Originally Published MDDI December 2004R&D DIGEST

Erin Bradford

December 1, 2004

3 Min Read
Diabetes Detection Improves through Imaging Technology

Originally Published MDDI December 2004

R&D DIGEST

Diabetes Detection Improves through Imaging Technology

Erin Bradford

MRI scans track type 1 diabetes by detecting nanoparticles.

A new technology that employs magnetic resonance imaging (MRI) may be useful for predicting whether and when type 1 diabetes will develop in humans.

Type 1 diabetes occurs when the body's immune system mistakenly launches an attack on the insulin-producing beta cells of the pancreatic islets. The attack may eventually destroy the beta cells, preventing them from producing sufficient insulin, so that diabetes strikes. Early in this process, white blood cells called T-cells invade the islets, causing an inflammatory condition called insulinitis. One very early marker of this inflammation is increased permeability, or leaking, of the tiny blood vessels surrounding and within the islets.

Until recently, the only way to track type 1 diabetes has been to measure blood levels of autoantibodies directed against pancreatic islet proteins. But such tests don't allow researchers to directly follow the disease's progression. However, a new technology that uses MRI may be able to do so by monitoring minuscule magnetic nanoparticles leaking from the blood vessels of the pancreas. Researchers from Joslin Diabetes Center (Boston) and Massachusetts General Hospital (Boston) published their findings in the August 24, 2004, issue of Proceedings of the National Academy of Sciences.

The imaging technology uses tiny probes called long-circulating magnetofluorescent nanoparticles (CMFN). The nanoparticles contain magnetic nanocrystals of iron oxide, which are easily detected by MRI. CMFN can be injected intravenously and can travel throughout the body, including through the tiny blood vessels of the pancreas. If the vessels have started to become permeable as a result of islet inflammation, signaling that insulinitis has begun in the body, CMFN tends to leak out of the vessels and collect in the surrounding tissue. Since the nanoparticles can be seen easily on an MRI scan, this technique enables researchers to observe this early inflammatory process over time.

Observing this process through MRI gives researchers “the means to noninvasively monitor the initiation and progression of insulinitis in mouse models of type 1 diabetes in vivo and in real time,” says Diane Mathis, PhD. Mathis was part of the Joslin research team.

Besides predicting when and if diabetes will develop, the researchers say that the new imaging process may aid clinicians in spotting early insulinitis. The researchers might be able to monitor how insulinitis changes during the development of the disease and how it reacts to experimental or therapeutic interventions aimed at stopping its progression. “Given the known safety of magnetic nanoparticles in humans, the technology might someday be used in individuals who are genetically at risk for diabetes to detect this autoimmune process in its earliest stages,” suggests Christophe Benoist, MD, a researcher at Joslin.

Benoist and Mathis hold the William T. Young Chair in diabetes research at Joslin and cohead the Section on Immunology and Immunogenetics. Both are professors of medicine at Harvard Medical School (Cambridge, MA). The research was funded by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.

The imaging technique has already been used safely and effectively by the Massachusetts General Hospital group. They successfully used it in human clinical trials to detect the spread of prostate cancer to the lymph nodes.

Copyright ©2004 Medical Device & Diagnostic Industry

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