The nerve function improved better in PE group than in the IVIG group. The treatment effectiveness in the PE and IVIG groups after 2 weeks were 96% and 79%, respectively. PE and IVIG significantly reduced blood immunoglobulins IgG, IgA, IgM, C3, and C4 in GBS patients, but they were significantly lower in the PE group than in the IVIG group. This evidence concerns the gene C3 and Guillain-Barre syndrome.