IL17A and Guillain-Barre syndrome: Characterization of CSF cytokines revealed that the levels of CSF IL-37 and IL-17A were dramatically lower than those of plasma IL-37 and IL-17A in both GBS patients and the HC and that the concentrations of CSF IL-37 and IL-17A in the patients were significantly higher than those in the HC (Figure 2, P < 0.0001 and P = 0.0002, resp).