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Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses, 2023, Spatola et al

Discussion in 'Long Covid research' started by SNT Gatchaman, May 10, 2023.

  1. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

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    Neurologic sequelae of COVID-19 are determined by immunologic imprinting from previous coronaviruses
    Spatola, Marianna; Nziza, Nadège; Jung, Wonyeong; Deng, Yixiang; Yuan, Dansu; Dinoto, Alessandro; Bozzetti, Silvia; Chiodega, Vanessa; Ferrari, Sergio; Lauffenburger, Douglas A; Mariotto, Sara; Alter, Galit

    Coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health emergency. Although SARS-CoV-2 is primarily a respiratory pathogen, extra-respiratory organs, including the central nervous system (CNS), can also be affected. Neurologic symptoms have been observed not only during acute SARS-CoV-2 infection, but also at distance from respiratory disease, also known as long-COVID or neurological post-acute sequelae of COVID-19 (neuroPASC). The pathogenesis of neuroPASC is not well understood, but hypotheses include SARS-CoV-2-induced immune dysfunctions, hormonal dysregulations, and persistence of SARS-CoV-2 reservoirs.

    In this prospective cohort study, we used a high throughput systems serology approach to dissect the humoral response to SARS-CoV-2 (and other common Coronaviruses - 229E, HKU1, NL63, OC43) in the serum and cerebrospinal fluid (CSF) from 112 infected individuals who developed (n = 18) or did not develop (n = 94) neuroPASC. Unique SARS-CoV-2 humoral profiles were observed in the CSF of neuroPASC, compared to serum responses. All antibody isotypes (IgG, IgM, IgA) and subclasses (IgA1-2; IgG1-4) were detected in serum, whereas CSF was characterized by focused IgG1 (and absence of IgM).

    These data argue in favor of compartmentalized brain-specific responses against SARS-CoV-2 through selective transfer of antibodies from the serum to the CSF across the blood-brain-barrier, rather than intrathecal synthesis, where more diversity in antibody classes/subclasses would be expected. Compared to individuals who did not develop post-acute complications following infection, individuals with neuroPASC had similar demographic features (median age 65 vs 66.5 years, respectively, p = 0.55; females 33% vs 44%, p = 0.52), but exhibited attenuated systemic antibody responses against SARS-CoV-2, characterized by decreased capacity to activate antibody-dependent complement deposition (ADCD), NK cell activation (ADNKA) and to bind Fcγ receptors.

    However, surprisingly, neuroPASC individuals showed significantly expanded antibody responses to other common Coronaviruses, including 229E, HKU1, NL63, and OC43. This biased humoral activation across coronaviruses was particularly enriched in neuroPASC individuals with poor outcome, suggesting an original antigenic sin (or immunologic imprinting), where pre-existing immune responses against related viruses shape the response to current infection, as a key prognostic marker of neuroPASC disease.

    Overall, these findings point to a pathogenic role for compromised anti-SARS-CoV-2 responses in the CSF, likely resulting in incomplete virus clearance from the brain and persistent neuroinflammation, in the development of post-acute neurologic complications of SARS-CoV-2 infection.

    PubMed | Link | PDF (Brain)
     
  2. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

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    Selected quotes —

     
  3. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

    Messages:
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  4. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

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  5. Hutan

    Hutan Moderator Staff Member

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    So, if I'm understanding correctly, a previous infection resulted in the body's recipe for fighting that infection (would that be in the long lived plasma cells in the bone marrow?) Then, when another infection comes along that is similar but different, the body is stuck on the old response and doesn't effectively deal with the infection. The result is ineffective clearance - so it's basically the 'viral persistence' hypothesis, with a bit of upstream elaboration.

    So, it leaves the question 'why are the infections that result in Long Covid so often mild, rather than more severe, if the viral response is inadequate?'.

    I can't read the paper right now.
     
    Peter Trewhitt, alktipping and RedFox like this.

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