RESUMO
BACKGROUND & OBJECTIVES: Susceptibility to psoriasis has been associated with the HLA-C*0602 allele, although it may be affected by other polymorphisms. MATERIALS & METHODS: We genotyped 142 patients and 160 healthy volunteers to evaluate the possible relationship between susceptibility to psoriasis and the HLA-C*0602 allele and polymorphisms in the TNF, IL12B, and IL23R genes. RESULTS: The frequency of the wild-type TNF-238, TNF-308, and TNF-1031 genotypes was greater in patients with psoriasis than in healthy volunteers, although that of the mutant TNF-857 genotype was higher. The only difference between psoriasis and psoriatic arthritis was TNF-857. The frequency of the HLAC*0602 allele was higher in psoriatic patients than in healthy volunteers. No differences were observed for IL12B and IL23R. Multivariate logistic regression analysis only confirmed these associations for TNF-238, TNF-857, and HLA-C*0602. CONCLUSION: Our results support an association between susceptibility to psoriasis and TNF polymorphisms in the Spanish population.
