Anonymous ID: 2722e0 May 17, 2020, 7:21 p.m. No.9219094   🗄️.is 🔗kun   >>9108 >>9143

F/U on discussion with anon concerned about covid19 damage to immune system re

1895 + macrophage + T Lymphocytes

 

COMMENT: The original concern about immune system damage by covid19 understandable but further review suggests unnecessary. T- cells and macrophages usually function as expected. Severity of disease likely associated at least in part with genetic factor HLA tissue types and accounts for some of the differences in impacted populations.

 

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Didn’t find anything on 1895 but found info on covid19 & T-lymphocytes. It is true the virus has the ability to attach and enter the T-cells but does not replicate within them (as HIV does) so likely of limited significance as far as impact on the immune system is concerned.

Here is the link to the original article that has a misleading title IMO and key points listed:

  • a structure in the spike of the coronavirus triggered the attachment of a viral envelope and the T-cell membrane.

  • the SARS virus, which caused an outbreak in 2002 to 2003, has a lack of a membrane fusion function.

  • unlike HIV that replicates faulty T cells, the coronavirus does not replicate,showing that the T cells and the virus may end up dying together.

https://www.news-medical.net/news/20200413/Novel-coronavirus-attacks-and-destroys-T-cells-just-like-HIV.aspx

 

Here is an article describing the immune response in a moderate to severe covid19 patient describing the immune responses. The T-cells and macrophages function as expected.

“We report the kinetics of immune responses in relation to clinical and virological features of a patient with mild-to-moderate coronavirus disease 2019 (COVID-19) that required hospitalization. Increased antibody-secreting cells (ASCs), follicular helper T cells (TFHcells), activated CD4+ T cells and CD8+ T cells and immunoglobulin M (IgM) and IgG antibodies that bound the COVID-19-causing coronavirus SARS-CoV-2 were detected in blood before symptomatic recovery. These immunological changes persisted for at least 7 d following full resolution of symptoms.”

https://www.nature.com/articles/s41591-020-0819-2?

 

Re severity of covid19 disease is concerned, reports suggest patient tissue type ( Human leukocyte antigen (HLA) is important. This has also been reported for other virus infections.

  • genetic variations that are associated with infection susceptibility and diverse clinical presentation of coronavirus disease (COVID-19) – including asymptomatic cases and severe forms of the disease in younger patients.

https://www.news-medical.net/news/20200510/Study-shows-COVID-19-vulnerability-is-highly-dependent-on-host-genetic-architecture.aspx

ORIGINAL ARTICLE:

“The landscape of host genetic factors involved in infection to common viruses and SARS-CoV-2”

Key Points:

  • Based on 1028 subjects tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we identify 7 class II HLA susceptibility alleles (5 associated with other viruses). We also observe that genetic determinants of ACE2 expression may influence SARS- CoV-2 susceptibility.

  • Our finding that certain HLA alleles are associated with SARS-CoV-2 may shed light on the diverse clinical presentations of this infection, including asymptomatic cases and severe COVID-19 in younger patients and those with few pre-existing conditions.

  • We identified two HLA alleles which may confer protection against SARS-CoV-2infection…previous studies have linked one to Guillain-Barré syndrome, which can result from viral challenge or vaccination.

https://doi.org/10.1101/2020.05.01.20088054

Anonymous ID: 2722e0 May 17, 2020, 7:22 p.m. No.9219108   🗄️.is 🔗kun   >>9143

>>9219094

And more on HLA haplotypes and severe SARS-CoV-2 infection:

Article title: “COVID-19 infection: the perspectives on immune responses” and is an excellent discussion on severity of disease and role of immune system in a cytokine storm & lung damage.

Goes on to talk about the importance of genetic susceptibility based on haplotypes (HLA).

 

Hyaluronan is discussed as a potential cause of covid19 fatality in these patients and possible protective role of hyaluronidase:

“ hyaluronan (HA) is associated with ARDS; moreover, during SARS infection, the production and regulation of hyaluronan is defective. The levels of inflammatory cytokines (IL-1, TNF) are high in the lungs of COVID-19 patients and these cytokines are strong inducers of HA-synthase-2 (HAS2)”

AND

“a clinically approved bile therapy drug, Hymecromone (4-Methylumbelliferone, 4-MU), an inhibitor of HAS2. LPS-induced lung inflammation can be relieved by 4-MU. 4-MU or its chemical derivatives exist widely in various herbs used in traditional Chinese medicine, which may explain the observed effectiveness of combined herbal medicine in some patients.”

https://www.nature.com/articles/s41418-020-0530-3?