Increased CD4/CD8 ratio as a risk factor for critical illness in covid19


Senior Member
My CD4/CD8 is 5 (normal is 1 to 2)
. said:

Low CD8 T lymphocyte is a kind of lymphocyte imbalance that is not much studied, not as much as low CD4 T lymphocyte, unfortunately.

But like low CD4, low CD8 can produce immunodeficiency and possibly auto immunity even though no consensus is really reached on it...

This older 2012 paper says:

"CD8+ T-cell deficiency is a feature of many chronic autoimmune diseases, including

multiple sclerosis,
rheumatoid arthritis,
systemic lupus erythematosus,
Sjögren's syndrome,
systemic sclerosis,
primary biliary cirrhosis,
primary sclerosing cholangitis,
ulcerative colitis,
Crohn's disease,
bullous pemphigoid,
alopecia areata,
idiopathic dilated cardiomyopathy,
type 1 diabetes mellitus,
Graves' disease,
Hashimoto's thyroiditis,
myasthenia gravis,
IgA nephropathy,
membranous nephropathy,
and pernicious anaemia.

It also occurs in healthy blood relatives of patients with autoimmune diseases, suggesting it is genetically determined. "
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Senior Member
Yup, I shouldn't have commented, just didn't want to look them up. Seems like they're all bad news.


Senior Member
An immune phenotype characterized by CD8 T cell depletion was associated with a high viral load and the highest mortality of 71%, among all cancer patients.

CD8 T cells compensate for impaired humoral immunity in COVID-19 patients with hematologic cancer

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Cancer patients have increased morbidity and mortality from Coronavirus Disease 2019 (COVID-19), but the underlying immune mechanisms are unknown. In a cohort of 100 cancer patients hospitalized for COVID-19 at the University of Pennsylvania Health System,

we found that patients with hematologic cancers had a significantly higher mortality relative to patients with solid cancers after accounting for confounders including ECOG performance status and active cancer status.

We performed flow cytometric and serologic analyses of 106 cancer patients and 113 non-cancer controls from two additional cohorts at Penn and Memorial Sloan Kettering Cancer Center.

Patients with solid cancers exhibited an immune phenotype similar to non-cancer patients during acute COVID-19 whereas patients with hematologic cancers had significant impairment of B cells and SARS-CoV-2-specific antibody responses. High dimensional analysis of flow cytometric data revealed 5 distinct immune phenotypes.

An immune phenotype characterized by CD8 T cell depletion was associated with a high viral load and the highest mortality of 71%, among all cancer patients.

In contrast, despite impaired B cell responses, patients with hematologic cancers and preserved CD8 T cells had a lower viral load and mortality.

These data highlight the importance of CD8 T cells in acute COVID-19, particularly in the setting of impaired humoral immunity.

Further, depletion of B cells with anti-CD20 therapy resulted in almost complete abrogation of SARS-CoV-2-specific IgG and IgM antibodies, but was not associated with increased mortality compared to other hematologic cancers, when adequate CD8 T cells were present.

Finally, higher CD8 T cell counts were associated with improved overall survival in patients with hematologic cancers.

Thus, CD8 T cells likely compensate for deficient humoral immunity and influence clinical recovery of COVID-19.

These observations have important implications for cancer and COVID-19-directed treatments, immunosuppressive therapies, and for understanding the role of B and T cells in acute COVID-19.


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High CD4‐to‐CD8 ratio identifies an at‐risk population susceptible to lethal COVID‐19 - De Zuani - 2022 - Scandinavian Journal of Immunology - Wiley Online Library

Marco De Zuani,Petra Lazničková,Veronika Tomašková,Martina Dvončová,Giancarlo Forte,Gorazd Bernard Stokin,Vladimir Šrámek,Martin Helán,Jan Frič

First published: 03 December 2021

Around half of people with severe COVID-19 requiring intensive care unit (ICU) treatment will survive, but it is unclear how the immune response to SARS-CoV-2 differs between ICU patients that recover and those that do not.

We conducted whole-blood immunophenotyping of COVID-19 patients upon admission to ICU and during their treatment and uncovered marked differences in their circulating immune cell subsets.

At admission, patients who later succumbed to COVID-19 had significantly lower frequencies of all memory CD8+ T cell subsets, resulting in increased CD4-to-CD8 T cell and neutrophil-to-CD8 T cell ratios.

ROC and Kaplan-Meier analyses demonstrated that both CD4-to-CD8 and neutrophil-to-CD8 ratios at admission were strong predictors of in-ICU mortality.

Therefore, we propose the use of the CD4-to-CD8 T cell ratio as a marker for the early identification of those individuals likely to require enhanced monitoring and/or pro-active intervention in ICU.