Vitamin A deficiency is associated with hepatitis C virus chronic infection and with unresponsiveness to interferon-based antiviral therapy

Recent data suggest that vitamin A modulates the expression of type I interferon receptor enhancing the antireplication effect of interferon-α on hepatitis C virus (HCV). This study aimed to investigate the prevalence of vitamin A deficiency among patients with chronic HCV infection and to assess whether vitamin A deficiency could be associated with unresponsiveness to interferon-based antiviral therapy. The analysis included 199 consecutive treatment-naïve chronic HCV patients in whom pretreatment serum vitamin A and 25-OH vitamin D were measured; 119 healthy blood donors were used as controls. Median (interquartile range) serum vitamin A in HCV-positive patients was significantly lower than in controls: 256 ng/mL (128-440) versus 742 (624-942, P < 0.0001). Overall sustained viral response was achieved in 122/199 patients, 46/109 infected by difficult to treat HCV genotypes. In these latter, 39/104 (37.5%) were nonresponders. At multivariate analysis, nonresponse to antiviral therapy was predicted by carriage of interleukin (IL)-28B T/* genotypes, baseline serum levels of γGT >60 IU/mL, of HCV RNA >600,000 IU/mL, of vitamin A ≤100 ng/mL, and a cumulative dose of ribavirin ≤80%. Seventeen patients (9.0%) had both serum levels of vitamin A ≤100 ng/mL and of vitamin D ≤20 ng/mL; the presence of a combined vitamin A and D deficiency was found to be a strong independent predictor of nonresponse to antiviral therapy. Conclusion: A high percentage of patients with chronic HCV infection have serum vitamin A deficiency. This condition is associated with nonresponse to antiviral therapy.