The association between intron 4 VNTR of NOS3 gene and clinical manifestations in patients with systemic lupus erythematosus

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Ceilândia, 2017.Systemic Lupus Erythematosus (SLE) is a multisystem, autoimmune inflammatory disease characterized by antinuclear autoantibodies, tissue destruction, complement system and interferon activation. The etiology of the underlying immune dysregulation seen in SLE remains unknown. However, an increased production of Nitric Oxide (NO) has been well documented in individuals with active SLE. NO is synthesized from l-arginine by the action of nitric oxide synthase (NOS), there are at least three isoenzymes of NOS: inducible NOS, neuronal NOS, and endothelial NOS (NOS3). The 27 bp repeat in intron 4 of NOS3 gene regulate the plasma levels of NO and could, therefore, play a significant role in the pathogenesis of autoimmune diseases. This study aim to determine the association between the NOS3 intron 4 variable number of tandem repeats polymorphism and SLE in Brazil´s Federal District group of patients and correlate the results with data of clinical manifestations. Genotyping of intron 4 VNTR of NOS3 polymorphism was performed in order to obtain a Polymerase Chain Reaction (PCR) product that was later analyzed using the fragment analysis method. The results were evaluated and 4bb genotype was more prevalent than 4aa and 4ab, demonstrating a significant difference in frequencies between the groups (P<0,05). Analysis of allelic frequency revealed that the 4b allele was predominant in the case group (68.3%) demonstrating a significant difference in frequencies between SLE patients and healthy subjects (P