Autoimmunity and cytokines in Guillain-Barré syndrome revisited: review of pathomechanisms with an eye on therapeutic options.

Guillain-Barré syndrome (GBS) is the most common cause of acute paralysis in the United States. Campylobacter jejuni is a common trigger for GBS, igniting autoimmunity as a result of molecular mimicry between C. jejuni lipooligosaccharide (LOS) and host gangliosides. Evidence also suggests an active role for cell-mediated and innate immunity in pathogenesis of GBS. Infection alone is not enough for GBS to develop, infection with the same strain might yield different outcomes in different patients. C. jejuni strains with low to absent molecular mimicry to self-antigens can cause full-blown GBS with positive autoantibodies. A role for T helper 17 and IL-17 in acute phase of GBS is also identified. Currently, no biological treatment is validated for severe, ventilation-dependent patients with GBS, who might not benefit from either IVIG or plasma exchange therapy. Use of biologic agents in treatment-resistant GBS, especially anti-IL-17 agents, such as secukinumab, ixekizumab, and brodalumab, is to be hoped. This review covers up-to-date knowledge on autoimmune mechanisms responsible in different subtypes of GBS: acute inflammatory demyelinating polyneuropathy and acute motor axonal neuropathy; as well as the experimental autoimmune neuritis (EAN), a commonly used animal model of GBS.