Recurrent polyradiculoneuropathy and PMP22 defects

COVID-19 as a trigger of Guillain-Barré syndrome: A review of the molecular mechanism

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic with serious complications. After coronavirus disease 2019 (COVID-19), several post-acute COVID-19 syndromes (PACSs) and long-COVID sequels were reported. PACSs involve many organs, including the nervous, gustatory, and immune systems. One of the PACSs after SARS-CoV-2 infection and vaccination is Guillain-Barré syndrome (GBS). The incidence rate of GBS after SARS-CoV-2 infection or vaccination is low. However, the high prevalence of COVID-19 and severe complications of GBS, for example, autonomic dysfunction and respiratory failure, highlight the importance of post-COVID-19 GBS. It is while patients with simultaneous COVID-19 and GBS seem to have higher admission rates to the intensive care unit, and demyelination is more aggressive in post-COVID-19 GBS patients. SARS-CoV-2 can trigger GBS via several pathways like direct neurotropism and neurovirulence, microvascular dysfunction and oxidative stress, immune system disruption, molecular mimicry, and autoantibody production. Although there are few molecular studies on the molecular and cellular mechanisms of GBS occurrence after SARS-CoV-2 infection and vaccination, we aimed to discuss the possible pathomechanism of post-COVID-19 GBS by gathering the most recent molecular evidence.

Genetic basis of Guillain-Barre syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disease in which the peripheral nerves are affected. GBS has different subtypes, such as acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Infections, e.g. Campylobacter jejuni, influenza, etc., can lead to GBS. Both environmental and genetic factors play a major role in the occurrence of GBS. Several studies have investigated the genetic basis of GBS. Human leukocyte antigens (HLA) genes, Cluster of Differentiation (CD) 1A, FAS, Fc gamma receptors (FcGR), Intercellular adhesion molecule-1 (ICAM1), different interleukins, Nucleotide oligomerization domain (NOD), Toll-like receptor 4 (TLR4), Tumor necrosis factor-α (TNF-α) are among the genes reported to be involved in susceptibility to the disease. Dysregulation and dysfunction of the mentioned gene products, even though their role in the pathogenesis of GBS is controversial, play a role in inflammatory pathways, regulation of immune cells and system, antigen presentation, axonal degeneration, apoptosis, and cross-reaction. This review aims to summarize associated genes with GBS to contribute to better understanding of GBS pathogenesis and discover the gene pathways that play role in GBS occurrence.