Association of TNF-alpha (-308 A/G) and IFN-gamma (+874 A/T) gene polymorphisms in response to spontaneous and treatment induced viral clearance in HCV infected multitransfused thalassemic patients.

BACKGROUND: Multitransfused thalassemic individuals are at high risk of developing transfusion transmitted Hepatitis C virus (HCV) infection. The aim of the study was to correlate the effects of host cytokine single nucleotide polymorphisms of TNF-α (-308 A/G) and IFN-γ (+874 A/T) in spontaneous or IFN induced treatment response in the HCV infected thalassemic individuals.

METHODS: A total of 427 HCV sero-reactive thalassemic individuals were processed for HCV viral genomic diversity and host gene polymorphisms analysis of TNF-α (-308 A/G) and IFN-γ (+874 A/T).

RESULTS: Out of 427 HCV sero-reactive individuals, 69.09% were found to be HCV RNA positive with genotype 3 as the predominant infecting strain (94.29%). Study highlighted that, A allele was significantly associated with (p < .05) spontaneous clearance of HCV infection and G allele was correlated with viral persistence at TNF-α (-308) gene polymorphism. Whereas in case of IFN-γ (+874) SNPs, A allele was significantly responsible (p < .05) for spontaneous clearance than T allele. Our study also indicated that in relapsed cases, IFN-γ (+874) T allele is more responsible than A allele. Though no significant correlation was found at both TNF-α (-308) and IFN-γ (+874) gene polymorphism among SVR and relapsed thalassemic patients.

CONCLUSION: A allele at both TNF-α (-308) and IFN-γ (+874) were strongly associated with spontaneous clearance among this population. But in case of SVR and relapsed cases no significant association was found. This cytokine gene polymorphisms pattern will help clinicians to take an informed decision about therapeutic management of HCV infected thalassemic individuals.