the reduced predictive value of interleukin 28b gene polymorphisms in a cohort of patients with thyroiditis developed during antiviral therapy for chronic hepatitis c: a preliminary study

background: single nucleotide polymorphism in the interleukin28b (il28b) gene was recently shown to be associated with a significant increase in response to interferon-α and ribavirin treatment in patients with chronic hepatitis c. similarly, thyroid disease (td) occurring during treatment confer an improved sustained virologic response (svr). objectives: to determine the role of il28b genotypes in a cohort of hepatitis c patients who develop td during treatment and its relationship to svr. patients and methods: il28b gene profiles including rs12979860, rs12980275 and rs 8099917 and their genotypes were determined in a cohort of 23 hepatitis c patients who developed td during treatment and their relationship to svr. results: out of 23 studies cases, 19 has one or more favorable genotypes, of which 15 (78.9%) achieved svr. eleven has all three unfavorable genotypes and yet achieved 72.7 % svr. the presence of more than one favorable genotype only correctly predicts svr vs. non- svr in ~50 % of cases, i.e. by chance. conclusions: despite the small number of subjects, the presence of one or more unfavorable il28b genotype does not portend a poor svr prognostic outcome. this suggests that td in this clinical context may be a critical factor in the achievement of svr, probably above that of the genetic predisposition.