Promising blood test for blood clots in development

US scientists say they have developed a urine test for hard-to-detect blood clots, which can cause strokes and heart attacks. Lead author and doctoral candidate Kevin Lin, postdoctoral fellow Gabriel Kwong and Sangeeta N. Bhatia, all at the David H. Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology and colleagues said blood clots -- clumps of platelets and fibrin proteins -- can threaten to choke off blood flow and lead to a wide range of serious and sometimes fatal conditions including atherosclerosis and stroke. The blood clots form a plug that stops the bleeding after an injury, but a clot can form when it really isn't needed, such as when a person sits too long on a long-distance flight and develops "deep-vein thrombosis" -- a clot forms in the leg, blocking blood flow and causing leg pain, the researchers said. But it also can dislodge and move throughout the body to the heart or even the brain, which is life-threatening. Diagnosing a blood clot, or thrombosis, can be difficult and clinical tests aren't always reliable, the researchers said. Bhatia's team added small pieces of proteins -- peptides -- onto nanomaterials that are similar to those already approved and used in the clinic. They injected the tiny nanomaterials into mice. The peptides got chopped up if a blood clot was actively forming in the mice, and those peptide fragments were detected in a simple urine test, the researchers said. "Our results demonstrate that synthetic biomarkers can be engineered to sense vascular diseases remotely from the urine and may allow applications in point-of-care diagnostics," the researchers said in a statement. The study was published in the American Chemical Society's Nano.