[Differential response to pegylated interferon plus ribavirin combination therapy in chronic hepatitis C and HIV/HCV co-infected patients].

OBJECTIVE: To investigate the potential differences in response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) combination therapy in patients with hepatitis C virus (HCV) mono-infection and human immunodeficiency virus (HIV)/HCV co-infection.

METHODS: Seventy HIV/HCV patients and sixty HCV patients, were administered a 48-week course of Peg-IFN + RBV. The HCV load was tested by the COBAS automatic viral load analysis system (lower limit of quantification = 15 IU/ml) at treatment weeks 0 (baseline), 4, 12, 24, and 48 and at week 24 after drug withdrawal. The patients were also genotyped by sequencing for the host-encoded interleukin (IL)-28B single nucleotide polymorphisms (SNPs) related to HCV Peg-IFN + RBV therapy outcome: rs8099917, rs12979860 and rs12980275. In addition, the HCV-encoded NS5B gene region was genotyped by nested-PCR and sequencing followed by BLAST searching of the Los Alamos National Laboratory HCV database. The significance of between-group differences in response to therapy and roles of SNPs were evaluated by statistical analyses.

RESULTS: The ratio of sustained virological response (SVR) was significantly lower in the HIV/HCV co-infected patients than the HCV mono-infected patients (32.9% vs. 71.7%; P less than 0.001). While the HIV/HCV co-infected patients did not show a significant difference in SVR ratio achieved between individuals infected with the HCV-1 genotype and the non-HCV-1 genotype (30.8% vs. 33.3%; P = 1.000), the HCV mono-infected patients did (86.1% vs. non 50.0%, P = 0.002). Moreover, the SVR ratio was higher in the HCV-1 genotype HCV mono-infected patients than in the HIV/HCV-1 genotype co-infected patents (30.8% vs. 86.1%; P less than 0.001). The different IL-28B genotypes were not significantly correlated to the PEG-IFN+RBV therapy response of either HCV mono-infected patients or HIV/HCV co-infected patients (P more than 0.05).

CONCLUSION: HCV mono-infected patients respond better to Peg-IFN + RBV therapy than HIV/HCV co-infected patients. The HCV-1 genotype may promote this therapy response in HCV mono-infected patients, but the IL-28B genotypes appear to play no significant role.