岡本 宏明

One hundred and twenty Sumo wrestlers in Japan received 20 mu g of a hepatitis B vaccine containing 20% (w/w) preS2-region product, while the other 181 received 10 mu g of the vaccine without preS2-region product, four times during 20 months. They were followed for antibody to hepatitis B surface antigen (anti-HBs) by passive hemagglutination up to 32 months after the first vaccination. The seroconversion to anti-HBs occurred more frequently in the wrestlers receiving preS2-plus vaccine than in those receiving preS2-minus vaccine at the end of observation (87% vs. 66%, P < 0.001). Among the seroconverters, anti-HBs titers were higher ill the wrestlers with FreS2-plus than preS2-minus vaccines (geometric mean hemagglutination titer (2(N)): 4.0 +/- 1.8 vs. 3.1 +/- 1.6, P < 0.001). In 27, 83 and ten wrestlers of light (less than or equal to 100 kg), middle (101-150 kg) and heavy(> 150 kg) weight who received preS2-plus vaccine, the seroconversion occurred in 96%,, 86% and 70%, respectively. In 43, 123 and 15 wrestlers of light, middle and heavy weight receiving preS2-minus vaccine, by contrast, seroconversion occurred in 81%, 60% and 67%, respectively. These results indicate that seroconversion to anti-HBs in Sumo wrestlers would be more efficient with preS2-plus than preS2-minus vaccines, and that the efficacy would be inversely correlated with the body weight. It remains to be seen whether an enhanced efficacy of the preS2-plus vaccine was due to the inclusion of preS2-region product or to the amount of S-gene product that was 1.6 times greater than in the preS2-minus vaccine. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

We have proposed that hepatitis C virus should be classified into eleven genetic groups (types) which further divide into more than 80 genotypes (subtypes). However, only eight genetic groups (1-6, 10 and 1 1) have been defined on the basis of the full-length sequence, Hence, the entire nucleotide sequences of three HCV isolates in genetic groups 7-9 have now been determined. Phylogenetic analysis :over the full-length sequences of these three isolates, along with 30 more in the other eight genetic groups, indicated that genetic groups 6-9 and 11 have bifurcated from a common branch and groups 3 and 10 from another. In the former branch groups 7 and 11, and groups 8 and 9, are closely related. Consequently, HCV can be classified into either eleven (1-1 1) or six groups (1; 2; 3 and 10; 4; 5; 6-9 and 11), allowing a clear separation of group and genotype similarity within the NS5b region or a subregion of 1093 nt, When painwise comparison of 1093 nt in the NSSb sequence was performed on 106 HCV isolates of 36 genotypes in eleven genetic groups, they were classified into either eleven (1-11) or six (1; 2; 3 and 10; 4; 5; 6-9 and Il)genetic groups, However, group and genotype similarities were not clearly separable in either classification, The overlapping range was smaller using the classification into eleven genetic groups as compared to six genetic groups (2 .7 vs 4.7%). These results indicate that HCV might not have evolved in the two-tiered fashion, at least in a strict sense.

Markers of GB virus C (GBV-C) and hepatitis C virus (HCV) were sought in 80 patients before and after they underwent BMT in a metropolitan hospital in Tokyo between 1990 and 1996, RNA of GBV-C was detected in 14 (18%) patients before BMT. Of the 55 patients who had been transfused, 14 (25%) possessed GBV-C RNA at a frequency significantly higher than in the 25 untransfused patients who were all negative (P < 0.01). HCV RNA was detected in three of the 55 (5%) transfused patients, but in none of the 25 untransfused patients. Sera at 3 months after BMT were available for 57 patients. GBV-C RNA persisted in all 10 patients who were infected before BMT, while it was detected in five of the remaining 47 (11%) patients who were not. However, persistent and/or ongoing GBV-C infection had no appreciable influence on patient morbidity or mortality. Two of the 57 patients were positive for HCV RNA before BMT and this persisted after BMT in both. HCV RNA became positive in eight of the remaining 55 (15%) patients who were negative before BMT. Of the 14 patients who received transfusions screened by the first-generation test at BMT, seven (50%) became positive for HCV RNA, a rate significantly higher than the one of 41 (2%) patients who received transfusions screened by the second-generation test (P<0.001). These results indicate that BMT patients are at increased risk of GBV-C infection transmitted by transfusions received before and at the time of BMT, and that the risk of HCV infection has decreased after the implementation of the second-generation anti-HCV test.

