Secreted Phosphoprotein 1 Promoter Genetic Variants Are Associated with the Response to Pegylated Interferon α Plus Ribavirin Combination Therapy in Egyptian Patients with Chronic Hepatitis C Virus Infection

BACKGROUND/AIMS The T-helper 1 (TH1) immune reaction is essential for the eradication of hepatitis C virus (HCV) during pegylated interferon α (PEG-IFN-α)- and ribavirin (RBV)-based therapy in chronic HCV patients. Secreted phosphoprotein 1 (SPP1) was shown to be a crucial cytokine for the initiation of a TH1 immune response. We aimed to investigate whether SPP1 single nucleotide polymorphisms (SNPs) may influence sustained virological response (SVR) rates. METHODS Two SNPs in the promoter region of SPP1 at the -443 C>T and -1748 G>A loci were genotyped in 100 patients with chronic HCV genotype 4 infection using a TaqMan SNP genotyping assay. RESULTS Sixty-seven patients achieved a SVR, and 33 patients showed no SVR. Patients carrying the T/T genotype at the -443 locus showed a significantly higher SVR rate than those carrying the C/T or C/C genotype (83.67% vs. 50.98%, p<0.001). At the -1748 locus, the SVR rate was significantly higher in patients with the G/G genotype than in those with the A/A genotype (88.89% vs. 52.63%, p=0.028) and in patients with the G/A genotype than in those with the A/A genotype (85.29% vs. 52.63%, p=0.001). CONCLUSIONS SPP1 SNPs at -443 C>T and -1748 G>A loci may be useful markers for predicting the response to PEG-IFN-α-2b plus RBV therapy in Egyptian patients with chronic HCV genotype 4 infection.