Comparison of serum hepatitis C virus (HCV) RNA and core antigen levels in patients coinfected with human immunodeficiency virus and HCV and treated with interferon plus ribavirin

Abstract

Trak-C (Ortho-Clinical Diagnostics) is an enzyme-linked immunosorbent assay-based method capable of quantifying hepatitis C virus (HCV) core antigen (CA) in serum and could be an alternative to molecular detection and quantification of HCV RNA. We have evaluated the Trak-C assay in comparison with an HCV RNA quantitative assay (Versant HCV v3.0; Bayer Diagnostics) in the follow-up of 348 treated, human immunodeficiency virus (HIV)/HCV-coinfected patients included in the ANRS HC02 RIBAVIC trial. ANRS HC02 RIBAVIC is a therapeutic, multicenter, randomized protocol comparing the efficacy of alpha interferon 2b (IFN-alpha2b) (3 million units three times a week)-ribavirin (800 mg/day) to that of pegylated IFN-alpha2b (1.5 mug/kg of body weight/week)-ribavirin (800 mg/day) during 48 weeks of treatment of HIV/HCV-coinfected patients naïve to HCV treatment. Patients were assessed for virological analysis at day 0 and weeks 4, 12, 24, 48, and 72. Correlation of HCV RNA and HCV CA at the initiation of treatment was excellent (r = 0.92). HCV RNA and CA kinetics were similar during follow-up of HCV treatment from day 0 to week 72 whatever the group of response and genotype. The positive and negative predictive values of response to the treatment at week 4 were 59 and 94%, respectively, for HCV RNA load reduction of >2 log and 54 and 94%, respectively, for HCV CA below the threshold value (4.18 log(10) pg/ml . 10(4)). Trak-C, a new assay able to quantify CA in HIV/HCV-coinfected patients, correlates well with quantitative HCV RNA assays and is cheaper and easier to perform than molecular technology. HCV CA could be a valuable alternative test for therapeutic follow-up of coinfected patients treated with IFN plus ribavirin in developing countries.

FIG. 1.

Correlation between HCV markers at the initiation of standard interferon or pegylated interferon plus ribavirin after 48 weeks of therapy for HIV/HCV-coinfected patients (n = 341). Dash-dotted light-gray line, threshold of HCV CA at 4.2 log; dotted light-gray line, threshold of HCV RNA at 2.5 log. Note the good correlation between these two markers of HCV infection (Pearson coefficient of 0.92; P < 0.001).

FIG. 2.

Dispersion observed for HCV RNA or HCV CA level per genotype in HIV/HCV-coinfected patients. (A) HCV CA variations; (B) HCV RNA variations. Means of HCV RNA or CA detection were similar whatever the genotype.

FIG. 3.

Viral kinetics for (A) NR (n = 198), (B) SVR (n = 93), (C) RR (n = 25), and (D) RB (n = 32). HIV/HCV-coinfected patients were treated by standard interferon or pegylated interferon plus ribavirin therapy for 48 weeks (gray bar). Dash-dotted gray line, threshold of HCV CA (○) at 4.2 log. Dotted gray line, threshold of HCV RNA (▪) at 2.5 log. Means and 95% confidence interval values are reported for quantitative HCV RNA and CA at each week point of follow-up.

FIG. 3.

Viral kinetics for (A) NR (n = 198), (B) SVR (n = 93), (C) RR (n = 25), and (D) RB (n = 32). HIV/HCV-coinfected patients were treated by standard interferon or pegylated interferon plus ribavirin therapy for 48 weeks (gray bar). Dash-dotted gray line, threshold of HCV CA (○) at 4.2 log. Dotted gray line, threshold of HCV RNA (▪) at 2.5 log. Means and 95% confidence interval values are reported for quantitative HCV RNA and CA at each week point of follow-up.