Diagnostics for All, a nonprofit startup in Cambridge, MA, has designed a cheap, disposable blood test for liver damage. The device uses a stack of paper the size of a postage stamp for a test of toxicity for drugs to treat HIV and tuberculosis.
“The device consists of a few layers of patterned paper, laminated for protection. A droplet of blood from a pricked finger will be placed on a small opening in lamination. A filter inside will stop red blood cells, and release emaining plasma into channels in paper. Reagents which’re sensitive to molecular indicators of liver damage will be picked up along the way, and collect with plasma on the final layer of paper. A color test will indicate how much of the damage marker is present in the blood sample.”
Some antiretroviral therapies and many TB drugs are toxic to the liver. Patients on HIV and TB medication in rich countries are typically monitored every month for liver damage and taken off the treatment if liver damage becomes imminent. “In U.S., [testing] is routine. It’s expected, it’s standard,” says Nira Pollock, a faculty member at Harvard Medical School and infectious diseases expert at Beth Israel Deaconess Medical Center in Boston.