Researchers at Dana-Farber Cancer Institute have developed a breakthrough method to detect inflammation in the body using positron emission tomography (PET) imaging. This innovative probe targets CD45, a marker abundantly expressed on all immune cells but absent from other cell types. In healthy animals, the probe provides remarkably clear images of immune system organs such as bone marrow, spleen, and lymph nodes. In disease models, it reveals inflammation in affected organs, such as the colon in inflammatory bowel disease and the lungs in acute respiratory distress syndrome.
The researchers found that the inflammation severity shown by CD45-PET correlates with both microscopic tissue analysis and clinical symptoms. They also developed a human CD45-PET probe and demonstrated its ability to detect human immune cells in a humanized mouse model. Furthermore, in animal models of graft-versus-host disease — a serious condition following bone marrow transplants — the human CD45-PET probe showed potential for early detection and precise localization of the disease, which can manifest in various body parts. The team is now working toward initiating clinical trials to validate their human CD45-PET probe.
Inflammation is a sign that the immune system is actively defending the body against disease. However, prolonged and excessive inflammation can become pathological and is a key factor in many chronic diseases, such as cardiovascular diseases, cancer, and diabetes, which collectively contribute to a significant portion of global mortality. Currently, there are no non-invasive tools to reliably detect and pinpoint inflamed areas within the body. The developed CD45-PET probe is the first to identify inflammation generally and with high sensitivity through whole-body imaging. Once validated in humans, this tool could have immediate clinical applications, guiding the selection of anti-inflammatory treatments, monitoring responses to anti-inflammatory medications and cancer immunotherapies, and aiding in the diagnosis of conditions with known inflammatory underpinnings.
Dana-Farber Cancer Institute, Parker Institute for Cancer Immunotherapy, Harvard Medical School, the National Institutes of Health, National Institute of Allergy and Infectious Disease, Brigham and Women’s Hospital Heart and Vascular Center.