Genotype, serum level of hepatitis C virus RNA and liver histology as predictors of response to interferon-alpha 2a therapy in Japanese patients with chronic hepatitis C.

To determine whether pretreatment HCV-RNA level, hepatitis C virus genotypes, alanine aminotransferase and histology correlate with subsequent response to interferon-alpha therapy or not, serum HCV-RNA levels and genotype were determined by branched DNA signal amplification assay and genotype-specific polymerase chain reaction in 43 patients with chronic active hepatitis C. Response to recombinant interferon-alpha 2a (504 million units in total) was defined as complete and sustained CR-->SR, n = 12), complete response followed by relapse (CR-->Rel, n = 17), and no response (NR, n = 10), excluding dropouts (n = 4). Patients who showed CR-->SR had a lower HCV-RNA level (0.438 x 10(6) eq/ml) compared to CR-->Rel (2.452 x 10(6) eq/ml, p = 0.008) and NR (4.882 x 10(6) eq/ml, p = 0.009). A higher proportion of patients with CR-->SR had type 2a HCV (67%) compared to the CR-->Rel (28%) and the NR (0%). There was a trend for type 1b hepatitis C virus infection to have higher serum HCV-RNA levels. There was no correlation between pretreatment HCV-RNA level and alanine aminotransferase. However, no relation between pretreatment HCV-RNA level and liver histology was observed; a high proportion of patients with CAH2a showed CR-->SR, compared to those with CAH2b (p = 0.001). Moreover, the patients with CAH2b who had low level hepatitis C virus viremia did not show CR-->SR. These data indicate that pre-treatment serum HCV-RNA levels, genotype and liver histology are good predictors of subsequent response to interferon-alpha therapy in Japanese patients with chronic hepatitis C virus infection.