LiFT test kit, image from the MAD Lab
Researchers at the USC Viterbi School of Engineering along with collaborators at the Keck School of Medicine at USC, have developed a low-cost kit for at-home testing of lithium toxicity. The kit, which relies on saliva or urine samples, could be a game changer for over one percent of the global population who rely on lithium to manage bipolar disorder and severe depression. It enables doctors and patients to adjust medication to the proper therapeutic dose in real-time. The test, called LiFT (a lithium fiber-based test), was featured in Advanced Healthcare Materials. It meets the FDA standard for less than 20 percent error.
According to researchers, lithium can be highly effective, but it has a “narrow therapeutic window.” In other words, it is hard to get the medicine just right and there are potential adverse side effects including neurological and kidney damage.
Professor Maral Mousavi is the study’s corresponding author
What they built: USC biomedical engineers designed, fabricated and tested a kit that includes “sensing membranes.” Corresponding author, USC Assistant Professor of Biomedical Engineering, Maral Mousavi who is the director of the Laboratory for Design of Medical and Analytical Devices (MAD Lab) at USC, wanted to create a test kit that could “make a difference in patients’ lives,” that is as easy to use as a glucometer. What is unique about this new test is that it could be easily and inexpensively fabricated by a manufacturer in a few steps.
How it works: The LiFT test kit includes a “bundle” of conductive cotton strings—think kitchen twine made conductive by dipping the string into a carbon ink. The bundle includes a lithium-sensing electrode (lithium metal is charged when it is in water, and thus this charge can be measured via an electrode developed by the researchers) and a reference electrode. The test also includes two calibration solutions and an electrical signal detector that reads the data from the test and communicates this data to a smartphone via Bluetooth. A smartphone app with a customized algorithm lets the user know if the kit is ready for testing, corrects for any erroneous signals and provides a reading. The test, which takes less than five minutes to conduct and get results, can detect unsafe concentrations of lithium in saliva or urine, alerting the patient to consult with their physician to adjust the medication dose promptly (hopefully avoiding or reducing unwanted side effects of the medication). The test results can also identify if the medication dosage is not high enough to have therapeutic effects, and thus can enable adjustment of the medication dosage to maximize lithium’s effectiveness for mood stabilization.
USC PhD student Farbod Amirghasemi is the lead author on the study.
While patients normally have to rely on regular blood testing to avoid the dangerous side effects of lithium toxicity, they have to travel to labs. This blood test necessitates a professional to draw blood, raising the cost. Further, traveling to a hospital for blood draws and the associated costs lead to infrequent and inadequate testing. As a result, patients may take unsafe doses of lithium for weeks, causing severe side effects. This issue can be avoided by enabling patients to test lithium levels more frequently and conveniently at home.
“Urine, or saliva are proxies for what is happening in the blood,” said Mousavi. “We engineered the test for saliva and urine to avoid the discomfort, inconvenience and cost that comes along with blood testing. We put significant effort into developing robust, user-friendly sensors that patients can operate without extensive training, with the goal of eventually translating the technology into a commercial device.”
Farbod Amirghasemi, a PhD student with the MAD Lab, and the paper’s lead author, explained the rationale behind such a project, “For decades, individuals facing mental health challenges have often been overlooked by society. Our mission is to destigmatize treatment of mental health, raise awareness, and provide the necessary tools to help people manage their medications effectively. We hope to foster a more supportive and informed community by bringing attention to this critical issue.”
Steven Siegel, the Chair of the Department of Psychiatry at Keck, is a co-author of the study
Steven Siegel, Professor and Chair of the Department of Psychiatry and the Behavioral Sciences at the Keck School of Medicine of USC, who was a co-author on the paper, explains that lithium is the gold standard for treating bipolar disorder as well as the difficulty of getting patients to take their medicine given the potential adverse effects. He says about the test’s potential application, “It’s one more tool in our armament to make it a little bit easier to take a much better drug, help keep more people safe and treat them.”
Next steps: The team is working to validate the test kit in a larger patient population and bring the test kit closer to commercialization. Mousavi indicates that she hopes the team will expand the testing to other medications.
Published on July 17th, 2024
Last updated on July 17th, 2024
