Paper-Based Test Monitors Liver Damage

A postage stamp-sized, paper-based device could provide a simple and reliable way to monitor for liver damage.

The paper-based microfluidic device is inexpensive and can be employed at the point of contact to test aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels concurrently, giving doctors near real time feedback and thus allowing them to make treatment plans, if necessary, on the spot.

Scientists at the Beth Israel Deaconess Medical Center (BIDMC; Boston, MA, USA) constructed the device using layers of patterned paper and a plasma separation membrane. A hole in the lamination allows for a finger stick or pipetted drop of whole blood or serum to be applied to the plasma separation membrane. The blood then wicks into the layers of paper, and through the microfluidic channels travels to separate zones for testing AST and ALT.

Jason Rolland, PhD, Senior Director of Research at Diagnostics for All (DFA; Cambridge, MA, USA) said, “A drop of blood is applied to the device and the activity of the enzymes present in the blood sample leads to changes in levels of specific dyes present in the paper zones. This gives rise to color changes that can be compared against a visual read guide and correspond to a concentration range for each of the enzymes." The test takes about 15 minutes to perform. The color changes, for example, from shades of blue to shades of pink, when increasing levels of AST are detected in the blood. In rigorous clinical tests using 223 whole blood and serum specimens from the paper-based test performed at greater than 90% accuracy compared against the gold standard automated platform test.


Additionally, the device could be used as a "triage test" in developed or developing nations to quickly and inexpensively rule out the need for automated laboratory testing. For example, if blood tested with the device shows that the liver enzymes fall below a certain threshold, more expensive testing could be avoided, saving healthcare costs and clinical resources. Nira Pollock, MD, PhD, the co-lead author said, “The next stage for the device is to test it in the field. We are working for a preliminary field study of the paper-based test in Ho Chi Minh City, Vietnam.” The study was published on September 19, 2012, in the journal Science Translational Medicine.

Related Links:
Beth Israel Deaconess Medical Center
Diagnostics For All