Evaluation of 1,25-dihydroxyvitamin D3 pathway in patients with chronic urticaria.

Background: Previous studies showed the role of vitamin D (Vit D) on the progression of chronic urticaria. To the best of our knowledge, there are no other results regarding the contribution of single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and vitamin D binding protein (VDBP) genes in chronic urticaria (CU). Aim: In the present study, we investigated the Vit pathway and the association between VDR and VDBP gene polymorphisms and CU risk in Iranian population. Methods: All participating individuals in the present study were evaluated for serumVit D and VDBP concentration VDR rs1544410 and rs2228570 and VDBP rs7041using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The associations of studied analytes and three SNPs with clinical and laboratory outcomes were investigated in CU patients. Results: Patients with CU showed lower Vit D compared to controls (19.26 ± 1.26 vs. 31.72 ± 7.14ng/ml, P-value=0.006). There was a significant correlation between Vit D levels and urticaria activity score. Serum VDBP was significantly higher in CU patients than controls (1317.3 ± 183.71 vs. 395.77 ± 12.96 µg/ml, P-value <0.0001) and had a positive correlation to progression of CU. The A allele of this polymorphism might be a potential risk factor for progression of CU [odds ratio 4.3434, 95% confidence interval (1.7331-10.8852), Z-statistic=3.133, P-value=0.0017]. Conclusion: In summary, this study demonstrated that change in Vit D pathway in the level of gene or protein may be a risk factor for progression of CU. [ABSTRACT FROM AUTHOR]