Stanford University School of Medicine researchers say they have developed an inexpensive, portable, microchip-based test for diagnosing type 1 diabetes that they believe could improve patient care worldwide and help researchers better understand the disease.
Described in a paper (“A plasmonic chip for biomarker discovery and diagnosis of type 1 diabetes”) published in Nature Medicine, the test employs nanotechnology to detect type 1 diabetes outside hospital settings. The handheld microchips distinguish between the two main forms of diabetes mellitus, which are both characterized by high blood-sugar levels but have different causes and treatments.
Until now, making the distinction has required a slow, expensive test available only in sophisticated healthcare settings, according to Brian Feldman, M.D., Ph.D., assistant professor of pediatric endocrinology, the Bechtel Endowed Faculty Scholar in Pediatric Translational Medicine, and the senior author of the paper. The scientists are seeking FDA approval of the device.
“With the new test, not only do we anticipate being able to diagnose diabetes more efficiently and more broadly, we will also understand diabetes better, both the natural history and how new therapies impact the body,” said Dr. Feldman.
Better testing is needed because recent changes in who gets each form of the disease have made it risky to categorize patients based on their age, ethnicity, or weight, as was common in the past, and also because of growing evidence that early, aggressive treatment of type 1 diabetes improves patients' long-term prognoses, continued Dr. Feldman.
Decades ago, type 1 diabetes was diagnosed almost exclusively in children, and type 2 diabetes almost always in middle-aged, overweight adults. The distinction was so sharp that lab confirmation of diabetes type was usually considered unnecessary, and was often avoided because of the old test's expense and difficulty. Now, because of the childhood obesity epidemic, about a quarter of newly diagnosed children have type 2 diabetes. And, for unclear reasons, a growing number of newly diagnosed adults have type 1.
Type 1 diabetes is an autoimmune disease caused by an inappropriate immune-system attack on healthy tissue. As a result, patients' bodies stop making insulin, a hormone that plays a key role in processing sugar. The disease begins when a person's own antibodies attack the insulin-producing cells in the pancreas. The autoantibodies are present in people with type 1 but not those with type 2, which is how tests distinguish between them.
“Delayed diagnosis of T1D [type 1 diabetes] can result in severe illness or death, and rapid diagnosis of T1D is critical for the efficacy of emerging therapies,” wrote the investigators. “However, attempts to apply next-generation platforms have been unsuccessful for detecting diabetes biomarkers. Here we describe the development of a plasmonic gold chip for near-infrared fluorescence–enhanced (NIR-FE) detection of islet cell–targeting autoantibodies. We demonstrate that this platform has high sensitivity and specificity for the diagnosis of T1D and can be used to discover previously unknown biomarkers of T1D.”
In addition to new diabetics, people who are at risk of developing type 1 diabetes, such as patients' close relatives, also may benefit from the test because it will allow doctors to quickly and cheaply track their autoantibody levels before they show symptoms, explained Dr. Feldman, who added that because the test is so inexpensive, it may also allow the first broad screening for diabetes autoantibodies in the population at large.