A group from Emergency Department, San Carlos Clinical Hospital, Complutense University, Madrid, Spain, etc. has reported on incidence rates of Guillian-Barre syndrome (GBS) in COVID-19 comparing with non-COVID-19.
https://onlinelibrary.wiley.com/doi/10.1002/ana.25987
The standardized incidences of GBS were 9.44 per 100,000 COVID inhabitants (95% CI = 7.30–12.0), and 0.69 per 100,000 non-COVID inhabitants (95% CI = 0.56–0.84). The OR for the standardized incidence of COVID with respect to non-COVID patients was 13.5 (95% CI = 9.88–18.4).
GBS is an autoimmune disorder of the peripheral nervous system which is usually triggered by virus/pathogen infections.
The onset mechanism of GBS is considered as follows.
Antibodies targeting glycolipid-like antigens on virus/pathogen eventually form membrane attack complexes through activated complement cascades triggered by the cross-reactive attachment of the same antibodies onto GM1 on axonal neurons, and cause damages on peripheral nerve system.
A figure cited from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8196284/
Blog admin is not sure what glycan structure on SARS-CoV-2 Spike induces a cross reactive antibody to GM1, but Galβ1-3GalNAc would be more likely comparing with others.