Thursday, February 14, 2013

Vitamin A deficiency reduced response to therapy for chronic HCV

Vitamin A deficiency reduced response to therapy for chronic HCV

Bitetto D. Hepatology. 2013;doi:10.1002/hep.26186.

February 14, 2013

Vitamin A deficiency is common among patients with chronic hepatitis C, and is associated with nonresponse to interferon-based treatment, according to recent results.

Researchers measured vitamin A and 25-OH vitamin D levels in 199 treatment-naive patients with chronic HCV before receiving interferon (INF)-based treatment, and compared them with 119 healthy controls. Participants also underwent genotyping for the IL-28B rs12979860 C>T polymorphism.

Patients with HCV had lower vitamin A serum levels than controls (256 ng/mL vs. 742 ng/mL; P<.0001). Vitamin A deficiency (200 ng/mL or less) was observed in 42.2% of patients, while 19.6% had severe vitamin A deficiency (100 ng/mL or less). Vitamin D deficiency (20 ng/mL or less) was present in 45.8% of evaluable patients; 9% were vitamin D deficient and severely vitamin A deficient.

Sustained viral response (SVR) occurred in 84.4% of genotype 2 or 3 patients and 42.2% of those with genotypes 1, 4 or 5. Nonresponse occurred in 21.6% of evaluable patients, including 2.3% of those with genotypes 2 or 3 and 37.5% of those with the more difficult-to-treat HCV genotypes. More people with severe vitamin A deficiency experienced nonresponse to treatment, overall (36.1% of cases vs. 18.2%; P=.019) and particularly among those with difficult-to-treat genotypes (61.9% vs. 31% of nondeficient participants; P=.015).

Multivariate analysis indicated associations between treatment nonresponse and vitamin A levels of 100 ng/mL or less (OR=3.68, 1.03-13.2); HCV RNA above 600,000 IU/mL (OR=4.87, 1.48-16.0); IL-28B T/* genotype (OR=22.8, 3.92-13.3); baseline gamma-glutamyltranspeptidase levels above 60 IU/mL (6.33, 1.92-20.8), and a cumulative ribavirin dose of 80% or lower (3.89, 1.05-14.4) for difficult-to-treat patients (95% CI for all).

“The real novelty and probably the most important finding … is the association between serum vitamin A deficiency and the condition of nonresponse to antiviral therapy, suggesting that vitamin A could be an important and modifiable factor interfering with IFN sensitivity in patients with chronic hepatitis C,” the researchers wrote. “ … vitamin A supplementation and normalization of its serum levels, before antiviral treatment, could enhance the responsiveness to IFN-based antiviral therapy.”

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