岡本 宏明

By means of representational difference analysis, a viral clone (N22) of 500 nucleotides was isolated from serum of a patient (TT) with posttransfusion hepatitis of unknown etiology. The N22 clone showed a poor homology to any reported sequences. Oligonucleotide primers were deduced from the N22 sequence for detecting it by polymerase chain reaction. N22 sequence in serum banded at a sucrose density of 1.26 g/cm(3), indicating its association with a viral particle which was designated TT virus (TTV). Since nucleic acids of TTV were sensitive to DNase I, it would be a DNA virus. TTV DNA was detected in sera from three of the five patients with posttransfusion non-A to G hepatitis, including the index case (TT). TTV DNA titers closely correlated with aminotransferase levels in the three patients. These results indicate that TTV would be a novel DNA virus with a possible capacity to induce posttransfusion non-A to G hepatitis. (C) 1997 Academic Press.

Objectives: To evaluate the response to interferon and capacity to induce liver disease of a putative non-A to E hepatitis virus designated GB virus C (GBV-C). Methods: RNA of GBV-C was detected by reverse transcription polymerase chain reaction with nested primers deduced from the 5'-noncoding region. It was titrated, along with RNA of hepatitis C virus (HCV), in 16 co- infected patients (11%) out of 140 patients who received interferon. Results: At the completion of a 6-month course of interferon (total dose: 516-774 million units), GBV-C RNA disappeared from serum in seven (44%) and HCV RNA from serum in 11 (69%) patients. At 6 months after interferon treatment ended, GBV-C RNA remained cleared in three patients (19%), and HCV RNA was persistently undetectable in four (25%). One patient lost both GBV-C and HCV RNAs. The three patients whose serum was cleared of GBV-C RNA had pretreatment titers of the virus (two with 101/ml and one with 102/ml) that were considerably lower than the titers of 13 patients (one with 102/ml, eight with 103/ml, and four with ≤104/ml) without such clearance. The decrease in alanine aminotransferase levels paralleled the response of HCV RNA but not that of GBV-C RNA to interferon. The response of HCV at 6 months after interferon in the co-infected patients (4/16 or 25%) did not differ significantly from that in patients without GBV-C infection (44/124 or 35%). Conclusions: The sensitivity of GBV-C to interferon is comparable to but independent of HCV. Coinfection with GBV-C does not influence the response to interferon of patients with chronic hepatitis C.

Hepatitis B e antigen (HBeAg) polypeptide in the circulation (p17(e)) is composed of ten amino acids (aa) coded for by the precore region and 149 aa by the core gene of hepatitis B virus. A monoclonal antibody (Y0583A) was raised against the N-terminal ten amino acids (SKLCLGWLWG) encoded by the precore region. The binding of Y0583A with a panel of 203 decapeptides on multipins, which covered the precursor of HBeAg polypeptide made of 212 aa shifting by one aa, recognized an epitope sequenced LGWLWG representing the C-terminal six aa coded for by the precore region. This HBeAg epitope was not readily accessible on HBeAg in serum, but it became exposed and bound with Y0583A by treatment with 0.2 N NaOH, Using Y0583A, an enzyme-linked immunosorbent assay was developed for specific determination of HBeAg. The test sample was incubated with the monoclonal antibody to an HBeAg determinant encoded by the core gene (904) that had been immobilized on a solid support, Captured HBeAg was treated with 0.2 N NaOH, neutralized and released into the fluid phase. The reactant was then tested for a sandwich between monoclonal antibody (C33) to the C-terminus of the HBeAg polypeptide immobilized on a solid support and Y0583A labeled with horseradish peroxidase. (C) 1997 Elsevier Science B.V.

