Genotyping was performed on 75 hepatitis C virus carriers in Japan, where ..... b ASC, asymptomatic carrier; CPH, chronic persistent hepatitis; CAH, chronic ...
JOURNAL OF CLINICAL MICROBIOLOGY, May 1997, p. 1184–1189 0095-1137/97/$04.0010 Copyright q 1997, American Society for Microbiology
Vol. 35, No. 5
Hepatitis C Virus Replicative Levels and Efficiency of Genotyping by Specific PCR and Antibody Assay NOBUKAZU YUKI, NORIO HAYASHI,* EIJI MITA, HIDEKI HAGIWARA, KAZUYOSHI OHKAWA, KAZUHIRO KATAYAMA, YUTAKA SASAKI, AKINORI KASAHARA, HIDEYUKI FUSAMOTO, AND TAKENOBU KAMADA First Department of Medicine, Osaka University Medical School, Suita 565, Japan Received 12 June 1996/Returned for modification 29 August 1996/Accepted 10 February 1997
We studied factors which influence the detection of hepatitis C virus genotypes by the group-specific PCR of the sequence within the core region gene and by the newly developed genotype-specific NS4 antibody assay. Genotyping was performed on 75 hepatitis C virus carriers in Japan, where patients with hepatitis C viremia are exclusively infected with genotypes 1b, 2a, and 2b. PCR failed to identify genotypes in 8 (11%) patients, whereas 12 (16%) patients, including the 8 patients mentioned above, could not be genotyped by the serological assay. Serological genotypes showed almost complete agreement with those found by the PCR except that double infection was revealed in only two of the eight patients serologically judged to be coinfected with genotypes 1 and 2. In each assay, disease activity and levels of viremia assessed by a competitive reverse transcription PCR assay were significantly lower in patients infected with untypeable isolates than in those infected with typeable ones (P < 0.01). The PCR could identify the genotypes of isolates from all 64 patients with levels of viremia of >106 copies/ml, and the genotype-specific antibody responses were found in 60 (94%) patients. In contrast, isolates from only 3 (27%) of 11 patients with low levels of viremia (