An enzyme-linked immunosorbent assay (ELISA) was developed for the determination of hepatitis B virus (HBV) core protein (p21(c)) using monoclonal antibody (mAb) directed to a phosphorylated C-terminal amino acid sequence that is not present in hepatitis B e antigen (HBeAg). HBV virions in the test serum were precipitated with horse polyclonal antibody to hepatitis B surface antigen (HBsAg), dissolved with Tween 20 and NaOH, and then neutralized. HBV core protein (p21(c)), released from HBV cores by this procedure, was sandwiched between immobilized mAb C33 directed to amino acids (aa) 133-140 of the core protein, fixed on a solid support and labeled mAb T2212 that recognizes aa 165-175, only when they are phosphorylated. The method was applied for the detection of phosphorylated p21(c) in sera from symptom-free carriers and patients with chronic hepatitis. The results indicated a higher extent of phosphorylation in p21(c) of HBV cores from symptom-free carriers than hepatitis patients. (C) 1998 Elsevier Science B.V. All rights reserved.

Clinical and molecular biological characteristics were compared between patients who presented with fulminant hepatic failure following acute infection with hepatitis B virus (HBV) and those who developed hepatic failure during they carried HBV. The 11 patients with acute HBV infection had higher levels of alanine aminotransferase (mean +/- SD: 4943 +/- 2867 vs. 1157 +/- 678 IU/L, P < 0.01), more often with a single peak (91% vs. 0%, P < 0.001), and lower total bilirubin levels (15.3 +/- 4.4 vs. 28.1 +/- 14.3 mg/100 mi, P < 0.01) than the 13 patients with chronic HBV infection. Hepatitis B surface antigen was detected less often (55% vs. 100%, P < 0.05) and viral DNA polymerase less frequently (0% vs. 46%, P < 0.05) in the patients with acute than chronic HBV infection. Hepatitis B e antigen was detected in one (9%) patient with acute infection, less frequently than in six (46%) patients with chronic infection (P < 0.05). Mutations in the precore region was detected in HBV DNA clones from ten (91%) patients with acute infection and only in those from eight (62%) patients with chronic infection. All HBV DNA clones from the five (38%) patients with chronic infection that did not have precore mutations, however, possessed mutations in the core promoter. These results indicate that HBV mutants incapable of translating hepatitis B e antigen would play a major role in fulminant hepatic failure occurring after acute HBV infection. In contrast, HBV variants with core promoter mutations for reducing the transcription of hepatitis B e antigen would play an additional role in fulminant hepatic failure developing during chronic infection. (C) 1998 Wiley-Liss, Inc.

RNA of GB virus C (GBV-C) was detected in 12 of the 99 (12%) patients with chronic liver disease in India, including two of 11 (18%) with antibody to hepatitis C virus (HCV), as well as in six of the 21 (29%) patients with anti-HCV in Iran and 16 of the 54 (30%) patients with anti-HCV in Slovenia. Of the 99 patients in India, 47 were without serological markers of hepatitis B or C virus infection and four (9%) of them were positive for GBV-C RNA. Genotypes of GBV-C in the 34 samples from the three countries were invariably G2 that is prevalent in Europe and the United States. In contrast, the distribution of HCV genotypes were much different among them with 2c, 4d and 5a detected locally, in addition to I/la, II/lb and V/3a. These results indicate frequent GBV-C infection with genetic divergence much less than that of HCV in patients with chronic liver disease in India, Iran and Slovenia. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

Efficacy of 24-week administration of recombinant interferon alfa 2a to 100 patients with chronic hepatitis B was investigated. 9 MU of Interferon was injected daily for 2 weeks followed by 22 week af 9 MU interferon thrice weekly. Among 52 HBeAg-positive patients who completed interferon therapy, e antigen became negative in 27 (52%) and ALT turned normal in 25 (48%) at 24 weeks after discontinuation of interferon. Serum HBVDNA decreased in all cases during therapy, although none of the patients persistently cleared serum HBVDNA. Of 39 HBeAgnegative patients, normalization of ALT was retained in 23 (59%) at 24 week after therapy. In this group, serum HBVDNA became negative during interferon therapy in 9 (23%) cases. Twenty four week administration of interferon seems to be an effective therapeutic approach for chronic hepatitis B, with or without serum HBe-antigen.

