[Use of DNA sequence hybridization with specific oligonucleotide probes to identify hepatitis C virus genotypes]

Recent development of an assay based on the hybridization of the amplification product obtained by polymerase chain reaction (PCR) of the RNA of hepatitis C virus (HCV) with specific probes for each viral genotype ("reverse-hybridization"), has permitted to have a rapid, simple and reproductible technique to identify the different genotypes of HCV. The identification of HCV genotypes seems to be important given their different pathogenic capacity and response to interferon therapy.

We prospectively studied 221 patients with HCV infection defined by the detection of viral RNA in serum by "nested-PCR". HCV genotype was determined by "reverse-hybridization" using specific oligonucleotide-probes for each genotype corresponding to the 5, UTR.

HCV 1b genotype was predominant in 221 patients studied (180/221, 81%), followed by 1a (10%) and by 3 and 4 (4% respectively). Two patients presented mixed infection (1a/1b). No case of infection by genotypes 2 and 5 was found. The predominance of 1b genotype was more evident in adults than in children (83 vs 62%) (p < 0.05).

HCV 1b is the predominant genotype among our patients with hepatic disease induced by HCV. The reverse-hybridization assay is a simple and rapid technique that permit the identification of the most important genotypes of hepatitis C virus.