Post-acute COVID-19 cognitive impairment and decline uniquely associate with kynurenine pathway activation, 2022, Brew et al

[jaybee00]

https://www.medrxiv.org/content/10.1101/2022.06.07.22276020v1

Abstract
Cognitive impairment and function post-acute mild to moderate COVID-19 are poorly understood. We report findings of 128 prospectively studied SARS-CoV-2 positive patients. Cognition and olfaction were assessed at 2-, 4- and 12-months post-diagnosis. Lung function, physical and mental health were assessed at 2-month post diagnosis. Blood cytokines, neuro-biomarkers, and kynurenine pathway (KP) metabolites were measured at 2-, 4-, 8- and 12-months. Mild to moderate cognitive impairment (demographically corrected) was present in 16%, 23%, and 26%, at 2-, 4- and 12-months post diagnosis, respectively. Overall cognitive performance mildly, but significantly (p<.001) declined. Cognitive impairment was more common in those with anosmia (p=.05), but only at 2 months. KP metabolites quinolinic acid, 3-hydroxyanthranilic acid, and kynurenine were significantly (p<.001) associated with cognitive decline. The KP as a unique biomarker offers a potential therapeutic target for COVID-19-related cognitive impairment.

 

[Violeta]

I wonder how the virus causes this effect? Anyone know?

I found this, but the first sentence seems to indicate that the infection increases IDO and the third sentence seems to be saying that the problem involves a decrease in IDO.

1) The SARS-CoV-2 infection affects the KYN levels by inducing the production of the pro-inflammatory cytokine, interferon-gamma (IFN-ɣ) that stimulates the kynurenine pathway enzyme, indoleamine-2,3-dioxygenase (IDO).

2) SARS-CoV-2 infection can lead to an inflammatory response that affects the levels of some intracellular glycoproteins, such as the intercellular cell adhesion molecule-1 (ICAM-1) and the vascular cell adhesion protein-1 (VCAM-1).

3) A decrease in IDO during pathogenic infections leads to an increase in VCAM-1 in endothelial cells of vessel walls.

 

[Violeta]

1) The SARS-CoV-2 infection affects the KYN levels by inducing the production of the pro-inflammatory cytokine, interferon-gamma (IFN-ɣ) that stimulates the kynurenine pathway enzyme, indoleamine-2,3-dioxygenase (IDO).

Kefir: A protective dietary supplementation against viral infection​

Kefir can act as an anti-inflammatory agent by reducing expression of IL-6, IL-1, TNF-α, and interferon-γ.


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655491/

 

[Violeta]

Interesting...

I know I'm late to the quinolinic acid party, but better late than never.

It's something to work on. I have seen info saying that glutamate is involved in postherpetic neuralgia, which is the cause of my worst, most consistent pain.

Quinolinic acid stimulates synaptosomal glutamate release and inhibits glutamate uptake into astrocytes​

https://pubmed.ncbi.nlm.nih.gov/11900857/
Quinolinic acid stimulates glutamate release by activating the NMDA receptor in the presynaptic neuron. ...in astrocytes it decreases the expression of glutamate transporters... thus increasing extracellular glutamate levels.