravenous immune globulin substitution more frequently, had a longer history of any form of immune globulin substitution and had a greater incidence of common variable immunodeficiency than patients without signs of liver disease. In most cases (21 of 26 patients) the liver disease was relatively mild. Three patients had granulomatous liver disease, with a relatively aggressive course in all three.

CONCLUSION

Hepatobiliary disease is a frequent complication in primary hypogammaglobulinaemia. Liver disease in HCV RNA-negative patients usually has a mild course. HGV does not seem to be a major cause of chronic liver disease in these patients.

Relation between GB virus C/hepatitis G virus and fulminant hepatic failure may be secondary to treatment with contaminated blood and/or blood products

BACKGROUND

The role of the recently discovered GB virus C (GBV-C)/hepatitis G virus in fulminant hepatic failure (FHF) has been debated. Although GBV-C RNA has been detected in many cases of FHF, recent data suggest that the relation between GBV-C and FHF may be accidental.

AIMS

To retrospectively investigate the possible relation between the presence of GBV-C markers (RNA or antibodies to the GBV-C envelope 2 (E2) glycoprotein) and FHF.

METHODS

The presence of GBV-C RNA was determined in serum samples from 58 patients diagnosed with FHF using a reverse transcriptase polymerase chain reaction. Amplified genetic fragments were directly sequenced by the dideoxy chain termination method. Antibodies to GBV-C in serum samples were detected by enzyme immunoassay based on a recombinant GBV-C E2 protein.

RESULTS

Nine (16%) patients with FHF had GBV-C RNA and 13 (22%) [corrected] had GBV-C E2 antibodies, which are higher frequencies than in healthy subjects (p<0.01 and p<0.05 respectively). Six of nine [corrected] patients with GBV-C markers during FHF tested negative for these markers before therapy with blood and/or blood products. Sequence analysis of the GBV-C NS3 region fragments of six FHF patients showed no common sequence pattern or motif.

CONCLUSIONS

The frequencies of both GBV-C RNA and antibodies are higher in patients with FHF than in healthy subjects. However, these increased frequencies may in many cases be explained by the use of contaminated blood and/or blood products given as therapy.

Prevalence and genotypes of GB virus C/hepatitis G virus (GBV-C/HGV) and hepatitis C virus among patients infected with human immunodeficiency virus: evidence of GBV-C/HGV sexual transmission

The development of new antiretroviral agents may improve survival of HIV-infected individuals, and therefore chronic viral hepatitis may become more relevant in these patients. The presence of GBV-C/HGV and hepatitis C virus (HCV) RNA were investigated by reverse transcriptase-nested polymerase chain reaction in plasma from 168 Spanish HIV-infected patients belonging to four different risk groups: intravenous drug users (IVDUs), hemophiliacs, homosexuals, and heterosexuals. GBV-C/HGV-RNA and HCV-RNA were detected in 18% and 43% of the patients, respectively. The prevalence of current infection with these viruses was notably high, 19% for GBV-C/HGV and 69% for HCV, among individuals with parenteral risk of infection (intravenous drug abusers and hemophiliacs), but sexual transmission with GBV-C/HGV was also suggested because 16.5% of patients with sexual risk, either homosexual or heterosexual, had GBV-C/HGV-RNA in plasma. Although investigation of GBV-C/HGV-RNA possibly underestimates the actual prevalence of infection with GBV-C/HGV, the above data suggest that sexual contact may play a relevant role in the spread of this virus. Phylogenetic analysis showed no evidence for clustering of NS3 sequences into different genotypes or subtypes of GBV-C/HGV.

Hepatitis G virus infection in chronic liver disease

BACKGROUND

The hepatitis G virus (HGV), a recently identified member of the Flaviviridae family, can cause chronic infection in man but the role of this agent in chronic liver disease is poorly understood.

AIMS

To evaluate the prevalence and meaning of HGV infection in a large series of patients with chronic liver disease.

SUBJECTS

Two hundred volunteer blood donors, 179 patients with chronic hepatitis C, 111 with chronic hepatitis B, 104 with alcoholic liver disease, 136 with hepatocellular carcinoma, and 24 with cryptogenic chronic liver disease were studied.

METHODS

HGV RNA was investigated in serum samples by reverse transcription and polymerase chain reaction amplification of the 5' non-coding region of HCV and hybridisation to a specific probe. The main features of HGV RNA seropositive and seronegative patients were compared.

RESULTS

The prevalence of HGV infection was 3% in blood donors, 7% in chronic hepatitis C, 8% in chronic hepatitis B, 2% in alcoholic liver disease, 4% in hepatocellular carcinoma, and 8% in cryptogenic chronic liver disease. HGV infected patients tended to be younger than non-infected patients but no differences concerning sex, possible source of infection, clinical manifestations, biochemical and virological parameters, or severity of liver lesions were found.

CONCLUSIONS

The prevalence of HGV infection in chronic liver disease seems to be relatively low in our area. Infection with HGV does not seem to play a significant pathogenic role in patients with chronic liver disease related to chronic HBV or HCV infection or to increased alcohol consumption, or in those with cryptogenic chronic liver disease.