Masako Fukuda

Fecal excretion of a nonenveloped DNA virus (TTV) associated with posttransfusion non-A-G hepatitis

Five patients with type B or C hepatocellular carcinoma were found to be infected with a nonenveloped DNA virus (TTV) associated with posttransfusion hepatitis of non‐A–G etiology. Paired feces and serum samples from these patients were tested for TTV DNA by polymerase chain reaction with seminested primers and their sequences were compared. TTV DNA was detected in sera from all of the patients, while it was detected in feces from three patients, including two with high viral titers in serum. When feces and serum from one patient were subjected to floatation ultracentrifugation in CsCl, TTV in feces banded at a peak density of 1.35 g/cm3 and that in serum at 1.31–1.32 g/cm3. TTV isolates in three pairs of feces and serum had the identical sequence of 222 base pairs. The excretion of TTV into feces indicates that TTV would be transmitted not only parenterally but also nonparenterally by a fecal–oral route. J. Med. Virol. 56:128–132, 1998.

Infection with GB virus C (GBV-C) in patients with chronic liver disease or on maintenance hemodialysis in Indonesia.

RNA of a non‐A to E hepatitis virus identified recently and designated provisionally GB virus C (GBV‐C), was sought in patients in Indonesia by reverse‐transcription polymerase chain reaction with nested primers deduced from a helicase‐like region. GBV‐C RNA was detected in 32 (55%) of 58 patients on maintenance hemodialysis at a frequency significantly higher (P < 0.001) than that in seven (5%) of 149 patients with chronic liver disease. Co‐infection with hepatitis C virus was observed in 26 (81%) of the 32 patients on hemodialysis and in five (71%) of the seven patients with liver disease who were infected with GBV‐C. Complete identity was observed in a sequence of 100 base pairs in the helicase‐like region for GBV‐C cDNA clones from some patients on maintenance hemodialysis. These results indicate that the patients on hemodialysis would be at high risk for GBV‐C infection, which would be transmitted by transfusion and patient‐to‐patient routes.

Species-specific TT viruses and cross-species infection in nonhuman primates.

ABSTRACT Viruses resembling human TT virus (TTV) were searched for in sera from nonhuman primates by PCR with primers deduced from well-conserved areas in the untranslated region. TTV DNA was detected in 102 (98%) of 104 chimpanzees, 9 (90%) of 10 Japanese macaques, 4 (100%) of 4 red-bellied tamarins, 5 (83%) of 6 cotton-top tamarins, and 5 (100%) of 5 douroucoulis tested. Analysis of the amplification products of 90 to 106 nucleotides revealed TTV DNA sequences specific for each species, with a decreasing similarity to human TTV in the order of chimpanzee, Japanese macaque, and tamarin/douroucouli TTVs. Full-length viral sequences were amplified by PCR with inverted nested primers deduced from the untranslated region of TTV DNA from each species. All animal TTVs were found to be circular with a genomic length at 3.5 to 3.8 kb, which was comparable to or slightly shorter than human TTV. Sequences closely similar to human TTV were determined by PCR with primers deduced from a coding region (N22 region) and were detected in 49 (47%) of the 104 chimpanzees; they were not found in any animals of the other species. Sequence analysis of the N22 region (222 to 225 nucleotides) of chimpanzee TTV DNAs disclosed four genetic groups that differed by 36.1 to 50.2% from one another; they were 35.0 to 52.8% divergent from any of the 16 genotypes of human TTV. Of the 104 chimpanzees, only 1 was viremic with human TTV of genotype 1a. It was among the 53 chimpanzees which had been used in transmission experiments with human hepatitis viruses. Antibody to TTV of genotype 1a was detected significantly more frequently in the chimpanzees that had been used in transmission experiments than in those that had not (8 of 28 [29%] and 3 of 35 [9%], respectively; P = 0.038). These results indicate that species-specific TTVs are prevalent in nonhuman primates and that human TTV can cross-infect chimpanzees.

Sequestration of TT Virus of Restricted Genotypes in Peripheral Blood Mononuclear Cells

ABSTRACT Peripheral blood mononuclear cells (PBMC) harbored TT virus (TTV) of genotypes (3 and 4) different from those (1 and 2) of free virions in plasma of the same individuals. PBMC may act as a reservoir, and TTV of particular genotypes might have tropism for hematopoietic cells.

Infection with GB virus C in patients with chronic liver disease

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. J. Med. Virol. 51:175–181, 1997.

Infection with hepatitis G virus and its strain variant, the GB agent (GBV-C), among blood donors in Japan

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 (< or = 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 per L (0/108) (p < 0.002), donors with ALT values > or = 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.

High Prevalence of e Antigen among Healthy Blood Donors Carrying Hepatitis B Surface Antigen in Japan

Abstract. Hepatitis B surface antigen (HBsAg) was detected by an immune adherence haemagglutination method in the serum samples of 292 voluntary, apparently healthy blood donors at four regional blood centres in Japan. Their serum samples were concentrated 3‐fold and tested for e antigen (e Ag) and antibody to e (anti‐e) by immunodiffusion. The e Ag was found in 41 samples (14.0%) and anti‐e in 57 (18.6%). When 100 randomly selected serum samples containing HBsAg were tested as they were (unconcentrated), and at 3‐ and 5‐fold concentrations, e Ag was detected in 3,16 and 27, respectively, and anti‐e in 10,21 and 26. Subtypes of HBsAg were similar in carriers with e Ag and with anti‐e. There is a high prevalence of e Ag in healthy individuals in Japan. There are also high rates of vertical transmission of hepatitis B virus from mothers to children, as well as a high incidence in the past of post‐transfusion hepatitis. This is a further evidence that e antigen is a marker for the infectivity of hepatitis B virus in carriers.