Tumor necrosis factor-α gene promoter −308 and −238 polymorphisms and its serum level in psoriasis

BACKGROUND: Psoriasis is a chronic, immune-mediated, inflammatory skin disease affecting genetically predisposed individuals and requiring long-term treatment. The etiology of psoriasis is not fully understood. This article aimed to determine association between genetic polymorphisms in tumor necrosis factor-α (TNF -α) promoter −308 (rs1800629) and −238 (rs 361,525) and its serum level in psoriasis patients. METHODS: The study was conducted on 70 patients with psoriasis and 70 age and sex-matched, healthy individuals. All patients were subjected to history taking and complete medical examination. The polymorphisms of TNF -α promoter gene −308 (rs1800629) and −238 (rs 361,525) were detected by real time PCR and Serum levels of TNF -α were measured by ELISA technique. RESULTS: AG polymorphism and A allele of TNF-α −238 G/A (rs 361,525) were significantly more in patients than controls, whereas AG polymorphism and A allele of TNF-α −308 G/A (rs1800629) were significantly more in controls than patients. There were significant high levels of TNF-α in serum of patients in comparison to controls. CONCLUSIONS: The AG polymorphism and A allele of TNF-α −238G/A (rs 361,525) may act as a risk factor for occurrence of psoriasis, whereas AG polymorphism and A allele of TNF-α −308G/A (rs1800629) may have protective role. There is pivotal role of TNF-α as a pro-inflammatory mediator in pathogenesis of psoriasis.