Infection with GB virus C (GBV-C) and hepatitis C virus (HCV) was surveyed in various populations in Kathmandu, Nepal. GBV-C RNA and HCV RNA were detected in four (2%) and none, respectively, of 181 normal controls. Viral RNAs were detected significantly more frequently (P < 0.001) in 32 (44%) and 43 (60%), respectively, of 72 users of illicit intravenous drug, and in three (14%) and one (5%) of 22 patients on maintenance hemodialysis. The three hemodialysis pa patients with GBV-C RNA had been transfused with more blood units than the 19 without GBV-C RNA (51 +/- 21 vs. 5 +/- 3 units, P < 0.01), and one was co-infected with HCV. Of 145 patients with chronic liver disease, GBV-C RNA was detected in four (3%) and HCV RNA in 12 (8%); only one patient with GBV-C RNA was without markers of HCV or hepatitis B virus infection. In the 32 drug addicts infected with GBV-C, genotypes were G1 in two (6%), G2 in 26 (81%), G3 in three (9%), and the remaining one (3%) was coinfected with G2 and G3. GBV-C genotypes in the 13 individuals in the populations other than drug addicts were G2 in 11 (85%) and G3 in two (15%). HCV genotypes in the 43 drug addicts with viremia were I/1a in 21 (49%), V/3a in 19 (44%) and I/1a plus V/3a in two (5%); these genotypes were not prevalent in normal controls and patients with chronic liver disease in Nepal. These results indicate that GBV-C infection is prevalent in healthy subjects in Nepal at a frequency (2%) comparable with those in the other countries and that GBV-C transmits efficiently by intravenous drug abuse among drug addicts and by transfusion in hemodialysis patients. (C) 1997 Wiley-Liss, Inc.

Sixty-eight consecutive patients with chronic hepatitis B received 702 million units of recombinant interferon-alpha 2a. Of the 24 patients negative for hepatitis B e antigen (HBeAg in serum, the normalization of serum transaminase occurred in 14 (58%) at the completion of interferon therapy and in 13 (54%) at 12 months thereafter: it was normalized in 17 (39%) and 13 (30%), respectively, of the 44 HBeAg-positive patients. Of the HBeAg-negative patients, hepatitis B virus DNA was cleared from serum in six (25%) at the completion and in one (4%) at 12 months thereafter, in contrast to only one (2%, p < 0.05) and none of the HBeAg-positive patients, respectively. The 1896th nucleotide of G (G1896) for codon 28 for tryptophan or A (A1896) for the stop codon 28 in the precore region was deter mined by restriction fragment length polymorphism. The ten HBeAg-negative patients with A1896 only in the precore region had lower pretreatment levels of viral markers, which decreased more rapidly and extensively after interferon than in the 14 HBeAg-negative patients with a mixture of G1896 and A1896 or in the 44 HBeAg-positive patients. These results indicate that patients with HBeAg-negative chronic hepatitis B may respond better to interferon than HBeAg-positive patients, and that the precore mutant with the stop codon 28 may be sensitive to interferon.

Of the 15 babies born to mothers infected with hepatitis C virus (HCV) and followed since birth, three developed HCV RNA in their serum. HCV RNA disappeared in two infants within 2 mo, but it persisted in the remaining infant. Mother-to-baby transmission was diagnosed retrospectively in an additional eight children aged 0.8-13.6 y. The eight children were followed for 1.4-5.0 y (mean +/- SD: 3.2 +/- 1.3 y) until they were 3.3-16.7 y old (8.5 +/- 4.3 y). Serum HCV RNA disappeared and antibodies to HCV decreased in the titer in two of the children when they were 3 y old. The spontaneous loss of serum HCV RNA was not observed in any of the other 14 children with posttransfusion infection who were followed for 2.6-6.1 y (4.0 +/- 1.1 y), until 3-22 y from the time they received transfusions and when they were 8.4-22.8 y old (15.4 +/- 4.1 y). These results indicate that the vertical transmission of HCV is rare, and some children can resolve the infection after a few years, whereas the infection persists in children who are infected by transfusion.

An epitope that acted as a weak agonist in the cytotoxicity assay was identified as part of the capsid protein of a hepatitis C virus (HCV) variant. In a low concentration, the variant epitope also had a weak antagonistic effect. When a minute amount of this variant epitope was added to the culture for induction, it selectively attenuated the expansion of major cytotoxic T cell populations and drastically reduced the cytotoxic responses against the wild-type epitope. Thus, antagonism to induction suppressed immune responses against both the wild type and the variant, thereby helping the persistence of not only variant itself but also the wild-type HCV. Because this variant was a weak agonist, most cytotoxic T cells induced with the wild-type epitope were cross-reactive with the variant and susceptible to the antagonism to induction. Only the T cells which were not cross-reactive with the variant and not susceptible to the antagonism survived the antagonism in induction. This implied that the specificity of the remaining immune response, if any, was directed exclusively to the wild-type epitope after the emergence of the variant. For viruses like HCV, being heterogeneous itself may contribute significantly toward persistent infection through antagonism to induction.

