Guillain-Barré syndrome: The first documented COVID-19-triggered autoimmune neurologic disease: More to come with myositis in the offing.

Objective To present the COVID-19-associated GBS, the prototypic viral-triggered autoimmune disease, in the context of other emerging COVID-19-triggered autoimmunities, and discuss potential concerns with ongoing neuroimmunotherapies. Methods Eleven GBS cases in four key COVID-19 hotspots are discussed regarding presenting symptoms, response to therapies and cross-reactivity of COVID spike proteins with nerve glycolipids. Emerging cases of COVID-19-triggered autoimmune necrotizing myositis (NAM) and encephalopathies are also reviewed in the context of viral invasion, autoimmunity and ongoing immunotherapies. Results Collective data indicate that in this pandemic any patient presenting with an acute paralytic disease-like GBS, encephalomyelitis or myositis-even without systemic symptoms, may represent the first manifestation of COVID-19. Anosmia, ageusia, other cranial neuropathies and lymphocytopenia are red flags enhancing early diagnostic suspicion. In Miller-Fisher Syndrome, ganglioside antibodies against GD1b, instead of QG1b, were found; because the COVID-19 spike protein also binds to sialic acid-containing glycoproteins for cell-entry and anti-GD1b antibodies typically cause ataxic neuropathy, cross-reactivity between COVID-19-bearing gangliosides and peripheral nerve glycolipids was addressed. Elevated Creatine Kinase (>10,000) is reported in 10% of COVID-19-infected patients; two such patients presented with painful muscle weakness responding to IVIg indicating that COVID-19-triggered NAM is an overlooked entity. Cases of acute necrotizing brainstem encephalitis, cranial neuropathies with leptomeningeal enhancement, and tumefactive postgadolinium-enhanced demyelinating lesions are now emerging with the need to explore neuroinvasion and autoimmunity. Concerns for modifications-if any-of chronic immunotherapies with steroids, mycophenolate, azathioprine, IVIg, and anti-B-cell agents were addressed; the role of complement in innate immunity to viral responses and anti-complement therapeutics (i.e. eculizumab) were reviewed. Conclusions Emerging data indicate that COVID-19 can trigger not only GBS but other autoimmune neurological diseases necessitating vigilance for early diagnosis and therapy initiation. Although COVID-19 infection, like most other viruses, can potentially worsen patients with pre-existing autoimmunity, there is no evidence that patients with autoimmune neurological diseases stable on common immunotherapies are facing increased risks of infection.