Ayse Feyda Nursal
Department of Medical Genetics, Faculty of Medicine, Hitit University, Corum, Turkey.
Hasan Mervan Aytac
Department of Psychiatry, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey.
Hayriye Sentürk Ciftci
Department of Medical Biology, Istanbul Faculty of Medicine, Istanbul University, Istanbul,Turkey.
Menekse Sila Yazar
Department of Psychiatry, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey.
Yasemin Oyaci
Department of Medical Biology, Istanbul Faculty of Medicine, Istanbul University, Istanbul,Turkey.
Mustafa Pehlivan
Department of Internal Medicine (Haematology), Faculty of Medicine, Gaziantep Univesity, Gaziantep, Turkey.
Sacide Pehlivan
Department of Medical Biology, Istanbul Faculty of Medicine, Istanbul University, Istanbul,Turkey.
Abstract:
Background: Tumor necrosis factor alpha (TNF-α) is a proinflammatory multifunctional cytokine produced by macrophages. A dysregulation of the immune system contribute to the pathogenesis of bipolar disorder (BD). In this study, we aimed to investigate the relationship between the TNF-α gene -308G/A promoter variant and the risk of BD. Methods: A total of 104 BD patients and 94 healthy controls were enrolled in the study. Genomic DNA was isolated and TNF-α -308G/A variant was analyzed using PCR-RFLP method. Results: TNF-α -308G/A variant GG genotype and G allele were more prevalent in BD patients compared to the controls (p = 0.002 and p = 0.017, respectively). The patients carrying GG genotype had a 5.927-fold higher risk of developing BD. Then, we divided patients into two groups as smokers and non-smokers. TNF-α -308G/A variant GA genotype was higher in non-smoker BD patients than smoker patients (p = 0.027). We found that TNF-α -308G/A AA genotype and A allele increased in smoker patients compared to non-smoker patients (p = 0.008, p = 0.002, respectively). Discussion: Our results provided evidence that TNF‐α -308G/A variant may contribute to development of BD in a Turkish cohort. In addition, this variant plays a relevant role in the smoker status of BD.
Keywords:Bipolar disorder, tumor necrosis factor alpha, variant, PCR-RFLP.