Vitamin D receptor gene polymorphisms and distinct clinical phenotypes of hepatitis B carriers in Taiwan.

Vitamin D exhibits immunomodulatory and antiproliferative effects through vitamin D receptor (VDR) in chronic infections and cancers. We genotyped the BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) polymorphisms of VDR gene in 250 Taiwanese chronic hepatitis B virus (HBV) carriers who were categorized into six phenotypes. After adjustment for age and sex, the frequencies of the VDR B/b, B/a, B/T, B/a/T in patients with hepatitis flare(s) were lower than those without (7 vs 20%, P=0.009; 1 vs 9%, P=0.004; 3 vs 10%, P=0.007; 1 vs 9%, P=0.005, respectively); in contrast, T/t, A/T, A/t, b/A/t were higher in flare(s) (8 vs 3%, P=0.003; 49 vs 34%, P=0.027; 2 vs 1%, P=0.004; 0.5 vs 0%, P=0.001, respectively). In addition, B/b, B/B, T/t, b/A, B/a, B/A, B/T, B/t, A/t, b/A/T, B/a/T, B/A/T, B/A/t, b/A/t were higher in patients positive for HBeAg. The distribution of VDR genotypes was comparable between patients with and without hepatocellular carcinoma (HCC). VDR gene polymorphisms are associated with distinct clinical phenotypes in Taiwanese HBV carriers but not with HCC development.