Persistent HCV-infection and liver damage change vitamin-D-metabolism

Introduction: Low vitamin D (vit. D) serum concentrations have been found in patients with chronic hepatitis C. A genetic background has been supposed. Methods: We analyzed pre- and post-treatment 25-OH vit. D levels in 126 genotype 1 chronic HCV-infected patients. Genetic polymorphisms of CYP27B1 rs10877012 within the vit.-D-cascade and of IL28B rs12979860 were determined. Conventional prognostic features were also assessed. Results: Mean value of pretreatment serum 25-OH vit. D level was decreased in all patients but 36% had pretreatment vit. D levels above >20 ng/ml. Polymorphism of CYP27B1 was not associated with pretreatment vit. D level of 20≤ and of 20> (AA/AC/CC: 11%/42%/47% vs. 11%/40%/49%; p=ns). The polymorphism was not associated with treatment outcome (AA/AC/CC: 50%/50%/42%; p=ns). 25-OH vit. D levels of responders increased significantly after treatment (18 vs. 22 ng/ml; p=0.036) but not of non-responders (18 vs. 20 ng/ml; p=0.29). In responders only posttreatment vit. D levels of patients with AC-genotype of CYP27B1 increased but not of AA or CC (AC: p=0.004) while there was no association with non-responders. In responders with pretreatment vit. D levels of ≤20 ng/ml and AC-/CC-genotype of CYP27B1 a posttreatment increase of vit. D level was detectable (AC: p=0.001; CC: p=0.03) but also in non-responders of CC-genotype (p=0.007). Patients with vit. D levels below ≤20 ng/ml had both significantly more bridging fibrosis/cirrhosis (p=0.002) and higher degrees of steatosis (p=0.02). Polymorphism of IL28B rs12979860 (p<0.001) was associated with treatment outcome. Conclusion: Eradication of chronic HCV-infection leads to normalization of 25-OH vit. D level independently of the CYP27B1 rs10877012 polymorphism. Liver damage due to chronic HCV-infection and not the genetic background may affect the vit.-D-metabolism. Measurement of vit. D serum level may be added to the non-invasive prognostic factors for treatment outcome.