Analysis of interleukin-10 gene polymorphisms and hepatitis C susceptibility in Pakistan.

INTRODUCTION Hepatitis C virus (HCV) commonly causes a chronic infection but few of patients are able to clear the virus naturally. Interleukin-10 (IL-10) is an anti-inflammatory cytokine that can suppress the immune response against HCV. Interindividual variations in IL-10 production are genetically contributed by polymorphisms within the IL-10 promoter region. This study aimed to investigate the association of the IL-10 gene promoter -1082 G/A, -819 C/T, and -592 C/A polymorphisms with HCV infection susceptibility in Pakistani individuals. METHODOLOGY Eighty-nine chronically infected patients and 99 controls were enrolled in the study. IL-10 (-1,082 G/A, -819 C/T, -592 C/A) genotyping was performed by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). RESULTS A suggestive evidence of association with hepatitis C was obtained for the IL-10 -819 C/T (-592 C/A) (p: 0.03) promoter polymorphism at the allele level  but not in genotype distribution. The IL-10 -1082 allele showed no association while positive association of GG (p: 0.001) gene and negative association for GA (0.001) gene were observed.  Higher frequencies were observed for GTA (p: 0.02), ACC (p: 0.01) haplotype and GCC/GTA (p: 0.005) diplotype in HCV patients than controls while diplotype GCC/ATA showed protective effect against HCV. CONCLUSIONS Our findings suggest that different IL-10 gene polymorphisms may lead to an imbalance between the pro-inflammatory and anti-inflammatory cytokine responses which may in turn influence the susceptibility to HCV infection.