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| New MR Technique Detects Early Signs of Type 1 Diabetes
New findings show that a powerful new imaging technology can provide
scientists with a peek into the earliest stages of the inflammatory process
leading to type 1 diabetes in laboratory animals. These new findings may, in
the near future, be used for prediction models of whether and when diabetes
will develop in humans.
Up to very recently, the only method to follow type 1 diabetes in its
earliest form was the assessment of blood levels of autoantibodies directed
against pancreatic islet proteins. However, these tests are only an indirect
sign of the disease process, and do not allow scientists to directly track
the disease progression.
This disparity may someday be solved by a new imaging technology that takes
advantage of magnetic resonance imaging (MRI) to monitor very tiny
nanoparticles leaking from the blood vessels of the pancreas, according to
scientists from the Joslin Diabetes Center and Massachusetts General
Hospital (MGH), both based in Boston (MA, USA). The investigators
demonstrated the efficacy of using this new technology to detect the
earliest stages of type 1 diabetes in a mouse model, and published their
results in the August 24, 2004, issue of the journal Proceedings of the
[U.S.] National Academy of Sciences.
This new technology utilizes small probes called long-circulating magneto
fluorescent nanoparticles (CMFNs). These particles contain magnetic
nanocrystals of iron oxide, which are easily detected by MRI. After being
injected intravenously, CMFNs move throughout the body, including through
the miniscule blood vessels of the pancreas. If these vessels have begun to
become permeable as a consequence of islet inflammation, more CMFNs tend to
leak out and gather in the surrounding tissue. Thus, we have the means to
noninvasively monitor the initiation and progression of isulitis in mouse
models of type 1 diabetes in vivo and in real time, noted Diane Mathis,
Ph.D., from the Joslin Diabetes Center.
The investigators report that this new technique may become an effective aid
in helping researchers and clinicians to observe early insulitis and to
track how it changes, during the development of disease and after
administering therapeutic interventions geared at stopping its progression.
Furthermore, they stress that the technique has been already safely and
effectively utilized by the MGH team in human clinical trials to detect
prostate cancer metastasis to the lymph nodes. 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, commented Christophe Benoist,
M.D., Ph.D., of the Joslin Diabetes Center
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