Of 74 patients who were infected with hepatitis C virus (HCV) and received interferon, 12 (16%) were positive for RNA of GB virus C (GBV-C). RNA of GBV-C was determined in sera from the co-infected patients retrospectively, and the effect of interferon on GBV-C was compared with that on HCV in them. Titers of both GBV-C and HCV RNAs decreased during interferon in all of them. Two patients lost both GBV-C and HCV RNAs and remained clear until 6 months after treatment with interferon, while 2 lost RNA for GBV-C only and 2 for HCV RNA alone. Low pretreatment RNA titers of GBV-C and HCV correlated with the efficacy of interferon in clearing. Alanine aminotransferase returned to normal only in the patients who lost HCV RNA, regardless of the persistence or loss of GBV-C RNA. These results indicate that the response to interferon of GBV-C is comparable to but independent of that of HCV and that the persistence of GBV-C would not prevent the normalization of aminotransferases in response to interferon in patients with chronic hepatitis C.

BACKGROUND: The purpose of the study was to survey the epidemiology of recently reported non-A through -E hepatitis virus designated hepatitis G virus (HGV) and its strain variant, the GB agent (GBV-C). STUDY DESIGN AND METHODS: Pilot samples from 2461 blood donors in Japan, randomly selected to form cohorts with different levels of alanine aminotransferase (ALT) and markers of hepatitis B virus or hepatitis C virus (HCV) infection, were tested for RNA of HGV/GBV-C by reverse transcription-polymerase chain reaction with nested primers deduced from the 5'-noncoding region. RESULTS: HGV/GBV-C RNA was detected in 23 (7.4%) of the 361 donors with anti-HCV and HCV RNA. This detection is more frequent than that in donors without elevated ALT levels (less than or equal to 45 U/L) or markers of HCV or hepatitis B virus infection (15/1303; 1.2%) (p<0.001), donors with ALT values between 46 and 99 U pei L (0/108) (p<0.002), donors with ALT values greater than or equal to 100 U per L (5/361; 1.4%), and donors with anti-HCV but without detectable HCV RNA (1/93; 1.1%) (p<0.05). CONCLUSION: More than 1 percent of Japanese blood donors were infected with HGV/GBV-C, and the prevalence was much higher in those with HCV RNA. Should persistent infection with HGV/GBV-C induce any hepatotoxic sequelae, either alone or in concert with the other hepatitis viruses, screening of blood units for HGV/GBV-C would deserve consideration.

A patient on maintenance hemodialysis was infected with a recently discovered putative non-A to -E hepatitis virus designated GB virus C (GBV-C) or hepatitis G virus (HGV) by transfusion. The Viral isolate was recovered from the patient soon after she turned positive for GBV-C/HGV RNA in serum (GSI85) and 8.4 years thereafter (GSI93) and the entire nucleotide sequences were determined. They both had a genomic length of 9391 nucleotides with a defective C gene made of only 42 nucleotides. Between GSI85 and GSI93, 31 (0.33%) nucleotides were different, which changed 5 (0.18%) of the encoded 2842 amino acids. Thus, GBV-C/HGV was estimated to have a mutation rate of 3.9 X 10(-4) base substitutions per site per year. Nucleotide conversions were distributed over subgenomic regions, except in the 5' untranslated region of 552 nucleotides and a defective short C gene, which were conserved in sequence. The change in the putative envelope genes (E1 and E2) was no different from that in the entire genome with only 6 (0.35%) nucleotide substitutions among the 1730, just 1 of which induced an amino acid conversion. Taken along with the comparison of the two isolates with the reported five GBV-C or HGV isolates, these results indicate that GBV-C/HGV would not have hypervariable regions and would use a strategy for Viral persistence that is different from immune escape. (C) 1997 Academic Press.

RNA of a putative non-A to E hepatitis virus, designated GB virus C (GBV-C), was detected in 40 (6.2%) of 645 hemodialysis patients, at a frequency significantly higher than in 3 (0.9%) of 336 blood donors in Japan (p < 0.001). A history of transfusion was more frequent (88 vs. 58%, p < 0.001), the duration of dialysis was longer (13.2 +/- 7.9 vs. 7.9 +/- 6.5 years, p < 0.001), and the detection of hepatitis C virus RNA was more often (38 vs. 18%, p < 0.01) in the 40 patients with GBV-C RNA than in the 605 patients without it. The prevalence of GBV-C RNA varied widely from 0 to 10% among the 8 dialysis centers. These results indicate that hemodialysis patients would be at increased risk of GBV-C transmitted by transfusions. The detection of GBV-C RNA in the 5 patients without a history of transfusion and a high prevalence restricted to certain dialysis centers would reflect nosocomial infection.

