/Cdx-2 AA Variant of Defines the Response to Phototherapy amongst Patients with Psoriasis.

1,25-dihydroxyvitamin-D plays a central role in the immune system via binding to the vitamin D receptor. polymorphisms have been associated with multiple autoimmune disorders, including psoriasis. Until now, five polymorphisms, , , , and /Cdx2, have been studied in psoriasis, with contradicting results. Therefore, this study aimed to evaluate the association of polymorphisms with susceptibility to psoriasis, effectiveness of NB-UVB phototherapy and concentration of proinflammatory cytokines and vitamin D amongst the Polish population. polymorphisms were analyzed by PCR-RFLP or real-time PCR. We found that the frequency of the /Cdx-2 GG genotype was significantly higher in psoriasis patients and was associated with regulation of IL-17 and IL-23 concentration. Moreover, /Cdx-2 AA might have a significant effect on the response to phototherapy amongst patients with psoriasis. Our results suggest that VDR is a susceptibility factor for psoriasis development. Moreover, /Cdx-2 variants have a significant effect on the response to phototherapy amongst patients with psoriasis and regulation of inflammatory response via decrease of IL-17 and IL-23 level after UVB phototherapy in the Polish population. Results of our study provide some evidence in support of the hypothesis that the vitamin D signaling pathway may be of relevance for pathogenesis and treatment of psoriasis.