HEPATITIS-C VIRAL COMPLEXITY DETECTED BY SINGLE-STRAND CONFORMATION POLYMORPHISM AND RESPONSE TO INTERFERON THERAPY

Background/Aims: Hepatitis C virus (HCV) genome heterogeneity by seque nce analysis in association with interferon (IFN) inefficacy has been reported. This study was performed to establish a convenient method fo r detecting the HCV quasispecies complexity and to determine the corre lation between the complexity and the responsiveness to IFN therapy in patients with chronic hepatitis C. Methods: The quasispecies complexi ty of HCV hypervariable region 1 in patients treated with IFN-alpha wa s analyzed by polymerase chain reaction-mediated single-strand conform ation polymorphism (SSCP). Results: Seven of 25 patients (28%) with lo w complexity (SSCP band number of less than or equal to 2) were HCV RN A negative after treatment, whereas in 24 patients with high complexit y (SSCP band number of greater than or equal to 3), the response to IF N was almost insignificant because only 1 patient (4.5%) remained HCV RNA negative after treatment (P < 0.05). Among type 1b patients, IFN t herapy was only effective for patients with low amounts of HCV RNA (le ss than or equal to 10(7.5) copies/mL serum) and low complexity. In co ntrast, most type 2a patients tended to respond to the therapy with ex ceptions being those with high amounts of HCV RNA and high complexity. Conclusions: The complexity of the hypervariable region 1 quasispecie s may be a factor for predicting IFN inefficacy in patients with chron ic hepatitis C.