Sustained viral response is rarely achieved in patients with high viral load of HCV RNA by excessive interferon therapy

Adequate dosing of interferon (IFN) and its cost-effectiveness for sustaine d virological response were evaluated in relation to viral load and subtype . Prospective analysis of IFN therapy on 326 patients with chronic hepatiti s C free from cirrhosis was performed using 9 or 6 million unit (MU) of IFN for six months daily and/or three times a week. Sustained virological resp onse was achieved in 50-94% of patients with less than or equal to 2 x 10(4 ) copies/ml (competitive RT-PCR) or <100 x 10(3) copies/ml (Amplicor monito r) of HCV RNA by 468-1206 MU of IFN, but response was only 0-25% of the pat ients with greater than or equal to 2 x 10(5.5) copies/ml (competitive RT-P CR) or >200 x 10(3) copies/ml (Amplicor monitor), even with 468-1206 MU of IFN. A high sustained rate was demonstrated in patients with 100-200 x 10(3 ) copies/ml of HCV RNA by 901-1206 MU of IFN, in comparison to that with le ss than or equal to 900 MU of IFN. Multivariate analysis showed that IFN do se had a significant value for the efficacy of IFN therapy in patients pres enting 100-200 x 10(3) copies/ml of HCV RNA. Cost efficacy analysis indicat ed that it cost approximately $10,000, $26,000, and $50,000-227,000 for one person-viral eradication in the patients with <100, 100-200, and >200 x 10 (3) copies/ml, respectively. High-dose IFN is only cost effective in patien ts with intermediate viral loads, and IFN therapy could be recommended in p atients with <200 x 10(3) copies/ml of HCV RNA.