Researchers at the University of California, Davis, in partnership with UC San Francisco, have launched a new study aimed at uncovering the underlying mechanisms of long COVID. Backed by a $3.2 million grant over four years from the National Institute of Allergy and Infectious Diseases (part of the NIH), the project leverages cutting-edge total-body PET imaging technology to investigate how immune responses and blood vessel damage contribute to long COVID symptoms.
Unraveling the Mystery of Long COVID
Approximately 10% of COVID-19 survivors experience persistent symptoms that last for months or even years. These symptoms—ranging from fatigue to neurological issues—are not fully understood. However, scientists suspect two key factors: the infiltration of activated immune T cells into organs and tissues, and damage to the inner lining of blood vessels.
While these events might be connected—since activated T cells can cause blood vessels to leak—they could also be coincidental. Leaky vessels may simply allow more immune cells to exit the bloodstream and enter tissues. Understanding this relationship is critical to developing effective treatments.
Total-Body PET Imaging Offers a New Perspective
Leading the investigation is Negar Omidvari, an assistant project scientist in the UC Davis Department of Biomedical Engineering and the principal investigator on the grant. She will use total-body positron emission tomography (PET) and kinetic modeling to explore how immune activity and vascular damage interact across the entire body.
Unlike conventional PET scanners, which can only image one organ or area at a time, UC Davis’s uEXPLORER PET scanner captures dynamic images of the entire body simultaneously. This allows researchers to track biological processes in unprecedented detail.
As reported by News Medical Lifesciences, this innovative approach could reveal how immune cells behave in different tissues over time. It may also provide critical insight into the progression of long COVID.
Tracking Immune Cells and Blood Vessel Damage
Omidvari’s team will work with CellSight Technologies Inc. in San Francisco to use a specialized tracer, 18F-AraG, which specifically binds to activated T cells. Researchers combine this tracer with total-body PET imaging to visualize where and when T cells accumulate. They also determine whether their presence correlates with vascular damage.
To complement the imaging data, researchers will analyze blood samples from participants for markers of inflammation and immune activity. This dual approach enhances the reliability of findings and could help identify biomarkers for long COVID.
Study Participants and Timeline
The study will include participants from UCSF’s LIINC (Long-term Impact of Infection with Novel Coronavirus) program. Patients with long COVID will undergo scans at baseline, four months, and eight months. Researchers will also scan individuals who have fully recovered from COVID-19 without lingering symptoms as a control group.
The research team aims to capture how immune responses evolve over time and across the entire body. These insights could lead to better diagnostics and therapies for long COVID sufferers.