A&A: Long COVID symptoms' scientific basis

A&A: Long COVID symptoms' scientific basis

Recent findings appear to shed light on the biology underlying long-lasting COVID symptoms such increased anxiety and despair as well as brain fog.

Researchers found that brain regions that regulate emotion and cognition are being impacted by an immune response in olfactory tissue in a study that was published in Science Translational Medicine.

The reaction to SARS-CoV-2 and influenza A in tissue samples was contrasted by Justin J. Frere, an MD/PhD student at the Icahn School of Medicine at Mount Sinai, and colleagues. Both viruses caused comparable reactions in lung tissue, according to the researchers, but only SARS-CoV-2 caused a chronic immunological reaction in the olfactory system that persisted one month after viral clearance.

Healio spoke with Frere about the reasons behind SARS-long-lasting CoV-2's symptoms and how the results of the recent study may help guide future investigations into potential therapeutic targets.

Healio: What is the simplest method to convey to patients why, after the initial phase of infection is over, SARS-CoV-2 causes symptoms including brain fog, depression, and anxiety?

Frere: When SARS-CoV-2 first infects a person, it triggers a powerful immunological response that affects practically every organ in the body. Even though it makes us feel ill, this systemic response to the virus enables our bodies to eventually get rid of it. Numerous illnesses go through this process, and in

In our research, we observe that the body's reaction to influenza follows a similar pattern. While the majority of the systemic immune response to SARS-CoV-2 fades when the virus is cleared, there is a small region of the brain called the olfactory bulb in which this immune response seems to persist for quite a while, even after the infection is gone. Normally, once the pathogen is cleared, the immune response is no longer necessary and it will quickly fade, returning your body to a normal, non-sick state. Long-term immunological reactions and the resulting inflammation in the brain can lead to abnormal nervous system behaviour, which can result in symptoms like anxiety, depression, and brain fog. Therefore, we think that this ongoing immune

Some of the cognitive and behavioural problems found in long-term COVID patients may have been mostly influenced by a chronic immunological response in the brain brought on by SARS-CoV-2 infection. Despite this, there is still much to be done before we can validate the specifics of what is taking place. SARS-CoV-2 can harm the body in a number of ways, so it's possible, if not likely, that this ongoing inflammation is only one of the ways the virus causes these protracted COVID symptoms.

Healio: What repercussions do your results have?

Frere: Our research sheds insight on a novel molecular mechanism induced by SARS-CoV-2 that may be responsible for some of the cognitive symptoms linked to protracted COVID. By describing this process, we intend to provide long-COVID patients with a viable target that might be medically treated, hopefully reducing or averting the emergence of these symptoms. We further demonstrate that, in response to SARS-CoV-2 infection, hamsters can exhibit chronic symptomology and pathologic processes, potentially

simulating comparable mechanisms that might be present in people with lengthy COVID. As a result, hamsters can be used as a model to test out novel extended COVID therapies. The identification of medications that can treat this illness should become simpler as a result.

Healio: How might this new discovery affect next studies on potential treatment targets?

Frere: We believe that our study has identified a therapeutic target that we might be able to successfully address with medication. The hamster was also demonstrated in our study to be a possible animal model for long COVID, and as such, we plan to use this information to test new treatments for long COVID in hamsters. In order to more swiftly find effective treatments for the condition, we anticipate that others will be able to test novel medications against newly discovered long COVID therapeutic targets in the hamster model.

Healio: What actions will your research take next?

Frere: First and foremost, we really want to investigate this ongoing olfactory inflammatory phenomenon in human patients. Additionally, we intend to begin testing medications in hamster models to see if we can successfully reverse any behavioural changes brought on by SARS-CoV-2 infection. To investigate if either Paxlovid or corticosteroids can effectively reduce the ongoing inflammation we observe and, thus, reduce the behavioural abnormalities we observe in the hamsters, we would love to try these medications.

Healio: Do you have any other comments?

Frere: We offer one of the first studies that allows us to benchmark SARS-CoV-2 infection against other pandemic-associated diseases by contrasting our findings from hamsters infected with SARS-CoV-2 and data from hamsters infected with influenza. By doing this, we were able to clearly identify processes that were specifically produced by SARS-CoV-2, as well as gain a better understanding of the severity caused by SARS-CoV-2 infection.

Science Translational Medicine, 2022; doi:10.1126/scitranslmed.abq3059; Frere, J.

The molecular basis of long COVID symptoms is explained by a study. https://nyulangone.org/news/study-explains-molecular-basis-long-covid-symptoms. released on June 7, 2022. 17 June 2022 access date.