The prevalence of hepatitis C virus (HCV) infection and factors relating to the HCV transmission were evaluated in a community without high mortality from chronic liver disease in Niigata prefecture. A total of 2,231 subjects were examined to detect anti-HCV core antibodies by enzyme-linked immunosorbent assay with synthetic peptides CP14 and CP9. The prevalence was 1.66% (95% CI 1.17% to 2.29%) and tended to increase with age. The values were lower than those reported from districts with hepatic disease endemic. Histories of blood transfusion (relative risk (RR) 5.51 95% CI 2.90 to 10.48) and surgery with hospital admission (RR 4.43 95% CI 2.04 to 9.65) were significantly associated with the anti-HCV core antibodies positive. Multiple logistic analysis corroborated independency of these factors. Among 188 subjects who experienced surgery and/or blood transfusion after 1990, only one (0.5%) had HCV infection. By contrast, 8 (3.5%) were positive in subjects who experienced first acupuncture therapy after 1990. The acupuncture therapy in alternative medicine could be still related to the HCV transmission.

Efficacy of standard regimens (e,g., 3-6 MU for 24 weeks) of alfa-IFN therapy for chronic hepatitis C has been limited, particularly in patients with HCV/1b. To see if higher-dose longer term treatment is more effective, we tried a 9 MU 60-week regimen. HCV/1b-infected chronic hepatitis patients received 9 MU IFN alpha 2a everyday but Sunday for 2 weeks and thrice a week for next 10 weeks, and 76 patients became HCV RNA-negative while 81 remained positive. The RNA-negative patients were then randomized to receive 3 MU (group I, n=37) or 9 MU (group II, n=39) for 48 weeks. Of che RNA-positive patients, only those with normal ALT received another 9 MU 48-week treatment (group III, n=45). Sustained responders (SR) were defined as those with negative RNA and normal ALT 6 months after the therapy. SR rates based on intent-to-treat principle did not differ significantly between groups I and II (30% vs 41%), but those based on the protocol-compatible cases showed a significant difference (32% vs 56%, p=0.034). SR rate in group III was significantly lower than those in group II. Adverse effects of IFN, developed more frequently in groups II and III than in group I, were mostly reversible. In conclusion, our results encourage 9 MU 60-week IFN alpha treatment in HCV/1b-infected patients with careful attention to adverse effects, and suggest that the treatment should be discontinued if HCV RNA does not disappear within 12 weeks.

The genomic DNA of a novel virus named TT virus (TTV), associated with posttransfusion hepatitis of unknown etiology, was cloned from plasma of a blood donor with an elevated transaminase level but without serological markers of known hepatitis viruses, and its sequence of 3739 bases was determined. TTV had a density of 1.26 g/cm(3) in sucrose, which did not change after the treatment with Tween 80. The viral genome was sensitive to DNase I and Mung Bean Nuclease. Hence, TTV would be an unenveloped, single-stranded DNA virus. Two possible open reading frames in different frames were identified, capable of encoding 770 and 202 amino acids, respectively. When a partial sequence of 356 bases was compared among TTV isolates from 78 sera from blood donors and hepatitis patients, it showed considerable divergence with differences of up to 30%. Oligonucleotide primers were designed on two well-conserved regions for the detection of TTV DNA in serum and biopsied liver tissues by polymerase chain reaction. TTV DNA was detected in sera from 9 of 19 (47%) patients with fulminant hepatitis and 41 of 90 (46%) patients with chronic liver disease of unknown etiology. TTV DNA was detected in liver tissues of all the five patients tested. in titers equal or 10-100 times higher than those in the corresponding sera. These results indicate that TTV would be responsible for a part of acute and chronic liver disease of unknown etiology. (C) 1998 Elsevier Science Ireland Ltd.

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.