RNAs of GB virus C (GBV-C) and hepatitis C virus (HCV) were sought by reverse-transcription polymerase chain reaction with nested primers deduced from the 5' untranslated region: 79 patients on maintenance hemodialysis, 205 commercial blood donors, and 205 voluntary donors in Beijing were studied. GBV-C RNA was detected in 43 (54%) patients and 17 (8%) commercial donors, and HCV RNA in 43 (54%) patients and 13 (6%)commercial donors, respectively. By contrast, GBV-C RNA was detected only in 2 (1%) and HCV RNA in none among 205 volunteer blood donors serving as controls. Thus both patients and commercial blood donors were at higher risk for infection with GBV-C (P < 0.001) than controls. HCV RNA was detected more often in patients with GBV-C RNA than without (29/43 or 67%, vs. 14/36 or 39%, P < 0.05) as well as in commercial donors with GBV-C RNA than without (5/17 or 29% vs. 8/188 or 4%, P < 0.01). A phylogenetic tree constructed on a sequence of 100 base pairs in the helicase region indicated that GBV-C isolates from Beijing are more similar to Japanese isolates than to isolates from the United States and Africa. Sequences from certain hemodialysis patients and those from some commercial donors were similar, suggesting nosocomial infection and spread among restricted groups. (C) 1997 Wiley-Liss, Inc.

Recently, putative viral agents responsible for human non-A to E hepatitis have been independently reported by two groups of investigators and designated GB virus C (GBV-C) and hepatitis G virus (HGV), respectively, The entire nucleotide sequences were determined for two viral genomes isolated from Japanese blood donors with GBV-C RNA. One of them (GT230) had a total genomic length of 9390 nucleotides (nt) with 5' and 3' untranslated regions of 551 and 313 nt, while the other (GT110) had genomic lengths of 9395, 281 and 315 nt, respectively. They both had a single long open reading frame, encoding 2842 amino acids (aa) in GT230 and 2933 aa in GT110, Surprisingly, they both lacked a clearly identifiable core gene, and possessed the E1/E2 gene with only four potential N-linked glycosylation sites, Pairwise comparison and phylogenetic analysis of the entire sequence indicated that the prototype GBV-C and two HGV isolates reported, as well as GT230 and GT110, are the same virus possibly of different genotypes, The five GBV-C/HGV isolates were variable up to 13.8% in the genomic nucleotide sequence, and contained deletions and insertions within the 5'-terminal 518-593 nt, which resulted in four different sizes of predicted polyproteins encoded by genomes of individual isolates. By contrast, the 3' untranslated region was well conserved, The high degree of sequence conservation within this region would favour it as a target for sensitive detection of GBV-C/HGV RNA.

A cytotoxic T lymphocyte (CTL) response to the hepatitis C virus (HCV) nucleoprotein residues 88-96 that are the minimal and optimal epitope for human leukocyte antigen (HLA) B44-restricted CTLs was assessed in 27 HLA B44-positive patients with chronic HCV infection. Serum HCV RNA concentration and the amino acid sequence of the residues 81-100 were also determined. Three patients were infected with HCV with uncommon amino acid substitutions within the epitope. One was infected with HCV with an amino acid substitution in the flanking residues of the epitope. To stimulate CTLs in the peripheral blood, 9-mer peptides that corresponded to the residues 88-96 of the individual patients were synthesized and used. Seven of the 27 patients demonstrated a CTL response to the residues 88-96 with specific cytotoxic activities higher than 20%. The CTL activities were significantly higher in patients with a low titer of serum HCV RNA than in those with a high titer of serum HCV RNA (P = .0006). Some of the patients that demonstrated a CTL response to the residues 88-96 also demonstrated a CTL response to a newly identified HLA B44-restricted CTL epitope or a known HLA All-restricted CTL epitope or both. No apparent association was observed between the CTL response and the stage of disease, or between the CTL response and the grade of necroinflammatory activity. The results suggest that the HLA B44-restricted CTLs together with other HCV-specific CTLs may inhibit the outgrowth of HCV and that high-titer infection with HCV may suppress the CTL responses.

