The TNF-alpha-308 polymorphism may affect the severity of Crohn's disease

OBJECTIVE: The goal of this project was to analyze the association between Crohn's disease, its clinical features, and the tumor necrosis factor alpha (TNF-alpha) -308 polymorphism. METHODS: This is a case-control and cross-sectional study that enrolled 91 patients with Crohn's disease and 91 controls. Patients with Crohn's disease were characterized according to the Montreal Classification, along with their clinical and surgical treatment history. Analysis of the TNF-a -308 polymorphism was performed using a commercial kit. A stratified analysis was applied using an OR (odds ratio) with a 95% confidence interval. The chi-square and Fisher's exact tests were utilized for analysis of the association between the polymorphism and the clinical features of Crohn's disease. RESULTS: The low producer predicted phenotype was present in 76.9% of Crohn's disease cases and 75.8% of controls (OR 0.94 [0.45-1.97]). The TNF2 allele and the high producer predicted phenotype were more frequent among patients with Crohn's disease penetrating behavior (p = 0.004). The TNF2 allele and the high producer predicted phenotype were also associated with a history of colectomy (p = 0.02), and the TNF2 allele was associated with small bowel resection (p = 0.03). CONCLUSIONS: The TNF-alpha -308 polymorphism appears to affect the severity of the disease. However, TNF-alpha -308 polymorphism does not appear to be important for the susceptibility in the development of Crohn's disease.