Detection of transfusion-associated hepatitis caused by non-A, non-B, non-C flavivirus.

Sera of patients suffering from acute hepatitis, and different forms of chronic hepatitis were found to be reactive to reagents prepared from the yellow fever virus (YF) vaccine strain. Serum samples of 1974 patients were tested, and 133 of them were positive. Hepatitis C virus specific antibodies were absent from the majority of them. The frequency of antibodies to other flaviviruses (tick-borne encephalitis, West Nile) and hepatitis B virus markers was similar to that measured among the population in Hungary positive for any of the surrogate markers of hepatitis infections. Results of both immunofluorescence tests, and Western blots suggest that there is a non-A, non-B, non-C hepatitis virus circulating among the Hungarian population, which possesses antigenic cross-reactivity with the yellow fever virus, but the identity to any of the known flaviviruses could not be verified yet. No history of yellow fever vaccination could be revealed in any of the patients included into this study. The anamnestic data on previous transfusions or surgical operations can be verified only in the case of the half of YFV-positive patients, nevertheless, the sexual transmission seems to be very infrequent. Attempts are continued in order to detect the viral RNA using polymerase chain reaction, and clone cDNA sequences for sequence analysis.

[Transfusion-associated non-A, non-B, non-C hepatitis caused by flaviviruses]. / A non-A, non-B, non-C flavivírus által okozott inokulációs hepatitis.

Hepatitis C virus was shown to be a member of the flavivirus family. Tick-borne encephalitis virus and West Nile virus, members of the same family occur in Hungary, too. Serum samples from patients suffering from transfusion associated hepatitis were tested with yellow fever virus antigens for specific IgG, and IgM using immunofluorescence test. Eight hundred serum samples were tested. Yellow fever virus related IgG antibodies were found in 232 sera. In the case of 72 patients specific IgM antibodies could also be detected. The majority of the IgM positive patients underwent surgical operation and/or blood transfusion 1 to 2 months before the onset of the disease. Fifty-four sera positive for yellow fever virus-related antibodies were tested with HCV reagents, but only 13 were found to be positive, or cross-reacting. The 20 patients with yellow fever related antibodies were controlled with tick-borne encephalitis antigens, too. Nevertheless, no measurable cross-reaction could be detected. No measurable cross-reaction could be detected with the West Nile virus. The hepatitis B markers also were tested in 44 sera positive for yellow fever antibodies. There was only one, which contained HBsAg, and 10 of them proved to be positive for anti-HBcAg. The results indicate, that a non-A, non-B, non-C flavivirus is also present in the Hungarian population, which can be detected on the basis of the antigenic cross-reactivity with the attenuated yellow fever virus. This virus seems to be responsible for every 11th transfusion associated hepatitis examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of antibody to hepatitis C virus in blood donors, high-risk groups and patients with liver diseases in Hungary. A multicentre study using ABBOTT EIA test and a comparison with an ORTHO ELISA test system.

Serum samples from 1185 individuals (blood donors, health-care workers, patients on haemodialysis, those from other high-risk groups and those suffering from non-A, non-B hepatitis or other liver diseases) were examined for antibody to a recombinant HCV antigen. An ABBOTT HCV EIA system was used throughout and in addition a parallel study with ORTHO HCV ELISA was done in 380 of the samples to compare the two anti-HCV tests. A confirmatory neutralizing ABBOTT ELISA probe was also performed in 45 cases. The anti-HCV test was positive in 1.60% of the healthy blood donors and in 9% of subjects excluded from donation for elevated aminotransferase. In patients on haemodialysis 47%, in other high-risk-group subjects 33% anti-HCV prevalence was found. Patients with acute and chronic post-transfusion NANB hepatitis showed 40% and 70% prevalence, respectively. The two ELISA tests revealed 95% agreement in the parallel determinations. Serial end-point-dilution studies of anti-HCV-positive sera suggest that the ABBOTT test was of superior sensitivity. The results of the confirmatory test suggest that reactive (positive) samples of low optical density near to the cut-off value, required a confirmation with the naturalization test. HCV infection seems to be a common aetiological factor in PT-NANB hepatitis in Hungary, therefore, screening of blood donors for anti-HCV may be justified.

HBsAg-like structures in immunosuppressed mice inoculated with human hepatitis B virus.

Thymectomised and irradiated DBA/2 mice were injected intraperitoneally with human serum containing high titer of HBsAg, and were positive for HBsAg. Through the entire experiment neither degenerative and inflammatory lesions nor hepatitis B virus antigens could be detected in the liver of these animals by histomorphology and immunofluorescence, respectively. The sera of all these mice were negative for HBsAg by radioimmunoassay. By electron microscopy, however, increasing amounts of filaments and round particles measuring 20-22 nm in diameter could be observed in the endoplasmic reticulum of the mouse hepatocytes from the 8th day following injection. From the 90th day after inoculation the number of the filaments increased in an extreme degree. After fixation with KMnO4 and EDTA preferential staining, the filaments proved to be highly electrondense. According to the authors the filaments observed in mouse livers are lipoproteins produced by the hepatocytes in response to HBV inoculation. The appearance of the filaments is HBsAg-like, though their immunological characteristics become modified.