Hepatitis C virus genotypes in patients with persistent infection--a preliminary report.

Hepatitis C virus (HCV) has nucleotide sequence diversity distributed throughout the viral genome, with variants showing even less than 70% homology. There is some evidence that sequence variation of HCV genotypes partly determines the course of infection and response to treatment with interferon. We studied the sera of 29 Israeli HCV patients, all suffering from chronic liver disease, and 34 patients with renal failure necessitating hemodialysis. HCV genotypes were detected using a reverse hybridization assay (LiPA), after reverse transcription polymerase chain reaction, using primers spanning the 5' UTR of the HCV genome. In this preliminary report the predominant HCV type detected was type 1, found in 65% of the chronic hepatitis patients and in 88% of the hemodialysis patients. Subtype 1b was the most prevalent and was detected in >40% of the chronic hepatitis patients and in >70%of the dialysis patients. Other types detected were 2a and 3, and in only two patients was type 4 found. More than 50% of patients with type 1 (1a or 1b) among patients with chronic hepatitis had received blood transfusion in the past, but only 16.6% of patients bearing subtype 2a HCV had such a history. Our preliminary evaluation revealed that patients bearing subtype 1b seemed to have a better response to interferon treatment, as compared with patients infected with subtypes 1a, 2a, who displayed a low response rate.