Infection with putative non-A to E hepatitis virus, designated GB virus C (GBV-C), was surveyed in 286 patients with chronic liver disease in Japan. RNA of GBV-C was detected, by reverse-transcription polymerase chain reaction with nested primers from the 5'-noncoding region, in 19 patients (6.6%) at a frequency higher (P < 0.001) than in three of 275 (1.1%) normal controls. It was detected in three of 83 (4%) patients with hepatitis B virus infection, 15 of 188 (8%) patients with hepatitis C virus infection, and one of 12 (8%) patients without evidence of ongoing infection with hepatitis B or C virus. GBV-C RNA was detected in nine of 186 (5%) patients with chronic hepatitis aged 51.2 +/- 13.3 years, six of 64 (9%) with liver cirrhosis aged 62.9 +/- 11.4 years, and four of 36 (11%) with hepatocellular carcinoma aged 62.0 +/- 11.1 years. Nucleotide sequences of 100 base pairs in the helicase region of GBV-C isolates from the 19 patients varied up to 21%, while sequences of 33 deduced amino acids were conserved and differed only by up to 6%. These results indicate that infection with GBV-C in patients with non-B, non-C chronic liver disease would not be frequent, although the sensitivity of the detection method could be improved. Coinfection of GBV-C with hepatitis B or C virus, as well as the duration of infection, might accelerate the progression of chronic liver disease. (C) 1997 Wiley-Liss, Inc.

RNA of a putative non-A, -B, -C, -D, or -E hepatitis virus named GB virus C (GBV-C) was detected by reverse transcription-polymerase chain reaction with primers deduced from the 5' untranslated region in 15 (24%) of 63 men with hemophilia in Japan at a frequency higher (P < .001) than that in 2 (0.6%) of 337 controls, By phylogenetic analysis, GBV-C isolates from some patients were similar in sequence, indicating infection with closely related strains, and those from certain patients resembled sequences reported from foreign countries, All patients were infected with hepatitis C virus, and genotypes that are rare in Japan were detected in 36 (57%) of them, These results indicate that patients with hemophilia in Japan would be at increased risk for infection with GBV-C and hepatitis C virus, some of which would have been transmitted via imported coagulation factor concentrates in the past.

We surveyed infection with hepatitis G virus (GBV-C/HGV) in 333 patients with chronic liver disease in a city hospital, Japan. RNA of GBV-C/HGV was detected, by RT-PCR with nested primers derived from the 5'-untranslated region, in one of 85 (1.2%) patients with type B chronic liver disease, 22 of 189 (11.6%) patients with type C chronic liver disease, none of 5 patients co-infected with hepatitis B and hepatitis C viruses, and one of 54 (1.9%) patients without evidence of ongoing infection of hepatitis B or C virus. GBV-C/HGV RNA was detected in 16 of 141 (11.4%) type C patients with chronic hepatitis, three of 35 (8.6%) with liver cirrhosis and three of 13 (23.1%) with hepatocellular carcinoma. And it was detected in 12 of 50 (24.0%) type C hepatitis patients with a history of intravenous drug abuse and five of 60 (8.3%) with a history of transfusion. There were no appreciable differences in demographics, liver function, severity of liver disease between patients infected and not infected with GBV-C/HGV.

In an annual survey for liver function tests in persons aged > 35 years in Iwate Prefecture, Japan, a town was identified where high levels of alanine aminotransferase abounded. Of 5152 inhabitants aged > 35 years in this town, antibodies to hepatitis C virus (HCV) determined by enzyme-linked immunosorbent assay with HCV core peptides were detected in 798 (15.5%) people, hepatitis B surface antigen was detected in 47 (0.9%) people and antibodies to hepatitis B surface antigen and/or hepatitis B core antigen unaccompanied by surface antigenaemia were detected in 1748 (33.9%) people. Antibodies to HCV core peptides correlated closely with the antibodies detected by passive haemagglutination with recombinant HCV proteins of the second generation. Antibodies to HCV core peptides were particularly common in one of the nine districts of the town (district 8), where 276 (45.3%) of 609 inhabitants tested positive; there were no differences in the frequency of serological markers of hepatitis B virus (HBV) infection among residents in the nine districts. Of the 798 individuals with antibodies to HCV core peptides, 257 (32.2%) were found to have elevated transaminase levels. A history of transfusion was associated with a high frequency of antibodies to HCV core peptides, except in district 8 where such antibodies were equally frequent in residents irrespective of transfusions. These results indicate an epidemiology of HCV distinct from that of HBV in this town and a very local spread of HCV, as well as a high frequency of hepatic injuries in individuals with antibodies to HCV.

