Allergy. 2014 Jan;69(1):118-24. doi: 10.1111/all.12337.
Vitamin D is increasingly recognized to play crucial roles in cutaneous immunity, and vitamin D treatment improved eczema control in small clinical trials. Several vitamin D-related genes were associated with asthma, but there are no data for eczema.
Twenty-three single-nucleotide polymorphisms (SNPs) of five vitamin D-related genes (CYP27A1, CYP2R1, CYP27B1, GC and VDR) were genotyped in 1442 Chinese children with eczema and 1231 non-allergic controls. SNPs that followed Hardy-Weinberg equilibrium and yielded ≥ 95% genotyping call-rate were included. Haplotypic associations and SNP-SNP interactions for eczema diagnosis and subphenotypes were analysed.
Atopic eczema was associated with rs4674343 of CYP27A1 (odds ratio 0.66, 95% confidence interval 0.53-0.83, P = 0.0004). Increased eosinophil percentage was associated with CYP2R1 rs2060793A (P = 0.001) and rs1933064A (P = 0.001). Two CYP2R1 haplotypes increased eczema risk whereas one VDR haplotype lowered eczema risk. GC rs7041 and CYP2R1 rs7935792 interacted to modulate total IgE (cross-validation consistency 10/10, P = 0.047). Specifically, high-risk eczema patients had higher log-transformed total IgE than low-risk patients (2.76 ± 0.76 vs 2.60 ± 0.80, P = 0.002).
A vitamin D-related SNP rs4674343 on CYP27A1 was found to be protective against atopic eczema. CYP2R1 and VDR haplotypes altered eczema susceptibility and eosinophil percentage, and GC and CYP2R1 interacted to determine total IgE among eczema patients.
维生素 D 日益被认为在皮肤免疫中起着至关重要的作用，且维生素 D 治疗可改善小样本临床试验中特应性皮炎的控制。一些与维生素 D 相关的基因与哮喘有关，但尚无特应性皮炎的相关数据。
在 1442 例患有特应性皮炎的中国儿童和 1231 例非过敏对照中，对五个维生素 D 相关基因（CYP27A1、CYP2R1、CYP27B1、GC 和 VDR）的 23 个单核苷酸多态性（SNP）进行了基因分型。纳入符合 Hardy-Weinberg 平衡且基因分型成功率≥95%的 SNP。分析了特应性皮炎诊断和亚表型的连锁不平衡和 SNP-SNP 相互作用。
特应性皮炎与 CYP27A1 的 rs4674343 相关（比值比 0.66，95%置信区间 0.53-0.83，P=0.0004）。嗜酸性粒细胞百分比升高与 CYP2R1 的 rs2060793A（P=0.001）和 rs1933064A（P=0.001）相关。两个 CYP2R1 单体型增加了特应性皮炎的风险，而一个 VDR 单体型降低了特应性皮炎的风险。GC 的 rs7041 和 CYP2R1 的 rs7935792 相互作用调节总 IgE（交叉验证一致性 10/10，P=0.047）。具体而言，高危特应性皮炎患者的 log 转换总 IgE 高于低危患者（2.76±0.76 与 2.60±0.80，P=0.002）。
发现 CYP27A1 上的一个与维生素 D 相关的 SNP rs4674343 可预防特应性皮炎。CYP2R1 和 VDR 单体型改变了特应性皮炎的易感性和嗜酸性粒细胞百分比，GC 和 CYP2R1 相互作用决定了特应性皮炎患者的总 IgE。
