A Study of CC-Chemokine Receptor 5 (CCR5) Polymorphism on the Outcome of HCV Therapy in Egyptian Patients

BACKGROUND: Chronic hepatitis C virus (HCV) infection is a globally serious public health issue. OBJECTIVES: In this study, we investigated CC chemokine receptor 5 (CCR5-59029) polymorphism which is considered an important component of the immune system in determining the outcome of HCV infection. Its critical role as a marker in response to interferon therapy of HCV infection is also investigated besides its effect on other clinical patient factors. PATIENTS AND METHODS: This study was conducted on 82 Egyptian patients with chronic Hepatitis C Virus (HCV) infection who received PEG-INF + Ribavirin treatment for 48 weeks. The study was also conducted on 50 healthy controls (with negative results for HCV antibody and RNA PCR). Full history of patients in this study was recorded. Clinical and histological examinations, qualitative HCV nested RT-PCR, quantitative real –time PCR, and genotyping of HCV RNA genome were performed. CCR5-59029 polymorphism with nucleotide substitution from G to A was amplified. The amplicons were digested with restriction endonuclease Bsp 1286I, and produced RFLPs of the CCR5 genotypes were determined. RESULTS: The present study showed a significant association between the functional SNP of CCR5 gene and the viral response to interferon in chronic HCV Egyptian patients. It was shown that the higher fibrosis stages (F2-F4) had significant association with nonresponse to treatment compared to the lower fibrosis stages (F0-F1) (95% confidence: 5.497 - 55.074, P = 0.0001). In addition, worse liver activity grade (A2-A3) had a very highly significant association with non-responder HCV patients compared to those with better liver activity grade (A1) (95% confidence: 2.242 - 20.974, P = 0.0007). Most importantly HCV patients with G allele had a high significant association with nonresponse to treatment, higher fibrosis stages and worse liver activity grades, while the A allele had a high significant association with sustained response, low fibrosis stages and relatively better liver activity grade (95% confidence: 3.347 - 15.036, P = 0.0001). CONCLUSIONS: SNPs within the CCR5 gene should be considered as an important factor used in combination with other host gene SNPs when developing a mathematical model for anticipating response to HCV therapy.