BDNF and Guillain-Barre syndrome: Evidence is still lacking to support the efficacy of IFN-β1a, brain-derived neurotrophic factor (BDNF), CSF filtration with PE, tripterygium polyglycoside, and eculizumab in treating GBS due to low or very low certainty of evidence for the interventions and outcomes (Pritchard et al., 2016; Doets et al., 2020).