Intravenous Immunoglobulin (IVIG)
IVIG has become the preferred treatment for GBS because of the availability and convenience of use . The therapeutic effect of IVIG in GBS may arise from blocking pathogenic autoantibodies and antibody-mediated complement activation . On the other hand, IVIG has shown to result in reduced number of Th1 and Th17 and expansion of the population of Treg cells in GBS patients [31, 32]. IVIG, when started within 2 weeks of onset of weakness, has been shown to be effective in AIDP patients with more severe disease manifested as inability to walk 10 m unaided (GBS disability scale score >3) . IVIG treatment has been demonstrated to be as effective as PLEX if given within 2 weeks in patients who lose the ability to walk [61, 62]. The dosage of IVIG used in the GBS clinical trials has been 2 g/kg divided over 5 days . The same dose can be divided over
2-4 days in selected cases, although a study suggested more posttreatment relapses in children who received the dose in 2 days . It has been suggested that some patients may have a better response with a higher dose than 2 g/kg total or a second course of treatment, for the following reasons: (1) about 10% of the IVIG-treated GBS patients have a relapse, which usually responds to further treatment with IVIG , and (2) a subgroup of GBS have poor initial response and slower recovery, which has been correlated with lower levels of serum immunoglobulin concentrations due to different pharmacokinetics . The latter subgroup may benefit from a higher dose or a second course of treatment .
Although the optimal immunomodulatory treatment for AMAN is still unclear, PLEX has been suggested to be more efficient and cost-effective than IVIG [2, 66]. The prognosis of MFS is generally good without treatment. Although the recovery started earlier in the MFS patients who received IVIG, the final outcome was not changed by the use of PLEX or IVIG in a study .
Considering the role of anti-ganglioside antibodies and complement activation in the pathogenesis of GBS variants, modulation of complement activation through monoclonal antibodies and synthetic serine protease inhibitors is emerging as a new treatment for GBS . Eculizumab is a humanized monoclonal antibody, which binds plasma C5 and blocks its cleavage to C5b, therefore preventing the formation of membrane attack complex . Eculizumab prevented the occurrence of anti- GQ1b-mediated neuropathy in a murine model . Nafamostat, a synthetic serine protease inhibitor which is used as a short-acting anticoagulant during hemodialysis, has been shown to ameliorate the phenotype of anti-GM1 antibody-mediated neuropathy in a rabbit model due to its anticomplement activity .