Influence of the IL6 − 147C/G polymorphism on clinical characteristics of chronic hepatitis C in Brazilian patients

- The study investigated if IL-6 -174C/G polymorphism was associated with clinical characteristics in chronic HCV patients.
- IL-6 -174C/G genotypes were not associated with HCV infection in Brazilian subjects.
- IL-6 -174C/G genotypes were not associated with markers of HCV infection (viral load, fibrosis, inflammation and levels of AST and ALT).

Interleukin-6 (IL-6) is a pleotropic cytokine which plays an important role in the immunological response to infections. Single nucleotide polymorphism at the promoter (− 174C/G) of the IL-6 gene was associated with IL-6 gene transcription rate and high circulating levels of IL-6 appears to affect the outcome of hepatitis C virus (HCV) infection. Therefore, the aim of our study was to ascertain if the IL-6 polymorphism is associated with HCV infection and clinical characteristics in Brazilian patients. Patients with chronic hepatitis C, infected with HCV genotypes 2 or 3, were studied. The IL-6 − 174C/G polymorphism (rs1800795) was analyzed by polymerase chain reaction (PCR) followed by restriction digestion. Viral genotype was obtained from medical records. A total of 125 patients and 125 healthy blood donor controls were evaluated. HCV genotype 2 was found in 28% of the patients and genotype 3 in 72%. The G allele frequency of the IL-6 − 174C/G polymorphism was 72.8% in the HCV patients. No significant statistically differences were observed in the IL-6 allele and genotype frequencies between HCV patients and controls as well as among markers of HCV infection (viral load, fibrosis, inflammation and aminotransferases) and IL-6 genotypes. In conclusion, IL-6 − 174C/G polymorphism is not associated with clinical characteristics of chronic hepatitis C in Brazilian patients.