Hepatitis B e antigen (HBeAg)-negative infections are an unusual form of chronic hepatitis B virus (HBV) infection in which viral replication and liver damage persist despite antibodies against HBeAg. This form of HBV may be associated with fulminant hepatitis. The molecular basis for an HBeAg-minus phenotype has been extensively studied and is most often a result of mutations in the precore region. However, other mutations can give rise to this phenotype and their investigation and characterization may reveal new insights into the pathogenesis of chronic viral hepatitis.

Background and objectives: Hepatitis-causing viral agents other than those designated A to E are being reported. Their epidemiology, modes of transmission, and infectivity are not yet clear, although they may be transmitted by transfusion. Materials and methods: Thirty five patients underwent open-heart surgery, receiving an average of 10.2+/-10.8 (range 1 to 35) units of blood. The patients were investigated postoperatively for the RNA of the putative non-A-to-E hepatitis virus designated as GB virus C (GBV-C). Results: Four patients (12%) acquired GBV-C RNA in the serum within 2 to 4 weeks after the operation. GBV-C RNA was detected in at least one of the blood units received by three patients, all of whose units were available for testing, with a sequence in the nonstructural 3 region identical to that from the corresponding patient. Three patients developed elevated alanine aminotransferase levels which persisted for two weeks or longer in two of them. Conclusions: GBV-C is transmissible by transfusion and can induce elevated transaminase levels.

Soon after the discovery of the hepatitis C virus (HCV) by the research group at Chiron Corporation in 1989 [1], HCV isolates were identified in Japan and these had a considerable sequence divergence from the HCV prototype reported from the United States. Since then, many HCV isolates have been reported from all over the world and attempts have been made to classify them by sequence divergence either of the entire genome or subgenomic areas in different genes and in regions of the genome. Initially, only a few HCV genotypes were reported and they attracted considerable interest in various fields of medicine, with regard to the biological relevance on the life cycle of HCV itself as well as their clinical significance in the care of patients with chronic hepatitis C. HCV has been estimated to infect around 1% of people around the world with predictable and disturbing sequelae. With the enduring efforts of biologists and clinicians in many countries, an increasing number of HCV isolates have been reported which differ in their genomic sequences, and many naming systems have been proposed to define and classify HCV genotypes. As increasing varieties of HCV are added to the list, few of which appear to be of clinical relevance, HCV genotypes are rapidly losing their initial impact. II would appear that interest in HCV genotypes is going to be confined to a very narrow field of virology, where only a handful of genotypists endeavour to classify them into infinitely diverse categories, and discuss the identity of newly reported genotypes. Such an intricate classification, impressive as it is, can scare away scientists and doctors working in the ether fields; most of them will find it difficult to catch up with ever expanding varieties of this RNA virus. The time may come when we start to consider the future of HCV genotypes and contemplate how to deal with them sensibly without losing the attention of biologists and physicians at large. The purpose of this mini-review is to focus on some controversial issues surrounding HCV genotyping nowadays, in the hope for finding a way Forward into the future. For extended overviews and historical perspectives, articles from research groups concerned in HCV genotypes will be referred to [2-7]. Updates on increasing varieties of HCV genotypes may be found in their most recent reports [8-10].

Buoyant density of a recently discovered putative non-A to E hepatitis virus designated hepatitis G virus (HGV) was estimated in plasma or serum samples from three symptom-free carriers and two hepatitis patients. HGV RNA was detected by reverse-transcription polymerase chain reaction in sucrose density fractions with a low density at 1.05-1.10 g/cm3, and the density shifted to 1.23-1.26 g/cm3 after a treatment of peak fractions with Tween 80. Fractionated HGV was precipitated with antibodies to apolipoproteins, but not at all with antibodies to IgG it was retained by affinity columns of lectins. These results indicate that the circulating HGV would be covered with lipoproteins of the host and has sugar moieties on the surface. The association of HGV with lipids would be responsible for the observed low density and prevent the binding with antibodies for viral persistence.

