G-231A and G+70C Polymorphisms of Endothelin Receptor Type-A Gene could Affect the Psoriasis Area and Severity Index Score and Endothelin 1 Levels.

BACKGROUND

The etiopathogenesis of psoriasis has not been clearly elucidated although the role of chronic inflammation, imbalance between pro- and anti-inflammatory cytokines, and many immunological events have been established. Endothelin 1 (EDN1) and endothelin receptor type-A (EDNRA) are implicated in the inflammatory process. The relationships between EDN1 and EDNRA polymorphisms with several diseases have been found.

AIMS AND OBJECTIVES

This study examined the possible association of EDN1 (G5665T and T-1370G) and EDNRA (G-231A and G + 70C) single nucleotide polymorphisms (SNPs) with the occurence of psoriasis, and evaluated the relationship between genotypes and clinical/laboratory manifestation of psoriasis.

MATERIALS AND METHODS

We analyzed genotype and allele distributions of the above-mentioned polymorphisms in 151 patients with psoriasis and 152 healthy controls by real-time PCR combined with melting curve analysis.

RESULTS

We did not find significant differences in the genotype and allele distributions of EDN1 T-1370G, EDNRA G-231A, and EDNRA G+70C polymorphisms between patients with psoriasis and healthy controls. Psoriasis area and severity index (PASI) score of EDNRA -231 polymorphic A allele carrying subjects (AA and AA + AG) was higher than that of wild homozygotes (P = 0.044 and P = 0.027, respectively). In addition, EDN1 levels in EDNRA+70 polymorphic C allele carriers (CC + CG) were elevated when compared with GG genotype; however, the difference was at borderline significance (P = 0.05).

CONCLUSION

Although there were no associations between studied polymorphisms and psoriasis susceptibility, the PASI score and EDN1 levels seem to be affected by EDNRA G-231A and G + 70C polymorphisms.