IL-1beta and IL-1 Receptor Antagonist Gene Polymorphisms in Myasthenia Gravis

ABSTRACT

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disorder characterized by an immune response against the nicotinic acetylcholine receptor at the neuromuscular junction. Genetic factors as well as abnormalities of immune regulation can increase the likelihood of MG. Proinflammatory cytokines interleukin (IL)-1alpha, IL-1beta, and their receptor antagonist (IL-1Ra) play major roles in initiating and modulating immune responses. The aim of the present study was to analyze IL-1beta and IL-1 Ra gene polymorphisms between MG patients and healthy controls. METHODS: TaqI restriction fragment polymorphism (RFLP) in exon 5 of IL-1beta and variable numbers of an 86-bp tandem repeat (VNTR) in intron 2 of IL-1Ra were analyzed in 80 patients with MG and 94 matched healthy control individuals. RESULTS: In IL-1beta TaqI RFLP, the genotype of A1/A1 and A1/A2 were 92.5% and 7.5% in patients with MG. In healthy controls, the frequencies of each genotype were 93.6% and 6.4% respectively. IL-1Ra polymorphism, the genotypes of A1/A1, A1/A2 and A1/A3 were 81.3%, 16.3%, and 2.5% in patients with MG. In healthy controls, the frequencies of each genotype were 87.2%, 7.4% and 3.2% respectively. There was no significant difference in the genotype frequencies of IL-1beta TaqI RFLP and IL-1Ra polymorphism between patients and the control group. CONCLUSIONS: These data suggested that the IL-1beta and IL-1Ra gene polymorphisms may not be associated with MG. However, further study is needed to clarify the possible role of IL-1beta and IL-1Ra gene polymorphisms in the susceptibility to myasthenia gravis.