Buoyant density of a recently discovered putative non-A to E hepatitis virus designated hepatitis G virus (HGV) was estimated in plasma or serum samples from three symptom-fret carriers and two hepatitis patients. HGV RNA was detected by reverse-transcription polymerase chain reaction in sucrose density fractions with a low density at 1.05-1.10 g/cm(3), and the density shifted to 1.23-1.26 g/cm(3) after a treatment of peak fractions with Tween 80. Fractionated HGV was precipitated with antibodies to apolipoproteins, but not at all with antibodies to IgG; it was retained by affinity columns of lectins. These results indicate that the circulating HGV would be covered with lipoproteins of the host and has sugar moieties on the surface. The association of HGV with lipids would be responsible for the observed low density and prevent the binding with antibodies for viral persistence. (C) 1996 Academic Press

Backgrounds/Methods: There appear to be hepatitis viruses other than hepatitis A, B, C, D and E, One of these has been proposed with a designation of GB virus C, Sera from 44 patients with fulminant hepatitis were tested for RNA of GB virus C by reverse-transcription polymerase chain reaction with nested primers deduced from the putative non-structural 3 (helicase) region, Results: RNA of GB virus C was detected in three (20%) of 15 patients with hepatitis B virus infection and three (12%) of 25 patients without markers of hepatitis A-E virus infection, Overall, GB virus C RNA was detected in six (14%) of the 44 patients with fulminant hepatitis, at a frequency significantly higher (p<0.001) than that in three (0.9%) of 326 blood donors matched for age with the patients, Conclusions: These results indicate a role of GB virus C in inducing fulminant hepatitis either by itself or in concert with the other hepatitis viruses.

Hepatitis B virus variants harboring nucleotide alterations in the preC-C promoter have been detected in fulminant hepatitis B as well as in HBeAg-seronegative persistent infection. However, it has not been demonstrated that variants with nucleotide alterations in the preC-C promoter cause various disease slates, We replaced the preC-C promoter region of a wild-type genome with the most frequent naturally occurring mutated form and introduced it into HepG2 cells. The mutant with coexisting A1762T and G1764A substitutions produced less than one-fifth of the wild-type level of HBeAg. Conversely, the mutant generated 2.4 times more core particle antigen and showed a high-replicator phenotype. RNase protection and quantitative 5' RACE showed a 16- to 32-fold reduction of preC transcripts and a 4-fold induction of C transcripts of the mutant compared to wild-type. The preC transcript of the mutant had a more heterogeneous 5' end than that of the witd-type. However, the mutations did not alter the initiation sites of C transcription. When the promoter region was cloned into CAT plasmids, the mutations had dual effects on preC and C promoter activities, decreasing and increasing them, respectively. These results suggest that these mutations are responsible for the reduced HBeAg production as well as the enhanced replication and core production. Analysis of revertants with either single point mutation showed that T at 1762 is critical for the mutant phenotype. (C) 1996 Academic Press, Inc.

Of 153 patients with chronic liver disease in Jakarta, Indonesia, who were positive for antibody to hepatitis C virus (HCV), 129 (84%) had HCV RNA in serum. HCV genotypes were II/1b in 55 (43%), III/2a in 33 (26%) and 1c in 15 (12%) patients genotypes were not classifiable into the common five (I/1a, II/1b, III/2a, IV/2b and V/3a) or 1c in the remaining 25 (19%) patients. RNA of a putative non-A-E hepatitis virus, designated GB virus C (GBV-C), was tested for by reverse-transcription polymerase chain reaction with nested primers deduced from the 5'-noncoding region, and detected in 18 (12%) patients of whom 14 (78%) possessed serum HCV RNA. These results indicate that 1c and the other indigenous genotypes of HCV, as well as the co-infection with GBV-C, would be common among Indonesian patients with HCV-associated chronic liver disease.

Of 153 patients with chronic liver disease in Jakarta, Indonesia, who were positive for antibody to hepatitis C virus (HCV), 129 (84%) had HCV RNA in serum. HCV genotypes were II/1b in 55 (43%), III/2a in 33 (26%) and 1c in 15 (12%) patients; genotypes were not classifiable into the common five (I/1a, II/1b, III/2a, IV/2b and V/3a) or 1c in the remaining 25 (19%) patients. RNA of a putative non-A-E hepatitis virus, designated GB virus C (GBV-C), was tested for by reverse-transcription polymerase chain reaction with nested printers deduced from the 5'-noncoding region, and detected in 18 (12%) patients of whom 13 (78%) possessed serum HCV RNA. These results indicate that 1c and thr other indigenous genotypes of HCV, as well as the co-infection with GBV-C, would be common among Indonesian patients with HCV-associated chronic liver disease.