Many of the most common diseases — cancer, diabetes, cardiovascular and lung disease, and even COVID-19 — have been linked to chronic or excessive inflammation. Blood tests can indicate that some part of a person’s body is inflamed, but doctors don’t have a good way to zero in on the site of inflammation and visualize the problem to help them choose the best course of action.
Now, researchers at Washington University School of Medicine in St. Louis have developed an experimental imaging agent that illuminates the location and the intensity of inflammation. The agent, known as Galuminox, has shown promise in imaging inflammation in the lungs of mice with acute lung injury, the researchers report in Redox Biology.
The agent is designed to detect inflammation via positron-emission tomography (PET) scans. Such scans are not invasive, so they could be performed repeatedly to monitor a patient’s response to anti-inflammatory medication or to track the development of inflammation in chronic diseases.
“Doctors don’t have a good way to image inflammation at earliest stages, which can hamper the diagnosis and treatment of disease. We focused on lung injury in this paper, but in principle, this tracer could be applied to other conditions where you have inflammation: atherosclerosis, cardio- and pulmonary toxicity caused by chemotherapy, transplant rejection, you name it,” said senior author Vijay Sharma, PhD, a professor of radiology at the university’s Mallinckrodt Institute of Radiology (MIR) and a professor of neurology and of biomedical engineering. “If we had approval today, this tracer could even be used for COVID-19. The kinds of scans doctors can do right now on COVID patients’ lungs tell you whether there is inflammation there but not how bad it is. A tracer like this could give doctors more information to make clinical decisions.”
Inflammation is how the immune system responds to infection or injury. Immune cells become activated, and some produce toxic molecules called reactive oxygen species that destroy bacteria and viruses. Sometimes inflammation does not resolve after the initial threat is eliminated. Such persistent inflammation has been linked to chronic diseases ranging from asthma to cancer, but there are no imaging agents approved by the Food and Drug Administration specifically targeting the molecular signs of inflammation.