Urine test could find blood clots early
Blood clots can form in anyone who sits on a plane for a long time, is confined to bed while recovering from surgery, or takes certain medications. And, unfortunately, there’s isn’t an easy way to diagnose these clots until they break free and potentially cause a major medical event, such as a stroke or heart attack. But new technology from MIT may soon make it possible to detect clots through a simple, non-invasive urine test.
The new diagnostic tool, recently described in the journal ACS Nano, relies on nanoparticles that detect the presence of thrombin, a key blood-clotting factor. Sangeeta Bhatia, senior author of the paper, notes such a system could be used to monitor patients who are at high risk for blood clots.
The new technology consists of iron oxide nanoparticles--which the Food and Drug Administration--has approved for human use, coated with peptides (short proteins) that are specialized to interact with an enzyme called thrombin. After being injected into mice, the nanoparticles traveled throughout animals' bodies. When the particles encountered thrombin, the thrombin cut the peptides at a specific location, releasing fragments that were then excreted in the animals’ urine. Once the urine was collected, the protein fragments could be identified by treating the sample with antibodies specific to peptide tags included in the fragments. The researchers showed that the amount of these tags found in the urine was directly proportional to the level of blood clotting in the mice's lungs.
The researchers envision two possible applications for this kind of test. One is to screen patients who come to the emergency room complaining of symptoms that might indicate a blood clot, and the other is to monitor patients who are at high risk for a clot, such as people who have to spend a lot of time in bed recovering from surgery. Sangeeta Bhatia, co-author of the study, plans to launch a company to commercialize the technology, with funding from M.I.T's Deshpande Center for Technological Innovation.