EXPRESSION OF INTERFERON RECEPTOR GENES (IFNAR1 AND IFNAR2 MESSENGER-RNA) IN THE LIVER MAY PREDICT OUTCOME AFTER INTERFERON THERAPY IN PATIENTS WITH CHRONIC GENOTYPE 2A OR 2B HEPATITIS-C VIRUS-INFECTION

Hepatitis C virus (HCV) genotype 2a or 2b is associated with a favorab le outcome after interferon therapy. However, 19% to 33% of patients d o not respond to therapy. We investigated whether interferon receptor gene (IFNAR1 and IFNAR2 mRNA) expression in the liver before interfero n therapy predicts long-term response to therapy in patients with geno type 2a or 2b HCV infection. Twenty-seven patients who subsequently re ceived interferon-alpha therapy underwent liver biopsies before interf eron therapy. Hepatic IFNAR1 and IFNAR2 mRNA were determined using a r everse transcription-polymerase chain reaction assay. Twenty (74%) pat ients responded to interferon therapy, while the remaining seven (26%) patients were nonresponders. The expression rates of IFNAR1 and IFNAR 2 mRNA in the liver were significantly higher in responders than nonre sponders (p < 0.01, by chi-square test). The presence of either IFNAR1 or IFNAR2 mRNA predicted complete response to interferon treatment, w ith a positive predictive value of 100%. Multiple logistic regression analysis showed that IFNAR1 and/or IFNAR2 mRNA expression was the only significant predictor of the effectiveness of IFN therapy (p = 0.0002 ). We conclude that expression of interferon receptor genes in the liv er is a useful index for predicting the long-term efficacy of interfer on therapy in patients with chronic genotype 2a or 2b HCV infection.