The cytotoxic lymphocyte antigen 4 polymorphisms affect response to hepatitis C virus-specific therapy in HIV(+) patients with acute and chronic hepatitis C virus co-infection.

OBJECTIVE: Cytotoxic lymphocyte antigen 4 (CTLA4), a co-receptor expressed on T lymphocytes, is involved in the regulation of T-cell functions. Here, we analyzed the potential impact of the CTLA4 polymorphisms on response to hepatitis C virus (HCV)-specific treatment in HIV(+) patients co-infected with HCV. PATIENTS AND METHODS: A total of 184 HIV/HCV co-infected Caucasian patients were enrolled into this study, including 109 patients with chronic and 75 patients with acute hepatitis C. CTLA4 genotypes were determined by LightCycler PCR.
RESULTS: We found the CTLA4 -318 C/C genotype to be associated with sustained virological response in HCV/HIV co-infection (P = 0.035). Moreover, response rates were significantly higher in patients with a +49G/G genotype [23/29 (79.3%)] than in carriers of other +49 genotypes [59/155 (38.1%); OR 6.2; P = 0.00005]. Of note, the CTLA4 +49G/G genotype was confirmed as an independent predictor for treatment response in both patients with acute and chronic hepatitis C.
CONCLUSION: CTLA4 polymorphisms are associated with treatment-induced resolution of HCV infection in HIV co-infected patients. These findings underline the impact of genetic host factors for successful treatment.