Patients with long Covid have distinct differences in their immune and hormonal systems compared to patients without the disease, according to a new study from the Icahn School of Medicine and Yale School of Medicine.
Researchers have identified specific blood biomarkers that can accurately identify patients with long Covid. Doctors identified long Covid in 2020 when patients reported persistent problems after initially being diagnosed with Covid-19.
These symptoms included cognitive impairment or “brain fog”, extreme fatigue, shortness of breath and chronic pain.
The US Centers for Disease Control and Prevention reports that One in 13 adults (or 7.5%) in the US has long Covid. However, the symptoms persist for more than three months after illness. Many patients do not have a clear cause for their symptoms. And this study, published in the journal Nature, provides new evidence of why they occur.
Researchers studied 271 patients between January 2021 and June 2022. They divided them into three groups:
- those who have not previously been infected with SARS-CoV-2,
- those who have fully recovered from a clinically confirmed case of Covid-19,
- those who have had Covid-19 for a long time, for at least four months or more after confirmed infection. The median time to long-term symptoms was twelve months from the acute phase of the disease.
Researchers took blood samples from all patients, identified differences and similarities in biomarkers between the three groups and then “run through a computer” to better understand which biomarkers were most effective in allowing the algorithm to identify Long Covid patients.
The algorithm was able to distinguish between people with (and without) long Covid with 96% accuracy.
Some of the most striking differences between the long Covid group and the other two groups relate to immune and hormonal dysfunction. This was characterized by biomarkers indicating abnormal T cell activity, reactivation of several latent viruses (including Epstein-Barr virus and other herpesviruses), and a significant decrease in cortisol levels.
“These results indicate that people with long Covid are living with a disease that can be monitored using the blood testing protocols identified in the study,” said lead investigator and professor of rehabilitation and human performance at the Icahn School of Medicine at Mount Sinai, David. Putrino.
The expert recalls that this is a disease that “penetrates complex systems such as the immune system and hormonal regulation. Complex diseases require complex therapeutic solutions, and we urgently need to continue to do research to better understand long Covid and discover innovative and promising treatments.”