It was observed that 'psoriasis 1' downregulated the concentrations of TNF‑α, IFN‑γ, IL‑22, IL‑17C, IL‑1β and IL‑4, and upregulated the concentration of 25HVD3; furthermore, 'psoriasis 1' downregulated the expression levels of NF‑κB, phosphorylated (p)‑NF‑κB, IKK, p‑IKK, STAT3, p‑STAT3, STAT4 and p‑STAT4, and upregulated the expression level of VDR in TNF‑α‑induced HaCaT cells.
rs744166GG in STAT3 and rs7574865TT in STAT4 had higher frequencies in the case than the control group, suggesting these 2 genotypes increase the susceptibility to psoriasis (p < 0.05).
We recently reported for the first time as a PS-associated SNP the signal transducer and activator of transcription-4 (STAT4) rs7574865 polymorphism, which is also associated with several autoimmune diseases.
We found that mutated allele T of the STAT4rs7574865 SNP, which previously was implicated in the predisposition to many autoimmune diseases, were more common in individuals with psoriasis than in controls (p = 0.045, odds ratio = 1.42, 95% confidence interval 1.01-2.00), thus concluding that the polymorphism examined is associated with the development of psoriasis in our population.