Background/Aim: Alopecia areata (AA), which is characterized by hair loss, is an inflammatory autoimmune disease. Tumor necrosis factor-alpha (TNFα) is a potent proinflammatory cytokine that has a highly significant role in inflammatory and immune responses. The aim of this study is to evaluate whether there is a relationship between TNFα -238 G/A gene polymorphism and AA in the Turkish population.
Methods: In this case-control study, the frequency of TNFα-238 G/A gene polymorphism and its relationship with some clinical parameters of AA patients were investigated. Seventy-eight AA patients and 78 healthy individuals were included in our study. TNFα -238 G/A polymorphism was evaluated by the PCR-RFLP method.
Results: The distribution of TNFα -238 G/A genotypes was significantly different between patients and control subjects (P<0.001). Frequency of genotypes GG and AA in AA patients (53.8 and 6.4%, respectively) were evidently lower compared to the controls (59 and 25.6%, respectively). Individuals with AA genotype had a lower risk of AA disease (odds ratio (OR)=0.27; 95% CI=0.09-0.79; relative risk (RR)=0.65 (0.49-0.86); P=0.013). GA genotype was significantly higher in patients with AA (39.7%) compared to the control group (15.4%) and an increased risk of patchy AA was observed (OR=2.82, 95% CI=1.28-6.21; RR=1.87 (1.11-3.15); P=0.008).
Conclusion: These results suggest that the TNFα -238 G/A gene polymorphism is associated with AA and individuals with GA genotype may have an increased risk of AA.