Article first published online: 14 OCT 2012
Copyright © 2012 American Association for the Study of Liver Diseases
Volume 56, Issue 5, pages 1641–1650, November 2012
How to Cite
Falleti, E., Bitetto, D., Fabris, C., Fattovich, G., Cussigh, A., Cmet, S., Ceriani, E., Fornasiere, E., Pasino, M., Ieluzzi, D., Pirisi, M. and Toniutto, P. (2012), Vitamin D binding protein gene polymorphisms and baseline vitamin D levels as predictors of antiviral response in chronic hepatitis C. Hepatology, 56: 1641–1650. doi: 10.1002/hep.25848
Potential conflict of interest: Nothing to report.
Mario Pirisi was supported in part by grants from the Ricerca Sanitaria Finalizzata Program, Regione Piemonte, Italy.
- Issue published online: 31 OCT 2012
- Article first published online: 14 OCT 2012
- Accepted manuscript online: 18 MAY 2012 11:50AM EST
- Manuscript Accepted: 7 MAY 2012
- Manuscript Received: 11 MAR 2012
Vitamin D deficiency seems to predict the unsuccessful achievement of sustained viral response (SVR) after antiviral treatment in hepatitis C virus (HCV) difficult-to-treat genotypes. Vitamin D binding protein (GC) gene polymorphisms are known to influence vitamin D levels. This study was performed to assess whether the interaction between basal circulating vitamin D and the GC polymorphism plays a role in influencing the rate of antiviral responses in patients affected by chronic hepatitis C. In all, 206 HCV patients treated with a combination therapy of pegylated (PEG)-interferon plus ribavirin were retrospectively evaluated. GC rs7041 G>T, GC rs4588 C>A, and IL-28B rs12979860 C>T polymorphisms were genotyped. Frequencies of GC rs7041 G>T and rs4588 C>A polymorphisms were: G/G = 64 (31.1%), G/T = 100 (48.5%), T/T = 42 (20.4%) and C/C = 108 (52.4%), C/A = 84 (40.8%), A/A = 14 (6.8%). Patients were divided into those carrying ≥3 major alleles (wildtype [WT]+: G-C/G-C, G-C/T-C, G-C/G-A, N = 100) and the remaining (WT−: G-C/T-A, T-A/T-C, T-A/T-A, T-C/T-C, N = 106). Four groups were identified: vitamin D ≤20 ng/mL and WT−, vitamin D ≤20 and WT+, vitamin D >20 and WT−, vitamin D >20 and WT+. In difficult-to-treat HCV genotypes the proportion of patients achieving SVR significantly increased with a linear trend from the first to the last group: 6/25 (24.0%), 9/24 (37.5%), 12/29 (41.4%), 19/29 (65.5%) (P = 0.003). At multivariate analysis, having basal vitamin D >20 ng/mL plus the carriage of GC WT+ was found to be an independent predictor of SVR (odds ratio 4.52, P = 0.015). Conclusion: In difficult-to-treat HCV genotypes, simultaneous pretreatment normal serum vitamin D levels and the carriage of GC-globulin WT isoform strongly predicts the achievement of SVR after PEG-interferon plus ribavirin antiviral therapy. (HEPATOLOGY 2012;56:1641–1650)