ABSTRACT
Background and study aim : Vitamin D is a potent immunomodulator. It is reported to be related to the severity of fibrosis and responsiveness to interferon-based therapy in genotype 1 chronic hepatitis C (CHC), so we aimed to evaluate if there is an association between vitamin D metabolism related genes and vitamin D level with the degree of liver damage and the response to treatment of CHC in our locality. Patients and methods : Two hundred and forty five Egyptian patients (123 patients with sustained virological response and 122 patients with treatment failure) were included. They were subjected to routine investigation needed for treatment, in addition to estimation of 25-OH vitamin D level in serum by ELISA and CYP27B1-1260 gene polymorphism by PCR-RFLP method. Results: We found that serum levels of vitamin D showed statistically significant increase in responders in comparison with non responders. The distribution of CYP27B1-1260 AC and CC genotypes were significantly presented in the non responders in comparison with the responders. CYP27B1-1260 AC and CC genotypes carriers had a high risk for treatment failure, (OR= 14.7, 95% CI= 2.3-20.1, P<0.001; OR = 20.4, 95% CI= 2.9-21.3, P<0.005 respectively). Serum levels of vitamin D showed statistically significant negative correlations with the activity and fibrosis of the liver in both responders and non responders. Also, there was negative correlation between vitamin D level and viral load in non responder patients (r= -.232, P=0.01). As regard the value of serum vitamin D level in discriminating responders from non responders; area under the ROC curve was 0.708 (95% CI 0.643-0.774). At a cutoff value of 19 ng/dL of serum vitamin D yielded sensitivity 79%, specificity 58%, positive predictive value (PPV) 65%, and negative predictive value (NPV) 73%. Conclusion: Vitamin D serum level and CYB27B1 -1260 genotype could be used as a predictor to anti HCV treatment response in our locality