Assessment of hepatitis C virus RNA and genotype from 6807 patients with chronic hepatitis C in the United States

Hepatitis C virus (HCV) RNA status and HCV genotype have become important t ools in the diagnosis and monitoring of therapy in chronic HCV infection. T o establish a database with respect to HCV genotype and serum HCV RNA conce ntrations in chronic hepatitis C patients in the United States, we analysed 6807 chronic hepatitis C patients who had HCV RNA and HCV genotype tests c onducted at a central laboratory. The HCV RNA concentration cut-off for the lower 25th percentile of this population (low titre) was 0.9 x 10(6) copie s ml(-1). The median HCV RNA concentration was 3.5 x 10(6) copies ml(-1) an d the cut-off for the upper 25th percentile (high titre) was 5 x 10(6) copi es ml(-1). Male patients had a median HCV RNA concentration of 3.9 x 10(6) copies ml(-1), which was significantly higher than the median HCV RNA level for females (2.75 x 10(6) copies ml(-1); P < 0.001). HCV genotype 1 was de tected in 73% of patients; genotype 2 in 14%; genotype 3 in 8%; mixed genot ype in 4%; and genotypes 4, 5 and 6 with a frequency of < 1%. Patients from the Northeast, Southeast and Midwest had significantly (P < 0.001) more in fections with genotype 1 than patients from the Western and Southern region s. African-American patients were more likely to be infected with genotype 1 when compared with Caucasian, Hispanic or Asian Pacific Islanders (P < 0. 001). Patients infected with HCV genotype 1 and mixed HCV genotypes had sig nificantly higher serum HCV RNA concentrations when compared with HCV genot ypes 2 and 3 (P < 0.001 for all comparisons).