Association of Estrogen Receptor α Gene Polymorphisms with Cytokine Genes Expression in Systemic Lupus Erythematosus

Aim To analyze the association of estrogen receptor alpha (OR alpha) gene polymorphisms with cytokine genes expression in patients with systemic lupus erythematosus (SLE) and controls. Methods Genomic DNA was extracted and polymorphisms of Xbal (XX, Xx, or xx genotype) and PvuII (PP, Pp, or pp) in intron 1 of OR alpha gene were detected by polymerase chain reaction-restriction fragment length polymorphisms (PCR RFLP) method. The messenger RNA (mRNA) levels of interleukin (IL)-10, IL-4, interferon (IFN)-gamma, and IL-2 were assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Results In patients with SLE with PpXx genotype, IL-10 and IL-4 mRNA expression was higher (P < 0.001 and P = 0.013, respectively), while in patients with SLE with Ppxx genotype IFN-gamma and IL-2 mRNA expression was lower than in controls (P < 0.001). There was no significant difference in mRNA expression of 4 cytokines among controls with various genotypes. Conclusion OR alpha gene polymorphism may be associated with the expression of IL-10, IL-4, IL-2, and IFN-gamma in patients with SLE.