Background:  HCV RNA clearance seems to occur more slowly in HIV/HCV-co-infected patients than in HCV-mono-infected subjects treated with pegylated interferon alfa (peg-IFN) plus ribavirin (RBV). As a consequence, concern exists on the feasibility to follow the rules applied to HIV-negative patients with chronic hepatitis C to HCV/HIV-co-infected subjects.

Methods:  All HCV/HIV-co-infected patients who completed a full course of peg-IFN + RBV in year 2002 at our institution (6 months for HCV genotypes 2 and 3; and 12 months for HCV genotypes 1 and 4) were analyzed. At baseline all had elevated ALT levels, detectable serum HCV-RNA, >350 CD4⁺ T-cells/mm³, and plasma HIV-RNA <10,000 copies/mL (with or without antiretroviral therapy).

Results:  We analyzed 89 HIV/HCV-co-infected individuals. As many as 29 (32.6%) reached sustained virological response. Reductions >2 logs in plasma HCV-RNA occurred in 52 (58%) at week 12 of treatment (early virological response). None of patients who showed HCV-RNA drops <2 logs at week 12 reached sustained virological response (negative predictive value:  100%). The positive predictive value of early virological response was 56%. On the other hand, relapses occurred in 19 (39.6%) of 48 patients who had negative HCV-RNA at the end of treatment, and did not differ comparing patients with HCV genotypes 2/3 and 1/4 (37.9% vs 42.6%). Thus, relapses were clearly higher than those reported in HCV-mono-infected patients, particularly in those with HCV genotypes 2 and 3.

Conclusions:  The quantitative assessment of plasma HCV-RNA at week 12 predicts the chance of sustained virological response using peg-IFN plus RBV in HIV⁺ patients with chronic hepatitis C, as it does in HIV^- individuals. Thus, discontinuation of anti-HCV therapy, which is associated with frequent side effects, might be warranted in HIV/HCV-co-infected patients showing HCV-RNA reductions <2 logs at week 12 of treatment. On the other hand, relapses in virological responders were unexpectedly high in HIV/HCV-co-infected patients when treatment was provided following the rules applied to HIV^- subjects. This is particularly relevant for HCV genotypes 2/3, which only rarely relapse in HIV^- patients. Therefore, extending therapy (for 12 months in genotypes HCV-2/3 and perhaps for 18 months in genotypes HCV-1/4) might be advisable in HIV/HCV-co-infected patients showing early virological response.

Keywords: hepatitis C; interferon; dynamics