Association of the TNF-α, IL-2, and IL-2RB gene variants with susceptibility to psoriasis in a Turkish cohort

Aim of the study
The aim of this study was to investigate the role TNF-α, IL-2, and IL-2RB variants in psoriasis (Ps) and to evaluate the association between these variants and clinical features.

Material and methods
A total of 74 psoriatic patients and 74 healthy individuals were genotyped for these variants by PCR and/or RFLP.

Results
The AA genotype of TNF-α (–308) was significantly more common in the patients (p = 0.013). TNF-α (–238) AA genotype was significantly increased in the patients (p = 0.028), while the GG genotype was decreased in the patient group, compared to the controls (p = 0.016). IL-2 (–330) variant GG and TT genotype was more common in the patients (p = 0.037, p = 0.009, respectively), while IL-2 (–330) GT genotype was increased in the control subjects (p = 0.001). IL-2 (–330) GG genotype frequency was significantly decreased (p = 0.021) and the TT genotype frequency was significantly increased among patients with psoriatic arthritis in comparison with Ps patients (p = 0.014). IL-2RB TC genotype frequency was significantly decreased and TT genotype frequency was significantly increased in the patients with positive family history of Ps compared to those who had a negative family history (p = 0.017, p = 0.014, respectively). Also, IL-2RB CC genotype was significantly increased among the patients with late-onset Ps in comparison with the early onset Ps group (p = 0.009). The frequency of IL-2 (–330) TT genotype was significantly higher in mild Ps patients than moderate-severe patients (p = 0.043).

Conclusions
Our data suggest a potential role of these genes as candidate genes for susceptibility to Ps in a Turkish cohort.