Letters to the Editors
Enhancing predictive ability of IL28B-SNPs for SVR in HCV
Article first published online: 15 DEC 2011
© 2011 Blackwell Publishing Ltd
Alimentary Pharmacology & Therapeutics
Volume 35, Issue 2, pages 317–318, January 2012
How to Cite
Amanzada, A., Schneider, S., Moriconi, F., Mihm, S., van Thiel, D. H. and Ramadori, G. (2012), Enhancing predictive ability of IL28B-SNPs for SVR in HCV. Alimentary Pharmacology & Therapeutics, 35: 317–318. doi: 10.1111/j.1365-2036.2011.04931.x
- Issue published online: 15 DEC 2011
- Article first published online: 15 DEC 2011
Sirs, We read with interest the article by Fattovich et al.1 dealing with chronic hepatitis C virus (HCV) infection. Patients chronically infected with HCV infection genotype 1 (HCV-G1) respond to an antiviral dual therapy with a sustained viral response (SVR) in only 40–50%.2
Presently, the most powerful genetic predictors for treatment outcome after combination therapy are the IL28B genotypes.3–5 This retrospective study of 264 chronic HCV-G1 infected patients evaluated the recently described IL28B rs12979860 and rs8099917 polymorphisms, as well as the patient’s pre-treatment serum γ-GT/ALT-ratio,6 as predictive factors for a favourable outcome following antiviral therapy in an unselected cohort of chronic HCV-G1 infected patients.
In contrast to the published studies, which were performed on highly selected patients, and reported SVR rates of 60% or 80% among patients with a favourable genotype,3, 7 the present finding of a 50% SVR rate for IL28B rs12979860 C homozygotes in an unselected, ordinary chronic HCV-G1 cohort may reflect the expected therapeutic outcome for patients with the preferred genotype more realistically.
Combining the IL28B genotypes with the pre-treatment serum γ -GT/ALT ratio identified individuals who have SVR rates as high as 87%, and logistic regression analysis revealed an odds ratio of 26.7 (Confidence interval: 10–71.1). The pre-treatment γ -GT/ALT ratio is an inexpensive, simple and reliable predictive factor, as both parameters are routinely determined in individuals with chronic hepatitis.
The present analysis has identified a cut-off value of 0.70, utilising receiver operating characteristics curve (ROC) analysis for genotype 1 patients with regard to the achievement of an SVR. Moreover, the present study documents the finding of a higher sensitivity, specificity, positive and negative predictive value of this ratio than that reported for both IL28B polymorphisms, with an area under the ROC of 0.75.
In conclusion, an assessment of the pre-treatment serum γ-GT/ALT ratio enhances the predictive value of the IL28B genotypes significantly.
Declaration of personal and funding interests: None.